Supratek Cabernet DHT / Grange / Cortese / Chardonnay / ETC

SaberPunch · April 30, 2023, 9:51pm

It’s been pretty much a short time since I had the Supratek Cabernet DHT, but I will go ahead and create a thread for Supratek because this preamp is pretty darn special I must say. It really deserves all the praises other forums have said about the Supratek preamp. The Supratek I have is the Supratek Cabernet DHT. It is a DHT preamp that can take 45 tubes, 300B tubes, 2A3 tubes (per the seller I talked with), and 6SN7 tubes for the output tubes. The Supratek Cabernet DHT in my opinion buff tonality, detail, clarity, tighten-up bass, and vocals just sound so sweet when I was using the 45 EML Mesh tubes with this preamp. In this first post, I will talk about its technicality and the issues I had in the short period of owning it. I will talk about my 1st impression of the Supratek regarding how it sounds in my system after.

Features:

The Supratek Cabernet DHT is Supratek first DHT preamp dated back in the 90s. One of the biggest updates to the newer Supratek Cabernet DHT preamps is that it now is able to utilize both 300B/45 tubes or 6SN7 instead of having to choose 1 or the other.

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1. * Tubes it could use:

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2 of each 6H8P/6SN7 and 300B/45/2A3 Go in main chassis
2 6N3C (5881, 6L6GC ok) Go into power supply
1 5RY4, 5U4C (5AR4, GZ37, GZ32, GZ34, 5V4G ok) Go into power supply

274b as a rectifier is not sufficient for the current draw of the unit. Do not use or you’ll burn it out quickly if not instantly. Stick to 5AR4 / 5U4G(B). I was informed that GZ34 metal or Elrog 5U4G for rectification would be best. No adjustment of bias or any other adjustments is necessary throughout tube life.

Per the seller that informed me that the local US repair guy for the Supratek DHT informed him, “On the DHT sockets. I placed a red dot (w/sharpie) between the 2 big pins facing toward the centerline of the unit. Those 2 pins around the ‘dot’ are the filament pins (2 larger pins on the tube). Make sure they face inwards/towards each other l/r. it is easy to insert them the wrong way if not paying attention and fry something. The switches (there is one on each side flanking the DHT sockets) behind the sockets are for the Filament Voltage, back (towards dome) = 5v (300b),… and forward = 2.5V (2a3/45). You will fry your 45’s pretty quickly if you run them at 5v… switch on the back is for the use of XLR or RCA,… it properly sets up the grounding between the 2. Switched towards the outside of the unit = XLR,. Towards the RCA = RCA.” 300B/45/2A3 goes at the top of the main unit and the 6SN7 tubes go at the bottom of the main unit.

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2. The Power

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Ok, so there is a big power button at the bottom middle of the power supply unit. The 2 6N3C (5881, 6L66GC ok) goes left and right in the power supply unit. Right in the middle is where the rectifier tube (5RY4, 5U4C (5AR4, GZ37, GZ32, GZ34, 5V4G ok)) goes. At the back of the power supply unit, there is a pin that connects to the main unit and a Power IEC socket. Right below the Power IEC socket is where the fuse is located. Use some tool to pull the rectangular drawer and you will find the fuse and the spare fuse located. I only had to replace the fuse twice. 1 time, it just blew up out of nowhere and the 2nd time, I didn’t know I put the fuse on backward, but I went ahead and replace it anyway. If you put the fuse on backward, you will get a lot of static distortion, so you will know if you put it on backward. I talked to the repair guy Johnny. Johnny told me that even though it’s rare, sometimes the DHT fuse will just blow up. His suspicion is that with some of the currently manufactured DHT’s today, as they heat up the grid shifts and pops a little and for a brief time will overdraw current which blows the fuse. Supratek recommends 3.15a or 4a fuse (5x20mm size). If the 3.15a keeps blowing up, it is recommended to just use 4a fuses because it’s due to the lower-rated fuse and just a surge of current as the pre is warming up. Johnny also informed me he likes the ceramic ones but glass is fine too. It’s not a big deal, you can buy backup fuses for like $7 USD for 5 fuses on Amazon.

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3. The pots, switches and connectors

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Now, there is Volume pot (left) and Selector pot (right) in front of the main unit. Volume pot controls volume in the preamp. Selector pot is how to select which input you will be using. There is a gain adjustment pot at the top of the main unit. If it’s flicked up, it will use the gain pot. If it flicks down, it will be in “gain bypass” and not use the gain pot, this is recommended. The only time you should be using gain is if you are using a high-power amp and you have to make adjustments until the unwanted noise disappears. Otherwise, the manual recommends flicking down for gain bypass. Below that switch is the mute switch. Flick up to mute and flick down to unmute. At the top bottom right, there is a balance pot. The balance pot lets you adjust if you want to hear more left or right. At the back of the main units is the input and output connectors. 1st input is the XLR input. 2-5 is the RCA input. 6th RCA is 6SN7 output. 7-8 RCA is 300B/45/2A3 output. The XLR output is only 300B/45/2A3 output. Flicking the switch at the back of the unit left will use RCA outputs. Flicking the switch right will use the XLR output.

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4. 1st impression

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Honestly only had like 3 days of serious listening (a short 3-4 hour session). The rest was casual listening. Probably had this unit about 1 in a half weeks, but I went to the Schiit meet for the weekends, so minus 3 days. So you can take this impression however you want.

For headphones I used the Audio Technica W10VTG (romantic sounding headphones that sound sweet with female vocals. Very good with pop genres with female vocals), Audio Technica L3000 (fun sounding bass headphones with a unique style of soundstage with the drivers playing behind your ears. Because of it’s tuning and fun distortion, it excel with rock, and pop genres), and Onkyo A800 (Most natural sounding headphones I ever heard. Tonality cannot be beat and is prefer with songs with vocals and acoustic instruments. Thanks to the collaboration with Gibson Guitar on tuning, electric guitar, electric bass, snare drums, kick drums, cymbals, and vocals also sound amazing and probably my favorite). For headphone amps, I used the Beta22 and Allnic HPA-5000XL.

For my speaker setup, I use the Polk Reserve R200 and Schiit Vidar 2. The Schiit Vidar 2 gives a nice clean sound output making the Polk R200 sound cleaner than I ever heard them on. Because I am so used to the tone in the Onkyo A800, I mostly play Jrock/Jpop music on the Polk Reserve R200. I think 1 thing I like the most about the Polk Reserve R200 is probably the snare drums sound. It’s only been a week, so still getting a feel for it.

The tubes I use are 45 EML Mesh tubes, 6SN7GT - VT-231 JAN RCA tubes, 6L6GC RCA tubes, and 5U4G RCA tube.

I still standby my Day 1 impression at Onkyo A800 – "MASTER CLASS" | Page 11 | Headphone Reviews and Discussion - Head-Fi.org

"The Onkyo A800 is already known for its natural timbre and it’s ability to replicate the artist tone. We all know that. But imagine, with the power of 45 tubes and just any 45 tubes, but the EML 45 Mesh Tubes and what you know with the Onkyo A800 natural timbre and it’s ability to replicate the artist tone, the just DOUBLE IT! Oh my god, it sounded so real, it just feel so unreal. Does that make sense? I just couldn’t believe what I was hearing. What I thought I knew about acoustic/electric guitar, vocals, snare drums, and bass guitars, the 45 tubes + Onkyo A800 will give you a reminder of this is what it’s suppose to sound like. It’s just so authentic and natural, it actually spoil me with my other headphones. Onkyo A800 and speakers is all I need. I knew the 45 tubes was going to be good, but I didn’t think it would be this good. It’s so shocking how magical the 45 tubes are in the midrange and how crazy good voices sound on these. Not to mention clarity gets another buff and clarity on my setup right now is just too insane, I think anything will sound clear on my setup. Bass hasn’t been affected negatively, I believe I got a good buff on it as well as I feel the bass tighten up a bit thanks to the Supratek Cabernet DHT. It could be all placebo, I’ll still take it because I am one happy camper. The Supratek Cabernet DHT + Allnic HPA-5000XL + Onkyo A800 is a fantastic combo. Supratek Cabernet DHT preamp for its magical 45 tubes and huge buff in timbre, Allnic HPA-5000XL for the minimum distortion thanks to its all nickel core transformer for a more clean sound output, but still has a little more musical sauce with its tubes, and then the Onkyo A800 being the main star of the show with its one of kind experience that you will not find in any other headphone with its natural sounding beauty."

I was 70% right. The 30% I was wrong about is that it wasn’t only the 45 tubes that buff my setup, it was mostly the Supratek DHT preamp. When I was using the 6SN7 tubes, I still got great tonality and natural sound from it. Both the 6SN7 and 45 tube was very sweet in the vocals, but I still prefer the 45 tubes for vocals. The 45 tubes were also more detailed, has better clarity, and the bass is tighter. I feel like reverb was less on the 45 tubes, but want to spend more time on it. Across all my equipment, I really like the sound of vocals with the 45 EML Mesh tubes and Supratek DHT preamp. But, no matter what tubes you use, you will still get more clarity, more details, and a more organic musical sound with the Supratek DHT preamp. The tubes are like a *slight change of sound in my opinion. At the end of the day, I still prefer the 45 EML Mesh tubes because female vocals is the sweetest I heard in my system and it gives slightly more detail.

The only preamp I could compare the Supratek was with the Nitsch Magni Piety. I used the Nitsch Magni Piety like 2 days when I had to ordered backup fuses for the Supratek. The Nitsch Magni Piety was pretty good, then I went back to the Supratek and was like, “ok, this isn’t a fair fight”. The Nitsch Magni Piety just sounded overall more artificial compared to the Supratek DHT preamp. The Nitsch Magni Piety is still a good preamp with its warmth sound signature, but it’s no match against the 45 tonality.

My system:
Main Speaker Chain: ROON Rock - Intel NUC 7i7 > EMM Labs NS1 > [AES] Mojo Audio Mystique EVO Basic > Supratek Cabernet DHT (EML 45 Mesh Tubes) > Schiit Vidar 2 > Polk Reserve R200

Main Headphone Chain: ROON Rock - Intel NUC 7i7 > EMM Labs NS1 > [AES] Mojo Audio Mystique EVO Basic > Supratek Cabernet DHT (EML 45 Mesh Tubes) > [RCA] Allnic HPA-5000XL / [RCA] B22 Amp > Onkyo A800

SaberPunch · June 15, 2023, 2:28pm

If anyone wants a Supratek Cabernet DHT Preamp, the repair guy Johnny (official Supratek repair guy) will put one up for sale in maybe July in USAM. Spent 2 months troubleshooting it because I really like this preamp but sucks I just couldn’t get it working properly in my chain. The worst part is when it did work for that little time period, it was so freaking good I didn’t want to give up. The clarity improvement in my speakers is so freaking dumb, it shows having a good preamp in the chain can make a great difference. Preamp really do make a difference for sure in any chain (speakers and headphones) imo. But the improvement is huge in a speaker setup and feels pretty little in a headphone tube chain. Gotta throw in the towel and just admit it just doesn’t work in my system.

Lesson learn, not buying used tube amp unless it’s local or it has full replacement warranty. Next pre-amp target is going to be a Allnic T-2000 (with warranty) and speakers that goes well with it and then I can finally just forget about audio equipments. Probably going to be a year to save for that, so I might wait for a 35th anniversary edition if they make one.

Talking with Johnny, I learned a lot about tube amps in speaker setup, so I know that I am more of a solid state kind of guy rather than a tube guy due to the nature of how loud I play music. 1 cool thing about the newer Allnic is the anti vibration system and I think that’s really perfect for me to still have a tube distortion in my setup.

Johnny is also one of the best repair guy to interact with. Really good patience and did everything he can to help me troubleshoot for like the last 2 months. I didn’t want to sell this myself because I really don’t know if it’s my system or maybe my environment or the preamp actually has problem, so I ask him to take a look at it and sell it for me. He is going to sell it with open customization, so you can make it cheaper by making it a 45 tube only based or add some features.

The guy that sold this pre-amp to me is a nice guy, so it’s nobody fault. Just really bad luck on my side that the preamp got to me with issues. Luck is still luck so I guess take it and hope the next one is a good experience.

I may also sell my 45 tube in the near future. Johnny tested my tubes and found all but the 6SN7 to be good. The 6SN7 tube was microphonics. I replace the 6SN7, but the issue persist, and the issue doesn’t switch to the other channels.

I would recommend the Supratek DHT preamp for people that is pretty good with DIY projects. It’s point to point wiring, so troubleshooting should be easy if you know what you are doing, hint if you know what you are doing.

Camus · June 15, 2023, 4:01pm

So what issues did you face with this pre-amp? I don’t recall you mentioning it directly.

SaberPunch · June 16, 2023, 12:27am

I mention it briefly in the 1st post, but the fuse blew out about 2 or 3 days after I got the pre-amp. Then after that just went down hill with the right channel will have intermittent issues, meaning the issue will happen sometimes. It wasn’t so bad in the beginning since it happens once a week. Then it started happening 2-3 times a week. The right channel will sometimes be in a very low volume and have a lot of distortion. I swap cables, tried both XLR/RCA inputs, swap all tubes to the other sides, bought new tubes and replace it, new power cable, different outlet, different fuse, and different source (DAC). The issue will always be at the right channel. I had it check with the repair guy and he honestly couldn’t find anything wrong with it and suggest it is a tube issue. Bought new 6SN7 tubes and issue is still the same on the right channel. Of course, I swap all the tubes to the other side and issue still remain on the right channel.

The only thing I haven’t done is replace the 45/300B tubes, but the issue will go to the left channel when I swap it to the other side if it was a tube issue. Plus, the repair guy already tested all my tubes are good except the 6SN7 which is why that tube I replace. I also replace the 5U4G tube as well to see if it was that since it seem like a power issue to me, but that wasn’t it either. I either spend probably $300 more on top of the funds I already spent trying to fix it to find out if replacing the 45 tubes is the answer or just give up right now and move on to a new product.

Listening to my other preamp, I know the repair guy told me not to get caught up on tubes, but dude. The 45 tubes really made vocals shine in my setup. I am already pretty depressed it is no longer in my system, but just like in life, I just move on. Either go for another DHT preamp or go for a brand I trust a lot which is Allnic. My Allnic HPA has been really good to me and sounds freaking incredible as well, so I trust that brand a lot. Plus the anti-vibration features in Allnic gears sound really good for someone like me that entire room basically vibrating with sound frequency.

Honestly, it could be my environment even though I never had issues with my other audio equipment. Had like 2 Chinese tube amps and they never had issues and my Korean tube amp is still going strong. I think I just got super unlucky with this purchase, but it’s a good wake-up call. After talking to the repair guy, I have been obsessing about the equipment more than just enjoying music. When I was upgrading my DAC and was DACless for a week besides my DAP, I started enjoying listening to music from any source again. Just playing my favorite song from my iPhone speakers is pretty dang enjoyable again. I may have flush $3500 down the toilet with this purchase, but with the valuable talk I had with a real human being about enjoying headphones/speaker equipment vs enjoying the music and remembering the consequences of buying used items, I now know what my next step will be.

Bad Habit: I am still going to buy 20±year-old audio equipment this year because F it, the guy gave me a 3rd chance so might as well go all the way with it. I need to complete the other missing piece for my other favorite audio equipment.

NickMimi · June 16, 2023, 12:47am

Sorry to hear of your issues, i had very high hopes for that pre-amp. It is a shame something inside is acting up, i think it has the potential to provide much quality and performance in the right system set-up.

I know how frustrating it can be diagnosing, and then getting an issue repaired…I’ve been in the same situation several times myself. Good luck in your next move

Camus · June 16, 2023, 1:14am

Lordy I have had my share of blown fuses, though that was primarily due to faulty rectifier tubes.

Definitely a frustrating experience, albeit an expensive experience. Has this repair guy physically looked at your pre-amp, or has it been remote troubleshooting?

The channel issue could be related to so many different components, as simple as a broken solder joint or a more complex issue

Good luck on a resolution

SaberPunch · June 16, 2023, 1:30am

He already looked at it physically already and didn’t find anything wrong with the pre amp and the only tubes he deemed microphonic was the 6SN7 that was replaced already with his 6SN7 tubes. I think this issue might be really hard to find since it’s a intermittent issue or it could be my environment. Either way, I am sending this pre amp to him again next week for him to take another thorough look before putting it in the market for sale. It just might be my environment honestly and the pre amp do work perfectly fine. Either way, it’s not going to work for me, so I gotta let it go.

Polygonhell · June 16, 2023, 2:03am

I’m not sure how a channel intermittently dropping out/low volume could be environmental.
Noises can be, but for a channel to play at less than normal volume, that either has to be a failing component, a bad connection, or a bad tube, and swapping left/right would have identified that.
Intermittent issues can be a pig to find.
Hopefully the repair guy can reproduce and fix it.

SaberPunch · July 1, 2023, 10:29pm

^ I still agree with my week 1 first impression but want to add that it buffs imaging as well or that might be part of its new perk. After weeks of issues and getting my Supratek Cabernet DHT fixed, I was able to listen to my audio system without the preamp. Finally got my Supratek Cabernet DHT back and it’s better than ever… or at least what the repair guy told me.

So, let’s start at the beginning. April 19th, the Supratek Cabernet DHT preamp arrived after purchasing it used in headfi. The description was that this was a previously broken preamp that was fixed and the original owner told the repair guy to sell it for him. The reason it was being sold is because the original owner inserted the tubes backward resulting in circuit failure. I talked about how I always wanted 45 tubes in my chain because they were being worshiped by a small group of people that use 45 tubes. So I wanted to get a taste of that and purchase the preamp knowing the risk. For 1 week, the preamp worked fine and sounded wonderful in my system at the time. Fast forward, to April 26th, the fuse exploded. I don’t know why, contacted the repair guy, and told me this, “My suspicion is that with some of the currently manufactured DHTs today, as they heat up the grid shifts and pops a little and for a brief time will overdraw current which blows the fuse.” So I just sum it up, I basically got bad luck because what happen is supposedly “rare”. Three days later, around April 29th, is when the intermittent right channel issue started happening. The right channel issue was that the preamp was sometimes out of random, the right channel will be at a very low volume. Then, when you raise the volume, the right channel would sound distorted, like the static distorted noise will be coming out. It’s intermittent, so it will only happen sometimes like 2 times a week. Spent 3 weeks troubleshooting when it happens on my own like swapping tubes to the other sides, replacing RCA cables, trying different outlets (not room), trying different input connectors, etc etc. At first I didn’t mind since it only happens about 2 times a week, but I got fed up and contacted the repair guy again at May 18th. Troubleshooted with him via email and concluded it was good on May 24th and that it might be a loose tube. I did a 5-day stress test and it worked for those 5 days. Then, the preamp right channel is acting up again 1 day after I told the repairer the DHT preamp is good. I tried some troubleshooting methods the repair guy taught me and honestly got too tired of troubleshooting myself. On May 30th, I ask if I can meet up with the repair guy since he is a local NC resident. The drive is about 1 hour in a half, so wasn’t that bad. I explain the situation and he said he will take a look at it. On June 3rd, he finish inspecting the preamp and concluded it was an issue with the 6SN7. He went through the preamp pretty thoroughly. Even I can tell because I check the fuse box and he replaces the fuse with a different type of fuse. He informed me that it’s in the first stage that feeds the 45 and 2nd stage the 6SN7. The testing was performed in his bench workstation and the graph looks good for multiple days. I bought some 6SN7 tubes from him and the preamp sounded cleaner. The tubes he gave me works great, preamp sounded better than before, but unfortunately, it still didn’t solve my intermittent right channel distortion issue. I think there is some miscommunication on what the issue is. I thought I could just live with it since it was an intermittent issue, but things started to get worse. I feel like it was happening more frequently. Then I started to get paranoid and always check the right channel of my speakers to make sure it’s working properly. The worse part is that it could be working fine for the first 2 hours and then the random right distortion issue would just happen out of nowhere. I got too paranoid and honestly felt like I was losing my mind. I contacted the headfier seller to see if he had issues so I can have evidence and informed the repair guy that it wasn’t my audio chain, my environment, or my tubes and there is something wrong with the preamp. The headfier seller told me he did not have this issue and the only issue he had is he used 300B tubes when the preamp was set to 2.5V so it was a user error. He did offer to troubleshoot with me, but I refuse and told him I will go back to the repair guy to figure something out. I felt defeated, so on June 14th, I went back to the original seller listing and saw in the description that the original owner told the repair guy to sell the preamp for him. So I told the repair guy just like the original owner did and ask the repair guy to sell this preamp to him at a very low cost and he can resell it after inspecting it to the used market. I and him had a friendly talk and he told me that if that is the route I wanted to go, he will make an exception for me and do it. We met up again on June 20th and I told him the issue, but in more detail, and that it was specifically happening in the 300B/45 tube output and not the 6SN7 output. He gave me an option, he said he will do everything he can to repair it for free or I can still proceed in the route of selling this preamp. I thought about it and told him that if he can fix the intermittent issue, I will accept his offer. Honestly, I really like what the Supratek Cabernet DHT brought to my system and I think it will be very difficult to find another DHT preamp like this one.

The repair guy kept me updated on repairs he is doing. The repair guy worked closely with Mick and they suspect that possibly the FET in the servo is acting up and the best course of action was to simplify this to a 45 only preamp and remove the servo. So the repair guy instead of putting the preamp on his bench, he tried it out on his stereo setup and finally got the issue happening to him. They found the issue and is beginning repairs.

So they (the repair guy and Mick) went down what route Mick suggested and Frankenstein this Supratek Cabernet DHT preamp. My Supratek Cabernet DHT can now only use 45 tubes only and no 300B tubes since it’s been simplified to just 2.5V. I could probably get away with 2A3 tubes, but it’s best to just stick with 45 tubes. Didn’t mind since I like 45 tubes a lot. I can still use the 6SN7 output. Since the repair guy remove the ability to use 300B, he didn’t want the switch behind the tubes to be useless. So that switch was converted instead of switching 5V to 2.5V, it has been repurposed as a “feedback” option. I will have the ability to use the preamp without feedback if I so choose. The repair guy told me since I like to use my preamp with a headphone setup, it may come in handy for that. I don’t have too much knowledge on what feedback does, but the obvious difference I heard when turning feedback on and off is that it affects gain. When I turn feedback off, the sounds get louder. I haven’t noticed any other differences yet. Some resistors were replaced to accommodate that DHT Preamp only uses 2.5V now. The repair guy removes the Servo Circuit and replace it with a Grange Circuit. The repair guy told me this will improve sound quality and make the preamp a bit more “bulletproof”. My current chain is NS1 Streamer > Mystique Evo B4B 21 > Allnic HPA-5000XL / Schiit Vidar 2 > Onkyo A800 / Polk R200. I honestly don’t know if this sounds better as the repair guy said. Everything in my chain sounds really freaking good to me right now. I recently upgraded my DAC and the Mystique Evo B4B 21 honeymoon phase is still going. Adding the new Frankenstein Supratek Cabernet DHT of course made everything sound better: buff tonality; detail; clarity; tighten-up bass; improve imaging; and vocals are sweeter. But is it better than my original Supratek Cabernet DHT preamp? It’s hard to say since my audio chain feels too new to me and I never got to use the original Supratek Cabernet DHT preamp with the Mystique Evo B4B 21. I don’t remember the original Supratek Cabernet DHT preamp doing this, but the new Frankenstein Supratek Cabernet DHT preamp has better imaging for sure. When listening to some pop songs ( Love In Bloom - HaKoniwalily. Sorry for my bad choice of music, just needed some bubbly cute pop song to improve the mood. Plus I like HoneyWorks produced music, it’s a guaranteed smile on my face.) in the speaker system with the Frankenstein Supratek Cabernet DHT (with my eyes close), there was backup vocals. The backup vocals sounded deep behind the main vocals, at least a couple of feet back. When I open my eyes, I am greeted by my wall pretty close to me. Closing my eyes again, it gave me the sense that the room was deeper and way bigger than it should. It gave a sense of illusion that I was in the stadium with them. That has to be part has to be with the DAC Upgrade because I mention the soundstage feel expanded in the Mojo Audio thread. What the Frankenstein Supratek Cabernet DHT did is that it give me a better pinpoint of where the sound is coming from. Main vocals front and center stage. I can hear electric noises coming from the left to right channel quickly with ease. I can hear the backup vocals a couple of feet back from the main vocals from the speaker’s left and the speaker’s right. The Frankenstein Supratek Cabernet DHT just paints a better picture of what the stage looks like to me. I won’t say my Frankenstein Supratek Cabernet DHT has better clarity, tonality, and others since I don’t how much of that was actually the B4B Evo DAC upgrade, but imaging was an obvious improvement to me. I also appreciate the channel balance knob a lot more since I can customize where the center stage should be for me. I also would like to add that I really appreciate 45 tubes in my system even more. Even with my Preamp 45 tubes, the distortion the 45 tubes make in my system makes vocals very attractive to my ears, I just can’t help but love these tubes.

Smiling this hard with my eyes a little wet from joy, I am glad to have my system back with a few upgrades. This went from a curse to a blessing. We were playing hot potato with preamp ready to explode anytime. We do not know why the servo went bad, but I just think I got really bad luck. On the flip side, I was really lucky the repair guy was an NC local, so I did not have to ship the preamp and got to talk to someone in the audio field with 20+ years of experience under his belt. Was a good learning experience, but I honestly wouldn’t want to go through that again. The end result was good, but that was a frustrating 2 months. I could have just instantly taken it to the repair guy, but it was hard because the problem was intermittent and I just got unlucky that the preamp work perfectly fine for everyone else. Another thing is that I could have just bought this brand new and never had an issue in the first place. Honestly, even though it’s bad luck, I don’t think I want to buy any more $2000 plus tube amps in the used market ever again unless it’s a local pickup. If I did not get lucky of having the repair guy in the same state, I think I would scream. Sorry I wrote this huge essay, just wanted to vent that this long 2 months is over… hopefully. I had the preamp running for 5 hours and it sounds amazing with no issues. Now, if it stays working for 1 week with no issue, then I can celebrate. Just wanted to write this before I forget this feeling right now. If it breaks, I will say something, if not, hurray! Shoutouts to the repair guy, he remained very friendly from start to finish and was patient with me in those 2 months with me. Also learned a lot of knowledge making small talk with him about this hobby.

Frankenstein Supratek Cabernet DHT changes: 45 Tubes only now; 5V to 2.5V option was removed and replaced with “Feedback” option that can turn feedback on or off; Servo Circuit replaced with Grange circuit; and resistors were replaced. Supposedly suppose to sound better than the original Supratek Cabernet DHT since it’s been simplified and has a Grange circuit per the repair guy. One huge noticeable difference in this 1st session is that imaging was hugely improved for me.

NickMimi · July 1, 2023, 11:57pm

Congratulations, you now have a well refreshed custom pre-amp that absolutely does something special. Good things, the really good things, require some sweat and effort. You gritted your teeth through the ordeal and were rewarded well.
Now, clean up that mess of a room, reorganize your equipment, dust and vacuum and for goodness sake take some time and put effort into organizing your rats nest of cables. You have thousands of dollars of beautiful hand crafted equipment and fragile tubes with hundreds of dollars worth of cables criss-crossing and hanging all over the place

Congratulations on getting this far, keep us updated as things get better

I too have become a big, big fan of the 45 tube, it’s my favorite above the 300B which I appreciate greatly and hands down my favorite beyond all others despite its diminutive power output. As far as I’m concerned it is the most exquisite single watt produced. I appreciate what it does and cannot put the qualities it imbues to my music into words. One day I WILL find the very special speakers that I can match perfectly that will be just right for me, i’ m close though, so very close

Congratulations again, i so very much hope you have good luck with the equipment and get to enjoy it much!

SaberPunch · July 2, 2023, 12:25am

LOL, thanks, I appreciate the kind words . I really do gotta fix this cabling hell and reorganize everything again. I was thinking of minimizing the equipment like moving the TV and equipments in the middle somewhere else or just free up another room and put the audio equipments there. I never imagine having so much audio equipment in my life so this was pretty overwhelming for me. I always thought I would have just a small DAC and headphone amp before joining this forum. After joining this forum, got a mini server, PSU for the mini server, network streamer, 40lb DAC, preamp and speaker amp, and a whole separate headphone amp. Now I gotta figure where to put all this chain and fix the wiring jungle got over here. Saving that for next Spring cleaning .

I agree that 45 tubes are amazing. I tried some tube amps at a audio show recently, tried 6SN7, and use to owned a 6V6 Tubes. There is something about 45 tubes that sound so great and organic to me and yet so unique compare to the other tubes. Especially vocals, the 45 tubes are probably my personal favorite maybe besides 6V6.

NickMimi · July 2, 2023, 12:39am

Lol, I’m waiting on some 6v6 gt’s to come in this week. Yes, they too are pretty special, along with the 807 tubes… My Decware tube tots in particular sound exemplary powered by them.

Best thing I ever did was get the nice speakers and stuff away from the TV stuff. Totally separate room. I love it and don’t mind the extra cost. Each space has its own use now and I can best maximize my seating position to take advantage of the space and sound better. Do it, separate the tv from the music

SaberPunch · February 6, 2024, 2:43am

Hooked up the Supratek preamp back to my system and everything just sounds sooooooo much better. When I said everything sounds better, I mean everything. Bass actually sounds more like heavy hitting bass to me again. I could feel the atmosphere being created in my core (bass sets the mood of the music for me). Its not clarity, but I don’t want to call this naturalness either. But something about the Supratek just breathes life into my music. Like when I was using the Schiit preamps, the color of my music feels grey. Then day 1 coming back to the Supratek preamp, I could see blue, I could see red, I could see yellow, I am feeling emotions again from listening to music. Don’t know if that’s the power of DHT, 45 tubes, or just the Supratek preamp in general (or maybe a little bit of all of the mentioned?), but music got me feeling like a human being again and it feels really good to experience these emotions again. I know I am comparing a entry level preamp to another preamp that cost thousands of dollars, but fuuuuuuudge I forgot the jump of performance between entry-level and whatever level the Supratek Cabernet DHT is supposed to be. The jump of performance is really huge lol (at least to my views after using entry level for a month and going back to the Supratek). People said don’t sleep on your preamp, because it can bottleneck the audio chain. They are right, you really can’t sleep on your preamp and got to make sure it synergize right in your audio chain and tune to your preference. Also remember what the Johnny (Supratek repair guy) told me about after the Supratek preamp its really just preference at that point. Because after the Supratek Cabernet price point, the jump in performance is very costly (10K plus) and the preamp is going to tune to a certain preference. If I don’t like whatever preference the next preamp is and I paid that $10K plus, then I just gotta hold that. Whatever preamp I am looking next after the Supratek, I should really know what I want from my music. I honestly currently don’t know what I really want because the Supratek is really hitting the right spots on what I want from a preamp. I will probably get a better idea once I become more experience with speakers, but for now the Supratek preamp is rocking my world.

Another thing I really appreciate the Supratek after using the Schiit preamps for about a month besides everything sounding much better and music sounds more lively to me is that my Polk Speakers sounds bigger again. I am not too sure if its because if the Supratek got more gains than the Schiit preamp, but my Polk R200 speakers sound huge again and I am really digging it!

^ This is what I wrote when I change my mind on selling my Supratek back in January. Thank god I changed my mind before I sold this preamp. I would’ve regretted this the most if I sold this. It’s because I really don’t appreciate preamp and undervalue them. I don’t know why I keep doing it, but I really underestimate that good sound the Supratek really bring to the table.

Why am I talking about this again?

I don’t know why, but I just randomly remembered my Polk R200 being hooked up to the Supratek vs being hooked up to the NITSCH Magni Piety. I bragged that the Platimon speaker sounded really freaking good with an entry level power amp and said this is crazy. Then, I really thought about it and remembered to myself that I am undervaluing my equipment again. I don’t know why I keep forgetting about the preamp, but I just keep doing it. So, even though its a weekday, I want to do a quick comparison if I change my Supratek preamp to the NITSCH Magni Piety preamp to see how much of a sound difference there really is…

Well, its pretty similar to my impression back in January. With the NITSCH Magni Piety in my system as the preamp, music sounds lifeless to me. It doesn’t sound bad per say, but it did not sound enjoyable. Mids sounded lifeless and boring. I say that because female vocals sounded good, but never really grabbed my attention. Electric guitar sounded bleh. Drums at least sounded really good still. Everything sounded more clutter and soundstage seems more flatten together. Resolution seems still pretty good, but not as clear as I remember what the Platimon could actually sound like. Imaging took a hit as well. The imaging is still good, but not as pinpoint. Soundstage width is still the same and I think I am still getting the same amount of details. Its just harder to hear it as things are more congested in the music. Music seems like it got brighter, but that isn’t the right word I want to use. Music just sounded less real to me I guess and there is more of a disconnect with me and the music.

So I put the Supratek Cabernet 45 tube preamp back to my system. Now, music sounds much better. Mids sounds much better to me. A little hard to describe in words, but female vocals seems to have more texture in them and a warmth in their vocals that I really like. Female vocals sounds much more complete to me with the Supratek preamp. On the NITSCH Magni Piety, I went from “its pretty good, but kinda bright for some reason” to the Supratek Cabernet 45 tube to “omg, I really love the way she sounds. This is really beautiful!” For electric guitar, my crunch is back and it sounds more clean. Maybe because I am able to hear the electric guitar a lot better with the extra help of separation from the Supratek. Soundstage gets more depth to it which really helps backup vocals for me. The Supratek just overall sounds bigger, but that might be because of the XLR input I am using from my DAC to the Supratek to provide more juice. Overall, similar to my January impression, the Supratek just breathes more life into my music.

So to summarize on what I learned what my Supratek 45 tube preamp adds to my system:

Make Midrange much more lovely and honestly more real to me.
Soundstage depth gets deeper
Helps with instrumental separation and that overall helps me hear more details in the music
Helps with clarity

The Supratek Cabernet 45 Tube Preamp adds more “soul” into my audio chain and help me forget I am listening to a digital system. There are probably more benefits as I said it help tighten bass when I first use it with my headphone amp. Its the weekday and a Monday, so I wanted to keep this short. I wrote this down so my bonehead learned to appreciate this preamp already and that will help me figure out a wonderful powerful power amp to go along with this preamp to complete my dream Platimon setup.

I also know I am doing this unfair comparison to the magni piety that cost $150 vs the Supratek Cabernet 45 Tube preamp that cost over 20x the price. I just need a base preamp vs my current preamp to help me realize how important a preamp is to my system and how things could get really bad if I bottleneck my preamp.

Current chain: EMM Labs NS1 > [AES] Mojo Audio Mystique EVO B4B 21 > [AES] Custom 45/6SN7 Tube Only Supratek Cabernet DHT > [RCA] Schiit Vidar 2 > Mon Acoustics Platimon VC One

When I tested the NITSCH MAGNI PIETY: same chain except… NITSCH MAGNI PIETY Preamp > [RCA] Schiit Vidar 2 > Mon Acoustics Platimon VC One

SaberPunch · April 18, 2024, 1:05am

It hasn’t been a day, but I truly think this RCA UX-245 tube is really special already lol. I truly understood the word “musical” because of this UX-245 tube. When people said this tube is the most musical tube they have ever heard or at least their top 3, they are not lying. If you got a preamp that could do 45 tubes, you got to try a RCA UX-245 tube. I only been listening to female vocals because I love female vocals, but this is peak realism of female vocals for me. It’s just so realistic sounding to me, it’s like a Mysphere 3.2 midrange in a tube form for me. I never heard vocals this realistic except the Mysphere 3.2 (and the SR1a on good recorded tracks). The Mysphere 3.2 in tube form may be out of line, but midrange is really realistic sounding.

My tube combo for this Supratek 45 tube preamp is 2 6L6GCs (RCA), 1 5U4G (RCA), 2 6SN7GTs (RCA), and 2 UX-245 (RCA). The only gear I used this with is the Platimon VC One speaker so far… Looking forward in how the headphone setup sound with these.

I will probably try out the regular globe 45 next week. I hope they sound the same because finding a good UX-245 is pretty hard lol. But I guess finding a good pair of 45 globe is hard in general. When the next batch of globe EML (or any brand that is willing to do a modern 45 globe tube) comes out, I think I have to stock up…

Edit: I found out one of the tubes is a 45 Globe tube label as UX-245. So during that session at the time was 1 RCA Radiotron UX-245 tube and 1 RCA Radiotron 45 Globe Tube label as a UX-245 tube. It was still a pretty cool session and I do want to get the full experience one day, one day…

Souldriver · April 18, 2024, 5:48am

They on rare occasions do globe mesh 45s i believe.

NickMimi · April 18, 2024, 11:32pm

Practically unobtainable

SaberPunch · April 24, 2024, 4:52pm

So it’s been an almost a week since I had the RCA 45 Globe in the Supratek. I didn’t really A/B, it’s mostly from memory on the EML 45 Mesh mainly because I feel really lazy swapping tubes back and forth:

RCA Globe 45 obvious difference from EML 45 Mesh on the Supratek Cabernet DHT (custom 45/6SN7 preamp):

Midrange is much more clear sounding
Midrange is fuller sounding
A little less exciting highs
Bass feels like it hits less harder (it might be because the EML Mesh bass disappear a little slower)

I should A/B, but I already store the EML 45 Mesh in a safe place already…

What I feel stand out the most on the EML 45 Mesh vs RCA Globe 45, but not too sure:

Not too sure on this one, but listening the Platimon from the EML 45 Mesh to the RCA 45 Globe on the same playlist (my favs of new song release of 2023), the EML 45 mesh soundstage is more engaging and room filling compare to the RCA Globe 45 in my system. I remember in one of the tracks, I felt like I was drowning in the music (in a good way). Like a metaphor of the feeling is me just falling deeper and deeper into the sea and the sea represent the music. Whenever tubes get involved, I swear things gets weird and trippy lol. It was also only obvious only on the Platimon for me since a change of soundstage is easily noticeable on that gear.

I will say the midrange is so irresistible on the RCA 45 Globe and everything just sounds more natural. I only used these gears so far: Platimon VC One speaker; Mysphere 3.2; Susvara; Onkyo A800; and Sennheiser HD580 Jubilee.

Music being played is mostly female vocals with small ensemble/acoustic/etc etc with female vocals being the center of attention. I do listen to other genre sometimes just to test some things.

I gotta say, my favorite combo so far is the Mysphere 3.2 and Sennheiser HD580 Jubilee. Holy Midrange… the midrange is soooooo omg. Midrange so wonderful is just melt my brain

The other 3 is very good sounding, but there is something really special pairing the Mysphere 3.2 and Sennheiser HD580 Jubilee with these 45 RCA Globe tubes.

I still got other gear to try out like my vintage ATH, vintage Yamaha, discontinue Sony, SR1a, and Beyerdynamic headphone. I am honestly not expecting it to be at the level of awe like the Mysphere 3.2 and HD580 Jubilee for the rest of the equipment, but I never know until I try. This is the best sound I am ever getting from the Susvara and clearest sound too, but that probably don’t mean anything since I never really plugged that headphone everywhere. I will say the Susvara level of midrange clarity I am getting is very very close or even maybe the same as my SR1a on the old EML 45 mesh setup. Every gear I tried got a midrange clarity buff, but Mysphere 3.2 and Susvara felt like it got buff way more than the last time I used them.

Last note for this post: I really regret selling the ATH-L3000 and I still regret selling the Sony CD3000. Man, I would really love to know how those headphones sounded on this setup, oh well .

SaberPunch · May 23, 2024, 2:27am

I wasn’t planning to post this early, but change of plans. I used my speaker power amp funds to buy more tubes

I do want to note some changes I made to my system before the other tubes comes in from Mother Russia. That way, I at least got a good reference of what that Russian tube and Cryotone tube will bring to my Supratek 45 preamp.

Its been 1 year since owning the Supratek, here is my new tube rolling:
(2) RCA UX-245, (2) RCA VT-231, (2) RCA 6L6GC, (1) RCA 5U4G

(mostly listening using the Allnic HPA-5000XL > Mysphere 3.2 / Onkyo A800 / Sennheiser HD580 Jubilee)

It’s basically the same tube set I got the Supratek. The guy who sold me the Supratek already tuned the Supratek for a really good musical sound. The only difference is I replaced the EML 45 Mesh with the RCA UX-245 making this a full RCA tube set.

The previous RCA 6SN7 (clear glass) that I used was pretty nice, but I just like the VT-231 better for a little more lushness in the music and better reverb effect in the music for this current setup. The improved reverberation gives my setup more liveliness and adds realism to it. The trade-off from the previous RCA 6SN7 tube I used is that the VT-231 is a touch veil compared to it. But I say the trade-off is worth it when it’s paired with the RCA UX-245 tube because that UX-245 has really good transparent mids. The recently obtained late 40s grey glass 6SN7GT and it is very similar sounding to the VT-231. It will be a nice backup if VT-231 fail for some reason.

Obviously, a good pair of UX-245s is stupidly hard to find. I say the RCA Globe 45 tubes are very similar sounding to the RCA UX-245 and I say you can be happy with an RCA Globe 45 if you cannot find a UX-245. The UX-245 is just a little more refined in the midrange and liquidy (but it’s like a very small comparison and they both honestly sound very similar if you are not really critical listening). But both RCA globe tubes have a very natural-sounding timbre that will musically please your ears. I say these RCA Globe 45 made my system midrange much more transparent and is the biggest reason why I am so in love with my current system midrange. The tradeoff of switching from the EML 45 mesh to the Globe RCA tube is it sounds less open and the highs were better on the EML 45 Mesh on my setup. I made up for that loss by adding the RCA VT-231 tubes back to the Supratek.

I heard 1 other globe 45 tube at an audio show which was the Philco 45 Globe and I do not remember the 45 tubes sounding this good and clear like the RCA globe 45 that I got in the Supratek. It was also in show condition, so maybe I couldn’t hear the full extent of that amp. My entire gear and my current tube roll combination also play a big factor of maybe why I like these RCA UX-245/RCA Globe 45 so much, so probably keep that in mind in the last 2 paragraphs of posts.

These were the last 45 tube amp I heard that is not my Supratek preamp:

I read that the RCA 6L6GC is already a great tube and the RCA 5U4G is a great value tube. No comment on them and I do not think I will replace the RCA 6L6GC anytime soon. The RCA 5U4G on the other hand will be replaced hopefully in July if there is no hiccup down the road.

I do not know what to expect from removing the RCA VT-231 tubes. I am going to replace them with some old Russian tubes. I know the RCA-VT231 brings a little more tube-goodness sound to my setup so I do not know how I feel about removing them. But I am hoping that the Melz Russian tube could deliver its hype like when I found the UX-245 tube. Even though I really like the combination of the all RCA tube rolls on the Supratek, I want to keep an open mind and try out the Melz 1578 tube to see if I can elevate the Supratek soundstage without the RCA VT-231 touch of the veil. I am going to replace the RCA 5U4G with Cryotone 5U4G-WC and I am hoping for an across-the-board improvement.

I probably won’t know how they sound for maybe a month since the Melz tube I bought it from a Russian sales guy, so I really hope these are legit and work lol. The Cryotone 5U4G-WC looks like are going to take 2 weeks. I hope my new power amp arrives before the new tubes because I do want to know how the Platimon sounds with this current setup where everything sounds musical pleasing with all my current faves headphones so far.

tunahulk · May 23, 2024, 10:37pm

I just bought a used Chardonnay and it should be here next week. I’m looking forward to trying it. I’ll need to pick your brain on tubes for it

SaberPunch · May 24, 2024, 1:36am

Nice, congrats! I heard in the Supratek owner forum that the Chardonnay and Grange is already a warm sounding preamp while the Cabernet DHT is a more neutral sounding preamp at least compare to the Supratek preamp lineup, so probably keep that in mind when tube rolling.

You can probably get some good idea reading other Supratek owners impression and their tube rolling the Chardonnay here : https://forum.audiogon.com/discussions/supratek-owners-thread

For 6SN7, a lot of people swear on Melz 1578 tubes. I get those next month whenever they get here and if they are legit post an impression with how they sound on the Cabernet. In my last post, old grey glass RCA in the 40s or VT-231 (which is probably the same thing or similar enough) for more of a tubey sounding tube, but don’t know how it will sound on the Chardonnay as it’s probably already a warm sounding preamp by default.

Or you can be really different and try one of those Cryotone tubes to see if those are really good. Some 6SN7 tubes that is still in my wishlist to try is a Ken Rad 6SN7 for something more clarity on the vocals from what I saw on other people impressions and for some reason I put a note to myself to try Sofia Electric blue glass 6SN7, but never put a side note why these are in the wish list.

There is a lot of tube rolling you could do with 6SN7, so have fun with it when your Chardonnay arrives and let us know what tubes you like it best!

Also, what audio equipment are you are going to use it with? Speaker chain or headphone chain or both?