Thank you
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Here are some pictures of the Radu 4P1L by itself, and with the PB MK2 and Taurus DAC. My Deluxe DAC is currently being modified for the GLD Deluxe Streamer that accompanies it. I was sent one as a gift for writing a letter on the owners behalf to the visa board. A welcome and very generous $7000 gift. It arrived today, but I wonāt take it out of the box until my DAC arrives home with the proprietary optical module that will allow me to use that connection on the Deluxe and I2S on the Taurus, which is how I have it currently set up through my Roon Rock and Roon Streamer. I donāt feel a need to have another streamer, although it is supposed to be amazing. I have my system dialed in, so I am nervous how the GLD will add to the synergy of my system. But I am trusting the owner of Cen.Grand who is brilliant and says it is the best thing he has built. Which is saying something as the Deluxe DAC is extraordinary. I miss it already. Fortunately the Taurus is an amazing R2R DAC and my system isnāt really missing anything. Just one less end point until it arrives.
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You know that is a chonker of an amp when that particular knob and outputs are just dwarfed by the rest of the build.
Do you have special feet on there?
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This is a beautiful piece of gear, the rounded corners is a nice touch along with the signature Bakelite knob!
I see two sets of RCA jacks, is that for 2 inputs or is the second for pre-amp duties?
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@geoffalter11 , so very happy for you, congratulations on the beautiful pieces 
Your timing was coincidental, as i was reading about your 4p1L amplifier i was busy getting ahold of one of Radu Tartaās 4p1L pre-amplifiers. Iām the third owner i believe, and not sure on its build date, the previous owner did send it in for some upgrades so i took the opportunity to snatch the piece up for myself, curious about the character itās capable of adding to the chain.
The 4P1L is a Russian direct heated Pentode, Radu has designed this pre to use the tube in triode mode focusing on the linearity and tonality the tube is known for. Because of the microphonic nature of these tubes extra damping is evident throughout the build which works well in my unit. I get a tube ringing noise upon start-up that can come through the speakers, it goes away after a minute or 2 and is more affected by the amount of tube based pieces in the system, the more solid state the less chances of it 
. I also need to get the unit on my bench eventually and apply some De-Oxit cleaning and protectant to the interior, this stuff works well and is worth the time and effort to revitalize your electronics. The unit has a 2 stage warm up process in order to protect against noises and such so i donāt bother it for a full 15 minutes after power-up, i see no point in pushing my fate, thus i just leave things alone for that first quarter hour.
My initial impressions are as varied as the wildly different pieces Iāve mated while trying to gain experience w/ this unique pre-amplifier and i need to take notes for myself so i can rememberā¦
Using only Charney Audio Companion Excalibur speakers w/ 2025 Lowther DX65 drivers.
Low end bass clarity, tightness and weight; my smaller listening room has chest thumping low end, itās tight and extremely well imaged. The 108ā long horn design of the speaker cabinets works nicely as designed and I blend REL T7/X subs for the added spatial depth and bottom octave fill. Thus far the Radu 4P1L based pre has done an admirable job w/ a variety of amplifiers maintaining great low end weight. Volume control is consistent, albeit a touch noisy (hopefully a good shot of de-oxit will minimize this further). Consistent low end control thus far has been exhibited using my Yamamoto A80-S, Decware 341.5, Line Magnetic 218ia and First Watt Sit3, iām excited to try a few more amps when the time allows but thus far my impressions of the low end capabilities of these Russian 4P1Lās running in triode mode is absolutely favorable. I have NOT experienced any flabby, loose, thick or overly soft low end bass character
Top end using various DACās; the 4P1Lās donāt hold back in their top end prowess and if you are a fan of a clean, etched, detailed and well pronounced top end this tube is for you. There seems to be genuine character pronounced in the upper echelons of the frequency range. My Lowther drivers do need taming in this region once in a while and I canāt imagine what a variety of high end tweeters known for their extremely resolving nature will do when presented w/ so much resolution.
-My Sonett Pasithea DAC sounded incredible but some particular songs were too much for me at times. The level of overall resolution this DAC and pre combo is capable of has been intense. 
-Similar experiences w/ my Lampizator Baltic 3 but i noticed a bit more in the lower registers of the upper frequencies. Iāve not had the time but this is where some tube rolling can really lead to a well blended group of components tuned to your exact pleasure
-In comes the surprise heavy hitter DAC 
the Line Magnetic LM-32, bam! we have an easy character synergy match, no extra effort needed. The slightly warmer richer texture and capability of this DAC when running in tube mode are the Yin to the Yang of the 4P1L tubes. Nice 
There will be more information i want to capture for myself, I simply forget if i donāt write things down 
Iām generally a fan of DHT tubes, the Russian 4p1l driven in this fashion is new to me, iām still learning, experimenting and experiencing. I donāt think this Radu design is some kind of neutral, transparent design built to pass signal and attenuate volume from one piece through to another. This a a tube based line stage w/ character and gain and probably a few other characteristics iām not technically proficient to speak to. My music playback has character and Iām enjoying it all 
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Thank you for your response. I spoke to Radu the other day, and he wants to build a 4P1L that mimics mine now as I have found a certain synergy with tubes that makes this amp as he stated āmore holographic than he ever imaginedā. I also agree that NOS/R2R DACs can be a bit much for the amp and almost becomes to much of a good thing. I use the Hegel HD30 and its incredibly quiet and clean nature while still having zero etch, peaks or nodes makes it the perfect compliment to Raduās amp. He does love this tube configuration and mixed with Lundahl Amorphous Core Transformers gives the amp as he calls it āthe right component and design synergyā and then I have found the right compliment of tubes to match that design and component synergy. I use a pair of Sovtek 1965 inverted c cup 4P1Lās that are cryoād and sound exquisite, a 6H30P-DR and a pair of 6CJ3 Sylvania NOS rectifiers from the 1950ās. All told I spent $300 for the 7 tubes. Only because the DR was expensive. Radu believes that I found the perfect synergy of tubes for the design and now he wants the exact same amp with the same build and tubes. I also love that he has used the Pentode in triode mode and the amp sounds more DHT than many many DHT amps Iāve heard. I love the character of the amp. The way it sets a deep pocket and how the midrange instruments image like a halo above the pocket. How it spreads out to all 4 corners of the frequency and I feel like sounds jet at me from all angles.
Thank you for your experience and for your DAC experimentation. I have experimented with 3 DACs and have found the best synergy with the Hegel. I have also tried the Musician Taurus which I absolutely love and has a permanent home with my EC Aficionado and CFA3, which benefit from its timbre and macro capabilities. I also have a Cen.Grand DSD Deluxe DAC and while it sounds wonderful with the 4P1L, it is a bit too polite as is DSD to my ears. According to Radu, the key to his design is that all of his designs are 2nd order dominant and he tries to keep all other harmonics as far away as possible from the 2nd order leading to a very clean and transparent sound. Something I definitely hear. I am definitely in the Radu got it right camp. Thank you for your thoughts, they are wonderful.
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Mine is from 1958.
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Yes, special feet. Not exactly sure what they are. I am not strong enough with my illness to lift them up, but I think they are a version of isoacoustic feet.
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Pre-amp dutiesā¦ The back set is for the headamp, and the front pair is for the pre-amp, which I would assume is wonderful, I just havenāt tried it in that configuration. I should though and see how it pairs with my other amps.
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I have been listening to the Shiny 4P1L with the Hegel HD30 DAC and the results are nothing short of stunning. With the Atrium Open I have never heard this headphone sound so technically adept, which isnāt how I would describe this headphone. I find it the most enjoyable listen, but not the most technical headphone. However, the combination of the Hegel and 4P1L is truly a magnificent pairing. The incredible depth, dark background and evocative musicality of the Hegel paired with the Shiny brings so much air, ambience and breath around every instrument and such incredible emotion. I am truly lucky to have this amp and have found the exact right pairing of tubes to give it more of a holographic sound while providing the tone/timbre that makes music sound like music and there is a transparency and organic nature that I am finding so alluring. So much so Radu reached out to me about building another for himself with the same tube configuration I have put into the amp. I just got lucky and found some 1965 4P1L inverted c cups that in combination with the 6H30P-DR and a pair of 1950ās 6CJ3ās has given this amp wonderful synergy. I have never used it as a pre-amp which I need to try, I just donāt have any speakers, so I would need to run it as a pre-amp into my CFA3 or Pure BiPolar MK2 which is easiest enough. This amp is more DHT sounding than any DHT amp Iāve heard or owned. Radu did quite well pairing the right components with the perfect design and has created what feels to my ears like a masterpiece.
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Being new to this site, is there a place where I can list a couple of high end products for sale? I have a Cen.Grand DSDAC Deluxe ($6800 msrp) and the new Cen.Grand GLD Deluxe Streamer with a proprietary module that completely eliminates the use of USB and jitter from the device. They sound amazing. The Streamer is also ($6800 msrp). I am willing to sell them together or separate, but donāt know where to put them in the site so I am not spamming this thread. Any help would be appreciated. They are both basically new, and work perfectly. I just prefer PCM to DSD, and would like to go a different direction. They are meant to go together, but the streamer can be used with other DACs. I have tested it with 2 different DACs at the same time plugged into the streamer. One BNC, and the other via I2S on the module of the streamer and the sound is sensational. The Streamer is truly magnificent. Any help would be greatly appreciated in getting to the right place. Thanks.
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You should be able to create your own sale thread no problem, I believe
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Try this section of the forum, i think newer members can see it: https://forum.sonusapparatus.com/c/buy-sell/12