Vintage DACs which are a great bang for the buck when available on the used market
Industry reviews:
Sonic Frontiers SFD-2 D/A processor:
Sonic Frontiers Processor 3 D/A processor:
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SFD-2 Mk.II vs. SFP-3
Listening Chain: Roon > Pi2AES → SFD-2/SFP-3/Chord TT2/HMS → Stratus V4/BW2/Bryston BHA-1/Pass HPA-1/ECP DSHA-3F → Utopia 2022/Utopia 2020/Rosson RAD-0/Senn HD650 (stock)
Music Examples: Radiohead, Sigur Ros, The National, The Rolling Stones, Pink Floyd, Led Zeppelin, Bon Iver, Iron & Wine, and Lana Del Ray. There is a shit ton more, but those should capture the genres I listen to.
SFD-2-Mk.II:
- This unit had the SE+ upgrade done last year, I added the Matushita 7DJ8 tubes as Chris gave me a deal on them. However I did not care for them and barely used them, found them quite boring compared to my main tube roll which is a nice set of Siemens E88CC with O-getter. Ironically I have a pair of A-frames which don’t sound as clean and spacious as these.
- At first this DAC had the most engaging soundstage I had ever heard, beat out my Chord TT2 with M-Scaler in terms of width/depth/height. Had a few more DACs pass through and none have captured this sphere around me when using headphones. These were the Yggdrasil, Bricasti M1 SE, Bifrost, and Rockna Wavelight.
- Macro-dynamics is one of its strengths, whereas micro-dynamics could come across as fuzzy at times but not smeared.
- Bass can be a chameleon, I blame this more on the recording quality than the DAC itself. It can hit hard on certain masters, and then seems non-existent on others, blame compression and loudness wars where stuff released in the 90’s and early 00’s is most affected here.
- Is it the most accurate and clean sounding DAC, hell no. I hate to use “analog” as a descriptor for a DAC, so will use raw instead. It has a raw in a natural (not organic) sense of reproducing the music. I have a vinyl rig, and this DAC is the closest I have heard to narrowing the gap between the two.
- Tonal texture is enough to satisfy my needs, especially on some great classic rock tracks like Brown Sugar. Can hear Keith’s Telecaster rip it up like only a Tele can. Though others may consider this to be a bit softer than say the Bricasti, which had sharper texture.
- Overall it is engaging and musical, I interpret this as a balance between accuracy and musicality, delivering a smooth and natural sound that draws me a bit deeper into the music.
SFP-3:
- I have only had this unit for about two weeks, and in that time I’ve listened to itfor about 9-12 hours. It came with a quad set of Amperex 7308 vintage tubes with the green globe imprint.
- RIght off the bat I could tell the sound signature was quite a bit more neutral compared to the SFD-2 which tilted towards warm (granted this could have been mostly due to the tube roll)
- I found this to improve on micro-dynamics, where it was a lot more detailed and transparent. Also, macro-dynamics were just as strong if not stronger than the SFD-2. In other words it has the clarity and resolution of a Chord or Bricasti without the fatigue or unnaturalness they tend to have. For example, I found the Bricasti M1 to have a bit of a dry signature, and the Chord TT2 to be a bit too analytical to a fault.
- It was a bit challenging for me to get a sense of how the soundstage compared, as I do not have them side by side at the moment. I would say it is probably similar as it did not strike me as being less. If anything maybe the placement was less spherical than the SFD-2, being slightly oval in presentation.
- Noise floor is significantly lower than the SFD-2, likely due to the external PSU and better isolation of components along with the separate IV modules which replaces the op-amps found in the previous SFD models. You can see this on the left side of the DAC modules.
- One great thing about the P3 is they provided a fix for that moronic HDCD lower output voltage found on the SFD-2 where the SE output was a measly 1.7v. On the P3 it is a full 3V due to an internal jumper which can bypass the HDCD -6db BS.
- Overall it takes some of the great traits of the SFD-2 and takes it from an E46 M3 to an E39 M5
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@NickMimi in case you were looking for a spot 
Edit: I am using the Sonic Frontiers Processor-3, SFP-3…I stand corrected.
Ok, i have procrastinated long enough on this and this morning listening to all sorts of a variety of Christmas music in various languages has given me a decent feel for the SFP-3 DAC @Camus has been kind enough to loan me and sample.
First things first, this is 2 piece unit w/ a separate power supply and overall has a very large footprint and will require space. I absolutely love the separate power supply though and i believe it adds much quality to the overall performance 
I decided to use the DAC on my K-horns today and i freely admit i could live w/ this unit easily despite the fact that it limits itself to 16bit/44.1. ROON does a better and smoother job than Innuos Sense in converting my stream to a bitrate the DAC can operate with and it’s been running flawlessly for many hours all day.
Resolution is excellent, soundstage, depth and separation are really good 
As a direct comparison to my OG Berkeley Alpha Reference DAC in all honesty w/ my K-horns i think i may prefer the Sonic Frontier a bit more for it’s slightly more relaxed and seemingly smoother less resolving presentation. A little less resolution w/ a grand soundstage goes well with Klipsch speakers, it offsets and tames their glare and some other issues their sound character and build is well known for. 
I’m using a really inexpensive Line Magnetic, el84 based SET amplifier, outputting 3wpc using some older Tungsol and 80’s SOVTEK tubes and i’m really enjoying both sound character and presentation. Nothing at all to complain about, all via streaming source w/ a wide variety of musical styles, most Christmas/holiday based, and at volume levels that fill the entire house for portions of the day so I’m working the system hard today, not my usual busllshit 45-50db listening sessions. 
I’m not here to sell anyone on anything, this is just a good reminder that even some of the older technology, especially well built pieces like this are viable options for many a quality system. I’m really pleased w/ the unit’s performance and the genuine synergy it has with all my other components 
it came as. A surprise to me that it was basically plug-and-play w/ almost no issues.
@Camus you might have to pry this unit out of my hands, i hope you don’t need it back anytime soon
Almost forgot the gratuitous pictures…
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One more time on the SFP-3, I can’t get enough of the beautiful synergy it along with my Alan Eaton 45 DHT mono-blocks feeding my Klipsch Heresy speakers are bringing out.
I’ve had Otis Taylor playing in the background for a few hours today as I prepare a birthday meal for my sweetheart and I turned up the music just enough to overcome the kitchen cacophony and I am so very pleased at the output this mixture of older and a few pieces of more modern equipment mixed together are putting forth
The Heresy is a particularly hard speaker to get any performance out of, it’s capable but can be harsh, overly horny in a bad way and bottom end light. I have learned to enjoy it but it takes work and a good mixture of equipment and this weekend has been a genuine pleasure and admirable performance all around.
Thank you so much for letting me borrow this DAC @Camus you have great taste in equipment I would have never considered an older piece like this.
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Like being a sophomore in high school?
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You are welcome, least I can do for all the fun stuff you have let me try these past few months.
There is something special about what this DAC and its siblings, SFD-1 & SFD-2, can do that modern DACS either choose to not do or not capable of rendering. I am not a DAC designer so I don’t know, all I know is I have never heard any of the more common DACs we talk about here, Mojo, totaldac, Lampizator, Rockna, Yggy, etc, sound like a Sonic Frontiers DAC.
This is why I waited patiently for over a year for the Sonic Frontiers you will hear next, the SFD-2, and nearly three years until a Processor 3 popped up for sale.
Friends ask me all the time why don’t I sell them, I definitely don’t need them due to their limited ability such as no USB input, max out at 16/44 16/48. They could easily sell on the open market, that is not the issue, I know once they are sold I would instantly regret it as I don’t have the patience to wait it out again.
@archer You know what I am talking about right?
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With my limited experience and knowledge I am not sure I can confidently say moden dacs are not capable of doing this. But I can certainly say that the SF series especially the PRO3 (upgraded to SE+ in my case) can match modern dacs in all respects.
When I got the SFD-2 I sold the Holo Spring 2 very soon.
I have had the Totaldac D1-Six and Rockna Wavedream Sig SE alongside the PRO3 and I never felt I was giving anything up when going back to the PRO3.
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Sorry, I did not mean this specific line but in general about the awesomeness of the Sonic Frontiers DAC line up. You have had some nice quality DACs in your line up with the PRO3 and SFD-2!
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I must have saved this post and forgotten it was sitting waiting for me to continue writing. I just stumbled across it a few months later and figure I’ll put it up for prosperity and a difference in the sound character that something in the system made between the two rooms and set-ups. 
Snow Day! 
@Camus , first impressions with the SFP-3 in the smaller room are not as exciting and positive as they were in the larger room. With the Klipsch Heritage speakers downstairs we had a really great synergy match, the SFD-3 was working well with the speaker, room and amplifier style.
Just Initial impressions but I’m not as in love and enamored w/ it upstairs in the small winter room, up here it feels as if we just veiled, and muted the sound character. Less detail and resolution overall This room is ALLOT “deader” than the big open room downstairs, so i assume there is some correlation between the room and what i’m hearing. I’m missing the vivid resolution and crisp pin-point details i’m used to from the Lampi B3. The left right soundstage has really good extension on both ends, center imaging and forward - back spacing is good but i’m just not getting the nice crisp spacing, detail and resolution I’ve gotten used to up here with the current equipment stack.
Musically, the character of the music portrayed is lovely, very relaxing, with open and wide soundstage spatial character, really extending all the way to the walls which is very impressive and i’m a bit jealous and want to recreate this much width with the Lampi B3 at lowest volume somehow. strong and dynamic bottom end with low volume and i believe that is really working to enhance the soundstage in this room.
I could probably toe the speakers in a bit, beaming the tweeters towards my head may give me a sense of more detail but I doubt it will do much for the overall resolution.
There are a ton of factors I’m probably not taking into consideration today but interesting to note the differences between the one setup and the other and how they impacted my appreciation and views on the DAC synergy in each location
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Thanks for posting, not surprised about the detail and resolution as it’s always been the sense of space that stood out when using it.
Ironically with your Heresy it’s not my favorite combo, the totaldac is a better match for me as it gives the speakers a faster sound, where the Sonic Frontiers P3 comes off holding it back and muted. I don’t want to use the word dull again, know it will trigger you like cream cheese
You got to experience it, that is all that matters!
Curious if anyone has experience with the SFD-2 SE vs mkii? I have the opportunity to pick up a mkii version (looks like non-SE) and wondering if it is a big enough difference or if anyone has preferences on the older model? Currently have the SFD-2 SE which I love with tube amps. Really great synergy with my vintage Aleph 3
I had thought about upgrading mine to the mkii but I think the better deal would be to grab this mkii off the used market then sell my mki if I want to go down the mkii road. Not sure how SE upgrades play in as I’d need to get the mkii model upgraded - tough to see the route to go here
1: Keep my SFD-2 SE model > upgrade to mkii…I think its about $1,200?
2: Buy the SFD-2 mkii > upgrade to SE version > sell my SFD-2 SE…not sure on Se cost here
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Some clarification needed if you would be so kind:
Do you mean the SFD-2 mk1 SE vs. the regular mk2?
I am not aware of PCX having the ability to convert a mk1 to a mk2 based on some of the changes;
- UltraAnalog AES21 input receiver boards. Mine went bust last summer and they had to pull a replacement board out of another device.
- HDCD specific part, PMD100 chip. This unfortunately lowers the overall output by half when not using HDCD encoded content (surprisingly very little out there, was likely the next bug feature back in the day), so for example a 3v RCA output becomes a measly 1.75v output.
- Output stage had bigger output coupling caps, and some other resistor upgrades
- Added addition digital inputs; BNC and Toslink
I have the SE+ upgrades done, and looking back it was not something worth the $1.3k cost, parts upgraded were minimal and the majority of the that cost was the labor rate. Come to realize I could have swapped out the capacitors and resistors myself, along with the pricey WBT RCA and Cardas XLR connectors.
Clearly this doesn’t help you in your deliberation process, if you enjoy your mk1 and have no need for HDCD encoding than I would stay put. The main benefit on a mk2 would be the push button front controls and the AES21 module as it had lower jitter and another benefit that is escaping my brain.
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Correct
You would be right on the money here - I had emailed them to check and they can’t offer mki > mkii upgrades since they do not have the digital boards
Wow, didn’t realize that was a result of the change, good to know as I think a lot of my amps like a higher voltage input
I use the AES input, however I wouldn’t use the HDCD feature. Sounds I’ll be staying put for the time being 
Really appreciate the input! This was a nice education of a vintage device I enjoy. It’s nice to have some historical knowledge floating around SA rather than scrap other forums.
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You are welcome, it’s hard to sift through the BS around the iterations of the Sonic Frontiers DAC lineup due to the bias of 1-2 people.
Apologies if I confused this component, it’s not specific to the AES input but rather the whole digital inputboard. It just happens to be called AES21, whereas the the version in your SFD-2 mki is the previous generation named AES20. They could have come up with a better naming scheme 
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Well that is really not helpful haha. Thanks for clarifying!
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You both got me interested in these. I did come across this https://www.stereophile.com/content/sonic-frontiers-sfd-2-da-processor-rh-sfd-2-mkii
There also looks to have been a mkIII version which could do 24/96
So what is the big thing about these dacs? Is there something out now that is similar? Camus and Nick, seeing you both heard my mojo, how does it compare or is it totally different?
You got me interested. I dont need or want another dac but there seems to be something about these and i have a date matched pair of NIB Amperex 7308s that need a worthy spot.
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Different pieces of equipment @Souldriver , the MOJO, the one in your hands in particular brings out a different level of resolution and separation with my gear in the various configurations I put it through. It did not matter if i were using USB or AES, the MOJO was not in the same league or of a sound character. The MOJO maximized and sometimes to a fault, as in the case when mated to my Charney speakers, detail retrieval at every frequency. The SFD-3 would in my vernacular and “taste” preference be the more “musical” DAC while the MOJO was squeezing out maximum performance and detail retrieval from the speakers.
If my memory serves the SFD-3 had a particularly grand sense of soundstage and was particularly wide in my larger room but for some reason I was not vibing with the piece mated w/ my equipment overall in my smaller room at the time.
Lastly, the ability of the MOJO to really squeeze out resolution very much impressed me in the low end as far as excellent detail in the bass and I remember at one point i had to go and re-adjust settings on my subs in the larger room to account for the performance uptik 
In particular I remember very much enjoying what the SFD-3 did w/ my Heresy speakers, taming them and simply allowing for a really enjoyable session, allowing their good characteristics and qualities to shine as opposed to the more technically capable MOJO which IMO lets you know what the maximum frequency extension of each transducer and crossover component is capable of and if they aren’t matched to synergistic components or the recording wasn’t up to snuff well, you may have to make more upgrades till you get it right. The SFD-3 i believe would be considered more forgiving
I remember thinking i could very easily live with the SFD-3 in my living room, not in my smaller room and the MOJO was an absolute delight in the confines of the smaller, more acoustically capable and silenced room where i really appreciated the resolution and detail retrieval along with the soundstage and imaging abilities. Talk about mating equipment to the space…lol
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These were rare and done as upgrades from the SFD-2 mk units, they deviate from the mono-DAC modules used in all the other Sonic Frontiers DACs in favor of 8 burr-brown chips. Also to do 24/96 one would need to get an additional component called the D2D-1 released by Assemblege, which was their lower-end brand prior to the takeover by Anthem. Assemblage carried on for a bit where they offered DAC kits. Other than that I’m not familiar, nor have heard the mk3 to make any comparisons.
The wonderful thing about the Sonic Frontiers DAC line is the UltraAnalog D20400A module, this is a Lavry design. Of course if the module fails, there are no replacements and PCX uses some new modules with AD chip sets.
https://www.soundstagenetwork.com/revequip/assemblage_d2d1.htm
The DAC which @NickMimi tried out was the Processor 3, their final and balls to the wall design before being folded up. While I can’t speak on Nick’s experience, I would counter his take on the resolution retrieval. The Processor 3 holds its own against my totaldac, I would say the big difference being both your Mojo DACs are NOS, whereas all the Sonic Frontiers DACs are OS.
What these DACs do, which separate from the other DACs I have had in house is they throw a wide stage, front/back depth, and tall height like no other. I hate to use the misused cliche of sounding analog like vinyl, but they really do. They aren’t particularly tubey sounding, as they tubes are used more as a buffer in the output stage.
The SFD-2 mk2 is the warm fuzzy blanket in comparison where it embraces you, yet has the tendency to be a bit too warm and as a result not be as nimble.
The SF-P3 is the wooly blanket, great at regulating temperature and able to keep up what is needed by the transducers.
They also perform their best in balanced output given they are dual mono DAC designs.
In terms of what else is out there which is comparable, at their asking price of $1.5k - $3k. Nothing I have come across in my exploration. Back in 1995 the SFD-2 mk2 cost $6k, approximately $11k today. So as a pure value in the used market it’s quite unique.
The big, and I mean really big caveat is their age and the option to send in for the SE/SE+ upgrades which in the case of my SFD-2 mk2 cost more than my unit. Add on the lack of parts and expense should something fail, such as my digital input board, I have spent well over 100% of my investment since 2021.
@M0N suggested having a look at some Lavry options, I will need to dig up my notes and can send them over if you want to dig a bit deeper.
You and @NickMimi are such tube hoarders
I say that as a compliment as my prized Siemans are double what they cost me and the thought of getting another pair now hurts 
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@Souldriver , i meant this statement, unfortunately i can’t give you a breakdown of how the DAC would sound on HP’s, i assume the grand soundstage would represent and shine through and I repeat the DAC has a beautifully “musical” presentation as far as I’m concerned, it did NOT lack in its ability to put forth absolutely well executed details. It was very different from the Z chipped MOJO, different in a pleasing well valued manner, at their reduced cost due to age a no brainer to own for what it offers🤌
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