Sonic Frontiers SFD-1mk2 Vintage DAC for $750 That Stomps Most Modern DACs

Trying to get the UA module desoldered w my dad rn, and it’s not coming out at all, I think we’re gonna go from the top and destroy the module w a dremel unless anyone has any ideas on how to get it out?

 

Here is my interim comparison, I think it captures enough to give a sense of the two DACs or maybe it is verbal diarrhea. I will let you all judge that bit

SFD-2 Mk.II vs. SFP-3

Listening Chain: Roon > Pi2AES -> DAC -> Stratus V4/BW2/Bryston BHA-1/Pass HPA-1/ECP DSHA-3F -> Utopia 2022/Utopia 2020/Rosson RAD-0/Senn HD650 (stock)/ZMF Verite Open

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

 

I feel left out with my E36 M3... hahaha - it's the SFD-1

 

Can you see the flat pins in the side of the module (like in DIP packages)?
If so, I would just cut/dremel them and desolder them one by one.

 

Finally fixed the dam DAC, dremeled out the stuck-in-place UA module (gore pics album here), and upgraded w four Jantzen Z-Superior for coupling caps in the output stage (nice finished pics album here) with my dad!

So happy to have music back after over 2 weeks, and even more of intermittent distortion...

Source is the King, source is Everything.

Once the caps burn in, I will do a write up of my memory of UA D20400A and AD1862 in the SFD-1.

 

Wait, are those teeny tiny ferrite cores on the positive RCA output wires?

 

Yep, those are original

 

Where do you even see that?!

Edit: Oh, this album.
https://imgur.io/a/uAm1KRm

 

still tho, out of focus and tiny, @yotacowboy has dem eagle eyes

 

UltraAnalog D20400A vs Analog Devices AD1862 as D/A in the SFD-1

Disclaimers: 1) As per usual, this belongs in the wacky editorial section of the NY Post, not "objective" front-page reportage of the Times or without the scary quotes, Al Jazeera.
2) New. unburnt-in caps were also installed at the time of DAC module switchover, so this almost certainly had an effect on my impressions of the diff between the two

OK, here goes:

• UA has dat spooky action wraparound soundstage, eerie things happen inside of its forcefield, imaging has a parallax or convex effect that is truly special (apologies to any physicists reading this)
• re: UA soundstage—via coax the stage was as described above, only more-er, via AES (from the pi2aes) it was still huge but less uniquely shaped—it was more straightforward, left, right width & up, down depth but less special seasoning
• UA has more quite a bit more liquidity, but less cohesion than AD
• re: AD's cohesion, it is v clear cut—this is bass, this mids, this treble, the transition is v linear
• UA has a more "vtg" je nais se quoi tone, hard to describe, it's warm, yes, but not as warm as you'd think with the tube buffer, it's just more... SAY THE LINE, BART *sighs* ...analog-sounding
• UA's midrange had an almost living (reminiscent of live recordings), breathing midrange, to say it's "organic" would also be fitting, but cliche and polysemous to diff people, so I'll stick with "breathing" lol
• AD has more modern R2R sensibilities in its rendition of D/A, it honestly sounded v close to my old Gungnir MB A1 or the LIM I heard briefly at the Schiit Corpus Meet II w the Vali 3 (only w tube output, so there was still a slight grain or grit to the sound, or maybe the brownish haze—different from the grey haze of Schiit—is just endemic to the SFD-1 no matter what, idk)
• AD hits harder in the bass, this was absolutely the first thing I noticed—both bass quality and quantity are gained, as well as better texture than UA
• AD has a more forward presentation (again, like higher echelon Schiit mb)
• AD leading edges more defined or cut, less ethereal or soft (which was lit my only complaint w UA, it could be a bit soft around the outlines of images)
• AD has a wider FR, and it is more even-keeled—the lowest and upper most octaves are not rolled or squishy, but midrange is less emphatic than w UA

I quickly sold my SFD after swapping modules, so take that for what you will.

Can also put it this way: If you love the Gungnir A1, but wished it had tubes, buy a SFD-1 and swap out modules for AD1862. If you want a vintage DAC that has some of the best tone, mids and staging I've ever heard from a DAC, roll the dice on a SFD-1 with original 30-year-old module and hope really hard it doesn't fail on you like mine did.

 

I have a UA based SFD1 MkII and a UA based Processor 3. As is, the P3 was a bit tighter in the bass and more improved in musicality and detail and soundstage as compared to the SFD. But the P3 is undergoing the Sparkos/AD1862 mod and SE+ mods at PCX. I will see how they directly compare afterwards.

 

Definitely interested to hear ab how you exp the difference! Pls post your impressions here. Valuable to have more impressions on UA vs AD for anyone going thru the process themselves.

 

Are you swapping out the UA DAC modules because they are busted, or it was recommended?
What did they quote you on the SE+ in terms of component upgrades?

 

**pending pics of internals from buyer**

so. Head-fi Buyer—who only has a usb-spdif converter and a CDT w coax—can’t lock onto a signal w my old DAC.

it was lit working for both coax and AES the night before I sent it out. Like a fool, I didn’t insure the shipment in PirateShip, went for the cheapest option.

he said he tried the converter, which worked w other DACs, and straight from his CDT to the SFD-1, but it will not signal lock no matter what he does. Think he mentioned getting a converter that has AES, but idk if that’s the issue…

the pic below is my dads handy work when we replaced the module (the inputs must be desoldered and he resoldered the coax back on w new wire.



Could it be that he did a less than professional job soldering it back on and something catastrophic—a major drop of fall—happened during shipping? Wire connecting coax input came loose or something?

or if photos come back looking good, could it be the AES21 receiver? I wish he had an AES source to test w, but it is what it is, and anyway, I made sure both were working the night before sending out, well, more than just “testing”—i was using it as my main DAC for a week or two after module replacement right up to before shipping out.

anyone got any ideas?

 

Hilariously enough it may be as simple as he is sending a signal higher than what the SFD-1 accepts. I freaked out for a while once with my previous unit and it turned out my streamer was sending an unsupported bit rate. It's pretty picky.

He should be able to choose the bitrate with his converter. To troubleshoot, ask him to make sure he is sending a sample rate and bit depth of 44.1kHz/16bit to the SFD-1. If it still can't signal lock something else is up.

The CDT however I would assume should work fine, unless it automatically upsamples everything. Then I could see why it wouldn't signal lock.

It's hard to tell from one picture, but the solder joints all look "ok" from your photo. If the buyer can send photos of how it looks now, we can try and help diagnose any obvious damage.

 

This could be dumb, but on my SFD it has a Coax output. Could he have been connecting it to the output instead of the input?
Otherwise if it is the AES 21, you are in the same boat as I am as there are not replacements yet. PCX is working on finding a new source and might be a few months.

 

I was literally about to say the same thing. This is most likely the issue, assuming nothing broke off in transit.

 

I still forget and make this mistake despite owning one of the SFD models for over a year.

 

holy shit if this is it you’re a f'ing genius! Just, very politely, asked now lol.

ok gentlemen, take your bets now: UPS beasthandling multiple mega-drop break or user error?

 

Happens to me too with the P3 when I forget to edit the PI2AES profile under Roon to downsample to 44/48. I remove it when switching to the Yggdrasil.