Vintage DACs

Fine DAC you got there sir! Mine is the "A" version which I understand "added dithering to the burito filter and 52 matched resistors". Not sure what that means but it sounds really good ... Not the same detail retrieval and transient attack as today's finest but a very solid and believable performance overall.

Nice amp btw ... Are those 6EM7's?

 

Mine is the A as well, according to the sticker on the back.

13EMZ tubes, Pete Millete Jonokuchi.

 

Bummer, you don't have the early 90's vintage BLUE led's -- those were hard to make and used a different chemical... cost $20 a pop, every other color was a penny (at the time, could not do white either). I have 2 from that era and it's actually a very strange color & deep looking. Not the cheap bright blue thats common now.

So cool you're running an eitr into it.

 

How early are we talking about? Blue LEDs weren't invented until 1992 and I'm sure it took time to commercialize.

 

? -- early 90's

progeny was mid 90's

 

Ah but I do. Just not aligned with the non attached front panel.

 

oh shit -- cool! lucky bastage

need to 3D print some push buttons

 

Fixed the front panel kinda, with some Velcro command strips.

Also found some weird stuff inside, some dynamat on the lid

And inside, 2 screw holding down the board are missing, and there seems to be an IC socket with no chip inside... hopefully there isn't supoosed to be one there.

 

A lot of the time something like that is a test socket for hardware people to test or troubleshoot a board.

 

@spwath - where's the screws on that jonokuchi?

 

PCB didn't line up correctly, wrong size spacers, IDK, blame @JoshMorr
So both my amp and dac have front panels not attatched by screws

 

How dare anyone assume those are forgotten screws and not an increased air flow mod.

After trying 3 different sized spacers for the PCB to chassis attachment, I never got around to getting the right ones. I would say I'm .5cm off. I eventually moved on to the next project and jono collected dust until it took a brief tour of eastern seaboard and ended up in Spwaths care. I'm sure dude will someday tear it all apart so the jono can be the beauty that it was meant to be (and no longer be shamed by bullies on the internet)

 

Yeah, one of these days ill fix it. But for now I have other things to worry about, like the 500-600 vacuum tubes I have. And college classes I suppose.

 

Hi All, I am new here and new to world of DAC. I missed out on a locally available Anodyne ATAS Tube DAC by Scott Nixon abt a month ago. And recently, I found an Aragon D2A2 for sale and was wondering if this would be a good first DAC for me. Both use PCM63. Unfortunately, there’s not much review on the Aragon D2A2.

Beside the PCM63, the D2A2 uses Ultra Anologue something for the HDCD.

I would appreciate if anyone here can tell me more abt its SQ.

Intended use will be from computer, either my macmini or I may just try set up a Raspberry Pi unit, going into Chinese tube Line Magnetic and a DIY Full Range Horn Speaker (Frugal Horn 3).

Thanks in advance.

 

Would this also be true for the Theta Gen V-A DAC? Not sure if that's lesser or greater then the Progeny. I've been considering picking up a 2nd hand unit based on the good things people say (amazing bass, organic overall sound) but worry it won't be to my taste due to the qualities you mentioned. Is it that far behind in detail and attack?

 

I snagged a vintage Counterpoint DA-10 and it arrived today. It was sold "as-is," with the only guarantee being that the seller plugged it in and the power light came on. It was reported to have been unused for the previous five years. Happily, it seems in good shape, but I wanted to ask advice here before I start celebrating.

This model has interchangeable DAC boards, so popping open the cover revealed more than just condition. Unfortunately, no ultrarare UltraAnalog D20400 card inside. Instead it has the most common DAC board produced for these, with dual AD1862 R2R chips. But at least that's the board that Stereophile thought sounded best. https://www.stereophile.com/content/counterpoint-da-10-digital-processor

This unit looks a little different from ones I've seen in pictures elsewhere online. I suspect it may be an earlier version. There's no quote from Stravinsky silkscreened onto the board; instead it says the DAC is "for higher highs and tighter bottoms." () Some of the part numbers on the board appear to be hand-painted. The board says it's "Rev C"; most pictures I've seen elsewhere are of a "Rev J." Other models have an array of 44 identical 470uf 50v capacitors; mine has the same overall number but two on the end are smaller 330 uF 50v caps. Maybe most crucially, there is no venting in the top-case whatsoever, which is something I've seen on every other unit.

I haven't plugged it in yet because I'm a little paranoid. I did a visual inspection of the inside, and all of the electrolytic capacitors appear to be in really good shape. However, there are two obvious problems I noted. First, the right-channel RCA jack is loose. This seems like a simple repair; just tighten the collar on the inside of the case. But of course, the existing jack connections (which appear to be intact) are in the way.
Any suggestions on how to tighten the bottom RCA jack collar as gracefully as possible? Needlenose pliers, or is there some better tool for this kind of job?

Second and more frightening, I noticed some etching on the circuit board in the right channel analog section.

Do I need to worry about that exposed metal on the surface of the board? Do I need to seal it with something?

 

Fixed the RCA output jack on the Counterpoint DA-10. I'm testing it with iTunes set to 24-44.1 WASAPI, feeding an Eitr connected to the DA-10 via a RCA-BNC adapter. Then to a HeadAmp Gilmore Lite mk2 driving an LCD-2.2 and pre-outs to powered monitors. My main point of reference is a Modi Multibit, currently my only other multibit DAC.

Summary: the DA-10 is better than the Modi Multibit in a couple of notable ways. It's close, though; the Modi Multibit is 95% similar to the DA-10. They sound extremely similar when you A/B them. I might even prefer the Modi's frequency response; the DA-10 seems to have a slight lift in the high end that doesn't fit my preferences as well, but this could be a product of limited warmup time.

I listened to the DA-10 alone after about 2.5 hours of warming up & playing music, then listened again another 4 hours later, after setting it up to A/B with the Modi Multibit. The Modi has been plugged in continuously for months at this point, so warmup isn't an issue there. I split the Eitr's RCA out to both the Modi and the DA-10, then fed them into the Gilmore's switchable dual inputs. The results:

• The DA-10 does macrodynamic swings better than the Modi Multibit. This is probably the biggest difference. Instruments muscle their way to the front of the mix easily when called for, with power behind them. With the Modi, big macrodynamic swells can sound a little compressed compared to the DA-10.
  
• DA-10 has better resolution than Modi, but you really have to listen for it, and you only notice the difference occasionally. Seems like the differences might be at the outer limits of what the rest of my chain can resolve. Really nice detailed resolution and microdynamics in the snarl and crunch of electric guitars. I'm noticing depth and layers to the guitar distortion in some tracks that I hadn't noticed before--I suppose that would be plankton. Very realistic pluck and vibration of acoustic guitars. Drum decays are more realistic too.
• DA-10 improves in the realism of instant attacks on notes... I think the jargon for that is transients? The resonance of a guitar string starts simultaneously with it being plucked, making Modi seem to have a momentary delay by comparison.
• Highs started out a bit overemphasized and harsh upon plug-in but have smoothed out and improved as the DA-10 warms up. Ultimately a similar tone and FR to the Modi Multibit, with a bit more emphasis in the highest frequency range. I might actually prefer the Modi's presentation; I'm pretty sensitive to high-frequencies and there's a teensy bit too much for me here, though it's a very slight difference. It would probably be an easy fix if I moved my Loki back into this chain. And it might smooth out with more warmup.
• Really nice quantity and texture of bass. Both are clear, if slight, wins for the DA-10 over the Modi.
• I notice a clear difference between sending 16-bit and 24-bit output signals to the DA-10. 24-bit is more realistic. 16-bit seems "flatter" both in staging and in the dynamic swings of individual instruments. Interesting, considering that the AD1862 is a 20-bit chip. The difference is larger with 24-bit tracks, but persists to a lesser degree even with 16-44.1 source material. This makes no sense, I know.
• The DA-10 has an "invert" mode that I believe inverts the polarity of the output. I've been playing with it and I'd be hard-pressed to identify any difference.

EDIT: A month after I wrote the above, it's now clear that the "slight lift in the high end" I was hearing with the DA-10 was DEFINITELY a consequence of not enough warm-up time. The DA-10 needed way more warmup than I expected. After a month plugged in, the perceptions have flipped--the DA-10 now has a slightly warmer tone than the Modi Multibit. The DA-10's highest-highs are now extremely pleasant and smoother/finer than the Modi Multibit's. Air, tone, weight/body and microdynamics/plankton have all improved significantly, and so the gap has widened between the DA-10 and Modi Multibit. And this is when I'm feeding it with Eitr via a RCA/BNC adapter; I discovered that using a glass Toslink cable to connect the DA-10 directly to my motherboard sounds even better. I find myself losing my critical awareness and just grooving out to the music with the DA-10 in a way I don't with other DACs, which is the biggest compliment I can give it. I'm not sure how much warmup time was enough, but I definitely didn't have enough when I wrote the above observations.

 

With the 16/24 bit thing bear in mind that I would expect everything would go through the oversampling filter and get sent to the DAC chips as 20 bit samples. In effect you are hearing the processing of the filter.
My old Adcom DAC also has an invert switch and I have not yet been able to hear any difference when trying it. I can see the waveform inverting on the oscilloscope, but I would love to find one track that somehow highlights the effect.

 

Anybody ever dealt with trimming an R2R DAC? Search isn’t coming up with much. The Counterpoint DA-10 actually has a user-accessible trim pot on the front panel.

Macro adjustment is done during production, and the user-accessible pot supposedly does micro-adjustment. Apparently Counterpoint recommended trimming by ear!? I have no idea what I would be listening for.

 

It just fine tunes the analog output level. No point in touching it if you don’t have to and don’t have meausurement gear or decibel meter. That’s why it’s screwdriver accessible only.