Yes, the 1:1 transformer helps a lot to subjectively sound better, similar to the DDDAC. It also gives me a balanced output, if needed for some trials with balanced devices. This particular example serves as a steep filter at 80kHz. It's just a pain to find the right transformer.
You can see when it's unsoldered, even if they try to hide it. Of course, it is always possible to deceive someone. The ones I bought were 99% never soldered/unsoldered, I took a good look with a magnifying glass and strong lite, there are no traces. And I don't know of another source of PCM1702P-K.
I bought from polida https://www.ebay.com/itm/362255965866
I received the same as in picture - Korea K - and it is working fine .It wasn't soldered/unsoldered - probably it was removed from IC socket . Buy only DIP not SMD .
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Sounds good. I bought it last year a pair 1702P-K but they were tortured (unstable voltage). It's a shame that I never listened them. So I think to buy a new one. I will talk to the intermediary about shipping. I found only old and used chips (not in good condition).
Bird's nest for testing DACs, with 1:1 output transformers. The direct output (with mute circuit) is also retained for comparison. OPAs are Burson V6 Classic freed from the plastic armor.He sent me a picture on Viber that he put the output transformers on PCM63P-Y. They have so much energy that he have to calm it down with transformers.
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Guys, I have the pair of the 1702J. This is working chips but not in good condition "according to some parameters". That's what the man told me. I was buyed them pretty cheap. So, what do think?
I can run the DAC only a month later - he is in the arms of a friend.
I can run the DAC only a month later - he is in the arms of a friend.
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Do all your dacs sound better through the transformers? Do you use an active line stage?
They don't all sound better. I use the original active I/V on Miro boards and different opamps. Let's say that tests with AD1865 & PCM56 showed that it is better without a transformer. I always leave both outputs, so I can choose with selector switch on a preamp. The PCM63P-Y, which is a bit hard to listen to because of the abundance of high frequencies and the lack of bass, sounds better to me through the transformer. It's a kind of sound manipulation, but useful in this case. For DDDAC, the transformer proved to be better than the output through the capacitors. The PCM1794A in NOS mode can sound sharp, the transformer corrects it wonderfully, and the bass gets meaty. There are no opamps, the I/V is passive. I just tried a dozen different transformers until I found a good match.
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In my search for the optimal sound for the Miro PCM1702 DAC I tried a bunch of OPAs that I had and some that I didn't. It turned out that the best match was SS3601, followed by OPA1656 (or 1655). From talking to others about that, there is also the Burson V6 Vivid as maybe a little better than the SS3601 in this position.
The OPA1656 has a slightly softer sound at high frequencies than the SS3601, so that might be an advantage for some. I don't have the V6 Vivid, so I can't compare. I'm talking about really small differences, the finesse is in question, and the price is many times lower.
The OPA1656 has a slightly softer sound at high frequencies than the SS3601, so that might be an advantage for some. I don't have the V6 Vivid, so I can't compare. I'm talking about really small differences, the finesse is in question, and the price is many times lower.
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