Vincent works as a telecommunications engineer and decided some time ago to develop a second activity in audio engineering. For more than ten years he has developed radio and audio equipment for critical environments like trains, cars, buses and mobile phones. Of course like the majority of DIYers, Vincent Brient has an immodest passion for sound and a religious zeal for zero-concession solutions. This his own system illustrates quite nicely. Vincent is a qualified engineer and radical audiophile. Due to his telecom expertise he has access to unconventional parts and specific digital solutions.
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So when I finally laid my hands on it I could not wait to peek inside. That sets expectations high. They got a bulk discount or something? Economies of scale? Is it 8 times better than simple one PCM? Or is it 8 bit better? Apparently they claim to squeeze 22 bits out of 20 bit chip by the way of 8x config and 32 x over sampling.
Is it high end or what? Everything else is identical. The hood is a thin and flimsy one, not highendish at all. No balanced outputs. Cheap plastic remote etc, etc. So we are dealing with a simple standard CD machine which for some reason has 8 top DAC chips inside. Kind of equivalent of Golf VR6. Easily accommodating fully balanced 4 tube output.
All the player fits on one PCB - a big and neat one. There is no doubt where the burr browns reside - 8 of them in two rows makes good impression. Why 8? Nobody knows.
While one is needed to make a mono DAC, we need 2 to make stereo set. Adding 2 more enables us to have mirrored balanced signal which still makes a lot of sense. But in this player all that has been doubled and paralleled - what for? To get more output? Or to average errors by SQRT2? Sqrt 2 anybody? Extra bit of analog resolution? Impressing customers at the cost of 10 bucks? Anyway, to use this player properly the only way is to add a balanced transformers from sowter and utilize all 8 chips at once.
With tubes of course. List of other fine players using the same DAC Back to lampization of DP Kenwood On the photo above you will see capacitors with a double dot - yellow and red for better legibility, which I think should be replaced with much better, low esr caps. Os-cons are marvellous here! There is over 30 of them but the bass and space improves a lot.
A portrait of the cheap JRC op-amp dual one. They had to go away, sorry. And galvanically isolate DAC from tube grid. Just add a Ohm resistor from leg 7 to 9 of tube base no more K there and wire the isolated DAC outputs to the leg 7. For SE system - only 2 per channel will be used, 2 will remain unused. The Sowter transformers they do miracles for this player. The signal is so powerful that it easily drives the amplifier without any tubes at all. The transformer can also convert the balanced signal to RCA single ended.
After the transformer installation, this player immediately jumps to the top league together with the Grundig, Copland, Revox and Shanling. After lampization - it is in top league. Absolutely stunning. Jaws dropping, drooling, etc etc. You know the story. Highly recommended.
PCM1702 R2R Isolated nonoversampling NOS Audio DAC with FIFO reclock
Incorporated into the PCM is an advanced sign magnitude architecture that eliminates unwanted glitches and other nonlinearities around bipolar zero. Applications include very low distortion frequency synthesis and high-end consumer and professional digital audio applications. Twx: ? Tucson, AZ ?