Or a slow one like 5.4 Mhz if NOS : see SC-CUT discroll osci project from ANdrea Mori.. We care of what happen below 20 hz in a xtal jitter measurment (see Jocko Homo work)
Ask Joseph I have not pcm1704 nore pcm63 at hands with the same i/V... the pcm1704 I heard from GrandAudio something and a pcm63 cd players was in my memory less good than both tda1541A and ad1862, but it was not as iso perimeter - understand same osurce & I/V of course, speakers, cable, amp; room, age of my ears-
seems your found of dac as I am, lol !
Never went of the tubes side cause lack of knowledge about this world and how to have a good layout with that, especially if air wired w/o pcb, but my understanding is that they are the winner as far i/v from a dac is involved... that's always the nos tubes price and the expensive output caps or OT that stopped me... and the short fear if an hand too close !
That's why I'm happy with the AYA as with nulling circuitry I don't need output caps nore OT... But the AYA I have is moded elswhere though stay simple but the front end (Iancanada spaghettis front end::: huge, needs big enclosure, lol and certainly an EMI trap, lol ! Do you see the price of coper those days ! Uh !
Never went of the tubes side cause lack of knowledge about this world and how to have a good layout with that, especially if air wired w/o pcb, but my understanding is that they are the winner as far i/v from a dac is involved... that's always the nos tubes price and the expensive output caps or OT that stopped me... and the short fear if an hand too close !
That's why I'm happy with the AYA as with nulling circuitry I don't need output caps nore OT... But the AYA I have is moded elswhere though stay simple but the front end (Iancanada spaghettis front end::: huge, needs big enclosure, lol and certainly an EMI trap, lol ! Do you see the price of coper those days ! Uh !
If I may suggest.. You could try also swapping out the second stage 861 (buffer) , and put in a buffer.. Like.. Opa1656..
Or some good chip that You like.
It could be done quite easily with the present setup, and a little piggy board..
Ciao, George
I tried AD1862 with PCM1704 one to one comparison (the same I/V, the same power supply) and I like AD1862 more. It is not like a big step, but is different. AD1862 is much more enjoyable from a longer run, a little more dynamic and spacious. When I listened to PCM1704 for a longer time (for example a month) and then switched back to AD1862, then I didn't want to go back to PCM1704
... I could define PCM1704 as neutral and AD1862 as enjoyable.
If an headphone or long long long cables it's advised but with a normal pre/amp, the second opa -reversed in buf config- was not usefull with my 50K pre. Ears were not able to make a difference with or without the second opa861... if single in i/V stage without buffer the output serie resistor must be adapted and it's enough for pre/amp - undersrand not passive input stage-
But yeah the opa 861 + opa1656 as buf sounds like an universal winner for both headphones (100 mA iirc) and high impedance pre/amp inputs ! The opa 627 seems to make right the both job, but better than these two together ? I really don't know. My point will be more the mariage between the output impedance of the dac chip and the I/V stage...it's above my head, my basic understanding is tubes makes that better... and discrete a little better than a video oap be it transconductance w/o feedback.
But yeah the opa 861 + opa1656 as buf sounds like an universal winner for both headphones (100 mA iirc) and high impedance pre/amp inputs ! The opa 627 seems to make right the both job, but better than these two together ? I really don't know. My point will be more the mariage between the output impedance of the dac chip and the I/V stage...it's above my head, my basic understanding is tubes makes that better... and discrete a little better than a video oap be it transconductance w/o feedback.
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Uhm I was talking about / thinking of the filter caps accross the I/V resistors..
And I'm not 100% sure that the direct local filters on the DAC chip's output - would be so clearly useless.. good caps could work into the 50/100MHz range, where even the 861 is not having anymore that low input impedance.
And an audio dac is just full of RF residuals coming from inner register switching and data / clock leaking through..
And I'm not 100% sure that the direct local filters on the DAC chip's output - would be so clearly useless.. good caps could work into the 50/100MHz range, where even the 861 is not having anymore that low input impedance.
And an audio dac is just full of RF residuals coming from inner register switching and data / clock leaking through..