A New Take on the Classic Pass Labs D1 with an ESS Dac

[buzzforb]

These are 1 3/8". Mine are 2".

EA-T220-64E-ND
Digi-Key Part Search

[qusp]

ahh 2" that way, not a chance... caps are pretty flush that way, pot is pretty flush across the board, the only way is up



please let me know when you are doing the order. have you made any further inquiry about the powercons?

[buzzforb]

That is bad music! The powercons were listed a couple of pages back. I think $15 for both pieces needed. Will send out PM tonight to all GB subscribers to confirm and ask for payment and then will place order.

[qusp]

yep, it was bad back then, its only value now is comic. did you make it to the 'chorus'? me linking it wouldnt have made any sense without that. of course, depending on your vintage you may have already been familiar with it.

I may or may not be involved in the actual parts GB, will see how its shaping up, I just have too many of the parts already, may not be worthwhile.

[buzzforb]

when taking into consideration the volume discount, the cost should stay the same even adding the caps for psu and larger sinks. This does not include extras like XLR or powercon conectors. It also assumes that everyone bought the Auricaps for coupling from you. Ill have more details when i hear back from folks.

[Rolle]

Hi Buzzforb

I noticed the Zener protection diodes is missing - is it still possible for you to add them to the order. They are not strictly needed, but would hate to fry the buffalo if something goes wrong :-)

OPC's bom specifies:

8pcs (MMSZ4683-TPMSCT-ND) DIODE ZENER 500MW 3.0V SOD-123

Happy New Year
Rolle

[buzzforb]

Will do.
Here is the last known GB list:
Parts GB
buzzforb - 1
Magsy - 1
vitalica - 2
Reenberg - 1
Emphrygian - 1
qusp - 1
Iancanada - 1
crazikid - 1
bigpandahk - 1
Rolle - 1
Coolhead - 1
woresseo - 1

PM's go out today so if you dont see your name, please give me a shout

[analog_sa]

Are people really building this using the 317/337 regs or are these just to get things started? It seems like an obvious contradiction to use super duper caps and resistors and ultra high bias and then suddenly cut corners where it really matters.

[qusp]

but it actually doesnt really matter that much, thats how the rather extensive measurements including one of -113dB THD+N were taken, many of us have used salas shunts, many will do so this time too, but myself I went back to using LT1085/1033 because its more convenient/compact and there are bigger fish to fry. the board is laid out well, with good quality SMD decoupling caps. people are welcome to try other things if they wish, just dont expect much improvement.

its very popular to beat on LM regs, here they are pretty fine IMO, its not a very demanding application, transient demands are not large, the caps are doing the work and its a pretty straight forward, but well executed regulator section. its also at the edge of a normal salas shunt application as far as voltage at +/-45vdc out and there arent many other regulated designs that will do it either. the output impedance of the shunt reg is meaningless, the noise performance of the LM/LT is already lower than the dac etc etc.

running a higher voltage on the fets will give you much more real improvement than running a lower voltage shunt reg. +/-45v shunts are doable of course and I tried it, but for me a dac that already dissipates 50W for each 2 channels is enough

[analog_sa]

Thanks for your view on this qusp. For the last 6-7 years i've been running everything on either the Jung variants or some type of shunt and this includes high psrr circuits. I would automatically assume that for a circuit as simple and PS sensitive as the D1 the difference will be plainly audible if not readily measurable. I'll definitely give the plain Jane regs a listen first but would be very surprised if they stay.