NOT QUITE NEVER AGAIN, THE GROUP BUY DAC BUILD

[nige2000]

Right I've tried the direct supercaps on board reg bypass with success
This is the equivalent sound of the finished product
If we don't change anything

After listening to it I can't imagine changing much
It's clean, refined and dynamic

I don't think anyone will be disappointed with the sound

[Derek]

Good enough for me. You're puttin' the hours in this week, fair play!

[Fran]

Excellent news Nigel, it's really great that the bypass worked out.......

[Sligolad]

Got me interested in finding out about Super or Ultra capacitors today....turns out i learned a bit about Estonia as well!!
https://youtu.be/KQ2Eo6wl5r0
https://www.skeletontech.com/ultracapacitor-webstore

[jkeny]

Well done Nige - I didn't see this thread before - Fran mention something about your DAC & I guessed it was the PCM1794 but I didn't know you were doing another Group effort

Never say never again - I'm told it's like childbirth - you forget the pain of the last birth & go ahead with another one :)

What do you think of the Supercap sound - more dynamic than batteries.

Look forward to hearing one - remind me again, what was the final CCS IC that we found best?

[nige2000]

Well done Nige - I didn't see this thread before - Fran mention something about your DAC & I guessed it was the PCM1794 but I didn't know you were doing another Group effort

several months ago i was looking at the rather large pile of dead 1794 chips in the shed, and regretted i never built anything permeant with that design.

Never say never again - I'm told it's like childbirth - you forget the pain of the last birth & go ahead with another one :)

yes its definitely something like that, although this is substantially smaller project

What do you think of the Supercap sound - more dynamic than batteries.

i think its likely better ive done little testing yet, only tried batt vs supercap pre regulators. in which i thought its substantially better

Look forward to hearing one - remind me again, what was the final CCS IC that we found best?

2sk208
ive got both "r" versions and "o"
so "which" needs to be tested too
might not make much difference

[Sligolad]

Finally took up the challenge of a front panel with no screw heads and added adjustable tilt just to make life difficult :-(
Posting some renderings below just for the concept and do not mind the colours since we can spray paint in any colour.
Will start some test prints to see if this will work. Ideas and feedback welcome.

[jkeny]

Nige
Are you using regulators on the DAC board or how are you keeping the voltage steady?
From what I can understand, you are not concurrently charging supercaps while playing DAC, are you?
Have you found the sound better when not concurrently charging?

[nige2000]

Nige
Are you using regulators on the DAC board or how are you keeping the voltage steady?
From what I can understand, you are not concurrently charging supercaps while playing DAC, are you?
Have you found the sound better when not concurrently charging?

We're using the amp power supply system
Nothing completely set in stone though
This is the way i envisage it
Five supercaps
Set to 1.65,1.65,2.35,2.35,2.35
So we have 3.3v 8v and 10 odd volts
The dac has on board regs 10v for that
That manages power up then there's the direct supercap power that bypasses that as soon as the voltages are correct
We're going to use a comparator and relay system to manage that probably on the 8v rail
Supercaps are been charged constantly

There's an interesting difference with the bypass

[jkeny]

We're using the amp power supply system
Nothing completely set in stone though
This is the way i envisage it
Five supercaps
Set to 1.65,1.65,2.35,2.35,2.35
So we have 3.3v 8v and 10 odd volts
The dac has on board regs 10v for that
That manages power up then there's the direct supercap power that bypasses that as soon as the voltages are correct
We're going to use a comparator and relay system to manage that probably on the 8v rail
Supercaps are been charged constantly

There's an interesting difference with the bypass

Ok, so during startup period DAC board is running off it's on board voltage regs (powered by the amp PS system + supercaps they are charging)
When supercaps reach their assigned voltages then on-board voltage regs bypassed & DAC board is powered by Supercaps being kept charged by the amp PS system.

How long does it take for supercaps to come to assigned voltage when starting from 0V - I would imagine it's very quick with that amp PS charging system?

Yes, I would expect an audible difference between Supercap direct power to DAC board & supercap power through voltage regulators on DAC board