poynton said:
very nice brent😀
what next???
bypass pcb, just keep it for display and control
custom pcb for decoder dac and output
allan
awpagan said:
very nice brent😀
what next???
bypass pcb, just keep it for display and control
custom pcb for decoder dac and output
allan
I will at some point do a custom pcb for output and get rid of op amps.
Also I have thought of a better DAC (if there is one)
Brent
awpagan said:
very nice brent😀
what next???
bypass pcb, just keep it for display and control
custom pcb for decoder dac and output
allan
Well, the front panel has not been looked at yet [apart from screening the ribbon] so there is room for more playing !
Changing the DAC is not a technical problem - the decoder outputs i2s so it could be a TDA1541A S2 or one of the latest chips in 8x oversampling
OR
How about a discrete R2R ladder DAC ?
Andy
rowemeister said:
passive discrete buffer😀 😀 😀 😀 😀 😀
taken from 10k resistor position, separate pcb for filter, buffer then to output
better dac's 🙄 probably each has there own views.
main part i think is implementation.
allan
poynton said:
I saw the i2s out and been looking at different dac's
prefer voltage out rather than current
also 256,384fs so can run with the cd850 and cd67
the TDA1541A S2 is very hard to find and very expensive unless you scrape a machine for parts, but it seems a waste of a player.
allan
I'm thinking of putting in a separate reg (7805) for the dac. Does anyone have a more detailed description of how to do this?
avr300 said:
look out the fleas are breeding
beware of infestations
see your local vet for solutions
allan
gy21 said:
Hi,
You need a few things, and need to decide how far to take it. Do you want a separate reg for each of digital, analogue and clock reference? I think you do...
Basically, you need:
3x 7805
a strip of veroboard/stripboard about 5 strips wide and about 5" long
wire not too thick to be inserted through pcb holes (stranded would be the easier)
2 caps for each reg (one before, one after)
possibly some screwdown terminals to allow removal of the power input for repair/work (your choice, but I like that idea)
You need to know:
*Where to take the voltage from (I used the +20v supply from)under C803.
*What parts to remove (RD01 and RD04)
*Where to feed the new 5v rails (U200 - lifted at the supply end will feed the DAC's analogue psu pins, hole of RD04 for digital psu pins, and hole of RD01 for clock ref. pin)
This post of mine has a pic showing more or less where they go and what it might all look like: http://www.diyaudio.com/forums/showthread.php?postid=910675#post910675
Also - you need to attach the ground of the regulator and associated caps to the ground of the player, in my case a star ground I added.
edit: or do it even more simply as Brent has shown above (fewer caps).
SimontY said:
Thanks Simonty and Rowemeister.
One question. My tentlabs clock is already on a dedicated board with a power supply (tentlabs schema), so does that mean I don't need the 7805 for clock ref anymore?
gy21 said:
No, I believe it doesn't mean that. This is a pin on the DAC and your masterclock needs an additional psu. So you'll still need 3 to run the DAC sweetly.
Simon