Cheers to that. This thread is my favourite place on the web ever.
Thanks for the tip, Ian. I thought PK would be a fair swap for the ZLG but I'll consider swapping them for something more suitable.
I had fun building that PSU, and the big snap-in Mundorf caps are 40% off atm, and I was thinking: I have all these separate +5v 317 supplies powering my chips - should I build separate PSUs for those? (I've got the bug quite badly now)
If so, should I regulate them separately to, say, 8v, and how much VA is enough per individual supply? Thanks guys.
Thanks for the tip, Ian. I thought PK would be a fair swap for the ZLG but I'll consider swapping them for something more suitable.
I had fun building that PSU, and the big snap-in Mundorf caps are 40% off atm, and I was thinking: I have all these separate +5v 317 supplies powering my chips - should I build separate PSUs for those? (I've got the bug quite badly now)
If so, should I regulate them separately to, say, 8v, and how much VA is enough per individual supply? Thanks guys.
Ah, looking back, Ray said 7VA was enough for the DAC and Lee suggested 50VA for the drivers would be a more valuable next step than the DOS.
Mmm.. I have 3 quite compact quad 5v reg modules for the chip supplies (12 regs total, of which I'm currently using 10). I'm thinking I might get 3x 9v 7VA transformers and 22,000uF AG caps to feed them. I should have room down the right side for all that.
Mmm.. I have 3 quite compact quad 5v reg modules for the chip supplies (12 regs total, of which I'm currently using 10). I'm thinking I might get 3x 9v 7VA transformers and 22,000uF AG caps to feed them. I should have room down the right side for all that.
I've done some work there. My op-amp section is recapped with BG FK/N/NX and 1% silver micas, but resistors are original and buried under big caps due to bad planning. If 7VA is big enough for each chip then maybe I'll get the ball rolling on that while I wait for the XOs.
DOS parts will take some research, I think...
DOS parts will take some research, I think...
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Hi Guys, is the servo power supply mod is exactly the same as for the 67 and 63 cdp?. I am fitting extra torroid for the op-amp(67cdp) and thinking of doing the servo as well. Would it be a good idea for them to share the power supply ? or best leave the stock tranny to power servo as concern re noise interference?
Quan
The servo driver ic section is different in the 67. That's what the additional 5v reg is about on the heatsink in the middle of the board. You could use an additional tx for this supply for sure. I'd go for about 50va with a 22000uf smoother there
Ok thanks.
I've done some mod (all from the good advice from this forum) on my Marantz 63 output stage after the op-amps & also by-passing the HDAM. I also removed the two 220uf capacitors before reaching the RCA output connectors. My player already sound fantastic. However will there be further improvements if the two100 ohms resistors & muting transistors are removed?
I recently bought a used Cambridge Audio AZUR 640C V1 and found there are also capacitors & a resistor immediately after the output of the op-amp pin 7. I thought of improving it as well like the Marantz CD63, can it be done??
Thanks & a Happy New Year 2012 to All!!!!
I recently bought a used Cambridge Audio AZUR 640C V1 and found there are also capacitors & a resistor immediately after the output of the op-amp pin 7. I thought of improving it as well like the Marantz CD63, can it be done??
- Can I actually remove the capacitors & resistor? Can I then connect the op-amp pin 7 direct to the RCA output? Any damages??
- What’s the purpose of the switch over contact (to ground), also connected to the RCA connector?
Thanks & a Happy New Year 2012 to All!!!!
You need to measure for any DC on the output before the caps (as you say on pin 7).
Assuming there is no DC or at least no more than a couple of millivolts, they can be removed safely. If there is DC present, you should replace with a 4.7uF MKP or better (Ampohm, Mundorf etc). The problem with most of these caps is they are fairly large by comparison. Generally speaking any electrolytic cap in the signal path is bad for audio (this includes xovers too!!!)
When you say switch to gnd, is that on the centre of the RCA? If so, that will be for muting.
There are a few threads for that DAC on the forum but the core principles are the same for everything!
Assuming there is no DC or at least no more than a couple of millivolts, they can be removed safely. If there is DC present, you should replace with a 4.7uF MKP or better (Ampohm, Mundorf etc). The problem with most of these caps is they are fairly large by comparison. Generally speaking any electrolytic cap in the signal path is bad for audio (this includes xovers too!!!)
When you say switch to gnd, is that on the centre of the RCA? If so, that will be for muting.
There are a few threads for that DAC on the forum but the core principles are the same for everything!