10V rail cap in CD63
Hi everyone,
I'm doing some more work on Steve's CD player but to start with I had a good listen last night. With previous mods it has got quite good - superb timing, good detail, and quite good treble. However, the sound is compressed and can, at times, verge on shrill. The treble could be cleaner and the midrange sounds pinched, not very full-bodied. This aspect was obvious when played back-to-back next to my modified CD650.
I started work last night, putting a 7805 on the C1 clock and then I wondered about something Lee and Brent had told me (more than once).
If you put a bigger cap on the +10V rail it does good things. So off I whipped the 4700uF Pana Fc and on went a 15,000uF cheap snap-in. I had to drill one new hole and enlarge the other hole. Then it was just a case of making a large solder bridge to reach the old pad.
The result has been quite surprising. The sound seems to have opened up and smoothed out, with cleaner treble and a fuller midrange. Partly I think this cap was important because I'm running 6 extra regs off that spot. Some of these will move to a new power supply when I get to that stage.
Just thought I'd share that one, even though I know others have mentioned it before.
Simon
Hi everyone,
I'm doing some more work on Steve's CD player but to start with I had a good listen last night. With previous mods it has got quite good - superb timing, good detail, and quite good treble. However, the sound is compressed and can, at times, verge on shrill. The treble could be cleaner and the midrange sounds pinched, not very full-bodied. This aspect was obvious when played back-to-back next to my modified CD650.
I started work last night, putting a 7805 on the C1 clock and then I wondered about something Lee and Brent had told me (more than once).
If you put a bigger cap on the +10V rail it does good things. So off I whipped the 4700uF Pana Fc and on went a 15,000uF cheap snap-in. I had to drill one new hole and enlarge the other hole. Then it was just a case of making a large solder bridge to reach the old pad.
The result has been quite surprising. The sound seems to have opened up and smoothed out, with cleaner treble and a fuller midrange. Partly I think this cap was important because I'm running 6 extra regs off that spot. Some of these will move to a new power supply when I get to that stage.
Just thought I'd share that one, even though I know others have mentioned it before.
Simon
LOL @ Lee
A large uF cap makes a nice improvement there, thats why I have 26,700uF Mundorf HC and BlackGate combo. Just measure that rail and you will see the voltage bounces around and the larger caps make a great improvement, also consider bypassing the fuses as this helps.
It adds grip and control over the bass too
Brent
A large uF cap makes a nice improvement there, thats why I have 26,700uF Mundorf HC and BlackGate combo. Just measure that rail and you will see the voltage bounces around and the larger caps make a great improvement, also consider bypassing the fuses as this helps.
It adds grip and control over the bass too
Brent
No you can't use those SImon - the prmary will saturate and the tx overheat.
Its ok to use higher-rated Transformers on lowwer AC voltages (eg 440v on 240 Vac). The output voltage will scale with the change in input.
Are you sure they don't have two , 120V primaries that you can connect in series? That's quite normal!
Its ok to use higher-rated Transformers on lowwer AC voltages (eg 440v on 240 Vac). The output voltage will scale with the change in input.
Are you sure they don't have two , 120V primaries that you can connect in series? That's quite normal!
Well, your english is not that bad or most users here are not that good
AFAIK it's the DAC, SM5872 from NPC (datasheet free on the Net) wich includes the 8x OS.
Thanks Malefoda,
but I`m looking for the non oversampling tweak.
I thought it is as simple as modifying a Philips CD 100:
6 wire bridges and a resistor 1k and thats it.
Is it even possible to get the CD63 / CD 67 in the non oversampling mode? I read about it, but I never saw some pictures or manuals.
I've spent a few more hours working on my friend Steve's player tonight. Only just finished so it's too late for a proper listen but the low-volume result is good!
I put 6 x COG ceramic capacitors (SMD parts) on the servo chip (in place of the nasty thru-hole ceramics). I also put one of these between pins 43-44 on the decoder as it looked an easy spot for some bonus decoupling. I'd say using such small parts is not a beginner's soldering job but it was less painful than expected.
I then put 3 x 7805 regulators on the decoder (pins 11, 15 and 44 IIRC!), which was a little bit of an annoying job, me being so tired, but it's done.
I then enjoyed the easy task of putting 4 x Black Gate Standards around the op-amps.
I'm almost surprised by the lack of smoke at this point
Full report in the morning.
Simon
I put 6 x COG ceramic capacitors (SMD parts) on the servo chip (in place of the nasty thru-hole ceramics). I also put one of these between pins 43-44 on the decoder as it looked an easy spot for some bonus decoupling. I'd say using such small parts is not a beginner's soldering job but it was less painful than expected.
I then put 3 x 7805 regulators on the decoder (pins 11, 15 and 44 IIRC!), which was a little bit of an annoying job, me being so tired, but it's done.
I then enjoyed the easy task of putting 4 x Black Gate Standards around the op-amps.
I'm almost surprised by the lack of smoke at this point
Full report in the morning.
Simon
Hi, I could be mistaken but I'm fairly sure that this player cannot be put into NOS.
According to the datasheet, the DAC has inherent 8xOS. I'm not aware of a way to bypass this.
You can put a TDA1541 based player into NOS as the Filter chip (7220 which does the OS) is seperate to the DAC chip (1541 which does the converstion). You can therefore bypass the 7220 to go into NOS mode.
TDA1541 typical set up with OS:-
SAA7210(decoder)-->SAA7220(Filter)-->TDA1541(DAC)
TDA1541 typical set up with NOS:-
SAA7210-->TDA1541
CD63 or similar
SAA7345(decoder)-->SM5782(Filter&DAC)
It is not possible to bypass the filter section.
Check out the datasheet for the chip, it doesn't show any connection into the DAC section other than via the filter stage.
Ian
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Simon, did you split the clock feed to the decoder chip yet? Looking at the Manuals reminded me about feeding the clean clock directly to the decoder as well as the filter. Just another freebie!
clock to pin 13 "CRIN" from the C1 (or whatever you're using) and cut the original clock supply to that pin.
clock to pin 13 "CRIN" from the C1 (or whatever you're using) and cut the original clock supply to that pin.
Exactly right. The '43/53/63/67 use a bitstream DAC, which means that a 'nonoversampling' state is meaningless.
The foundation of 'bitstream' is an approximation to replace a 16-bit, 'multibit' dac with a 1-bit dac (a switch) fed with data oversampled (fast)enough times that the dacs lack of resolution isn't directly audible. That's all! That oversampling is internal, and fundamental, to the dac, and the only way to get reasonable sound out of the (cheaper) part
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Hi Ian, I considered the extra clock feed but I know it doesn't always work and didn't want anything temperamental in a player I'm doing for someone else.
If Steve wants more mods it's one I can crack out for him, but the player sounds very good indeed now.
It has 9 extra 7905s on top of the standard regs, some good caps, nice op-amps and a good clock.
I had a listen this morning and it's really musical and now quite sweet (thank you Black Gates!) but dynamics and image are still a touch restricted in absolute terms. I put this down to a lack of power supply goodness.
Also the midrange is still a tiny bit nasal - but that's how all CD63s sound in my opinion.
Simon
If Steve wants more mods it's one I can crack out for him, but the player sounds very good indeed now.
It has 9 extra 7905s on top of the standard regs, some good caps, nice op-amps and a good clock.
I had a listen this morning and it's really musical and now quite sweet (thank you Black Gates!) but dynamics and image are still a touch restricted in absolute terms. I put this down to a lack of power supply goodness.
Also the midrange is still a tiny bit nasal - but that's how all CD63s sound in my opinion.
Simon
The link is is far too technical for me to understand but may be relevant.
diyparadise - A Non-Oversampling DAC for RM20!
Regards
Pete
MMMM!!! Indeed it is a 63 with NOS! It completely bypasses the 63's SM5782 (filter/DAC) chip and replaces it with TDA 1547 DACs.
so you end up with:-
SAA7345(decoder)-->TDA1543(DAC)
No oversample filter. It does mean you'll completely change everything from the decoder onwards in the player! You'd need to design a output stage, noise shaping and filtering etc! Def no quick win. In my experience, NOS is not the way to got in any case!?
