Funny, I read that they're ace on digital, lol.
I'll have to build a couple and see how they go.
Lee.
Yes, I've looked at them, the current available seems to be a bit limited though. Don't think they'd do a 7220. I've user Spowers and audicom regs in other players before. Not noticed an amazing difference when they're fitted though, fitting seperate regs seemed to be a more easily noticable change to me.
I'll be interested in seeing what you do with your alpha. I've got an alpha 5 ready to play with at a later date, collected a whole load of suggested mods for them as well, funnily enough none of them include splitting the regs.
Pete
Just changed the -15V LM337 in this Alpha for an S Power - huge improvement. It does in turn feed the -5V reg and it also powers all the op-amps I think so it's affecting lots of areas. They're very hard to fit in with decent heatsinks, lots of tweakery needed!
If the Alpha 5 is anything like this the standard regulation is way better than some players so extra separation isn't as urgent as in some (e.g. CD63). You do, however, need separate regs for the digital filter and decoder. It doesn't matter who has listed this or not, you just need it
If the Alpha 5 is anything like this the standard regulation is way better than some players so extra separation isn't as urgent as in some (e.g. CD63). You do, however, need separate regs for the digital filter and decoder. It doesn't matter who has listed this or not, you just need it
CDM2 drive
Hi,
I have 2 CDM2 drives both of which play commercial discs fine but not CDRs. I recently came across 1 commercial cd (Pink Floyd - Dark Side of the Moon) that 1 drive didn't recognise at all and the other would only play tracks 1 -3. I assumed it was just a duff disc.
While I had one of the drives out the other day I decided to replace the 6 electrostatics on the board under the drive and found that DSOTM now played ok, also CDRs now play as well. I did the same with my other drive and same results. The odd thing is that all the electrostatics that I removed read ok on a DMM.
Regards
Pete
Hi,
I have 2 CDM2 drives both of which play commercial discs fine but not CDRs. I recently came across 1 commercial cd (Pink Floyd - Dark Side of the Moon) that 1 drive didn't recognise at all and the other would only play tracks 1 -3. I assumed it was just a duff disc.
While I had one of the drives out the other day I decided to replace the 6 electrostatics on the board under the drive and found that DSOTM now played ok, also CDRs now play as well. I did the same with my other drive and same results. The odd thing is that all the electrostatics that I removed read ok on a DMM.
Regards
Pete
As an aside I have found upgrading those caps down there to make a large improvement in SQ on my CDM4/19 and a MASSIVE improvement on CDM2 (Philips CD650). On the latter I used Rubycon ZL and for that electrolytic filter cap a 1uF polyester box cap. I've put os-cons on my CDM4/19 (Arcam Alpha) plus some decoupling caps for TDA8808/8809 (missing in standard player). I did the same for 4560D (motor drive op-amp) and TCA0372 (focus drive/radial arm drive) dual op-amp. I put an os-con on the laser output and on the Vref decoupling on TDA8809.
A tip for anyone doing the same is make sure the mech will still fit afterwards. The arm needs loads of room to swing round. I had to mount most of these caps flat on their side.
Gains were considerable but I also installed a clock on the digital filter and changed some other parts at the same time.
Simon (is very happy and hasn't installed any new suppplies or output stage yet)
A tip for anyone doing the same is make sure the mech will still fit afterwards. The arm needs loads of room to swing round. I had to mount most of these caps flat on their side.
Gains were considerable but I also installed a clock on the digital filter and changed some other parts at the same time.
Simon (is very happy and hasn't installed any new suppplies or output stage yet)
Just measured the capacitance. I replaced them with similar values, couldn't match them all so went slightly up in same places (47u instead of 33u, 2.2u instead of 1.5). Didn't knowingly use anything special in terms of quality, just whetever I could get that was a near match.
Pete
Hi Pete,
Capacitors have a rated life. The dielectric deteriorates over time as a result of chemical reactions within the capacitor and this together with the leakage current slowly decreases the capacitance value and increases the ESR. Even before they eventually fail short circuit ESR, capacitance and leakage parameters may exceed the design tolerances of the circuit and they simply fail to function adequately. Replacing key electrolytics in equipment manufactured up to the mid 90s would be good practise and can give it a fresh lease of life.
High ESR will make the capacitor useless for decoupling and leakage is an important factor for the filter caps. I'd second the recommended suggestions made previously - polyester for the low value caps (up to 1uF), Oscon for digital and Rubycon ZL / Panasonic FM / or similar for analog ICs.
Cheers,
Jon
Capacitors have a rated life. The dielectric deteriorates over time as a result of chemical reactions within the capacitor and this together with the leakage current slowly decreases the capacitance value and increases the ESR. Even before they eventually fail short circuit ESR, capacitance and leakage parameters may exceed the design tolerances of the circuit and they simply fail to function adequately. Replacing key electrolytics in equipment manufactured up to the mid 90s would be good practise and can give it a fresh lease of life.
High ESR will make the capacitor useless for decoupling and leakage is an important factor for the filter caps. I'd second the recommended suggestions made previously - polyester for the low value caps (up to 1uF), Oscon for digital and Rubycon ZL / Panasonic FM / or similar for analog ICs.
Cheers,
Jon
Cd160 has packed up!
Help,
Switched on my CD160 today and no sound.
Haven't touched it in any way since it was working last time that I used it. No smoke or any outward signs of anything having failed.
Still reads and plays discs so I guess the clock and 7310 are ok?
Voltages to TDA1541 and opamps are all ok.
Any suggestions on what to check next?
Regards
Pete
Help,
Switched on my CD160 today and no sound.
Haven't touched it in any way since it was working last time that I used it. No smoke or any outward signs of anything having failed.
Still reads and plays discs so I guess the clock and 7310 are ok?
Voltages to TDA1541 and opamps are all ok.
Any suggestions on what to check next?
Regards
Pete
Sorry to hear this Pete. Op-amps can be silent or near-silent when fried. Is there any muting on your CD160? Perhaps that is stuck on, or perhaps the TDA1541 is stuck in mute-mode. I assume you'll have checked for continuity of signal and ground on your RCA outputs. And I assume you've already plugged in another source to your amp to check the rest of the system is outputting sound.
Simon
Simon
Hi,
It's got a clock fittted but I haven't changed anything on it recently. I normally assume if the disc is recognised the clock is all ok.
Yes, I tested with a different amp and the same, it was a headphone amp and I realised that while one channel is completely dead one has very, very faint music playing (and a lot of static). Seems odd that 2 opamps would both fail together unless one of the regs failed in some way but they all read ok at the moment. I'm guessing if they spiked to blow the opamps the regs would have failed as well?
I have a disc which plays a constant signal and I'd like to check continuity/consistency of signal levels in and out of dac chip, opamps etc but I'm not sure what measurements I can check with a DMM and what values I should expect at any given point.
The only changes that I've made recently are the cap replacements on the servo panel but as the disc seems to be playing ok and recognising track numbers I don't think it's that. Could it be the little np cap? I replaced it but I'm not sure what it does.
Regards
Pete
It's got a clock fittted but I haven't changed anything on it recently. I normally assume if the disc is recognised the clock is all ok.
Yes, I tested with a different amp and the same, it was a headphone amp and I realised that while one channel is completely dead one has very, very faint music playing (and a lot of static). Seems odd that 2 opamps would both fail together unless one of the regs failed in some way but they all read ok at the moment. I'm guessing if they spiked to blow the opamps the regs would have failed as well?
I have a disc which plays a constant signal and I'd like to check continuity/consistency of signal levels in and out of dac chip, opamps etc but I'm not sure what measurements I can check with a DMM and what values I should expect at any given point.
The only changes that I've made recently are the cap replacements on the servo panel but as the disc seems to be playing ok and recognising track numbers I don't think it's that. Could it be the little np cap? I replaced it but I'm not sure what it does.
Regards
Pete
The small NP cap in the servo section looks to be part of a filter. I don't think it's your problem. If the value was critical Philips wouldn't have used an electrolytic here.
Unlike more recent players (CD63 etc.) these players can read and play the disc even if the DAC is broken. The older machines are more discrete and have the digital filter and RAM as separate entities, whereas the newer DAC chips have these parts built-in. So the fault could be as far back as the DAC. Most likely is a voltage rail missing on the DAC. My +5V went missing due to some poor wiring and the result was no sound (but it played discs).
Carefully check your +5, -5 and -15V if you've not already done so.
Simon
Unlike more recent players (CD63 etc.) these players can read and play the disc even if the DAC is broken. The older machines are more discrete and have the digital filter and RAM as separate entities, whereas the newer DAC chips have these parts built-in. So the fault could be as far back as the DAC. Most likely is a voltage rail missing on the DAC. My +5V went missing due to some poor wiring and the result was no sound (but it played discs).
Carefully check your +5, -5 and -15V if you've not already done so.
Simon
I just had an issue of no sound from one channel on my Arcam. I'd put OPA627 at the output. I swapped the chip for another, still no sound. Swapped yet again for the original NE5534 and I appear to have sound again (not tested in the main system yet). I'm not saying this because it will help you particularly, just because it's perhaps amusing. At least two of my old OPA627 I pulled from some Browndog adapters seem to have died! BD boards are very hard to remove op-amps from.
I measured DC volts in the signal path before and after each op-amp and at the DAC. This pin-pointed the output op-amp. I then used a very small radio speaker tagged on to various points to listen for music, confirming what I thought. You can also test for AC (music) with a disc spinning but I noticed the voltage from the DAC is too low to measure with a normal DMM.
Simon
I measured DC volts in the signal path before and after each op-amp and at the DAC. This pin-pointed the output op-amp. I then used a very small radio speaker tagged on to various points to listen for music, confirming what I thought. You can also test for AC (music) with a disc spinning but I noticed the voltage from the DAC is too low to measure with a normal DMM.
Simon
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