Modifying a Philips CD160
I like my Philips Cd160. It fits in the limited space. It makes a nice noise. And I like to pick up cd's from second hand stores, charity shops, flea markets, et cetera.
CDs these days are like LPs were 10 years ago, i.e nobody wants them so they are cheap.
There are a huge amount of them around so it's easy to get stuff you like on CD for peanuts. Every now and again I like to get a load of random music in to keep my collection refreshed, and my musical horizons broad. Its all too easy to find yourself listening to the same things over and over again. The Interest starts to wane when things get too familiar.
What I like to do is to go on Ebay with a budget of a tenner, into music, then cd's, and then to buy the first thing that is 99p and is ending soonest in each music category. Ive picked up far more music I have liked than stuff I've thought was crap. I listen to them, then import them into itunes. And it's abit of fun.
The CD160 was bought in with a little system I bought for my daughter who is at the age that she wanted something of her own to listen to 'her' music on. I couldn't bring myself to buy a cheap crap little all in one thing, that would be treasonous. The hifi gods would have smote me down in a fit of pique.......
25 quid got me the 160, a Marantz RX153 receiver amp, its matching tape deck, a pair of Sony bookshelf speakers and an Acoustic Solutions turntable which is a pile of crap, but I have plans to do something nice with it.......
The Marantz isn't bad actually, it makes a reasonable noise.
At the time I hadn't had a cd player for a while as the big Sony CDP-XB930 QS I had was abit too big to fit in the space it occupied once I got hold of the Pass F5 power amp. I also had an el cheapo Sony low end early 90s spinner I'd got off a flea market for a couple of quid. Dunno why.............
The nice Sony went off to my dads to take up his rack space, the el cheapo went to the daughter for her to use, and the 160 was kept for me.
I must admit that the system I bought for her was not bought entirely out of generosity, there was an element of selfishness in it's purchase. Namely, I spotted it in the charity shop, or rather I spotted the turntable and went for a closer look. Then saw the deck was a piece of shite, saw the 160, and immediately though TDA 1541............................
CDs these days are like LPs were 10 years ago, i.e nobody wants them so they are cheap.
There are a huge amount of them around so it's easy to get stuff you like on CD for peanuts. Every now and again I like to get a load of random music in to keep my collection refreshed, and my musical horizons broad. Its all too easy to find yourself listening to the same things over and over again. The Interest starts to wane when things get too familiar.
What I like to do is to go on Ebay with a budget of a tenner, into music, then cd's, and then to buy the first thing that is 99p and is ending soonest in each music category. Ive picked up far more music I have liked than stuff I've thought was crap. I listen to them, then import them into itunes. And it's abit of fun.
The CD160 was bought in with a little system I bought for my daughter who is at the age that she wanted something of her own to listen to 'her' music on. I couldn't bring myself to buy a cheap crap little all in one thing, that would be treasonous. The hifi gods would have smote me down in a fit of pique.......
25 quid got me the 160, a Marantz RX153 receiver amp, its matching tape deck, a pair of Sony bookshelf speakers and an Acoustic Solutions turntable which is a pile of crap, but I have plans to do something nice with it.......
The Marantz isn't bad actually, it makes a reasonable noise.
At the time I hadn't had a cd player for a while as the big Sony CDP-XB930 QS I had was abit too big to fit in the space it occupied once I got hold of the Pass F5 power amp. I also had an el cheapo Sony low end early 90s spinner I'd got off a flea market for a couple of quid. Dunno why.............
The nice Sony went off to my dads to take up his rack space, the el cheapo went to the daughter for her to use, and the 160 was kept for me.
I must admit that the system I bought for her was not bought entirely out of generosity, there was an element of selfishness in it's purchase. Namely, I spotted it in the charity shop, or rather I spotted the turntable and went for a closer look. Then saw the deck was a piece of shite, saw the 160, and immediately though TDA 1541............................
I was quite happy with it for a while, just using it to play the CD's I'd got from various places and revisiting my collection. I'm of the CD generation, me and my mates used to spend the weekends trawling through the shelves in Andys Records, HMV the old Virgin records stores, and the small shops that had a more eclectic mix of music.
I can pick up a CD from my collection and tell you exactly where it was bought and the story behind it's purchase. Back in the 90s We used to listen to Hallam FM, Atlantic 252 and radio one in the 6th form common room while playing cards and generally not doing whatever it was we were supposed to be doing, then go buy what we had heard during the week. Some of the lads would just buy the singles, and some of us would just buy the albums. I was an album guy. The missus also uses it, generally it gets used when either of us can't be arsed to faff about switching the mac on and trawling through the itunes library.
It seems strange to think that CD's are considered pretty retro these days.
A chap called Mark contacted me recently and we got to discussing the CD160. He has 2, and he likes them too. Seems that alot of people like the 80s spinners these days. I have had quite a few of them. A meridian MCD which I wish I still had, a marantz CD75 which seemed to do everything wrong so was moved on, A Mission PCM4000 which didn't do anything wrong but was pretty flat and boring, and an Arcam Delta 170.3 transport (which I REALLY with I still had) with a black box DAC. The last of the TDA1541s. That was stunning.
The subject of mods to the players came up in conversation with Mark, and it was arranged that he would send me one of his spare 160s to act as a kind of control model, a benchmark to measure the proposed mods against.
There are a million and one mods that can be done to bring these players up to very high standards, I am going to concentrate firstly on the simple and the logical mods.
Here is the 160 sans lid
I can pick up a CD from my collection and tell you exactly where it was bought and the story behind it's purchase. Back in the 90s We used to listen to Hallam FM, Atlantic 252 and radio one in the 6th form common room while playing cards and generally not doing whatever it was we were supposed to be doing, then go buy what we had heard during the week. Some of the lads would just buy the singles, and some of us would just buy the albums. I was an album guy. The missus also uses it, generally it gets used when either of us can't be arsed to faff about switching the mac on and trawling through the itunes library.
It seems strange to think that CD's are considered pretty retro these days.
A chap called Mark contacted me recently and we got to discussing the CD160. He has 2, and he likes them too. Seems that alot of people like the 80s spinners these days. I have had quite a few of them. A meridian MCD which I wish I still had, a marantz CD75 which seemed to do everything wrong so was moved on, A Mission PCM4000 which didn't do anything wrong but was pretty flat and boring, and an Arcam Delta 170.3 transport (which I REALLY with I still had) with a black box DAC. The last of the TDA1541s. That was stunning.
The subject of mods to the players came up in conversation with Mark, and it was arranged that he would send me one of his spare 160s to act as a kind of control model, a benchmark to measure the proposed mods against.
There are a million and one mods that can be done to bring these players up to very high standards, I am going to concentrate firstly on the simple and the logical mods.
Here is the 160 sans lid
The board on the left is the main board for the player which holds the power supply, regulators, dac, clock and output stage. The sub board that has been moved is the logic board for the controls, with the other board behind it holding the display circuitry.
No need to touch either of these boards, the work will be done on the main pcb. The transport is the Philips CDM2/10 single beam laser swing arm mech and is practically bulletproof.
There are a couple of stages of modification that I will go through, the first being to replace all the electrolytic capacitors in the machine. The reason for this is twofold. Firstly, the electrolytics have a service life of several thousand hours based on operating temperature. The service life is reduced by higher temperatures. They start to degrade after this time and the capacitance reduces, they get leaky, they swell, and eventually stop working altogether. Performance drops off a cliff after the service life. If the player was used for 1 hour a day, after ten years the caps would be well past their service life. 3650 hours is over the average service life of a common or garden cap. This player probably passed that by 1996 when I was the spotty yoof poring over the racks of CD's in Andys Records.............
The second part of the twofold, is that capacitors have a sound. Why do you thing Arcam stuffed as many Black Gate caps into the Delta 170.3 and the black box dac.
This player was built to a price in 1986, priced very keenly and made midi sized in order to shift as many units as possible. Lets not forget that in 86 cd hadn't been around long and was still the new kid on the block. Philips and Sony wanted to push the product into every home, so made a million different models to suit every budget. So components were the key to reducing costs, and interchangeable modular PCBs, transport mechs, displays and the like were shared between the myriad of models. They were all basically the same. With either more expensive components on the boards in the pricier models aimed at the audiophools or cheaper ones in the 'consumer' models that were meant to get a cd player in every home. You will notice that the board on the 160 has loads of unpopulated sections on the board, the same board in a higher spec player would have had these filled with whatever technical marvel they were meant for. There is a section for at least one other op amp and another IC.
As you can see, there is alot of scope to upgrade the boards with better components
So I started with the caps. I have replaced all of the electrolytics with new Nichicon gold FW audio grade electrolytics. I don't think there was such a thing as an audio grade cap in 86'. Some of these are in the signal path so there will be a performance gain there to start with. The replacement caps will also put the machine back to spec; i.e the player will function with the voltages and currents it was designed to function with originally as these will not be the same after 30 years.
No need to touch either of these boards, the work will be done on the main pcb. The transport is the Philips CDM2/10 single beam laser swing arm mech and is practically bulletproof.
There are a couple of stages of modification that I will go through, the first being to replace all the electrolytic capacitors in the machine. The reason for this is twofold. Firstly, the electrolytics have a service life of several thousand hours based on operating temperature. The service life is reduced by higher temperatures. They start to degrade after this time and the capacitance reduces, they get leaky, they swell, and eventually stop working altogether. Performance drops off a cliff after the service life. If the player was used for 1 hour a day, after ten years the caps would be well past their service life. 3650 hours is over the average service life of a common or garden cap. This player probably passed that by 1996 when I was the spotty yoof poring over the racks of CD's in Andys Records.............
The second part of the twofold, is that capacitors have a sound. Why do you thing Arcam stuffed as many Black Gate caps into the Delta 170.3 and the black box dac.
This player was built to a price in 1986, priced very keenly and made midi sized in order to shift as many units as possible. Lets not forget that in 86 cd hadn't been around long and was still the new kid on the block. Philips and Sony wanted to push the product into every home, so made a million different models to suit every budget. So components were the key to reducing costs, and interchangeable modular PCBs, transport mechs, displays and the like were shared between the myriad of models. They were all basically the same. With either more expensive components on the boards in the pricier models aimed at the audiophools or cheaper ones in the 'consumer' models that were meant to get a cd player in every home. You will notice that the board on the 160 has loads of unpopulated sections on the board, the same board in a higher spec player would have had these filled with whatever technical marvel they were meant for. There is a section for at least one other op amp and another IC.
As you can see, there is alot of scope to upgrade the boards with better components
So I started with the caps. I have replaced all of the electrolytics with new Nichicon gold FW audio grade electrolytics. I don't think there was such a thing as an audio grade cap in 86'. Some of these are in the signal path so there will be a performance gain there to start with. The replacement caps will also put the machine back to spec; i.e the player will function with the voltages and currents it was designed to function with originally as these will not be the same after 30 years.
As you can see, the new black and gold caps are much smaller than their 80s progenitors. The large blue cap is the 6800uf reservoir cap and is not a Nichicon, my supplier didn't have the right value in stock, so it is a low esr Panasonic replacement of the same value.
As one of these caps was part of the 11.2896mhz clock circuit, and the values of these caps were very specific, we should get better performace, as jitter performance is directly related to the master clock.
The 2 in the rear right section behind the sockets are the output caps and are in the signal path. there is a 4k7 resistor to ground as part of the output filter which gives a f3 point of 0.3hz, so again, if the capacitance of the output cap is much less than it says on the tin after 31 years, which it will be, that filter corner frequency will be rather different to what the designers at Philips intended. And a better sounding audio grade cap should be an improvement even if the originals were ok. (They weren't as it happens, they were bulging at the top which is a sign of degradation) To be honest, I think it's pretty logical to do this with a disc spinner of this age given the very fact that it is so old. And when a capacitor goes, it makes a right mess.
I nailed it back together, Then did an A-B test with the original 160 that Mark kindly sent as a benchmark.
As one of these caps was part of the 11.2896mhz clock circuit, and the values of these caps were very specific, we should get better performace, as jitter performance is directly related to the master clock.
The 2 in the rear right section behind the sockets are the output caps and are in the signal path. there is a 4k7 resistor to ground as part of the output filter which gives a f3 point of 0.3hz, so again, if the capacitance of the output cap is much less than it says on the tin after 31 years, which it will be, that filter corner frequency will be rather different to what the designers at Philips intended. And a better sounding audio grade cap should be an improvement even if the originals were ok. (They weren't as it happens, they were bulging at the top which is a sign of degradation) To be honest, I think it's pretty logical to do this with a disc spinner of this age given the very fact that it is so old. And when a capacitor goes, it makes a right mess.
I nailed it back together, Then did an A-B test with the original 160 that Mark kindly sent as a benchmark.
So, how did the modded player fare compared to the standard one? well it was noticeably better in several areas. The bass end was tighter with less bloom the top was much better, less harsh but more focused and clean. There is better definition across the board. The mid was initially abit shouty, but after a few hours that has lessened. Basically the player is much less hazy. Instrument separation is better, imaging is a smidge wider.
The two players were connected to my passive with identical cable sets, the F5 was warmed up for an hour and both players powered up during that time so that everything was nice and warm and equal.
Bear in mind that it only has about 4 hours on the new caps at this time, I'd say that was a result. It seems to be opening up the more hours it has on it.
I reckon given a few more hours there will be some more gains from this first stage modification, and that it will probably sound a little bit better than it did when new. The next stage will be to either replace the axial cap set, or to swap out the op amps for something better (which is the simpler of the two). There are plenty of alternatives to the lm833n's, I've been recommended the LME 49720 by a chap who knows a sight more than me about op amps..... the axials will be replaced anyway when I get around to it.
To be continued.....................
So a couple of weeks (months?) have passed, and I have done another mod, the aforementioned op-amp upgrade.
Ive dropped the 2 LME 49720's and run through a couple of cd's so far. I Made sure I used a zap strap so I didn't fry the chip with static, and used a sucker to desolder the original LM833's. I discussed the best way to remove the IC with some forum pals, and mooted using braid to desolder them. Apparently there is a knack to using braid. Having been taught to use a solder pump when desoldering, and being unable get any braid locally, I've sacked that for now. I'll order some though and give it a go on a PCB from something that is buggered. Best to practice sometimes first.
Didn't get any DIL sockets, I just dropped the new op-amps into the board, after discussions about possible parasitic capacitance when using them.
A little diversion from the player, to talk about the soldering iron I use. I mentioned on my ten tips for building, that its best to buy the best tools you can't quite afford. This applies to an iron too. a crap iron will give crap joints, and a crap joint will give a crap connection, and it can be an absolute pain in the arse to track down a dry joint when trying to cure an intermittent fault. In this case a good iron was very affordable. It's a Precision Gold A55 KJ. Not a top dollar iron by any means, but really nice to use, with 3 user selectable temp settings which have made this project abit easier with the smallest tip. I did have a Maplin blue temperature controlled iron which was ok for my normal work, if abit crude for more intricate work. This one is much better. I have steady hands, but crap eyesight, must also invest in a magnifier at some point.....
Happily, there is quite a difference with the new op amps. There is always a possibility of a sideways move or a backwards more in terms of sound quality, but this was not one of them. It seems easier to listen to if that makes sense, no need to strain to follow an instrument, its just there. Marginally better imaging, marginally better depth. More subtle. Less shouty.
Bass is much more controlled, and that signature early cd screech seems to be much improved. Details are easier to pick up and follow.
It seems more natural, more atmospheric. The little details are there. Especially at the top on things like ride cymbals and the like.
I looked at the datasheet for both the original and new op amps, the LME's THD is quoted as 0.00003%, the LM833n is quoted as 0.002% so there is a pretty good explanation right there for what I seem to be hearing, in terms of it sounding more natural.
If its oscillating I cant tell, only way to see would be to scope it. I could, but it means dragging the scope out from wherever it is, and I cant be bothered. I can't remember when I last had it calibrated either...... Another job to add to the never ending list.
Neil Young's harmonica on his unplugged album isn't wince inducing now.
I'd say mod number 2 is a successful upgrade over standard rather than just being a sideways move which is always a possibility.
Next step, maybe a set of regs?, change the 1541 decoupling caps?, swap out all the axial caps on the board? swap out the Nichicon FW lytic output caps for something else?, clock upgrade? The possibilities are endless!
I have read people have removed the muting transistors, but I'm not sure why as they don't seem to be in the signal path on the circuit in the service manual, they appear to drop off the track that goes to the sockets rather than the signal going through them and out unless its to do with back emf from the transistors getting into the output path. Just musings, I don't know. Someone who has much more knowledge than me will know. So I cant see any point in doing that unless someone knows better and i've missed something fundamental which is entirely possible. Answers on a postcard if you please :-)
Suggestions welcome on step 3.
Im finding this quite an enjoyable little side project :-)
I have also upgraded both of Mark's cd160's to the same spec for him, and he is quite happy with the results too. Which is good, a vindication of sorts, for buggering about with something that according to the glossies has no right to sound quite so nice. But then I don't really read the glossies so who cares. And I have something else up my sleeve...
The two players were connected to my passive with identical cable sets, the F5 was warmed up for an hour and both players powered up during that time so that everything was nice and warm and equal.
Bear in mind that it only has about 4 hours on the new caps at this time, I'd say that was a result. It seems to be opening up the more hours it has on it.
I reckon given a few more hours there will be some more gains from this first stage modification, and that it will probably sound a little bit better than it did when new. The next stage will be to either replace the axial cap set, or to swap out the op amps for something better (which is the simpler of the two). There are plenty of alternatives to the lm833n's, I've been recommended the LME 49720 by a chap who knows a sight more than me about op amps..... the axials will be replaced anyway when I get around to it.
To be continued.....................
So a couple of weeks (months?) have passed, and I have done another mod, the aforementioned op-amp upgrade.
Ive dropped the 2 LME 49720's and run through a couple of cd's so far. I Made sure I used a zap strap so I didn't fry the chip with static, and used a sucker to desolder the original LM833's. I discussed the best way to remove the IC with some forum pals, and mooted using braid to desolder them. Apparently there is a knack to using braid. Having been taught to use a solder pump when desoldering, and being unable get any braid locally, I've sacked that for now. I'll order some though and give it a go on a PCB from something that is buggered. Best to practice sometimes first.
Didn't get any DIL sockets, I just dropped the new op-amps into the board, after discussions about possible parasitic capacitance when using them.
A little diversion from the player, to talk about the soldering iron I use. I mentioned on my ten tips for building, that its best to buy the best tools you can't quite afford. This applies to an iron too. a crap iron will give crap joints, and a crap joint will give a crap connection, and it can be an absolute pain in the arse to track down a dry joint when trying to cure an intermittent fault. In this case a good iron was very affordable. It's a Precision Gold A55 KJ. Not a top dollar iron by any means, but really nice to use, with 3 user selectable temp settings which have made this project abit easier with the smallest tip. I did have a Maplin blue temperature controlled iron which was ok for my normal work, if abit crude for more intricate work. This one is much better. I have steady hands, but crap eyesight, must also invest in a magnifier at some point.....
Happily, there is quite a difference with the new op amps. There is always a possibility of a sideways move or a backwards more in terms of sound quality, but this was not one of them. It seems easier to listen to if that makes sense, no need to strain to follow an instrument, its just there. Marginally better imaging, marginally better depth. More subtle. Less shouty.
Bass is much more controlled, and that signature early cd screech seems to be much improved. Details are easier to pick up and follow.
It seems more natural, more atmospheric. The little details are there. Especially at the top on things like ride cymbals and the like.
I looked at the datasheet for both the original and new op amps, the LME's THD is quoted as 0.00003%, the LM833n is quoted as 0.002% so there is a pretty good explanation right there for what I seem to be hearing, in terms of it sounding more natural.
If its oscillating I cant tell, only way to see would be to scope it. I could, but it means dragging the scope out from wherever it is, and I cant be bothered. I can't remember when I last had it calibrated either...... Another job to add to the never ending list.
Neil Young's harmonica on his unplugged album isn't wince inducing now.
I'd say mod number 2 is a successful upgrade over standard rather than just being a sideways move which is always a possibility.
Next step, maybe a set of regs?, change the 1541 decoupling caps?, swap out all the axial caps on the board? swap out the Nichicon FW lytic output caps for something else?, clock upgrade? The possibilities are endless!
I have read people have removed the muting transistors, but I'm not sure why as they don't seem to be in the signal path on the circuit in the service manual, they appear to drop off the track that goes to the sockets rather than the signal going through them and out unless its to do with back emf from the transistors getting into the output path. Just musings, I don't know. Someone who has much more knowledge than me will know. So I cant see any point in doing that unless someone knows better and i've missed something fundamental which is entirely possible. Answers on a postcard if you please :-)
Suggestions welcome on step 3.
Im finding this quite an enjoyable little side project :-)
I have also upgraded both of Mark's cd160's to the same spec for him, and he is quite happy with the results too. Which is good, a vindication of sorts, for buggering about with something that according to the glossies has no right to sound quite so nice. But then I don't really read the glossies so who cares. And I have something else up my sleeve...
Philips CD 371
I couldn't help it again, I bought another player to... well ...... play with.
Again, it cost beer money, and was bought for several reasons.
Firstly, I wanted a player that had a 'proper' drawer rather than the daft flap on the 160 as I can see it being a recipe for being broken at some point by either cack handed me, or cack handed children of mine.
Secondly, I wanted the die cast CDM2 mech rather than the plastic CDM2/10 out of nostalgia for the Arcam Delta 170.3 I used to have.
Thirdly, I was curious as to what difference the actual transport made.
And fourth, I wanted something that didn't feel quite as much like a toy in use. Lovely as the 160 is, it still has a nasty plasticky feel to it, with too much play in the buttons.
Heres what I got.
Again, it cost beer money, and was bought for several reasons.
Firstly, I wanted a player that had a 'proper' drawer rather than the daft flap on the 160 as I can see it being a recipe for being broken at some point by either cack handed me, or cack handed children of mine.
Secondly, I wanted the die cast CDM2 mech rather than the plastic CDM2/10 out of nostalgia for the Arcam Delta 170.3 I used to have.
Thirdly, I was curious as to what difference the actual transport made.
And fourth, I wanted something that didn't feel quite as much like a toy in use. Lovely as the 160 is, it still has a nasty plasticky feel to it, with too much play in the buttons.
Heres what I got.
It fulfils these requirements, and doesn't feel so mickey mouse in operation.
Handily, it had already had an op amp change and output cap change when I received it, which I didn't know about until I opened it up to have a look at the board.
I've had a poke about in it to see what I've got.
It has a really nice CDM 2 mech in it. Die cast alloy drawer, subframe, and other parts, with a cast and machined resin chassis for the laser block and swingarm. Pretty much the same as the CDM 1, and very similar to the CDM1 mk2 mech that was in the Arcam delta 170.3 and Philips cd880. The cast and machined resin chassis rather than machined alloy chassis of the CDM1 mk 2 was the difference.
Apparently the cdm2 was designed as a replacement for the CDM1 to make it cheaper to manufacture ( the resin chassis and simplified drawer mechanism) but it turned out that it was not cheaper to manufacture the resin chassis, so was pointless. So they made the cdm2/10 instead, which used the resin chassis they had developed, but with plastic drawer parts instead of the die cast bits to reduce the costs that way instead. So to me, it means that the CDM2, is basically a small update on the CDM1, rather than a new design. It was only used for about 18 months, then phased out in favour of the 2/10.
Whoever has been in it already, has kindly replaced the output caps with some Nichicon Muse non polarised caps of the correct value, and has replaced the original LM833n op amps with some Motorola MC34082's.
Thats all they have replaced, so i'll do the same with this one as I've done with the 160, and replace all the electrolytics with Nichicon gold FW's. When I get around to it.
The 6800uf psu cap was leaking in it, so I powered it up, checked it works, reads and plays discs, and skips to different tracks then powered it down. Then went to Maplins and got a replacement cap. They didn't have a 6800uf cap, so I got the nearest value as a stopgap until I can get some more Panasonic's.
I've given the transport abit of a service. Just some grease on the runners and top clamp, and a quick check on the drawer motor which is fine.
The unit feels alot less plasticky than the 160, and the transport weighs a ton.
I like playing with these, maybe I'll be able to get hold of the mother in laws cd303. I want it, it's the Philips version of the Marantz cd73. Twin TDA1540 dacs in it, and battleship build quality. No output at the minute though....
Handily, it had already had an op amp change and output cap change when I received it, which I didn't know about until I opened it up to have a look at the board.
I've had a poke about in it to see what I've got.
It has a really nice CDM 2 mech in it. Die cast alloy drawer, subframe, and other parts, with a cast and machined resin chassis for the laser block and swingarm. Pretty much the same as the CDM 1, and very similar to the CDM1 mk2 mech that was in the Arcam delta 170.3 and Philips cd880. The cast and machined resin chassis rather than machined alloy chassis of the CDM1 mk 2 was the difference.
Apparently the cdm2 was designed as a replacement for the CDM1 to make it cheaper to manufacture ( the resin chassis and simplified drawer mechanism) but it turned out that it was not cheaper to manufacture the resin chassis, so was pointless. So they made the cdm2/10 instead, which used the resin chassis they had developed, but with plastic drawer parts instead of the die cast bits to reduce the costs that way instead. So to me, it means that the CDM2, is basically a small update on the CDM1, rather than a new design. It was only used for about 18 months, then phased out in favour of the 2/10.
Whoever has been in it already, has kindly replaced the output caps with some Nichicon Muse non polarised caps of the correct value, and has replaced the original LM833n op amps with some Motorola MC34082's.
Thats all they have replaced, so i'll do the same with this one as I've done with the 160, and replace all the electrolytics with Nichicon gold FW's. When I get around to it.
The 6800uf psu cap was leaking in it, so I powered it up, checked it works, reads and plays discs, and skips to different tracks then powered it down. Then went to Maplins and got a replacement cap. They didn't have a 6800uf cap, so I got the nearest value as a stopgap until I can get some more Panasonic's.
I've given the transport abit of a service. Just some grease on the runners and top clamp, and a quick check on the drawer motor which is fine.
The unit feels alot less plasticky than the 160, and the transport weighs a ton.
I like playing with these, maybe I'll be able to get hold of the mother in laws cd303. I want it, it's the Philips version of the Marantz cd73. Twin TDA1540 dacs in it, and battleship build quality. No output at the minute though....
It turns out that the board in this player is a full width board that goes under the transport. So the entire thing had to be pulled apart to get at the board to replace the leaky cap. This meant that the fascia panel had to come off in order to get the drawer off its runners, and the transport out to get the board out of the chassis.
Much swearing followed, trying to track down the one retaining screw that eluded me to the last. It was where it couldn't be seen underneath the cd drawer, hence taking the drawer out of the transport.
Once found, it was simple enough, and now I know where it is, there wont be so much swearing when I come to recap it.
Oh, and it has probably the most useless headphone socket in the world, as it doesn't have a volume control..........
More to follow.......
Much swearing followed, trying to track down the one retaining screw that eluded me to the last. It was where it couldn't be seen underneath the cd drawer, hence taking the drawer out of the transport.
Once found, it was simple enough, and now I know where it is, there wont be so much swearing when I come to recap it.
Oh, and it has probably the most useless headphone socket in the world, as it doesn't have a volume control..........
More to follow.......