Hi all,
I’ve recently replaced the laser unit of my Arcam Alpha 9 CDP. I bought the player new back in 1998 and as far as I’m concerned it sounds as good as new with the new laser. Now I’ve come across a few articles that suggest that all capacitors and diodes of the CDP’s power supply and other circuits will deteriorate and may need replacement within a period as short as 5 years. See for example this PDF: http://www.condoraudio.com/wp-content/uploads/Projects/Arcam-CD92-CD-HDCD-Player-Restoration-Repair.pdf
My question is: Is there any truth in this? I’m not interested in upgrades, I just want the original sound. If there’s no audible problem and the player has great detail and sound stage and plenty of tight bass, could there be any noticeable effect from replacing capacitors and/or diodes? Personally I’m very skeptical about this. I think Arcam used good quality parts and at least the low voltage components should all be fine..
I’ve recently replaced the laser unit of my Arcam Alpha 9 CDP. I bought the player new back in 1998 and as far as I’m concerned it sounds as good as new with the new laser. Now I’ve come across a few articles that suggest that all capacitors and diodes of the CDP’s power supply and other circuits will deteriorate and may need replacement within a period as short as 5 years. See for example this PDF: http://www.condoraudio.com/wp-content/uploads/Projects/Arcam-CD92-CD-HDCD-Player-Restoration-Repair.pdf
My question is: Is there any truth in this? I’m not interested in upgrades, I just want the original sound. If there’s no audible problem and the player has great detail and sound stage and plenty of tight bass, could there be any noticeable effect from replacing capacitors and/or diodes? Personally I’m very skeptical about this. I think Arcam used good quality parts and at least the low voltage components should all be fine..
Diodes (all semiconductors) don't change or deteriorate over time.
From memory of other threads on here I believe Arcam is a brand that can suffer with failed caps (the larger reservoir ones in the power supply) and signs of this happening could be the vents on the top starting to split open or bulge.
Caps that have been properly specified and that are suitable for the intended use should last at least 10 to 15 yrs as a minimum. Problem with a lot of modern equipment is that it only has a standby function and not a proper on/off which means most of the circuitry is still active and powered.
From memory of other threads on here I believe Arcam is a brand that can suffer with failed caps (the larger reservoir ones in the power supply) and signs of this happening could be the vents on the top starting to split open or bulge.
Caps that have been properly specified and that are suitable for the intended use should last at least 10 to 15 yrs as a minimum. Problem with a lot of modern equipment is that it only has a standby function and not a proper on/off which means most of the circuitry is still active and powered.
Well, I guess the Alpha 9 must be okay then. Within a few days I will receive an Arcam FMJ CD23 (from 2004) which is basically the same player with an improved power supply. I will compare the two players. I think the CD23 should sound slightly better overall but not much better.
Anyway, what I was deliberating is whether any gradual capacitor deterioration would be audible as a gradual deterioration of sound stage, detail, et cetera, or would it only be audible as some clear distortion or other acute problem when a capacitor finally fails or reaches some threshold value outside its tolerance?
Anyway, what I was deliberating is whether any gradual capacitor deterioration would be audible as a gradual deterioration of sound stage, detail, et cetera, or would it only be audible as some clear distortion or other acute problem when a capacitor finally fails or reaches some threshold value outside its tolerance?
You would probably get a hundred different answers to that one. If any caps are going to fail then it is going to be the power supply ones and any others that are located near heat sources such as the voltage regulators.
How far do they have to fail for it to cause a problem ? that's open to interpretation.
When the regulators can't handle the extra ripple and noise starts appearing on the rails are when the problems start... and they are not necessarily 'audio' problems in the true sense. Its just as likely to be a tracking or servo problem that show up as a result of cap failure.
How far do they have to fail for it to cause a problem ? that's open to interpretation.
When the regulators can't handle the extra ripple and noise starts appearing on the rails are when the problems start... and they are not necessarily 'audio' problems in the true sense. Its just as likely to be a tracking or servo problem that show up as a result of cap failure.
Mooly is spot on with this. My own CD player is an Arcam Alpha 5 which doesn't have a true on/off switch but rather a standby function which leaves several sections of the player live 24/7. I've repaired several of these players which have failed because the caps which remain 'on' all the time have died and leaked electrolyte out all over the PCB. Even if they aren't yet leaking I change these particular caps on an Alpha 5 as it usually results in bringing the SQ of the player back to 'as new'.
My own Alpha 5 now has an in-line bedside lamp style on/off switch on the powercord so that I can conveniently turn the whole player fully off. The downside is that it takes 40 minutes or so to warm up fully and sound its best.
I suggest you try to find out if the Alpha 9 has a similar standby function or a true on/off switch.
The Alpha 9 and the CD23 have a true on/off switch. But the dCS ringdac of these players gets hot, hotter than any other DAC/CDP I know. And there are quite some capacitors positioned on the four layer DAC board, apparently as parts of multiple DC stabilization circuits:
The DAC board of both players is exactly the same. So if the CD 23 sounds much better than the Alpha 9, I can swap the DAC boards. If that makes the Alpha 9 sound better, then it must be time for a cap replacement..
The DAC board of both players is exactly the same. So if the CD 23 sounds much better than the Alpha 9, I can swap the DAC boards. If that makes the Alpha 9 sound better, then it must be time for a cap replacement..
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I'd be surprised if the DAC was generating enough heat to seriously shorten the life of the caps. The device on the heatsink could run hot but even here the caps are some distance away.
The caps will have a temperature rating printed on them, 85C was cooking commercial grade for many years, these days 105C rated parts are the ones of choice.
The caps will have a temperature rating printed on them, 85C was cooking commercial grade for many years, these days 105C rated parts are the ones of choice.
Hi Mike. I replied earlier that the Alpha 9 has a true on/off switch, but I found out that’s actually not the case!
There’s still a slight hum from the PS and the player remains slightly warm to the touch when the power should be completely off! I never noticed this.. Luckily, when I’m not using my audio system, I turn off the grid-power to all components (CDP, pre-amp, power-amp, sub, et cetera) with one central switch.There are no caps with split or bulged vents in the Alpha 9, but I will certainly look for these signs in the CD23 when I receive it, which should be any day now. I suppose it’s possible that caps in the much younger CD23 are in worse condition than corresponding caps in my Alpha 9..
Personally I would replace any electrolytic caps that have been left running 24/7 for anything more than about 10 years. If the component is switched off when not in use they can of course last much much longer.
In my original Alpha 5 all the caps looked superficially OK but the player didn't sound as good as I expected until I replaced some of the tired capacitors. Once I'd done a partial re-cap things improved massively.
If the player sounds good then I wouldn't do anything straight away but if you aren't happy with the sound replace the likely capacitors before you make a final judgement on the player.
In my original Alpha 5 all the caps looked superficially OK but the player didn't sound as good as I expected until I replaced some of the tired capacitors. Once I'd done a partial re-cap things improved massively.
If the player sounds good then I wouldn't do anything straight away but if you aren't happy with the sound replace the likely capacitors before you make a final judgement on the player.
Well, the CD23 (actually the Arcam FMJ CD23T) has arrived and it clearly sounds better than the Alpha 9. The CD23 sings more natural and effortless and refined and sweet, with a deeper bass and a bigger, wider and more up-front sound stage. 😀
I don’t think I’m even going to bother to swap the DACs at this point. I will first replace the electrolytic capacitors on the main board of the Alpha 9 (17 caps). Any suggestions which caps are most likely to make a difference are welcome..
I don’t think I’m even going to bother to swap the DACs at this point. I will first replace the electrolytic capacitors on the main board of the Alpha 9 (17 caps). Any suggestions which caps are most likely to make a difference are welcome..
Pleased you like your latest acquisition. Beyond recommending replacing electrolytic caps that are in obviously hot locations (which would include all those in the picture as they are near 'heatsinked' or hot running parts) its difficult to give advice.
For what they cost, its easier to replace all in the machine than wonder 'what if'. An engineer fault-finding would look to identify a problem by measurement using a 'scope.
For what they cost, its easier to replace all in the machine than wonder 'what if'. An engineer fault-finding would look to identify a problem by measurement using a 'scope.
The current caps are rated 85C. I’ve noticed btw that the CD23T player gets significantly less hot (in the area where the ringdac is located) than the Alpha 9. The CD23 has openings in the bottom as well as in the back for ventilation..
I wonder why the Alpha 9 player doesn’t have these ventilation holes in the back which seem to be keeping the CD23 relatively cool to the touch. I think it might be a good idea to just drill some holes in the back of the Alpha 9..
I'm not sure drilling holes is a good idea tbh at least not cosmetically. Once done there is no going back. Another very real problem are circulating air currents pulling dust into the player. Optics need to be kept clean and many players are almost hermetically sealed in that regard.
I wouldn't go down the holes route 🙂
I wouldn't go down the holes route 🙂
I wouldn't block them unless I was 100% certain that no local heating effects could occur internally. They could be a necessary evil needed for that player.
Yes. And the CD23 only has 12 small holes in the bottom, whereas the bottom of the Alpha 9 has many more large openings directly beneath the main PCB. 😕 I could measure the temperature inside the players with holes open or closed using a thermocouple, but I think I’ll just leave it as is..
Regarding the recap, the following 23 electrolytic caps are on the main PCB of my Arcam Alpha 9:
C33, C43,C 44, C45, C47, C48, C51: Rubycon 25V 1000uF
C29, C39, C40, C41, C42, C49, C50, C292: Rubycon 25V 100uF
C37, C38, C56: Rubycon 50V 10uF
C46: Rubycon (Nonpolar) 35V 10uF
C34, C35: Samwha 100V 100uF
C53: OSCON (?) 20V 22uF
I found a service manual with the CD23 and Alpha 9 circuit diagrams and parts lists here:
Download service manual
Strangely, some of the caps are missing from the parts list for the Alpha 9 main PCB (see page 38) and some are on the list but not on the main PCB and some of the values of the caps on the list differ from the values of the actual parts. On the parts list:
C38, is spec’d 100uF (!) 25V ZA RUBYCON
C39, C40, C47, C48, are missing
C44, C45, are spec’d: 1000uF 35V
C46, is spec’d: 1000uF (!) 25V
C49, C50, are spec’d 470uF (!) 25V RA
I suppose I should stick to the values of the parts on the actual main board, possibly with higher voltage and temperature ratings.. What caps should I use? I’m thinking of using Panasonic FM capacitors. Any suggestions are welcome.. 🙂
The differences all sound typical of production changes during the life of a product. Don't go altering or adding or removing parts. Keep it as it is and its worth taking pictures for your own reference is there is any doubt that things could get mixed up.
When it comes to choosing caps I always stick to good quality commercial grade, and usually the 105C temperature rating. So typically Vishay/Philips and Rubycons. I've used Panasonics (they are fine) but I've not used them in 105C rating.
When it comes to choosing caps I always stick to good quality commercial grade, and usually the 105C temperature rating. So typically Vishay/Philips and Rubycons. I've used Panasonics (they are fine) but I've not used them in 105C rating.
Advice 2 seems Wise, if caps look fine :keep it !
Avoid FM, choose FC serie instead for the main reservoir caps if you want to change the main smoothing/reservoir caps cap but it doesn't seem the unit needs it ! What serie are the 1000 uF caps ?
Of course changing the serie/brand would change the sound signature and not always for the best ! The idea is more you can tune the device to a better mix with the whole rest of the system... but can be a dangerous and time consuming game while not having a reference point (a non modified device) can't permitt to say if it's really better !
Maybe work on a better output DC caps (two Silmic 2 in reverse position to make a standalone bi-polarized one : + - - + in serie with twice the capacitance value of each cap in relation to the one you swap on the pcb ! At least is it already bipolar ?
If you like the sound : keep the device as it is but if you see a visual problem : post 2 of Mooly. If not broken: an old cap as smoothing position after the diodes is not worst when ageing : the ESR becomes worst and it's a good news as it's about pulsing current ! If it was a pure reservoir cap it could be an other story of course !
I have some CD player from the 80 not recaped and they are just good. Seing one photograph you linked we can see Elna cerafine, Silmic I (not II from what I 'm able to see)... not by chance : I will change nothing but just tests on the output DC blocking caps of the RCA plugs or maybe a little test on the main reservoir caps without desoldering them ! If the second line of the Rubycon 100 uF you write are not already decoupling caps of the first 1000 uF line : try to // the 1000 uF on the leads with 100uF to 200 uf with Panasonic FC : take care with the polarity !
But the better way to have great pleasure with a device is not to break it... and as you like it already : stay on post 2 advice !
hope this helps.
Avoid FM, choose FC serie instead for the main reservoir caps if you want to change the main smoothing/reservoir caps cap but it doesn't seem the unit needs it ! What serie are the 1000 uF caps ?
Of course changing the serie/brand would change the sound signature and not always for the best ! The idea is more you can tune the device to a better mix with the whole rest of the system... but can be a dangerous and time consuming game while not having a reference point (a non modified device) can't permitt to say if it's really better !
Maybe work on a better output DC caps (two Silmic 2 in reverse position to make a standalone bi-polarized one : + - - + in serie with twice the capacitance value of each cap in relation to the one you swap on the pcb ! At least is it already bipolar ?
If you like the sound : keep the device as it is but if you see a visual problem : post 2 of Mooly. If not broken: an old cap as smoothing position after the diodes is not worst when ageing : the ESR becomes worst and it's a good news as it's about pulsing current ! If it was a pure reservoir cap it could be an other story of course !
I have some CD player from the 80 not recaped and they are just good. Seing one photograph you linked we can see Elna cerafine, Silmic I (not II from what I 'm able to see)... not by chance : I will change nothing but just tests on the output DC blocking caps of the RCA plugs or maybe a little test on the main reservoir caps without desoldering them ! If the second line of the Rubycon 100 uF you write are not already decoupling caps of the first 1000 uF line : try to // the 1000 uF on the leads with 100uF to 200 uf with Panasonic FC : take care with the polarity !
But the better way to have great pleasure with a device is not to break it... and as you like it already : stay on post 2 advice !
hope this helps.
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Hi Eldam. So basically you say that if the caps look fine then don’t change them, right? But the (reference) Arcam CD23T really sounds much better than the Alpha 9 which it shouldn’t.. Yet the caps of the Alpha 9 all look fine.. The series of the Rubycon 1000 uF caps are: S9715 and 1M9735..
not something more usefull marked on it : as ZA, ZL, etc ?
With all those chips & roms I would just change the reservoir caps only and that's all : you risk to collapse a chip. Better caps at the output of some regs can give worst result for some reasons !
Page 10 : C4/C104 outputs caps are polarized Elna Cerafine : you can try 2 x20 uF Silmic 2 in serie but reversed : + - - + (so 2 Silmic for each channel L then R output): as there is only two holes for one caps : the two negativ(-)leads are tied together but floating while the two positiv (+) leads go in the pcb holes ! But if Cerafine was putted here this is certainly for a certain smoothness, no? Silmic 2 in serie could be more transparent while not giving a better tonal result ! Try&error for the Go/No-go !
It seems main reservoir caps are in a Pi configuration : page 9 ; e.g. C44 smoothing with C47 reservoir cap, etc ! If looking fine at eyes : keep it and if any space Under the pcb try a // Panasonic FC 100 to 200 uF on each second 1000 uf cap, i.e. : C47 & C48 only.
You have just 3 caps after diodes bridges : C44/45/36 : only this one could be changed if looking bad (post 2).
I will keep it at it is. If really want to risk the device : try // C47&C48 (page 09) : listen to ! I bad come back in the initial conf !
I will keep all the others caps for the 20 years to come !
With all those chips & roms I would just change the reservoir caps only and that's all : you risk to collapse a chip. Better caps at the output of some regs can give worst result for some reasons !
Page 10 : C4/C104 outputs caps are polarized Elna Cerafine : you can try 2 x20 uF Silmic 2 in serie but reversed : + - - + (so 2 Silmic for each channel L then R output): as there is only two holes for one caps : the two negativ(-)leads are tied together but floating while the two positiv (+) leads go in the pcb holes ! But if Cerafine was putted here this is certainly for a certain smoothness, no? Silmic 2 in serie could be more transparent while not giving a better tonal result ! Try&error for the Go/No-go !
It seems main reservoir caps are in a Pi configuration : page 9 ; e.g. C44 smoothing with C47 reservoir cap, etc ! If looking fine at eyes : keep it and if any space Under the pcb try a // Panasonic FC 100 to 200 uF on each second 1000 uf cap, i.e. : C47 & C48 only.
You have just 3 caps after diodes bridges : C44/45/36 : only this one could be changed if looking bad (post 2).
I will keep it at it is. If really want to risk the device : try // C47&C48 (page 09) : listen to ! I bad come back in the initial conf !
I will keep all the others caps for the 20 years to come !