Hi, i have an old Electrocompaniet 4.5 i am using as a test bench
I want to recap the power supply with just decent new caps
I have narrowed down the choice for new caps to Panasonic FC and Nichicon Gold because they are available in quantity and value on ebay.com
What would be your pick ?
Another question
I have seen some very high end units using Rubycon
But i do not know nothing about which series could be a good alternative to the two above mentioned
Thanks a lot and kind regards, gino
I want to recap the power supply with just decent new caps
I have narrowed down the choice for new caps to Panasonic FC and Nichicon Gold because they are available in quantity and value on ebay.com
What would be your pick ?
Another question
I have seen some very high end units using Rubycon
But i do not know nothing about which series could be a good alternative to the two above mentioned
Thanks a lot and kind regards, gino
Hi and thanks a lot for the kind and valuable advice
I have a great respect for Panasonic because i read something about long R&D together with Siemens on caps.
I read something like famous Siemens Sikorel (now Epcos i think) being the best caps ever for audio.
I also read an enthusiatic review of a solid state units recapped with Sikorel
The sound took from a very solid state character to a tube character
Maybe in preamps is different ... but for power amps where the output stages are directly connected to ps caps i think that the quality of caps impacts greatly the sound ... i have some experiences of this
Speaking instead of preamps ... i would like so much to have 2x1000uF at least very very high quality and very close to the amp circuits
For instance i like this preamp ... that i am thinking to buy
An externally hosted image should be here but it was not working when we last tested it.
i would replace the 4 caps close to the two channels with bigger (even 2000uF) and better grade possible
I am sure the sound would benefit.
I like this preamp so much ... two channel perfectly equal ... clean layout
Beautiful indeed.
Sorry for the OT. Kind regards, gino
Do you have a schematic of the preamp? Would be interested to see what power supply regulator it has. Maybe you can gain more if your use an C-R-C lowpass filter or an better regulator.
Can you measure the output voltage of the preamp with the input shorted (e.g. no input signal) and a resistor across the caps and ground (to simulate normal loading)?
This tells you if the power supply rejection is adequate.
Can you measure the output voltage of the preamp with the input shorted (e.g. no input signal) and a resistor across the caps and ground (to simulate normal loading)?
This tells you if the power supply rejection is adequate.
hi and i am sorry. No schematic.
I have just read some positive comments on its sound in internet
I have the feeling that if a design is fundamentally good some little improvements can be done, especially in the power supply but also in some strategic parts like the components in series with the signal.
I prefer low noise parts in general. I think that noise is always a bad thing because it is not in the original signal.
I do not have the preamp actually. I am just thinking to buy it.
The seller asks about 400 USD.
i am still undecided on what to do actually.
Thanks again, gino
I've used Panasonic FC, Nichicon Muse, Nichicon Gold, Mundorf MLytic (because they were the cheapest available for large values), and I've used Elna Silmic II, several lines within Rubycon Black Gate. I have nothing bad to say about any of them. I can vouch for Mallory, as their capacitors have proven to last forty years now. Generally, modern aluminum substrate capacitors are considered consumables and have an appropriately short lifespan. In audio equipment, some will last as short a time as 10 years, while others like Black Gate and Mallory are known to last at minimum 30 years. There is alot of audiophoolery and paranoia around capacitor lifespan, and there is no one size fits all. The lifespan can vary from one device to another depending on some factors in the next paragraph. One thing I recall from Rubycon's BG papers was they were designed to last about this time, and possibly longer, that being the primary benefit to their charcoal content. For the most part, their lifespan at which point they no longer perform to specification more or less has yet to be determined.
If I was going to restore an amplifier at this time, I would not over-think this aspect of work. I would simply determine the ripple current present, the voltage, thermal capacity and the size requirements. Ripple current and heat are the slow killers of these types of capacitors. Over-voltage typically results in a quick pop, while the others slowly degrade performance. For the most part, re-capping is quite straight forward and doesn't require skill. It is not a big deal to replace them in a decade if they must be updated, although long-life specific types do cut the frequency between service intervals.
When it come to low versus high voltage ratings, there are two trains of thought. I've read papers that high voltage capacitors have a lower equivalent series resistance, but that they don't work as well when used below a percentage of that aforementioned voltage. I would not lose any sleep on it, as it will unquestioningly be better than whatever aluminum substrate el-cheapo cost saving 10 cent capacitor or horrific surface mount types has been in service for the time being. Classe and some brands have been stooping down to surface mount junk and have the audacity to charge thousands for gear with audibly noisy SWM power supplies and signal coupling capacitors that vary with temperature. Just identify the circuit requirements and choose from there.
I'll bypass large capacitors in power supplies with small value capacitors to negate the large electrolytic's upper pole. I will also do this with some smaller ones close to semiconductors or chipsets, but I exercise reasoning and practicality. It depends completely upon the circuit and layout, and no false audiophile placebos.
If I was going to restore an amplifier at this time, I would not over-think this aspect of work. I would simply determine the ripple current present, the voltage, thermal capacity and the size requirements. Ripple current and heat are the slow killers of these types of capacitors. Over-voltage typically results in a quick pop, while the others slowly degrade performance. For the most part, re-capping is quite straight forward and doesn't require skill. It is not a big deal to replace them in a decade if they must be updated, although long-life specific types do cut the frequency between service intervals.
When it come to low versus high voltage ratings, there are two trains of thought. I've read papers that high voltage capacitors have a lower equivalent series resistance, but that they don't work as well when used below a percentage of that aforementioned voltage. I would not lose any sleep on it, as it will unquestioningly be better than whatever aluminum substrate el-cheapo cost saving 10 cent capacitor or horrific surface mount types has been in service for the time being. Classe and some brands have been stooping down to surface mount junk and have the audacity to charge thousands for gear with audibly noisy SWM power supplies and signal coupling capacitors that vary with temperature. Just identify the circuit requirements and choose from there.
I'll bypass large capacitors in power supplies with small value capacitors to negate the large electrolytic's upper pole. I will also do this with some smaller ones close to semiconductors or chipsets, but I exercise reasoning and practicality. It depends completely upon the circuit and layout, and no false audiophile placebos.
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Hi and thanks for the advice.
I have been confusing ... i have already the electrocompaniet
What i do not like ? its complexity. I am a believer on minimalism.
Then i saw this Aragon 18K ... not minimalist but beautiful lay-out and i am considering buying it and recap it as well.
When i sess long rows of transistors in a line preamp i really wonder if a line preamp must be so complex ... most of the times non voltage gain is required only a volume control and a little buffering.
Anyway ...
no service manual/schematic in both cases unfortunately
This is the main issue actually
About modifications i am targeting only:
- ps caps
- coupling caps
- ps diodes
Nothing else
I am also against balance controls in general
I like to bypass them
Thanks again, gino
Hi and thanks a lot for the very helpful advice
I have experience with the Panasonic and they have been very ok.
I read that Panasonic has carried out a lot of R&D activity on electrolitic caps together with Siemens i think ... so they have accumulated a great know-how.
The exotic caps can be superior ... but their price can be higher than the value of the unit to be recapped
I am focusing line preamps at this stage
I think that a very good line preamp can help the other elements of the chain to express them at their best, or worst.
Thanks again, gino
Hi and thank for the hint !
This is interesting
i will check prices ... thanks again, gino
I favor the Nichicon Fine Gold caps. They are cheap and sound good from the moment they go in. I have tried other audio caps (elna Silmic and Cerafine) and they sound harsher to me, with no additional detail or "air" that I don't get from the Nichicons, just hard-edges. Doesn't flow with the Sony sound. Some claim they must "form" or "break in" but I think you just get used to the new sound, better or not. I have been convinced that I improved my CD player by switching op-amps (5532 to OP270FZ) then I blind tested with a friend and I unanimously preferred the old ones after many tests of switching, not switching and saying they were switched etc. There is a reason you'll find no less than a billion 5532s in most studio gear, I suppose. I am no fan of Panasonic caps, sure they sound lovely, but in my experience they fail quickly, like some Elna lines. Nichicon and Nippon/United Chemicon have been the most reliable caps I have seen. I pull 25+ year old Nichicons and UCC/Nippon caps for replacement all the time at work and when tested they are still within tolerance for capacity and ESR. The worst caps I have seen besides Taiwanese/Chinese junk units are Elna Duorex- what an ironic name.
http://www.diyaudio.com/forums/parts/151392-best-electrolytic-capacitors.html
http://www.diyaudio.com/forums/pass-labs/112149-ono-xono-output-coupling-caps.html
http://www.diyaudio.com/forums/parts/171907-elna-silmic-ii-elna-cerafine.html
http://www.diyaudio.com/forums/power-supplies/126697-bypassing-psu-capacitors-effective.html
http://www.diyaudio.com/forums/lounge/232600-audio-grade-capacitors.html
http://www.diyaudio.com/forums/parts/246921-input-capacitors-what-way-does-size-matters.html
http://www.diyaudio.com/forums/solid-state/242535-psu-bank-silmic-2-a.html
http://www.diyaudio.com/forums/parts/23453-sanyo-os-con-any-good.html
http://www.diyaudio.com/forums/solid-state/239525-power-caps-life-expectancy-changing-specs.html
http://www.diyaudio.com/forums/power-supplies/106648-paralleling-film-caps-electrolytic-caps.html
http://www.diyaudio.com/forums/pass-labs/112149-ono-xono-output-coupling-caps.html
http://www.diyaudio.com/forums/parts/171907-elna-silmic-ii-elna-cerafine.html
http://www.diyaudio.com/forums/power-supplies/126697-bypassing-psu-capacitors-effective.html
http://www.diyaudio.com/forums/lounge/232600-audio-grade-capacitors.html
http://www.diyaudio.com/forums/parts/246921-input-capacitors-what-way-does-size-matters.html
http://www.diyaudio.com/forums/solid-state/242535-psu-bank-silmic-2-a.html
http://www.diyaudio.com/forums/parts/23453-sanyo-os-con-any-good.html
http://www.diyaudio.com/forums/solid-state/239525-power-caps-life-expectancy-changing-specs.html
http://www.diyaudio.com/forums/power-supplies/106648-paralleling-film-caps-electrolytic-caps.html
Hi and thanks a lot for the very helpful links
I have stuff to read for the next 3 months !
I was reading an article saying that in the end very little can be done on a circuit to improve the original design. It is like the dna ...
Instead especially for circuit with low PSRR the power supply can be improved lowering the noise and this should be beneficial
In particular i was reading a technical review of a preamp with low distortion but with noise not particularly low.
I should try soon to carry out some measurements of noise with inputs shorted.
Doing this before and after mods should give some indications.
Thanks again, gino
I have stuff to read for the next 3 months !
I was reading an article saying that in the end very little can be done on a circuit to improve the original design. It is like the dna ...
Instead especially for circuit with low PSRR the power supply can be improved lowering the noise and this should be beneficial
In particular i was reading a technical review of a preamp with low distortion but with noise not particularly low.
I should try soon to carry out some measurements of noise with inputs shorted.
Doing this before and after mods should give some indications.
Thanks again, gino
It is true that if the design is prone to adding distortion and the devices that are used are also prone to generating noise and distortion, then the weight that the capacitors will have on the performance will be quite small. I would use any of the proven capacitors that have been mentioned, provided they come from registered distributors and not ePrey.
Hi and thanks for the helpful advice.
Without schematic i have no chance to show how these preamps are designed
This is the first and most critical issue.
I can only hope that the actual caps are a little exhausted and new ones will perform better reducing noise and impedance from the supply, even if they are before the voltage regulators i suppose.
I see also few very small uF closer to the circuits ... i would like to beef them up a little ... i believe in the importante to place uF very close to the circuits
Yes i think you are right because i see strange prices on ebay
From here i have access to mouser.com ...
The selection tool is very well done and it is very easy to buy the right quantities
I have already ordered diodes ... but caps i will do in the weekend
Thanks a lot again, gino
The Nichicon caps are definitely in Panasonic's league sound wise. I imagine that in a double blind test I couldn't tell the difference. I mention the reliability because I have seen many Panasonic capacitors fail in TVs in less than five years. This is the primary place I have seen Panasonic capacitors used in the field, they don't get too much love from manufacturers. I am with you regarding the good and cheap comment, that is why I roll with the Nichicons. They publish full specifications for them as well, which most manufacturers withhold for "audio grade" capacitors. They must be proud of them for some reason, and I can hear why.
Hi and thanks you again. No more doubts about Nichicon quality.
I will buy them during the weekend. I hope Mouser lists the Fine Gold series because i have been recommended that online shop from a Norwegian member of this forum.
I like very much the selection tool on Mouser site.
I find it very educational also to get an idea of different specifications and so on. Very very good.
Thanks a lot again. Kind regards, gino
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