The Control Board PCB and Power AMP PCB use old Nichicon VX caps.
Could you kindly give me your recommendation for replacements?
Some of the old VX are very small: 0.10uF / 5.5VDC, 0.47uF / 50VDC and 1uF / 5VDC.
Many thanks again for your time and help.
Normally such small values can be replaced for film caps like Wima MKS2. It would be better to have a schematic to determine if they won't pose a problem (ESR is lower).
Many thanks for your help, guys.
The amp is a Nakamichi IA-2 (50W + 50W). I have attached the schematic and parts list for the control board PCB.
The IA-2 power amp PCB uses the same schematic and parts list as the Amplifier 2. Unfortunately, I can't get the service manual. So, I attached the schematic and parts list for the Amplifier 1 (80W + 80W). The Amplifier uses the same value electrolytics as my amp, except mine has 4 x 220uF / 63VDC electrolytics whereas the Amplifier 1 seems to have 2 x 20uF / 63VDC electrolytics.
All the best.
The amp is a Nakamichi IA-2 (50W + 50W). I have attached the schematic and parts list for the control board PCB.
The IA-2 power amp PCB uses the same schematic and parts list as the Amplifier 2. Unfortunately, I can't get the service manual. So, I attached the schematic and parts list for the Amplifier 1 (80W + 80W). The Amplifier uses the same value electrolytics as my amp, except mine has 4 x 220uF / 63VDC electrolytics whereas the Amplifier 1 seems to have 2 x 20uF / 63VDC electrolytics.
All the best.
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Electrolytic caps 3.3 uf & under are not generally stocked at distributors.
I replaced those values freely in organs I've refurbished with polyester film caps, with great sound improvement over the 45 year old caps. change versus original? I don't know I couldn't afford one in 1968. The organs cost more than a pony car then. You wouldn't even rate a demonstration in a showroom if you didn't wear a coat & tie in those days.
I used roederstein polyester 63 v caps because that was what was in stock. In some places they wouldn't fit, and I used Aerovox gold 50v ceramic caps. Again the sound is very nice. Using 25x the signal voltage on the ceramic cap linearizes the performance somewhat for a 2 v signal.
The great advantage of film or ceramic caps, they lack the planned obsolescence feature. They don't dry up & cause the device to **** out in 10-20 years as the original design is planned to do. They do have a service life, but if you stay well below rated voltage film & ceramic caps will outlive you. Life is too short to do this re-cap job over & over.
Audio grade electrolytic caps like the muse line I see as unnecessarily premium in the wrong specificationi. I use nichicon caps frequently, but I try to buy the industrial line rated 10000 hours service life. I've had to replace e-caps in an amp I own four times since 1970 (low power out), and view standard life 1000 hour or 500 hour TV parts house stock caps as vile time wasters.
I replaced those values freely in organs I've refurbished with polyester film caps, with great sound improvement over the 45 year old caps. change versus original? I don't know I couldn't afford one in 1968. The organs cost more than a pony car then. You wouldn't even rate a demonstration in a showroom if you didn't wear a coat & tie in those days.
I used roederstein polyester 63 v caps because that was what was in stock. In some places they wouldn't fit, and I used Aerovox gold 50v ceramic caps. Again the sound is very nice. Using 25x the signal voltage on the ceramic cap linearizes the performance somewhat for a 2 v signal.
The great advantage of film or ceramic caps, they lack the planned obsolescence feature. They don't dry up & cause the device to **** out in 10-20 years as the original design is planned to do. They do have a service life, but if you stay well below rated voltage film & ceramic caps will outlive you. Life is too short to do this re-cap job over & over.
Audio grade electrolytic caps like the muse line I see as unnecessarily premium in the wrong specificationi. I use nichicon caps frequently, but I try to buy the industrial line rated 10000 hours service life. I've had to replace e-caps in an amp I own four times since 1970 (low power out), and view standard life 1000 hour or 500 hour TV parts house stock caps as vile time wasters.
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That was very interesting, particularly about the roedersteins.
http://www.diyaudio.com/forums/part...k-capacitors-living-legend-looney-legacy.html
Keep well.
The roederstein caps I used were PVC cased, not bakelite. Purchased 2010 from farnell. Also the discussion linked to above was talking about TV service where coupler caps in horizontal or vertical circuits are run near the voltage limit at high currents, there is a lot of self heating and the environment is hot too, and the polyester will actually break down. See the service life limit on any plastic film cap, test condition 85 or 105 deg C.
Audio amp coupler caps tend not to run at high voltage & current because they are in the low current early stages, the input, feedback, or low/high cut boost circuits. The high voltage high current stages are direct coupled without caps, VAS transistor to driver transistor to output transistor. Capacitors in those locations went out of fashion about 1966, except in school textbooks where the math is simpler without DC coupling of stages.
Audio amp coupler caps tend not to run at high voltage & current because they are in the low current early stages, the input, feedback, or low/high cut boost circuits. The high voltage high current stages are direct coupled without caps, VAS transistor to driver transistor to output transistor. Capacitors in those locations went out of fashion about 1966, except in school textbooks where the math is simpler without DC coupling of stages.
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Ok,then use multilayer ceramics X7r,x8r and similar on that position because is power supply decoupling for microcontroler.For Bigger value caps use Panasonic Fc,Fm,oscons,anything with low impedance.
Many thanks, Basi. I owe you a good dinner when I get to Croatia.
My spreadsheet already used Panasonic FCs wherever poss.
Final question about C304 (100uf / 16vdc bipolar electrolytic). Its shown at right of (PROTECTOR) in A-1 Power Amp CD.pdf.
Panasonic ECEA1EN101U or Nichicon UES1C101MPM best in this application?
Cheers, and many thanks also to Jean-Paul and Indianajo.
I'd be thrilled if either panasonic or nichicon non-polar caps were in stock in the US. In past all non-polar electrolytic caps stocked at newark were keypunch errors, delivering polar caps, and mouser only stocked lacon or some such brand with a **** datasheet. I just tried to check these part numbers at digikey, my browser says their security certificate is obsolete, and avnetdirect, is now an unsupported url.
So if you find non-polar 100 uf caps 16v or higher in stock, from either of those manufacturers, count your blessings as you issue the order.
So if you find non-polar 100 uf caps 16v or higher in stock, from either of those manufacturers, count your blessings as you issue the order.
Hi again!!!Go for Nichicon.
As for dinner i would love to.Just let me know when u come. 😀 😀
Many of Japanese tourists visit my country.
Best regards!!
Digikey stocks bipolar (aka non polar) Nichicon Muse, and many others in a wide range of values. I purchased a significant quantity of bipolar Nichicon Muse early this year to replace the many coupling caps in my two BSS Varicurves parametric room equalizers. (That's a work in progress)
https://www.digikey.com/products/en/capacitors/aluminum-capacitors/58?k=&pkeyword=&pv69=80&FV=d0000f%2Cffe0003a%2C1f140000&mnonly=0&newproducts=0&ColumnSort=0&page=1&quantity=0&ptm=0&fid=0&pageSize=25
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