So I was gifted an very early production run Onkyo M-505 DC dual mono power amplifier. The nameplate says "Model 505" with no reference to Integra branding putting it in the first production run for US export. You can tell too, factory bodge wires and all.
Anyhow, I've already rebuilt the input and protection circuits and have the parts to get started on a recap of the channel boards (all the caps are gone) this afternoon. This thing was covered in rat poop and cat pee so I'm checking every last component, replacing all caps with higher quality modern panasonic FM/FC electrolytics and kement MKP for film types, and replacing out of spec components as needed.
Today I removed the PS filter caps pics of which are attached to this post. The M-505 uses plain screw terminal caps unlike later models with crazy copper bus plates and puddles of solder.
Would the DIY community be willing to help me source some suitable replacement caps? Fortunately Onkyo was kind enough to print most of the specs on the outside.
I am having trouble finding a replacement at less than $50-60 (kemet) and welcome suggestions as that is out of my price range with a baby in the works any day.
How critical is it to match the ESR? Is 20mOhms vs. 10mOhms really going to make a difference? I can find ones that seem to be suitable but with 2x the ESR@100hz - this Onkyo cap doesnt specifically say what freq was used to calculate ESR.
Thanks!
Anyhow, I've already rebuilt the input and protection circuits and have the parts to get started on a recap of the channel boards (all the caps are gone) this afternoon. This thing was covered in rat poop and cat pee so I'm checking every last component, replacing all caps with higher quality modern panasonic FM/FC electrolytics and kement MKP for film types, and replacing out of spec components as needed.
Today I removed the PS filter caps pics of which are attached to this post. The M-505 uses plain screw terminal caps unlike later models with crazy copper bus plates and puddles of solder.
Would the DIY community be willing to help me source some suitable replacement caps? Fortunately Onkyo was kind enough to print most of the specs on the outside.
I am having trouble finding a replacement at less than $50-60 (kemet) and welcome suggestions as that is out of my price range with a baby in the works any day.
How critical is it to match the ESR? Is 20mOhms vs. 10mOhms really going to make a difference? I can find ones that seem to be suitable but with 2x the ESR@100hz - this Onkyo cap doesnt specifically say what freq was used to calculate ESR.
Thanks!
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Does anything from the United-Chemicon U32D series caps come close to fitting?
https://www.mouser.com/datasheet/2/420/1061909384505b66a161392-218321.pdf
https://www.mouser.com/datasheet/2/420/1061909384505b66a161392-218321.pdf
U32D
Physically yes it comes close enough to adapt the original cap clamps. However I couldn't find any info about the technical specs of the cap.
10mOhms ESR seems to be the hard to match spec.
http://www.newark.com/kemet/als70a203kf100/cap-alu-elec-20000uf-100v-screw/dp/14AC3298
LNR2A223MSE Nichicon | Mouser
Are two other options. The Kemet is 22mOhms and under $24/cap. The ones you mentioned are $17/cap but I can't find published ESR figures.
Would bypassing each filter cap with a parallel metal film cap of approximately 1% (2uf) to 10% (20uf) allow me to get away with a higher ESR cap, or does it really matter? There is a lot of wire between the hot lead and the actual signal.
Physically yes it comes close enough to adapt the original cap clamps. However I couldn't find any info about the technical specs of the cap.
10mOhms ESR seems to be the hard to match spec.
http://www.newark.com/kemet/als70a203kf100/cap-alu-elec-20000uf-100v-screw/dp/14AC3298
LNR2A223MSE Nichicon | Mouser
Are two other options. The Kemet is 22mOhms and under $24/cap. The ones you mentioned are $17/cap but I can't find published ESR figures.
Would bypassing each filter cap with a parallel metal film cap of approximately 1% (2uf) to 10% (20uf) allow me to get away with a higher ESR cap, or does it really matter? There is a lot of wire between the hot lead and the actual signal.
The CDE 3199 series seems to be ideal, but I cannot find any distributors who carry them. This is same series of PS filter cap used in Mark Levinson amps, and is listed as a standard CDE item, but nobody carries them.
http://www.cde.com/resources/catalogs/3199.pdf
http://www.cde.com/resources/catalogs/3199.pdf
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UCC U32D 80V 18,000uf is around $17 each at Digikey, the Kemet I linked is next least costly at $24/each. To get ones with an ESR similar to the originals starts at around $42/each and I would have to go for a much higher capacity of 22000uf or higher to get an ESR that low.
Could I get away with the Kemets (much better specs than UCC part) with a film bypass cap to reduce percieved ESR? There are more expensive Kemets that match ESR but are WAY higher in capacity (2x roughly).
Could I get away with the Kemets (much better specs than UCC part) with a film bypass cap to reduce percieved ESR? There are more expensive Kemets that match ESR but are WAY higher in capacity (2x roughly).
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Sweet! I must have skimmed past that in reviewing so many possibilities. I'll order them next week when I get paid. Any thoughts on quality vs Nichicon/CDE/Kemet?
Thanks for pointing out I missed that!
Thanks for pointing out I missed that!
I found this part with the Digi-Key mobile app. E36D750MLN183TC79M United Chemi-Con | Capacitors | DigiKey
I was incorrect the U36 series are the ones I cant find esr data for. The U32 have published esr data but are about $50/each instead of $17.
I was incorrect the U36 series are the ones I cant find esr data for. The U32 have published esr data but are about $50/each instead of $17.
Before you order, you should find out two things:
1) What is the actual rail voltage these caps will sit at? If it's close to 63V then I would get 63V caps and not 80V caps.
2) Do you have space for taller caps? Then use the largest that will fit in the old space.
1) What is the actual rail voltage these caps will sit at? If it's close to 63V then I would get 63V caps and not 80V caps.
2) Do you have space for taller caps? Then use the largest that will fit in the old space.
Rail voltage is around 72V so I'm stuck with 80V or I'd drop down to 63V.
Have room for taller caps but likely dont need it most of them in the right diameter are short. Is there an advantage to a taller cap?
I could even get away with larger diameter by .5" inches or so.
Have room for taller caps but likely dont need it most of them in the right diameter are short. Is there an advantage to a taller cap?
I could even get away with larger diameter by .5" inches or so.
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