Re-capping Denon HA-1000 mc headamp

[jeshi]

thanks everyone. I think my plan is to first send an email to Nippon chemicon for more information on these old SL and ST series. I'll also desolder a cap in the outboard psu and measure it. Those caps right after the rectifier diodes should be ones with the most stress and most likely to have losses over time. If that one is still good, then I might just leave everything alone and enjoy it until I start to have problems (don't fix what isn't broke).

 

[mdpaudio]

Good plan. Measure that cap a few times over a few minutes to see how fast it is losing charge too. It will go down but if it does so quickly it is a problem. So give it a charge by jumping some clip leads to the position where it was in the amp to charge it up. Disconnect it from the amp and measure the voltage on the cap at 30 second intervals. If it drops like a stone then it is bad. If it slowly drops you are good. If the capacitance is within like 10% and it holds a charge you are good. Common sense is a good guide. Try the polystyrene bypass caps on the input and output caps too, you might like the result. You only need like .001uf or so.

 

[xrk971]

Hi Jeshi,
Great to see you working on a project again. I also have an amp I built 5 years ago with bulging and leaky caps. These were because I used cheap no name brand ones. I learned my lesson and only use major name brand ones now.

Maybe just change the ones that are leaky.

 

[jeshi]

I've made a table with all the caps I'm thinking about with all the markings and sizes. This might also be usefule for someone in the future finding this thread and wanting to recap their HA-1000
https://docs.google.com/spreadsheets/d/1pQDDZTqayxWvGWJijx2g0rKswcyRAuZ1OP5Qc1w8g5k/edit?usp=sharing
position value voltage dia lead spacing maker series or other markings
C4 2200uf 35v 26mm 12.5mm nippon chemicon 19-H top, CEO4W 85C
C5 2200uf 35v 26mm 12.5mm nippon chemicon 19-H top, CEO4W 85C
C33 2200uf 10v 16mm 7.5mm nippon chemicon SL 24-N top, CEO4W
C9 2200uf 10v 16mm 7.5mm nippon chemicon SL 24-N top, CEO4W
C35 2200uf 10v 16mm 7.5mm nippon chemicon SL 24-N top, CEO4W
C7 2200uf 10v 16mm 7.5mm nippon chemicon SL 24-N top, CEO4W
C34 2200uf 10v 16mm 7.5mm nippon chemicon SL 24-N top, CEO4W
C10 2200uf 10v 16mm 7.5mm nippon chemicon SL 24-N top, CEO4W
C36 2200uf 10v 16mm 7.5mm nippon chemicon SL 24-N top, CEO4W
C8 2200uf 10v 16mm 7.5mm nippon chemicon SL 24-N top, CEO4W
C11 1000uf(K) 6.3v 12.5mm 5mm nippon chemicon ST 1N-R CEO4W
C13 330uf(K) 10v 12.5mm 5mm nippon chemicon ST 16-F CEO4W
C15 1000uf(K) 6.3v 12.5mm 5mm nippon chemicon ST 1N-R CEO4W
C14 330uf(K) 10v 12.5mm 5mm nippon chemicon ST 16-F CEO4W
C12 1000uf(K) 6.3v 12.5mm 5mm nippon chemicon ST 23-X CEO4W looks to have leak
C16 1000uf(K) 6.3v 12.5mm 5mm nippon chemicon ST 23-X CEO4W
C1 470uf 6.3v 10mm 5mm nippon chemicon SL 19-N CEO4W 85C
C3 470uf 6.3v 10mm 5mm nippon chemicon SL 19-N CEO4W 85C
C4 470uf 6.3v 10mm 5mm nippon chemicon SL 19-N CEO4W 85C
C2 470uf 6.3v 10mm 5mm nippon chemicon SL 19-N CEO4W 85C

 

[jeshi]

A little update. I heard back from Nippon Chemicon about the old caps. They found the spec sheets for the SL series but could not find the ST series. I can attach the SL series PDF here. But they also said that there is no modern equivalent, but the KMQ is there current general purpose cap. I found some threads on audiokarma too about the Chemicon SL and it was apparently really good for the late 1970s and used in many luxman, marantz amps of the time.
After more searching and discussions with a friend off line, I've decided to order

• Nichicon UPM for the power supply bypass (C7-C10, C33-C36). There were a lot of threads on Audiokarma where this cap was one of the top picks for refurbishers and some prefer it over the Panasonic FC.
• Nichicon Muse UES (bipolar) for the signal path: feedback loop and inputs (C11-C16, C1-C4)
• ELNA SILMIC for an alternate set for the signal path
• some small polystyrene and other types to try parallel bypass on the input/output

I've also decided to skip the output caps since they are a Matsuo blue/silver type I've never seen before and I suspect they were carefully chosen by the designers for their sound. I can try some small parallel bypass but I don't want to remove them.
https://photos.google.com/photo/AF1QipNfsvpsSFqqex-PHkaDl65fsnQb1-KK_Q4q7QRD


I will follow the suggestions of @mdpaudio and @phase to go really slow, make only a few changes at a time and then listen for some days/weeks before moving onto changing some other caps. I've ordered caps for the inputs (C1-C4), but probably won't swap for a long time. I'll probably start with the feedback loop caps (C11-C16) since that is where I can see some leaks.

thanks for the help everyone

 

[phase]

Wow, that’s cool to have that data sheet, thanks for sharing that.
It looks like the main feature is that they are (were) a low-loss type.

You can try and search for a low loss type of standard electrolytic, but the parts you chose are likely good for that.
Those ES bipolar are great parts, much better than the silmic imo, those are better with power supply applications, imo.

 

[wayne]

I just recapped my 1978 Marantz that was full of Nichicon parts. They were all actually still good with no actual failures. They did not measure as well as the new ones however.

 

[jeshi]

No experience with OSCON myself, but what I read is OSCON is not recommended for signal path usage. If you want to replace them, I would use UES or UKL. You might want to consider replacing the tantalums (C29-32, C37/38) with UKL.

I've now learned enough about these cap names to understand what you mean. Those matsuo blue/silver on the outputs (picture above) are the Tantalums, and the Nichicon UKL are their low leakage type. I had found a thread at AudioKarma where someone mentioned they liked the UKL in the signal path as much as some of the nichicon muse capacitors.
Thanks so much @vinnysj . This is in my todo list now but I think it will be one of the last things I will try.

 

[vinnysj]

Not sure, but the stuff around the capacitor looks like glue. Make sure you clean it up, if not they will eventually corrode the parts.
For the caps, it is recommended to bump up to the next voltage rating, ie. from 2200uf 10v to 2200uf 16v. They will last longer and have similar diameter and lead spacing.

 

[jaycee]

The brown stuff is likely glue.. this glue is best removed though as it becomes conductive with age and causes all sorts of issues. Scrape it off anywhere you find it. While you're at it you can replace the capacitors, though it likely isnt needed. Don't go overboard with fancy "audiophile" caps, just use a good quality brand such as Rubycon, Nichicon, Nippon Chemicon or Panasonic. Avoid stuff from eBay.

 

[67339]

Hello,
Cannot be said to often " avoid stuff from ebay "
The feedback caps are the ones that could be very critical. It could well be that if you would use a better cap there the sound might not improve .
Just like you already wrote change one or two parts and listen for a week or so before making the next change.
Greetings,Eduard

 

[gibber]

I recapped just the 2200uF/10V caps. Used the 3000uF/16V ELNA ("Pioneer" labelled) surplus lytics available on eBay. Great result. Denon did install 10Vdc smoothing on a 9.9V (my meas) supply rail, which may explain why they get leaky. I did not find other caps to show any deterioration and left them as installed to preserve the character of this pre. To my ear the HA-1000 is one of the few components that can really make a vanilla DL-103 rock (i.e. supply ample thump).