Anybody work on Friedmans? Maybe a Runt 50??

napalmdeath

napalmdeath

Well-known member
So, I bought a used Runt 50, (yeah, again), and it's had some hum since day one.. It's a 2016, with Black ARS Filter Caps, which after talking to Dave, are the culprit. I think he had a bad batch of these at one point and did a number of warranty repairs on the Runt 50. The hum is in standby, and when turning off standby, it'll occasionally get louder intermittently, and fade back to a lower hum. It's gotten worse. I initially paid no mind, and assumed it was the wiring in this old house, and it wasn't extreme. But it's gotten more prominent.

I've reached out to several techs in the area, and apparently with this being a PCB, it's not a simple task, atleast more time-consuming.

Has anyone changed these out, and can give me an idea of what a competent tech would charge? The other problem is, everyone around here works when they feel like it. So, naturally, you're lucky if they even look at it in 2 weeks.

I believe the seller knew it needed caps. It's a 2016, and when I reached out to see if he noticed any audible hum or had any issues, he ghosted me. Should I just contact PayPal and return it and let the seller deal with it? Getting it fixed around here is ridiculous, and shipping it off will be expensive and probably just as time-consuming.

What to do....It's the only amp I got.
 
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Scammeron is the only answer. jk
shoot Dave an email : RACKSYSTEMS@yahoo.com
 
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What's the chances this just happens suddenly? Of course the seller says it was quiet as a church mouse. I don't believe it.
 
SoooRad said:
If it was shipped, it’s plausible that something got messed up on the move.
Click to expand...
Filter caps? Dave's pretty adamant it needs filter caps. I know he had some quality issues with ARS, and I think I read somewhere that the double-vented black ones were problematic, which are what's in this one. I can say they're all clean. No corrosion, leaks, bulging, but that doesn't mean they aren't failing. Aside from the hum, the amp sounds phenomenal.

I went trough it yesterday and made sure tube sockets were up to snuff, tightened up the power tube sockets. Deox'd, and threw in E34L's just in case the KT77's were iffy, and damned if they don't sound ferocious. I had them in my last Runt, and they're staying in this one.
 
it's not hard to change them ...... it just might be a total bitch to get to them ..... I'll see if I can find some gut shots

ok found this ......

it's what I thought ... you can access them from the top ... no need to remove the board or anything for that matter

that would take me an hour .... not rushing at all
 
griff10672 said:
it's not hard to change them ...... it just might be a total bitch to get to them ..... I'll see if I can find some gut shots

ok found this ......

it's what I thought ... you can access them from the top ... no need to remove the board or anything for that matter

that would take me an hour .... not rushing at all
Click to expand...

Yeah, i watched that one earlier. Do you know anything about different brands of caps? The local guy i found carries Nichicon. I know the ARS is preferred by Dave, but he's also gotten bad batches multiple times, and even the tech I spoke to said that they don't carry them because of quality control over the years, but said he'd order them if that's what I wanted.

FWIW, I have no tonal issues, they amp sounds great. But the hum is definitely filter caps. And, these are vented on both ends, which he's stated Dave's had problems with.
 
I think my Runt 50 is bone stock, not sure. But it screams. I love it so much, I will never change a thing on it other than required maintenance. And then I will install newest versions of whatever needs replacing.
 
Nichicon caps are some of the best on the market. However, I don’t think they make axial caps anymore (what is in the Runt 50). F&T and MOD are also good quality caps and are available in axial format.

There have been a few revisions to that amp. If you send it back to Dave, I suspect he’ll update it to the latest spec. for you. I’m a tech and if you don’t know a good trustworthy local guy, that is what I would recommend.

It’s not a difficult repair but the board has to be pulled to do the job right. Dave designed the amp so the main board can be fully removed in about 10 minutes -so there is no excuse not to do it right. The board in that amp is wave soldered and, while it can be soldered from the top side, the pads on the top are pretty small. I’ve seen a lot of guys who’ll just cut the leads on the old caps and solder the new caps to the old leads. That is crap work and you don’t want it.

EDIT: BTW - The Runt 50 hums a little bit even with everything in good working order.
 
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