SWR Workingman 15 crackling problem, repair or replace?

[agedhorse]

So… I finally found a small Swiss online shop that has it in stock, and I just ordered one (free shipping, nice!). Let's see how it works out. Thanks for the tip.

Tiniest amount possible.

 

[Al Kraft]

IME there actually aren't lot of things WD 40 is the best, or in many cases even a good answer for, particularly in the electronics product realm. I use it to loosen/clean up rusty or otherwise contaminated parts. It will act as a lubricant and rust preventative in certain simple mechanical type applications as long as high speeds or heavy load carrying of the parts is not why you picked this for a lubricant.

For me it is not the best at difficult penetrating oil jobs or at heavy duty lubrication. It will clean up tools, free up a door hinge or a lawn chair folding mechanism, remove grease or rust from something and is a jack of all trades kind of product that is best when your task is on the simple, lightweight end of the spectrum. IMO using WD 40 on/in electronic equipment is not a repair technique, it's an accident that needs to be looked at by a technician. YMMV!

 

[Deleted member 409896]

No update on the amp yet, unfortunately. Shop has only had it since mid-October, and he did say it would be "5 to 6 weeks" before any news.

I do have a clue as to why he's so busy. He's the authorized warranty repair shop for something like a dozen different amp brands. That must keep him busy, in addition to repairs like mine.

 

[Deleted member 409896]

Still no news. End of next week will mark 5 weeks out.

I got a 40W practice amp to use in the meantime. The headphone amp was OK, but of course the Markbass sounds better and it's more fun to play "out loud."

Decided that if the SWR can be economically repaired, great. I'll do that and probably sell it. It's too dang heavy to be a good "travel" amp, and the power (and physical size) are unnecessary for practice at home.

If it can't be fixed, then that's one problem off my plate.

 

[Deleted member 409896]

Still no word from the repair shop. They are that backlogged.

 

[squirtalert]

Still no word from the repair shop. They are that backlogged.

Thanks for keeping us updated, Hack.

I've got a Workingmans 15 I've had since 1998 that's showing very similar issues (crackling with the gain knob, broken tweeter).

Haven't tried cleaning the pots yet, but will be curious to see what they say about your amp.

 

[Deleted member 409896]

Not much of an update, but thanks.

I last emailed them middle of January. I don't plan to pester the guy. It's a 2-man operation at best, so I believe I'll email them again end of this week, only to say that I hope they're doing well, and that I'm looking forward to their diagnosis. No pressure, no demands, simply keeping in touch.

If the amp head is in fact toast, I may keep the SWR to use as a cab for my newer amp, if that's feasible (re: impedance matching and all). I suspect the shop would know if that's the case. Owner seems very knowledgeable.

update: no that won't work. The Markbass (CMB 101 Blackline) doesn't have an "output" jack, only a preamp-out jack.

It would need a powered cabinet. At which point I might as well buy a bigger (and newer, and much lighter) combo amp, or go full "head and cab."

 

[Deleted member 409896]

Good news: It was just dirty pots. He cleaned those up, and amp now works perfectly. I can pick it up next week. He's only charging me the basic diagnostic fee.

While this is likely an "easy" repair I could have done myself, the trick was in the knowing how and where to do what. I don't feel like I know enough to go poking around inside an amp. having an EE background I'm all too aware that capacitors can retain enough charge to give you a really bad day, or even a last day, even if the system has been unplugged for some time. Same reason I don't try opening a power supply on my PC when it goes bad.

 

[Deleted member 409896]

Happy ending time!

Picked up my SWR Workingman 15 today, and got it home. It works perfectly again.

FWIW, the repair shop was these guys:

Caldera Electronics

www.calderaelectronics.com

They aren't fast, but were worth the wait.

He stated that the amp looked really good inside - none of the heat damage he sometimes sees in older SWR amps. Maybe because I let it sit for years when I wasn't playing, ha. Looks like it will be with me for a while longer.

 

[squirtalert]

Thx for the update, I was hoping it might just be the pots and glad yours is working again now.

I'll mess with the wood and steel of a bass, but have the same feelings about messing with amps and electrical charge.

I ordered some quick dry electrical cleaner I hope I can spray into the pot shafts and will see if that helps.

 

[squirtalert]

Here's my update, and is working now, at least for the time being....

Unplugged it, Took the knobs off, laid the amp on it's back and sprayed CRC QD electronic cleaner down the pot shafts best I could. Most turned clean, but 4 or 5 were pretty sticky when turning and took a few more rounds of spraying and turning back and forth until smooth.

Plugged it all back in and the crackling was still coming in and out, or no sound at all while moving knobs and switches.

THEN WHAT WORKED FOR ME: Sprayed the cleaner into the the Passive/Active input! Now all the knobs and switches work, even the horn switch and pretty much sounds like before!

 

[agedhorse]

Here's my update, and is working now, at least for the time being....

Unplugged it, Took the knobs off, laid the amp on it's back and sprayed CRC QD electronic cleaner down the pot shafts best I could. Most turned clean, but 4 or 5 were pretty sticky when turning and took a few more rounds of spraying and turning back and forth until smooth.

Plugged it all back in and the crackling was still coming in and out, or no sound at all while moving knobs and switches.

THEN WHAT WORKED FOR ME: Sprayed the cleaner into the the Passive/Active input! Now all the knobs and switches work, even the horn switch and pretty much sounds like before!

Hope you didn't ruin the pots, that's NOT how you clean pots, not what you clean pots with.

This is why I hesitate recommending buying used amps. I am seeing more and more that require very expensive repairs because of hack repair attempts like this.

Sure you may have fixed the immediate symptoms, but let's see how it works down the road.

 

[squirtalert]

Hope you didn't ruin the pots, that's NOT how you clean pots, not what you clean pots with.

This is why I hesitate recommending buying used amps. I am seeing more and more that require very expensive repairs because of hack repair attempts like this.

Sure you may have fixed the immediate symptoms, but let's see how it works down the road.

Yeah, we'll see... I'm so dumb I probably didn't even spray it right

Hope you don't end up buying this amp

 

[agedhorse]

Hope you don't end up buying this amp

It was a caution to other members who might consider buying used amps, that hidden damage due to this kind of hack repair is sometimes a reality.

 

[squirtalert]

It was a caution to other members who might consider buying used amps, that hidden damage due to this kind of hack repair is sometimes a reality.

Buyer beware... I lubed it all up with some DN5 I forgot I had, for better or worse

Any advice for removing the cat hair? Don't wanna do another hack job