What the heck is wrong with my BadCrap Customshop?

LanierP

LanierP

Active member
I bought this amp used for 900$, and it's been a bit of a PITA. When she's running on all cylinders, it sounds really good, but that's only 50% of the time. Do you guys think this is a tube issue. All tubes are lighting up fine. It has 4 El84's for power, and a crapload of 12ax7's, including 2 that are inside the chassis laying sideways. I'll post a gutshot soon. Have a look at the video. This thing went to the shop for the same thing, and the guy said it was a bad toggle switch on the front of the amp that changes the midrange frequency. He replaced it, but now after about 10 hours of practice time, it's doing it again. The Fonzi trick doesn't seem to work any more. Any suggestions are appreciated.
Thanks
 
If you have a tube amp and you don't check the tubes when there is a problem, you should get your tube amp card revoked. Just because they light up doesn't really matter.
 
Bluplirst":2ee9dgvn said:
If you have a tube amp and you don't check the tubes when there is a problem, you should get your tube amp card revoked. Just because they light up doesn't really matter.
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Ok, maybe you didn't watch the video, or maybe I didn't explain things clearly. None of the preamp or power tubes show visible signs of having an issue, i.e..flickering or dimming when this problem occurs, non of the power tubes are redplating or going nuclear or anything like that, an they all were checked by a very reputable amp guy to make sure they are fine. What's happening as you can see in the video is that all the treble is rolling off, and comes Back momentarily with a knock on the top of the headshell.
Just looking to see if someone out there has a suggestion brother. My tube amp card is quite intact.
 
Well that's point-to-point... I'd send it back to BadCat. I have a hard time believing that anyone else could get a handle on that.
 
Post this in the tech corner thread. I would still say it could be a preamp tube, replace them all one at a time with a known good preamp tube and see if that fixes it.
 
The way it comes back when you give it a good rap on top gives me the impression of a bad connection, not a bad part. Perhaps a solder joint or loose wire in there somewhere. Might be tedious, but a close inspection with a magnifying glass while you slightly wiggle each component may reveal the loose part.
 
stratjacket":2gvaouib said:
The way it comes back when you give it a good rap on top gives me the impression of a bad connection, not a bad part. Perhaps a solder joint or loose wire in there somewhere. Might be tedious, but a close inspection with a magnifying glass while you slightly wiggle each component may reveal the loose part.
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+1 for a loose connection. But look at all of that... BadCat might have a guess where problem is based on the symptoms. Otherwise, finding it would be a needle in a haystack, I would think.
 
Thanks guys for the suggestions. I have to say this things guts are unlike any amp I've ever seen,,,the isn't really any tag boards. Kinda like the Mark Sampson era Matchless stuff where the goal is to keep all the components connections and signal path as short as possible. There are many 'Matchless' labeled parts inside, and the date written inside is 11-06. I've looked on the BadCat website and there isn't anything that looks like this.
I am going to try to prod around inside over the weekend and see if anything obvious comes to light, including the tube rotation test.
 
I can't watch the video but does it do this on both clean and dirty channels?

Always suspect tubes first and always try swapping known good tubes for each preamp tube before going any further. If it's intermittent a tube tester might not see it act up.

A simple test you might be able to do is to plug a cable into the Send and send that to another power amp. Then you could do the reverse and send a preamp signal from another amp into the Return of the BadCat. That might tell you if it's the preamp or power amp (or FX loop itself).

The best approach is to try and narrow it down to pre vs power amp, and if preamp which preamp or both. You might be able to rule out certain areas of the amp and focus on others. That amp looks like spiderwars. :D

EDIT: And if you don't have any chopsticks, you might want to snag a few. ;)
 
Most tubes that have gone bad (in some way or another) have not given me any visual indication of this. The heating elements (which are what you see lighting up when you look at tubes) only make up a portion of the tube, so the heaters can work fine and other aspects don't. It seems people think of tubes like light bulbs, in that problems will always be obvious just by looking at them, but that's not the case.

Your tech may have tested the output tubes but not the preamp tubes. Also the tubes (either type) can have an intermittent problem that the tech didn't notice, or they just got worse since then. Your Fonzi test would indicate that it's likely there's an intermittent problem of some kind, and if it's in the tubes then because it's intermittent it could be missed during a single test.

Swapping tubes for ones tested to work properly (starting with preamp tubes since that's easiest) is a good idea.

Poking around the rest of the amp should wait until after you've eliminated tubes as a variable in this problem. I'm not saying it can't be somewhere in the amp besides the tubes, but it's more likely statistically to be the tubes than anything else, by a large margin. If you want to look over everything with a flashlight and magnifying glass while the amp is open, that's fine. But I wouldn't touch anything until the tubes have been sorted first.
 
You might also try a short cable from Send to Return just to verify it's not jacks but those are usually go/no-go not bright/dark.

Also, Fonzi always said; "Ayyyyyy" after he did something cool. Maybe try that. :LOL: :LOL:
 
SpiderWars":pdgrjl32 said:
I can't watch the video but does it do this on both clean and dirty channels?

Always suspect tubes first and always try swapping known good tubes for each preamp tube before going any further. If it's intermittent a tube tester might not see it act up.

A simple test you might be able to do is to plug a cable into the Send and send that to another power amp. Then you could do the reverse and send a preamp signal from another amp into the Return of the BadCat. That might tell you if it's the preamp or power amp (or FX loop itself).

The best approach is to try and narrow it down to pre vs power amp, and if preamp which preamp or both. You might be able to rule out certain areas of the amp and focus on others. That amp looks like spiderwars. :D

EDIT: And if you don't have any chopsticks, you might want to snag a few. ;)
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Great advice man. Didn't even think about that. Will try this and see if it narrows things down, as well as rotating a good preamp-tube thru the preamp.
Thanks!
 
-baaaahaha!!!-(fonzy trick!!)-

-I don't think its a tube issue, but if you have a tube stash yeah, do some tube rolling to cross that off the list, just judging by the wiring harness someone has been inside that amp, and I'm willing to bet it wasn't BAD CAT, like was mentioned earlier, you have a bad connection, where "the fonzy trick" no longer work's I'm assuming its working, but working badly, do what was mentioned, pull the chassis, put it upside down, use a chop stick or drum stick and lightly push on components and especially the connections to and around the pots, what on/in it isn't stock? I'd hit those items carefully, do you have a gut shot pic of the same model and year as yours?
 
JamesPeters":i98ctnmo said:
SpiderWars":i98ctnmo said:
Also, Fonzi always said; "Ayyyyyy" after he did something cool. Maybe try that. :LOL: :LOL:
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Also, wear a leather jacket when hitting your amp to "fix" it. :)
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Haha, thanks for the tips and advice. I forgot about the leather jacket,,I'll put it on when attempting to fix her and see if that does the trick.
 
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