Have you tried swapping in known-good tubes one at a time and testing? Check Bias?
That's usually where I start in such a case, and then move to probing with the O-scope and sig generator, stage by stage until you find the culprit.
Enjoy the benefits of a premium membership!
Upgrade Account
-
TalkBass has been independent since 1998. Add your voice.
Create a free account to reply to discussions, view embedded media, and browse with fewer display ads.
Join free Log in
Want zero display ads or expanded classifieds tools? Compare plans.
Stoner/Doom Bassists Thread, Part 90: Maxed Out
- Thread starter Korladis
- Start date
Have you tried swapping in known-good tubes one at a time and testing? Check Bias?
That's usually where I start in such a case, and then move to probing with the O-scope and sig generator, stage by stage until you find the culprit.
I brought both heads and cab to my dads. We got an o scope, and tube tester, meter. I don't think we have a signal generator or high voltage probe, so he wasn't sure how to bias without a probe or what all we should have to do it well.
I got a pair of new jj 6l6's I brought down and we have a selected group of 4 12ax7/ecc83s that work. I'll probably buy more for next time I visit and we continue figuring it out.
This is very helpful, thanks! So the cap value increases help with bass response, yes? Obviously the higher quality components will improve the sound as well. I was just going to with the stock standard parts for this build, but I think the better low-end frequency response and high-quality components will allow me to charge even more money for this thing so I'll probably go ahead with your suggestions.
I officially owe you a beer. We'll have to make that happen some time soon.
Skype interview for job in Mesa, AZ tomorrow afternoon. Wish me luck, gents.
DAMMIT! My trusty fender 300 pro shut down at practice last night!! just blew the fuse and shut off.
WTH??? Never had an issue ever and the week before a show it goes boobies up.
so... having NEVER had a problem with a tube amp before, whats a possible cause of a blown fuse?
bad news is my local tech is out of commission for MONTHS because of a hand surgery with complications.. argh.
WTH??? Never had an issue ever and the week before a show it goes boobies up.
so... having NEVER had a problem with a tube amp before, whats a possible cause of a blown fuse?
bad news is my local tech is out of commission for MONTHS because of a hand surgery with complications.. argh.
if it shut down then it's the main fuse. likely a power surge. if it were a tube then the secondary fuses would blow and that pair of tubes would not be used but the other pairs would continue to work and so would the amp, just a little less power.
replace the main fuse and fire it up. just use the same spec fuse. easy to replace.
some butthole stole two of our 23" imacs from the photoshop lab on friday, no fingerprints, no clear security video, and he broke one dropping it on it's face too, lame
(i'm super paranoid about leaving a bass in the art room and my nikon df)
(i'm super paranoid about leaving a bass in the art room and my nikon df)
What's the brightest fender? Tele/esquire?
I missed mine, but also have jaguar itch. Strangle switch for life
I missed mine, but also have jaguar itch. Strangle switch for life
Your o-scope probe likely can handle the tube amp. For a signal generator, there's an app you can get that will throw a sine wave. Otherwise, you can get cheap ones on ebay or the like. Some simple DIY circuits too. Pretty useful to have around, if you plan on digging around amp guts often.
I bought a socket-type bias probe kit, but you can do without, just a bit more of a chore. Got any 1 ohm resistors?
I'm afraid I haven't kept up with the thread as of late, are there any details/backstory as to how you came upon the amp, or did it "die" on you or? Often knowing how it died helps diagnose, as I'm sure you know.
Cool! You got it, beefs things up a bit to compensate for the typical lower tunings our genre typically uses. Additionally, the increased low freq energy tends to hammer following gain stages harder and create more distortion. And yeah, the cap flavor makes a big difference IMO. Going from one "flavor" of film (polyester vs polypropylene for example) is nearly unnoticeable to most people, but going from a polarized electrolytic to any sort of film cap is much more noticeable for me. I mean, it's a polarized cap, of course it's going to be quite non-linear and asymetrical. They used EL caps for large values just for monetary reasons. A 5.6uF cap would be $.75-$1.50, where a cheap EL cap would be cents.
Because of that, I'd opt to leave the stock .022's before I'd leave the EL caps in, if you're cutting costs for better profit.
Will definitely take you up on the beer! I'm sure once we meet IRL, we'll be like "Oh, yeah, THAT guy, I've seen him around" Ha!
Agree, one caveat could be in the heaters shorted somehow, or a tube had an internal heater short, or possibly a tranny shorted. Heaters generally run on the mains fuse, while B+ on it's own fuse. Unlikely though.
It is super local, and closer to where I would like to potentially settle long term.
Good luck!
Most of the gear has been moved from the practice space, and so far no drama. Everyone said they saw it coming, and they all agreed I did EVERYTHING I could do to make us successful. No bad blood, no bad words, friendships intact. I'd call it a win, or at least a draw.
Now, just the drummer has to get his stuff and we'll square away the PA system. Me and the good guitarist are gonna buy out everyone's shares since we plan on continuing and we all pitched in to get it. Unfortunately, the drummer's the one guy we were worried about taking this badly. Wish me luck next week when he comes!
Now, just the drummer has to get his stuff and we'll square away the PA system. Me and the good guitarist are gonna buy out everyone's shares since we plan on continuing and we all pitched in to get it. Unfortunately, the drummer's the one guy we were worried about taking this badly. Wish me luck next week when he comes!
Yeah, i was just talking about seeing the same people around town at all the shows.
Did you go to Melvins or Torche?
Getting show offers hand over fist right now. Had to start turning them down.
I don't think these guys have ever been mentioned on these threads...similar to Colour Haze, but a lot more interesting.
@Satyrnine
I tend to just buy all the cheap cool gear on Craigslist. I know every so often I won't get a working piece but it's nature of the situation. So I paid $60 for the voodoo and the cab, and the pignose I traded a bad monkey for it. So no clue why they don't work, previous owner/s error would typically be the place I put blame.
In other news, my friend came last night with 8 boxes of 70's and earlier recording gear. reel to reel, like a hundred tapes, all the splicing cutting and editing/maintenance gear. About 8 vintage Mics, from OG shure green bullet to a realistic pzm room mic. Old tube amps, preamps, hundred cables, patch cables etc. mixing gear, cassette recording gear too and much more I can't think of as I onky got 3 hours sleep.
I tend to just buy all the cheap cool gear on Craigslist. I know every so often I won't get a working piece but it's nature of the situation. So I paid $60 for the voodoo and the cab, and the pignose I traded a bad monkey for it. So no clue why they don't work, previous owner/s error would typically be the place I put blame.
In other news, my friend came last night with 8 boxes of 70's and earlier recording gear. reel to reel, like a hundred tapes, all the splicing cutting and editing/maintenance gear. About 8 vintage Mics, from OG shure green bullet to a realistic pzm room mic. Old tube amps, preamps, hundred cables, patch cables etc. mixing gear, cassette recording gear too and much more I can't think of as I onky got 3 hours sleep.
I think the P90's in the Jags are brighter then Tele pups or get a Tele model loaded with P90's. Icepickville
Last edited:
Precisely why I haven't touched it. Everyone's already "out to get him" and my leaving the band and what appears to be its subsequent dissolution may have already put me on that list. Don't need to do anything else to guarantee a spot there.
