Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: bnwitt on August 12, 2010, 10:51:37 am
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So yesterday I'm rushing an amp build (AB763 BFDR) because the customer wants it by the afternoon. :cry: I can't believe how much I got done in one day. I went from all separate parts and a loaded turret board to a completely assembled and wired up amp in 6 hours and was finishing right when the new owner was closing in on the shop. The solder smoke was flying and the finger tips were burning.
About 10 minutes before he arrives I start it up on the light bulb limiter and all is well. Then I plug it into a normal outlet and dial down the bias voltage until I get 430VDC 23ma. Looking good. I plug in a guitar and nada. I look thought the amp and find I've not connected the grids of the PI. Shut her down, drain the caps (not quite enought cause I'm in a hurry and I get bitten) Crank it back up and still no sound.
I hook up my signal injector and find with my tracer that I've got signal on the V1a and V2a grids but nothing on the plates. I do a voltage check and I've got 384VDC on the preamp tubes. Customer arrives. I tell him it's not ready and I have some troubleshooting to do. But, he picks up the Silvertone 1484 I have ready for him so its not a totally wasted trip. I go back into the shop and shut everything down. I tell myself, "Rushing with high voltage appliances is a bad thing." and resolve to find the problem in the morning when I'm rested and my back isn't aching from slaving over a hot amp all day.
I'm laying there in bed with the day's build going through my mind wondering what I did wrong. The wife is asleep and I have an aha moment. As I'm going through every single connection I made during the build in my mind's eye, it occurs to me that I don't remember hooking up the 4 cathode grounds from the turret board to the ground buss. That explains the high preamp voltages. No ground, no current flow and therefore no voltage drop.
So I'm now convinced that rushing anything brings shaky results. I was majorly stressed trying to meet the customer's deadline and it made me scatter brained. Also, as I get older, I probably will make similar mistakes again if I don't really start taking my time. Knowledge and experience are great but wisdom tells me to slow down. Without doing so I'm making mistakes like the ones I made as a beginner without the experience. So, the message is slow down, take your time and triple check everything. And don't let anxious players rush your work.
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I agree totally.Tell those moron guitar players that a good thing takes time.If they wanted a cookie cutter amp they could go to Guitar Centre.
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yep, could not agree more.
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I don't think it has anything to do with "Senior Moment-itis"! I like to use that excuse when necessary with my wife's requests, but I think you hit the nail on the head. You made mistakes a beginner would make. That has EVERYTHING to do with rushing and probably very little to do with age. I've noticed (in my advanced age..) that if anything, I've become more regimented, organized, and much more anal than ever. Besides, we are not getting older, we are getting BETTER! :grin: Take your time and be safe!
Jim
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I've had a lot of those AH HAH! moments right before I doze off.
It amazes me how well I can think when I clear my head of the mumbo jumbo of the day.
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I've had a lot of those AH HAH! moments right before I doze off.
It amazes me how well I can think when I clear my head of the mumbo jumbo of the day.
Yep. I always say when something starts looking like a bowl of spaghetti walk away. It usually means your brain is overloaded with unimportant stuff in relation to the the task at hand. That's what happened to me on this one. My mind was "..hurry up, hurry up, hurry up.." instead of focusing on the actual work
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As one of those moron guitar players that y'all build amps for the simple fact is YOU BUILD AMPS FOR THEM!!!!!!!!!!!!!!!!!!!!! To call them morons shows exactly what I have been trying to bring out here on this forum. How so many amp builders look down at the people they build for. Excuse me but if not for us moron guitar players you would not have a job or make the extra money you do. Thanks to us moron guitar players there is whole business of booteek amps and guitars because the big corporation also views us as moron guitar players.
The same problem exists though out the music industry and that's why music sux now. Everybody is more important then the artist and musicians. They are an after thought and can easily be replaced, who needs them now, we have computers that can do the same thing....NOT!!!!!!!
Bad attitude toward the people you provide a service for. Now y'all know why musicians HATE soundmen, amp repairmen and guitar techs. Y'all WISH you could play as good as some of the barely adequate performing musician. Although some can play as good and better but don't have the looks to become a rock star.......that's why I started doing sound and repairing guitars.
Yeah tell those moron guitar players to stop whining and wait till the master builder is done. I know not all amp builders are like that but I have ran into a lot, same for pickup winders who are even worse, some who can hardly play guitar but consider themselves more important then the guitar player in the scheme of things.
Rant over!!!!!!!!!!!!!!!!!!
If anybody needs a rush job you have to drop everything you're doing and by doing that charge the person a fee for rush jobs. That's what pro builders do....of course unless you're on a major tour that's a different story. If for some reason a guy can't wait, charge him extra for your time and to have to drop whatever else you're doing in your life.
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There is not one single customer in the world that is so important as to risk electrocution.
The 'player' in question would only have been a moron if they'd got pissy when the amp wasn't finished. They didn't....so they aren't...relax.
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So, the message is slow down, take your time and triple check everything. And don't let anxious players rush your work.
Of course, + 1 ! Totally agree. I can't figure out a tube amp lover & player (your customer) anxious to get the whole thing over with. Your activity is ‘arts and crafts’, & thus must be respected just as it should be.
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I can't figure out a tube amp lover & player (your customer) anxious to get the whole thing over with. Your activity is ‘arts and crafts’, & thus must be respected just as it should be.
Well I can understand it. He wants to play the darn thing. :laugh:
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:laughing7:
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nowadays, I sleep, hoping I will wake up in the morning.
I'm with you there brother. Every day is a precious thing. I find little things don't bother me much any more since having a few health scares. :wink:
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I used to keep this 8 x 11 sign posted where customers could see it:
You want it bad.......
You get it bad
You want it worse.....
You get it worse
Keeps a bit of humor going for those rush jobs
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Craneclimber that's a great sign. I also like "Lack of planning on your part does not constitute an emergency on my part"
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Craneclimber that's a great sign. I also like "Lack of planning on your part does not constitute an emergency on my part"
Yup, that's a good one too