Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => AmpTools/Tech Tips => Topic started by: mikehende on October 16, 2017, 09:21:53 am
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Hello, I am new here. I am a Computer tech but have always been involved in music since childhood. why now at my age I am seeking to learn to repair amps I have no idea really, maybe I am just tired of having to pay techs to repair my amps each year and figure I might as well learn to do it properly myself?
Anyway, that is all I am seeking to do, repair quality DJ amps like lab Gruppen, Crown, QSC e.t.c. Can anyone tell me what hardware tools I will be needing for this please? Thanks.
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Welcome.
> what hardware tools
Little more than screwdriver and pliers.
But opening the box is the easy part. Diagnosing modern power amplifiers is a heavy head game. The circuits have become incredibly complex. To diagnose you have to understand, and this has become way too hard. Also they are packaged for factory convenience, not yours. The parts are often rare and hard/impossible to get. It works out that you can buy a whole new box for less than the cost of parts and the value of your time. I don't see power amp repair as a thriving business, or even a fun hobby.
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a thriving business, or even a fun hobby
+1
I fixed some of the more complex systems out there as a career, after say about '97, once you got it to a board, you swapped it.
if you have access to mirco-repair, SMT, multi-layer service equipment, maybe.
the last crown style amp I attempted, I felt confident I had it to a "processor" chip but without a 10grand smt repair station I was done. I could source the board for like 70% the cost of a new "box". Like PRR says, my time was worth more than negative $25/hr to do the swap
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Well that's certainly a kick in the nuts info but appreciate the reality check. I paid $220 last year to repair a blown output on one Crown 3600 and $200 the year before on another. A used crown costs on average $800 so you guys are saying if I were to replace parts it would around that amount?
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get a schematic of one you have, open up the amp, use a scope an just follow the signal from input to output. After that break out the Fluke, measure all the DC volts. Put it back together. does it still work?
was it pretty easy?
let your wisdom, technical skills, and common sense guide you
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Thanks for the instructions/help but that's too advanced for me right now, I have and can use use a multiMeter for basic functions with directions and I can solder but first I am thinking of doing this course to learn the basics:
https://www.udemy.com/electronics-week-02/#instructor-1 (https://www.udemy.com/electronics-week-02/#instructor-1)
Would you guys recommend it for amp repair?
Also if I have to get a "scope", can you guys link me to an example of one which would be ok enough please? I am typing the words "electronics scope" and technician's scope on google but coming up with all sorts of things that's not it.
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Thanks for the instructions/help but that's too advanced for me right now, I have and can use use a multiMeter for basic functions with directions and I can solder but first I am thinking of doing this course to learn the basics:
https://www.udemy.com/electronics-week-02/#instructor-1 (https://www.udemy.com/electronics-week-02/#instructor-1)
Would you guys recommend it for amp repair?
Also if I have to get a "scope", can you guys link me to an example of one which would be ok enough please? I am typing the words "electronics scope" and technician's scope on google but coming up with all sorts of things that's not it.
try oscilloscope in your search.
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here's a link to my 1st exposure to the world of fixin broke sh :cussing: t
http://www.fcctests.com/neets/neets.htm (http://www.fcctests.com/neets/neets.htm)
from there about 8,000 hours in tech schools n college
You just realize at some point there are things way more important than fixing what has become "throw-away" things
me, I went to the woods n mountains for "detox" :icon_biggrin:
that course, some good, easy builds, either tube, or sand, will get you the foundation to fix what can be fixed, and accept that which you can't
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try oscilloscope in your search.
Thanks but there are so many from $25 ........ any specific recommended model for my purpose please, just need something simple to use which is not expensive as I don;t know how often I will have need for it.
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You will need a variety of hand tools, soldering equipment, desoldering equipment, and test equipment. The more sophisticated equipment such as you mentioned will require more sophisticated tools and a deeper understanding of complex circuits, often integrated with microprocessors. This will be quite different from working on simple handwired tube amps. But most important, you will need a solid electronics understanding to successfully maintain sophisticated amplifiers. The training needed will be quite more involved and lengthy than training for an A+ certification. Hands on experience working in a shop with other technicians is invaluable too. You will learn what tools you need as your experience grows. You will also learn if you really even want to do this.
You may want to find a discussion forum that is more specific to repairing the type amps you're interested in. Not trying to discourage you from participating in this forum at all. But you will find that the mainstream stuff we deal with here is quite different from high end sophisticated dj equipment.
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You may want to find a discussion forum that is more specific to repairing the type amps you're interested in. Not trying to discourage you from participating in this forum at all. But you will find that the mainstream stuff we deal with here is quite different from high end sophisticated dj equipment.
You've hit the nail on the head, that is what I was seeking when I found this site so I had thought this site covers DJ amps repair. If it doesn't I will look for one again, thanks.
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I did a search on the word "crown" and only found 4 discussions. I would also think that tube based equipment is not in demand for dj work.
There are 179 pages of tube based discussions spanning 7 years on the main forum. There are only 6 pages spanning 8 years that deal with solid state and many of those discussions deal with solid state channel switching in tube amps.