LooseChange
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Posts: 3470
Keep it greasy so it goes down easy.
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« on: October 22, 2007, 06:24:42 am » |
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Do you guys like my "One the Bench" Stories?
I would like to see more from some other repair guys here. Anyone agree??
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TubeStake
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« Reply #1 on: October 22, 2007, 06:49:55 am » |
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I like 'em a lot. Very educational, please keep it up.
Roger
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12bz7
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Posts: 220
I love tube amps
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« Reply #2 on: October 22, 2007, 07:23:58 am » |
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I agree. Really enjoy them. Thanks for sharing ;D
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TubeGeek
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« Reply #3 on: October 22, 2007, 02:30:34 pm » |
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I like them. I have them too.
Many times I don't post what I am up to because they are pretty minor repairs but I do have amps that challenge me at times.
May I recommend creating an "ON THE BENCH...WORK IN PROGRESS" category for these type of troubleshooting, bench repairs?
I have a couple to post right now!
Later today I'll be adding them if I can't get it fixed.
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LooseChange
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Keep it greasy so it goes down easy.
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« Reply #4 on: October 22, 2007, 05:14:23 pm » |
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It's not only if you can't fix them. In many cases it's to point out how you did fix them. Especially a nice picture. Many are just curious and that's why I do it.
Yes. I would like to see a category for "On the Bench". (It's funny, without thisnking I typed in "On the Beach".)
Thanks Guys!
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alcee
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Just one knob.
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« Reply #5 on: October 22, 2007, 06:02:17 pm » |
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I like 'em, too, and I don't really fix other people's amps that often. I like the rare bird stories.
Pictures are nice.
Alcee
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« Last Edit: October 22, 2007, 06:02:47 pm by alcee »
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2twang2
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I came, I saw, I soldered
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« Reply #6 on: October 22, 2007, 07:18:37 pm » |
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I also read them and find them interesting and helpful.
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Dynaflow
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« Reply #7 on: October 22, 2007, 07:59:51 pm » |
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I like em, keep em up, lets me live vicariously through someone else's experience. :D I often cut and paste that stuff into a file I have just in case I ever run into a similar problem (unlikely, but hey it COULD happen! ).
Regards,
Dyna
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« Last Edit: October 22, 2007, 08:00:53 pm by Dynaflow »
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Making the world deaf 18 watts at a time...
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birt
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I love tube amps
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« Reply #8 on: October 23, 2007, 01:44:20 pm » |
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it DOES happen
edit: is that correct english? :-?
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« Last Edit: October 23, 2007, 01:45:03 pm by birt »
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jjasilli
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« Reply #9 on: October 23, 2007, 04:40:58 pm » |
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Please keep it up. There's nothing like actual experience.
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LooseChange
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Keep it greasy so it goes down easy.
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« Reply #10 on: October 23, 2007, 05:10:22 pm » |
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I would like to see others post their experiences with repairs. I spent a lot of time talking with a really good tube tech about certain repairs and learned a lot. Although the ultimate experience was designing and building an amp from scratch.
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Platefire
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How many tube amps do you need? One more!
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« Reply #11 on: November 07, 2007, 11:30:15 am » |
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I am one of those "want to be" repairmen because trouble shooting is fun to me. I seem to have a hard time getting anyone to trust me with their amp but on the ones that have trusted me, I have had good success.
The story I have is very elementry but was a revelation to me being pretty new to amps and repair starting in 2000. The first amp ever brought to me was a SS Marshall 30 watter. Can't remember the model number. The customer a young heavy metal rocker had failed to tighten a loose input jack and continued to use it loose until the jack was distroyed and board was effected.
After finding a replcement jack and getting it in, the amp still wouldn't work.
I began to do ohm test on the traces to make sure the signal path wasn't shorted. Immediatly I found a short. It seemed like a distroyed board to me! I talked this prolblem over with the only experianced amp repair guy I know in my area who is also a personal friend. He said simply install a jumper wire over the trace. Wow revelation! sure enough, I installed the jumper wire over the shorted trace and it worked fine. Platefire
Now how about some real bench stories!!!!
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« Last Edit: November 07, 2007, 02:29:34 pm by Platefire »
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On the right track now<><
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Tiny_Daddy
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« Reply #12 on: November 11, 2007, 08:11:25 pm » |
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OK, just repaired a large almost new Marshall combo. Someone installed new JJ E34L tubes but was unable to set the bias so I got it. Problem was, one of the 4 output tubes was a loose fit in it's socket. Just move the tube and you could hear it in the speaker, intermittent crackle and hum. Another output tube was dang tight so I swapped the tubes. No more problem, the bias had been set correctly. Other work on this unit: repaired cold solder joint on 5W screen resistor, installed 1 0hm cathode resistors, installed UL mains 18GA grounding wire (no soldering or under-size conductors allowed). The back is missing - the screws were loose in the cabinet so I put them in a plastic bag and stuck them on a speaker magnet. Also replaced the speaker cable because the original was made from teensy wire, and tie-wrapped the cable so it cannot touch the power tubes.
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Platefire
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How many tube amps do you need? One more!
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« Reply #13 on: December 21, 2007, 01:01:35 am » |
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Well recently I had a post on Bears 5F1 conversion project that was made from a voice of mucic reel to reel. The plate voltage was running like 436 on an old vintage 6V6 he was running in it. Also the layout was terrible with everything that shouldn't be next to each other
was! With the help of PRR---I re-arranged the main power resistors on the filter caps and added a 3k/10watt dropping resistor. Also changed the 6V6 cathode resistor from 1K to 470. This got the plates down to a 284 and bias about 41mA. I re-arranged a few wires that I could re-locate to get high DC away from grid as much as possible. I also had to change out one of the preamp cathode resistors to adjust/balance the preamp plate voltage. The complaint from Bear was the break up was harsh and raspy.
I sent it back to Bear and now he is raving about how much better it sounds---so this is a success story thanks to suggestions from others especially PRR. Platefire
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On the right track now<><
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