How to fix Tube Phono Guitar amp Motorboating Precision Electronics S10
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- Опубліковано 23 сер 2024
- Recently purchased this cool 6BQ5 amp at a radio swap meet. Yes, I planned to repair this amp, however due to unforeseen circumstances, the repair actions were cut short. Unfortunately the cause for the motorboating was due to a damaged output transformer. I may have been slightly taken at the radio sale event, however this amp is related to Western Electric, so I should be able to recover the loss and maybe make a few $$ on the deal after all. I do not plan for this amp to meet its end. It will live on as a fine guitar recording amp. Stay tuned. TD
Dont forget about the wine:) It may make the project go a lot more smoother... no harm intended. You have valuable information to share with the world and people like me appreciate it very much. Keep up the good work!
The motorboating sounded like something from Monty Python and the Holy Grail with the noise sounding like two coconuts being whacked together. ;)
Ha, it sounded exactly like that. Great call! LMAO.
I was going to say it sounded like a horse trotting :)
Good series, Terry. I did a vid on this same model. I thought it was odd they only had one preamp tube with that output.
Looking forward to the next repair video on this amp. Really looking forward.
I have a couple P.E tube amps they were associated with grommes somewhere along the line. very well built amps
Good vid! Thanks. I didn't realize a bad OT could cause motorboating.
Makes a great Valve powered Metronome!!!
Looking forward to hearing it once you run your magic over it.
It looks to me the 62 ohm output is also the 25V, and the 500 ohm is also the 70V. Those numbers both add up to about 10W. I suspect the plugs underneath went to a lead (that's now missing) that selects the proper tap for the speakers. That's why the line from the plugs to that hole.
Hi Ter.. will be interesting to see if the motor boating persists after the O.T. transformer problem has been repaired... Love your videos..
Dang, Terry. I sure hope you didnt give much! Maybe its just a busted lead under a few paper wraps? Either way, I see good prices for those PP OPT for 6bq5's on that auction site fairly regularly. Sorry boutcher luck! Looking forward to the finished product!!
Fuse holder corrosion is due to iron/copper electrolysis mediated by atmospheric water content.
If you have an old 5v or 9v DC wall wart (one with an actual transformer rather than switch-mode) you can crack it open and use the transformer as an output transformer.
Well, at least you still have a useable single ended opt !
Brilliant.
Sounds a lot less like a motorboat than a horse clip clopping down a cobblestone street! ;)
This noise has just started happening with my evh stealth, haven't got a clue why but I need a tech ASAP haha
I had a Magnavox stereo power amplifier that had motorboating but not that loud
I have a Precision Electronics S35. It's basically just like this amp. I'm trying to learn how to make it into a Peavey 5150esk guitar amp. Do you have any ideas for me?
My 67 super reverb is “motorboating” at a slightly faster pace than this amp here was. Do I need to take it for repair or can I fix it myself?
Also should I not use the amp at all until its fixed?
Forgot to ask,,, What are you using for an Isolation set up to protect your oscilloscope? Thank you.
Could be used as a metronome.
Gotcha
Hmmm, the repair "propelled" itself towards a new "transformation"....LOL
That's pretty good size, but not yet rare or uncommon.
I think many tube PA amps used xformers like it.
DLAB is the right place to get this one fixed. I wonder if Dick from the Internet had anything to do with that Output Transformer :)
Not the kind of motorboating I was thinking of :)
First thing that occurred to me as well.
It doesn't have the original OT, IMHO. It looked smaller than expected when I 1st looked at the topside.
I would left it as is but that's just me
Sounds more like a 3 legged horse.
I’ll give you $20 for it!
little ticker
...THROW OUT THE ANCHOR-(?)
My jet ski sounds better, but it uses 7027’s, not 6BQ5’s.