Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: strangedisc on July 02, 2020, 10:03:49 am
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looks to be in very good shape. plugged it in, everything works. read about adding a 1/4" input for guitar. any other ideas, thanks,
strangedisc
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You may find this adapter handy...
http://www.switchcraft.com/Product.aspx?ID=6923
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Looks pretty good/useable as is! A quick look on the google says folks change the tone stacks but really it looks pretty solid. Not sure how the voicing would be for guitar but really just converting Mic 1's input jack to something useable should be enough.
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Looking at the schematic a little closer.. you'll need to convert the outputs as well, but you have 16/8/4 multitaps. thats pretty awesome. Great pickup!
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sounds good! thanks ---- the old guy I picked this up from, said he only used it to play square dance records in the 60's. the speakers in the cabinets look very good too! I'll try the adapter first. thanks again
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any other ideas
I've converted a few Stromberg and Bogen PAs. Oddly enough one was from a friend's Uncle who had been a square dance caller. It came with a pair of Jensen 10" speakers!
Ideas for the amp depend on how comfortable you are with tube circuits. There's dangerous voltage in there.
If you are comfortable and know the safety issues, my ideas to start with are:
Install a 3 prong grounded cord, getting rid of "death cap"
Check to make sure the fuse rating is correct. Just a few days ago I pulled the fuse out of an old amp - 20 amp; 10x too high!
Likely want to replace the electrolytic filter capacitors - but sometimes those old can capacitors survive.
Next are the other electrolytic - cathode bypass mostly
The signal caps may or may not still be good.
Reminder - these suggestions are valid if you know the safe procedures - if you don't my suggestion is to read up on them.
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ok, I guess I am not that familiar with safety precautions. what is the "death cap" ? Unfortunately I am no where near any electrical technicians.
I am fairly secluded in the mountains of wv. I'll try and find all the info I can to read. I'm not into electrocution!!!
thanks much strangedisc
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The mountains of WV is a beautiful place to live! (Banjo jokes are so tempting) For safely working on tube circuits a good place to start is here; https://robrobinette.com/Amp_Stuff.htm (https://robrobinette.com/Amp_Stuff.htm) Rob Robinette has a great site for the info on how tube amps work and how to safely work on them.
BTW - I've found Stromberg Carlson equipment to be really well made. Solid chassis, good components, good wiring techniques.
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Banjo jokes are so tempting
until you find yourself surrounded by quads and guns :icon_biggrin:
they were polite though, even explained where I made the WRONG turn :laugh:
personally, I'd do the 3 prong and test before messing with anything. if the powers up without smoke, measure every DCvolt on the plates n cathodes and PS.
then put a plan together
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my lousy 2 cents! :icon_biggrin:
happy hacking!
--pete
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until you find yourself surrounded by quads and guns :icon_biggrin:
they were polite though, even explained where I made the WRONG turn
Turned onto Copperhead Road, eh?
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until you find yourself surrounded by quads and guns :icon_biggrin:
they were polite though, even explained where I made the WRONG turn
Turned onto Copperhead Road, eh?
Copperhead Road my neck of Tennessee/VA/NC.. but for sure you mind yourself in the hill country. went looking for trout streams and got turned around on a garbage road.. there were two trucks there by the time i got back to the main road.
West Virginians are proud and tough folk. not to be trifled with. And if they can figure out mining equipment systems they can certainly figure out tube amps!
strangedisc: this is a good series for explaining the basics.. skip ahead through the stuff you know. https://www.youtube.com/watch?v=x5SSKX74DKg (https://www.youtube.com/watch?v=x5SSKX74DKg)
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Love that part of the country. My wife is from NC and went to school in Asheville. When we drive down to visit her family, we typically take a few days and wander about in the hills. She plays clawhammer style banjo - which I love - so I have to watch the banjo jokes.
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Copperhead Road
Nope F.S. road outside Onego, finished a day climbing Seneca and was just enjoying a jeep drive, smoke rollin music playing, my climbing partner was a 19yr old suburban kid, She's now a suburban wife, 2 kids and a dog, she still tells "that story" :laugh:
I added a cent to DL's 2, you're ballin now :laugh:
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thanks guys for all the help and info. I'm pretty sure this isn't going to be a project for me. So this amp will probably hit the marketplace.
I guess if I really want another tube amp, I'll just buy one. thanks again