Shopping & Learning: starting DIY on guitar amps

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Maggieo
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Shopping & Learning: starting DIY on guitar amps

Post by Maggieo » Fri Jul 18, 2008 7:05 am

Cat-approved 1965 Vibro Champ:

Image

Musicmaster Bass Amp in the background.  It sounds great, but has developed a wicked, wicked bad hum.  The plug is bad, which I hope is the problem, because that's easily fixed...
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Post by parry » Fri Jul 18, 2008 7:11 am

Okay, WOW!  :o
That looks JUST like a cat we had when I was a kid...  :(
Wow...
Thanks for the memory trip...
:)
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Post by Maggieo » Fri Jul 18, 2008 7:13 am

hansonparry wrote: Okay, WOW!  :o
That looks JUST like a cat we had when I was a kid...  :(
Wow...
Thanks for the memory trip...
:)

Another Bob twin!  Cool!
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Shopping & Learning: starting DIY on guitar amps

Post by mjet » Fri Jul 18, 2008 9:16 am

Maggieo wrote: Cat-approved 1965 Vibro Champ:
I know that Champs are small, but still - that's a massive piece of cat you've got there. It almost looks as if the photo was photoshopped!
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Shopping & Learning: starting DIY on guitar amps

Post by Maggieo » Fri Jul 18, 2008 9:24 am

mjet wrote:
Maggieo wrote: Cat-approved 1965 Vibro Champ:
I know that Champs are small, but still - that's a massive piece of cat you've got there. It almost looks as if the photo was photoshopped!
Bob is pretty massive.

All the Bob photos you could ever want.
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Shopping & Learning: starting DIY on guitar amps

Post by mjet » Fri Jul 18, 2008 12:07 pm

Eek! Look what they did to that 2x10" cab!! Bad kitty!   :P

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Post by øøøøøøø » Fri Jul 18, 2008 12:37 pm

Maggieo wrote:
Musicmaster Bass Amp in the background.  It sounds great, but has developed a wicked, wicked bad hum.  The plug is bad, which I hope is the problem, because that's easily fixed...
In old Fender amps, everything is easily fixed.  ;)

that's why I like 'em so much. 

It's most likely that you need a cap job.  Which is more involved than replacing the plug, but is still not too bad. 

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Post by mjet » Fri Jul 18, 2008 12:44 pm

øøøøøøø wrote:
In old Fender amps, everything is easily fixed.  ;)
With one exception - the Musicmaster Bass output transformer is a real odd bird. I'm no techie but it was explained to be as almost a transformer within a transformer - totally unlike other Fender standard designs. I know because I had to buy a new one a few months back. Luckily Mercury Magnetics make a clone. Not cheap, but at least it's good quality.

Of course I was a bit peeved when I saw someone who had some MM Bass guts (including a working OT) on eBay that went for $15...  [grrrr]
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Post by Maggieo » Fri Jul 18, 2008 1:42 pm

mjet wrote:
Eek! Look what they did to that 2x10" cab!! Bad kitty!   :P

Image
It would totally rock to have a wall of kitty tree cabs.  Take THAT, Brian May!
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Post by Maggieo » Fri Jul 18, 2008 1:44 pm

øøøøøøø wrote:
Maggieo wrote:
Musicmaster Bass Amp in the background.  It sounds great, but has developed a wicked, wicked bad hum.  The plug is bad, which I hope is the problem, because that's easily fixed...
In old Fender amps, everything is easily fixed.  ;)

that's why I like 'em so much. 

It's most likely that you need a cap job.  Which is more involved than replacing the plug, but is still not too bad. 
That's easy for you to say!  :D

I'm askeeert of the lectricity!  :o  Everything I read about working on amps comes with a huge THIS WILL KILL YOU disclaimer.  :wtf:

BTW, the Weber sounds fantastic in the Vibro Champ!!!
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Shopping & Learning: starting DIY on guitar amps

Post by BenHagerty » Fri Jul 18, 2008 2:03 pm

Maggieo wrote: Cat-approved 1965 Vibro Champ:

Image

Musicmaster Bass Amp in the background.  It sounds great, but has developed a wicked, wicked bad hum.  The plug is bad, which I hope is the problem, because that's easily fixed...
Wow that thing is in excellent shape.

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Post by øøøøøøø » Fri Jul 18, 2008 5:25 pm

Maggieo wrote:
That's easy for you to say!  :D

I'm askeeert of the lectricity!  :o  Everything I read about working on amps comes with a huge THIS WILL KILL YOU disclaimer.  :wtf:
Understood.  And it can indeed be dangerous.  But the procedures to make it safe are very easy as well.  An abundance of caution is never a bad thing, I guess, when dealing with amps.  But discharging the caps is simple.

I always just like to nudge people in the direction.  ;)  Getting into amps is a great hobby.  It requires you buy about $100 worth of stuff to get started (good soldering iron, decent multimeter, some clip test leads are about all you need to start) but it will pay for itself with the first cap job you do and is very rewarding for me, anyway.  But I guess it's not for everyone!

I do know that the basic skills I picked up from reading about 3 books and doing some experimenting have made me thousands of dollars.  For awhile, I was buying broken tube amps off craigslist for next to nothing, fixing them up (which generally required about an hour and $35 in parts each), and selling them for massive profit.  I kind of got out of that rat race when craigslist got too big and started changing to "bidding war list," but for awhile it was a pretty good racket I had going.  :)

Learned a little bit about amps along the way and kept some of the better ones for myself!

Since this is the "what amps do you use" thread, I'll share a little story.

This is my 1959 Magnatone 260-A, one of about 4-5 amps I've kept for my personal use.  I kept it because it's so rad.  2x12 but only about 25 watts, weird tone controls that are actual 'boost/cut' (baxandall tone stack) as opposed to the standard Fender configuration, and most importantly... true pitch-bending vibrato (as opposed to mis-labeled tremolo which is in almost any amp that doesn't say "Magnatone" on it). 

Image

When I bought it, it looked like this: (yes, it was just half an amp chassis). 

Image
Image
Image

I don't remember how much I paid, but it wasn't much.  Craigslist.

There was a website called Vibroworld (closed now) and they made custom cabinets and specialized in vintage magnatone.  It just so happened that they had an extra cab laying around that someone didn't pay for, so I got it for 200 bucks.  Which is a good deal.  It's made just like the original Magnatone cabs.

I got two Signature series Weber 12" alnico speakers second-hand. 

Image

I re-capped it and did some basic troubleshooting and cleaning it up. 

Image

And buttoned it up.

Image

I was a little nervous because I didn't know that the transformers were even good. 

But it fired right up the first time, and that true vibrato is just gorgeous!

I don't have a tally of exactly how much I spent, but I'm pretty sure it's a bit less than buying a Magnatone 260-A in working condition would've cost me.  And I had a fun project!  And a story to tell.  It's really "my" amp now, as I brought it back from the dead.

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Post by Maggieo » Fri Jul 18, 2008 7:07 pm

Man, that's cool!!

I asked my dad about working on amps and all he had to say was "I failed electrical engineering! Wanna build a dam?"  (retired civil engineer)

So, how would a girl go about taking up a new hobby and fixing her Musicmaster Bass amp?
Last edited by Maggieo on Fri Jul 18, 2008 7:13 pm, edited 1 time in total.
“Now I am quietly waiting for/ the catastrophe of my personality/ to seem beautiful again.”- Frank O'Hara
I am not an attorney and this post is for entertainment purposes only. Please consult a licensed attorney in your state for legal advice.

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Post by BenHagerty » Fri Jul 18, 2008 7:27 pm

Wow that is nifty

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Post by øøøøøøø » Fri Jul 18, 2008 7:28 pm

Edit:  See reply #27 for a more complete tools list and safety procedures.  :)
----

Do some reading first, and then get a decent soldering iron.  I recommend the Weller WES-51, which you can get for about $75-90 bucks.  It's the last soldering iron you'd ever need, but it's a good one.  You could also get the Hakko 936 which is a good iron and competitively priced.  Then go get a digital multimeter... a cheap one is adequate for most amp work and is about $20-25.  Then from an electronics supply store get some of those little wires that have alligator clips on each end.  These are handy.  Now you're ready!

Unplug the amp and open it, locating the first preamp tube (farthest from the power amp tubes).  Locate pin "1" on that and use one of your little alligator clip wires to clip it to pin 1 on the socket, clipping the other end to the metal chassis.  Now with the amp still unplugged, turn the switch(es) to the "on" position.  Wait 30 seconds.  Now your amp is discharged and you're safe to move about the cabin... er... chassis.  :)

More to come but that's lesson 1, haha.
Last edited by øøøøøøø on Mon Jul 21, 2008 6:39 am, edited 1 time in total.

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