The Steel Guitar Forum

I have 2 BF Bassman heads that need (at minimum) cap jobs and three prong power cord retrofit.
Can someone point me to the resources to do this work myself? "How to", cap "kits" and the like..
I'm having haphazard luck googling for info, and I know I've seen the 3 prong cord instructions somewhere before.


any suggestions willingly accepted.

the amps have been sitting unplugged for at least 2 years now. I want to get them functioning for possible sale and/or use

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"I've got the 'ZB Jeebies™' !"

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Hey Dave.
This Here Gerald Weber video is not super duper excellent but it's not bad and it is what gave me the confidence to safely discharge the caps and to do the full filter cap job on a couple of my amps and for that I am grateful.
I have a couple of tutorials on power cord jobs somewhere here in my computer (they are downloads that you may well have already found in your googling). If I can find them, you want me to send them?

thanks Jon- please do...

please be careful, there is enough juice in there to KILL you. If you can find a good tech, some repairs can be surprisingly cheap.

Old fenders are becoming highly collectible these days and commanding pretty good prices...it might be worth it to have em pro-repaired?

I would recommend getting Dan Torres' book "Inside Tube Amps". He also sells the parts. Me, I'd also do a "tone cap" replacement, which really cleans up the sound for steel. I bet you won't sell them after that. (I love Bassmans) (Bassmen?) Dan also explains how to 'voice' the amp to your preference, if you want to go further. Like Ben says, learn how to not die first - they can kill you even when unplugged. Good luck and have fun!

Oh, yeah, he's at: http://www.torresengineering.com/

Dan's book is good,so are Gerald Weber's. For parts, check out Mouser. I checked Torres' price on 100mfd/350V electrolytics and Mouser is $3.50 cheaper.

No offense intended, but if you don't really know what you're doing, I'd take them to a qualified tech and have them do it.

This is a relatively simple job, but it is also relatively easy to mess this up and damage yourself or the amps or both beyond repair.


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Artie McEwan

Dave, if you decide not to do the work yourself, here is the guy to take them to: http://www.alessandro-products.com/repair.html

He is not too far from you, and has worked on Eric Clapton's old Fenders. He also makes small tube amps to die for.

Dave
Most of those Bassman's are the AB165
circuit, unless its a '64. Consider
having it rewired to a AA864 circuit.
The AA864 is more like the Blonde Bassman's
that are so highly coveted.
This will rework the old bias balance
pot into a true bias adjustment pot.
The conversion should only take an hour
for a qualified tech and add a minimum
of 50.00 to the cost of a re-cap. Some
of the wires have to be re-routed from
under the circuit board.
The mod makes the bass channel sound
like the normal channel of a Super Rev
and it gives the normal channel of the Bassman a Marshall sound. It makes a
monster lead guitar amp.

If you have not done a cap job before
I would pass on it and hire it done.
True its not hard but you need to know
how to discharge the amp and the danger
of the 400/500V that will knock the crap
out of you, maybe even kill you.
Then theres the danger of not having a
speaker load on when you energize the amp
you could really damage the unit.
I had my Bassman done this way and its
a great amp.
Best wishes.

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Rick Johnson

I'll pile one.

If you haven't worked on amps before, a cap job is the worst place to start because it is simply the most dangerous to you and the amp. Do yourself a favor and take it to a tech. Then buy Weber's book and read it, and do minor tweaks bfore a cap job. PS - the bias cap also should be replaced during any cap job.

And I wwould do some thorough research on alt.guitars.amps and other amp boards before touching anything by Torres. his reputation is less than stellar amongst professional techs.

Labor and parts included, I have never charged as much as Torres does just for his #3 (complete kits)! That a lot of bucks and you have to do the work!!

I sent you a spreadsheet on a full job I did for a Dual Showman a while back. Like I said, I do not need the work right now! I hope it helps you know what to ask for and an idea of fair prices and reasonable labor charges.<font size="1" color="#8e236b"><p align="center">[This message was edited by Ken Fox on 16 December 2005 at 05:58 AM.]</p></FONT>

Dave Doggett;
George Allessandro is my tech of choice- he's reworked both my '72 Vibrolux and my '68 Twin and has been just great to deal with,and fairly priced. Plus he's only 25 minutes away...

I was just looking to learn something and possibly save some bux by doing it myself.

I an a computer technician by trade in my day job, and understand the issues of capacitor danger of electrocution, Discharging CRT's in old Mac all-in-ones being not dissimilar. But that said,
I'll probably just bite the bullet and "let George do it" as they say.

But I want to say Thanks for the feedback guys.

we can close this now if moderator wants.

Dave.

If you want to email me, I will walk you through this. It is very easy and I promise as long as you are not standing in a puddle of water bare footed while holding on to a water pipe, you will not get electrocuted.

You must have a good dig meter that will read in MA for the current draw measurement to bias the amp and also a variac to power up the amp slowly after installing the new caps. You will also need a good soldering iron--much more heat than you use for your computer work and one of those old Weller type guns for real high heat work if you need to solder to the chassis. If you don't have these--let George do it.

Dan's stuff is expensive, including his book, and I have also heard less-than-glowing things about his services. I hesitated to mention this because I've had good dealings with him, and I've learned alot from his book. But - If you don't want to jump into this with both feet, and have a stellar amp guy close by, I'd sure let him do it. Chat page instructions and off-brand parts might be more expensive in the long run.

Hey Dave,
If you're an ex Mac Cracker, a cap job isn't a big deal. Discharge all the caps, using the same technique for the flyback connector at the CRT, and observe proper polarity of the caps when you remove the old ones.
One thing though, the CRT is Hi voltage but little current. The Amps caps can stop your heart, no problem. Lots of current available.
-andy-

<SMALL>This Here Gerald Weber video is not super duper excellent but it's not bad and it is what gave me the confidence to safely discharge the caps and to do the full filter cap job on a couple of my amps and for that I am grateful.</SMALL>

Maybe the video is better than his book, "A Desktop Reference to Hip Vintage Guitar Amps."
I seem to recall someone pointing out an error in one of the schematics he provided in the book for a "blackface" mod. I checked the schematic again and it did look like you would instantly fry your nice new 6L6's if you wired the bias circuit that way...

Ken Fox is a forum member that does great work.....I have not had any work done by him, but his reputaton is good on the forum , so that 's good enough for me...I have also had some high end work done by George Alessandro, and can vouch for his work ...I had him locate me an original transformer for a Park 75 amp
( not many of them made ) and he located it , and installed it ....Sorry I sold it !!...Jim

I agree that Torres charges big bucks and you have to do it yourself. I also had a bad experience doing business with Torres, however you may find this company different.

Also, how often do you do a cap job, once every 15 years or so? Is it really worth doing it yourself and taking any chances? I would opt for a qualified tech to do the work.