Musicmaster Bass Amp

StevePirates · Post by **StevePirates** » Sun Apr 10, 2011 12:04 am

I've had an MMB amp for a long time. I got it from a pawnshop in 1996. It's got some problems, like I don't think it's properly grounded, and I know it needs re-tubing. The tolex has some scratches and gouges and the grille cloth has some fraying. Because of the electrical problems, I can't play it right now. It shocks me when I try.

I guess my options are (1) sell it, (2) repair it, (3) repair and customize it.

I wonder what it would look like in tweed. I really like the tweed Blues Deluxe and Blues Jr., but they have very different constructions than the MMB.

Oh also, I have 0 experience with repairing or modifying amps. And I would very much not like to electrocute myself and die.
And if I were going to have to spend more than $500 fixing the thing, I'd just as soon buy a tweed Blues Jr.

Thoughts? Feasibility?

kypdurron · Post by **kypdurron** » Sun Apr 10, 2011 10:20 am

construction-wise this amp is as easy as amps can get. Now way its gonna cost you that much to get it repaired. Let's assume some 20 $ for tubes, maybe another 20 for other parts (caps, 3prong cord etc) and about 50 for the guy who installs them? If you want it retolexed though, you're looking at other numbers, so either don't do that or do it yourself if money is an issue:)

Definitely have it done when you have no experience and there's work on the inside of the amp needed. My rule is, I can do all by myself that's on the outside: Adding a modern power jack, changing tubes, maybe speaker and screws etc.

then, imho a MM Amp is much cooler, lighter and more usable than a BJ. But if it doesn't work properly, you won't get more than let's say 150 if you sell it. the next player down the road sure is not more interested in fixing hassle than you are. So imho you need it repaired if you sell it or not.

What I would do: Maybe buy a used BJ play that until it bores me and then in some months have the old amp repaired. Then I'd have two cool amps in working order and can decide which one to keep.

stewart · Post by **stewart** » Sun Apr 10, 2011 11:10 am

it's easy enough to earth it. you'll need some 3 core flex and a set of crimps:

you could probably find step by step instructions online without too much hassle.

StevePirates · Post by **StevePirates** » Sun Apr 10, 2011 7:23 pm

I guess my concern is that I have no way to gauge what a fair repair price is, and I don't know what is wrong with it. I don't want to pay a ridiculous repair bill, when I could just buy a new amp instead. But I am very sentimentally attached to the MMB.

Living in Reno, there aren't many reputable guitar or amp stores.

I'm sure I'll figure something out eventually. In the meantime, I can always play through my JCM 900 halfstack... with the volume on 1.

Billy3000 · Post by **Billy3000** » Sun Apr 10, 2011 9:25 pm

If you are attached to the amp then find someone to fix it. Don't sell it to buy a different amp. A project amp won't be worth too much anyway. Just get it fixed so you can use it.

Sidney Vicious · Post by **Sidney Vicious** » Sun Apr 10, 2011 9:36 pm

Post some gut shots and I'll see what you got - the grounding problem is likely obvious and something you can be talked through.

StevePirates · Post by **StevePirates** » Sun Apr 10, 2011 10:09 pm

Sidney Vicious wrote:Post some gut shots and I'll see what you got - the grounding problem is likely obvious and something you can be talked through.

Ok, so step #1... how do I get inside? I mean, I see the screws. Do I just open them, or is there something I need to do in order to not fry the amp... or myself?

Sidney Vicious · Post by **Sidney Vicious** » Mon Apr 11, 2011 1:46 am

CAUTION: Amp caps can hold an electric charge so don't go sticking your fingers or a screwdriver into the top side unless you know what you are doing.

To remove the chassis:

Unplug amp.

Remove tubes.

Unplug speaker from amp.

Unscrew strain relief from left side of cab.

Take Phillips head screw driver and start loosening the top four chassis strap screws. In my experience it is very rare to need anything other than an index finger to hold the corresponding nuts. If you need a wrench to break them loose, do so.

The chassis will start to drop down so while holding the nut you are catching the amp chassis.

Once all four are out - pull them up they are LONG - the chassis is now loose and will come out to the rear.

DON'T STICK YOUR FINGERS IN THE OPEN TOP SIDE OF THE CHASSIS!!! - Caps can hold a charge and give you a jolt. It's never happened to me and I've opened and messed with the guts of dozens of amps and I'm just a hack player and a lawyer by trade - but I've been careful - you need to watch what you are doing.

Put the chassis down on a table - open side up - and take some pictures and get back to me.

taylornutt · Post by **taylornutt** » Mon Apr 11, 2011 4:45 am

I am currently going through similar issues with my MM Bass amp. My guitars sound like they aren't grounded, though they sound fine through my Marshall. Though mine has a 3 prong plug, I am going to swap it for an new one, swap the tubes and replace the pots since they don't work before 4. You can read my thread about it and see if that helps

http://www.shortscale.org/forum/viewtop ... sc&start=0

StevePirates · Post by **StevePirates** » Tue Apr 12, 2011 1:18 am

Sidney Vicious wrote: Yes, this can kill you, but I've totes done it before, and I'm a lawyer, so you should be fine.

I am a new lawyer, currently working as a judicial law clerk.

hotrodperlmutter · Post by **hotrodperlmutter** » Tue Apr 12, 2011 1:33 am

the Bl00ze LAWYER TAKEOVER of 2011

Sidney Vicious · Post by **Sidney Vicious** » Tue Apr 12, 2011 1:36 am

StevePirates wrote:
Sidney Vicious wrote: Yes, this can kill you, but I've totes done it before, and I'm a lawyer, so you should be fine.

I am a new lawyer, currently working as a judicial law clerk.

Well that's good to know - if you get hurt you wouldn't sue a brother lawyer would you?

Good career, being a lawyer - I have been at it for 31 years - (wow!) - and clerking for a judge for a time is an excellent step - gives you a perspective on the law that law school can't come close to giving you.

P.S. where did you get that garbled quote attributed to me?

mickie08 · Post by **mickie08** » Tue Apr 12, 2011 4:13 am

kypdurron wrote:more usable than a BJ..

Kyp needs some help here people. NOTHING is more useable than a BJ.

Sloan · Post by **Sloan** » Tue Apr 12, 2011 7:39 am

mickie08 wrote:
kypdurron wrote:more usable than a BJ..
Kyp needs some help here people. NOTHING is more useable than a BJ.

Agreed.