Music Man 100 RD

[abbey road d enfer]

If that were my amp, I would yank that board and put a dumble OD board set in there.  Make it all tube and retire with 1 amp that can be tweaked and worked on for as long as there are tubes. 

Way more fun and very well documented.  Dumble did it with several MM amps.

That would be rejecting the unique sonic character of this amp in favour of another, which may be great for you, but not for others (at least not for me). I'm not sure now, but Albert Lee used to swear by his MM amp. The list of famous users is quite long.
http://www.pacair.com/discus/messages/75/75.html
The big issue there is that these amps are not popular, because they are heavy (BIG transformers) and too loud (beaucoup Watts), so people tend to let them go for a pittance; as a result, they are in favour with tweakers. That's exactly what happened with Princetons, when they lost favour because they were too small and underpowered (which shows that different causes can have same effects) when big amps (Sunn, Kustom) became the fashion du jour. People got rid of them and Howard D. bought them as donours.

 

[buildafriend]

That would be rejecting the unique sonic character of this amp in favour of another, which may be great for you, but not for others (at least not for me). I'm not sure now, but Albert Lee used to swear by his MM amp. The list of famous users is quite long.
http://www.pacair.com/discus/messages/75/75.html
The big issue there is that these amps are not popular, because they are heavy (BIG transformers) and too loud (beaucoup Watts), so people tend to let them go for a pittance; as a result, they are in favour with tweakers. That's exactly what happened with Princetons, when they lost favour because they were too small and underpowered (which shows that different causes can have same effects) when big amps (Sunn, Kustom) became the fashion du jour. People got rid of them and Howard D. bought them as donours.

My MM HD150 had HUGE transformers and was one of my favorites. It was also the loudest amp I ever owned. It had a solid state pre and tube output. The spring reverb was pretty nice too.. Wasn't MM by a Fender Engineer? I just double checked the wiki and it said the MM owner was a plant manager in the early Fender days. 

 

[abbey road d enfer]

My MM HD150 had HUGE transformers and was one of my favorites.

Same as the one I use in my amp room when I want to shke the walls!

Wasn't MM by a Fender Engineer? I just double checked the wiki and it said the MM owner was a plant manager in the early Fender days.

That's correct; MM amps have a lot of Fender DNA in them. Leo was a silent partner, but Forrest White was the electronics guy at Fender (Leo was not, brilliant and tedious mechanical designer though and luminary about guitars).

 

[fazer]

Maybe for bass.  Not for guitar.  Dumble is more versatile.  Clapton used them during the 70s.  Plays a dumble these days.  Also Clapton is having a bandmaster being redone by HAD currently.  But what ever works.  Different strokes.  Any small amps are very popular these days and agreed should not be touched but that amp?  How often do you use it?    I’d tweak that bayby right now. Not a second thought. 

 

[fazer]

Holly crap 715 volts B+ on the output center tap .  That means you would need to come up with a power transformer or drop that one with zener on the bridge ground.  I wonder what HAD did?  I found a single 12" combo on eBay for 400.  Still would be a nice start for my Dumble Dream amp. 

 

[abbey road d enfer]

Maybe for bass.  Not for guitar.  Dumble is more versatile.  Clapton used them during the 70s.  Plays a dumble these days.  Also Clapton is having a bandmaster being redone by HAD currently.  But what ever works.  Different strokes.  Any small amps are very popular these days and agreed should not be touched but that amp?  How often do you use it?    I’d tweak that bayby right now. Not a second thought.

As I said, it has a unique sonic character that I don't want to loose, even if I use it very seldom; I have other amps for other sounds.

 

[fazer]

it has a unique sonic character

Agreed Abby.  If it works for you its great.  I just like the idea of spending 400 for the Chassis , cabinet and transformers and swapping boards.  Way better than a Ceritone OD.  Or at least cheaper with better parts.  Someday Maybe.    Like you I have an amp arms race around the studio and can't stop thinking about adding another one.  "Somebody stop me". ;D ;D ;D

 

[Tubetec]

I had the use of a 'Sixty Five' MM at one point years back ,pair of EL34's with an ecc83/12ax7phase invertor ,transistor pre stages .
An amp that didnt crank or distort in the way most tube amps do , maybe its just what you want for country ,but definately not a hard rock amp ,the big Jbl 15 with the quacky aluminium dome didnt  break up nicely either . If you want your guitar to sound like a Glen Campbell record from the mid to late 70's it could be just the ticket though .

 

[abbey road d enfer]

Holly crap 715 volts B+ on the output center tap . 

Yes, that's one reason that makes them less attractive for dumbling. You need to change the PT or add some kind of bleeder (dropping 200+V at about 200mA makes 40W!), and the OT has a higher than standard plate-to-plate impedance.
I guess people who buy them evaluate them at the price of a chassis, cabinet and speaker, no more.

 

[tony hunt]

I had the use of a 'Sixty Five' MM at one point years back ,pair of EL34's with an ecc83/12ax7phase invertor ,transistor pre stages .
An amp that didnt crank or distort in the way most tube amps do , maybe its just what you want for country ,but definately not a hard rock amp ,the big Jbl 15 with the quacky aluminium dome didnt  break up nicely either . If you want your guitar to sound like a Glen Campbell record from the mid to late 70's it could be just the ticket though .

Similar experience with a HD130 back in the early eighties, but it was merely the wrong choice of tool for me. On the other hand, I swear it helped the car corner better when on the back seat.

At one gig we were having some trouble in the check. I noticed one of the EL34 valves was smashed. The other band had a Burman Pro amp and they said I could use it.
Now, on paper it's the same game, typical of those times: 130W into two twelves, but a slightly different way of getting there.
The difference became clear on the first song's intro. The Burman gave absolutely incredible touch response and was so direct.  I never smiled so much on a stage. I think I also dribbled a little.  Well, I moved over to the British Burmans after that and still have a few still on the old KT77s.

I agree that the iron in one of these MMs is not an ideal starter for a me-too Dumble homebrew, or much else for that matter. It would be great to see and hear those things running as intended. I still have a soft spot, even though we didn't get on.

 

[CJ]

that is a big list of MM amp users,  JW Captured Live is an all time favorite, 

Music Man also had good luck with that bass, probably quite a few hits there,

one of the joys of working is a music shop is the plethora of instruments that come through the door,  we had a Martin harp in the other day that a gal bought at a garage sale, did not know that Martin made harps, so she emails Martin and they offer her 5 grand as it was a rare part of their history,

since this is a brick and mortar shop, buy - sell - trade, the weirdness factor is at an all time high, you plug into an amp and all of a sudden a certain song pops into your head, so if you were playing covers, then having a different amp for every song would be the way to go, and maybe a few guitars to go with it.

the Music Man is kind of clean but this might mean it has an affinity for stomp boxes of the right flavor.

just played the best sounding clean amp i have ever heard in my life, it was sitting upstairs in the lesson room for 18 years before it needed repair,  it is a Roland GA-120, came out after the JC-120, Toshiba fets and a plus/minus supply for the preamp, (JC 120 is single supply) holy crap does it soung good, no chorus but lush reverb. no schematic either. might have to trace the preamp.