great video . Love the tone on the end demo 😎

In collaboration with Dick Dale, surf guitar legend, the Fender Showman was made to handle the higher volume he needed without overheating and frying components. Thanks, I appreciate your videos!

Very nice work. Good explanation of the circuit enhancements.

Those MOD caps look awesome 👍😎

Nice work, glad I found your video 👍🏽

I did the same thing with my grandpa but we made mine into a mini Fender 65 reverb style amp I have a RCA 12AU7 tube for the preamp I prefer cleans and the other tube is a 6V6 and the spring reverb tank I bought on eBay My style is more like Luther Perkins when I play I play classic country and Rockabilly and blues I don't use pedals and the speaker is a 8inch Jensen C8R I get that late 60s Luther Perkins tone I also use flatwound strings I took out the gain knob so it's just volume mids treble bass single reverb knob and I took out the FX select and the the white button is now a bright switch and I added a classic tube amp on off switch we took out the PCB board it's now hand-wired point to point like back then And I also turned a Fender frontman into a mini 1952 style Bassman style tube amp it's also got 12AU7 tube in the preamp I have a 6L6 tube 6inch custom bass guitar speaker to fit in the amp

G'day there The circuit schematic you were referencing to was incorrect for this year of "silver face" Fender Vibro Champ. Fender's initial B+ was 355V on the AA764 circuit in the early 60s (for the "black face" VCs) but raised it to 420V on the late 60s and 70s models using the AB764 circuit. There were also changes to the filtering caps going from 20/20/20uF to 40/20/20uF, which is the capcan you used.

Your job was ok, but your analysis of the power amp is wrong, sorry to say that. I am the owner of the model 2165 rp. It contains the pcb named "GP2". My amp was made in January 1980. The pcb of your amp looks different; it may be the "GP3" version. There ist not much difference electronically. I call these amps the "NEW", the "MODERN" MusicMan powerAmps. These amps are not anymore "hot", the powertubes are surprisingly "cold". These amps don't copy anymore the "Williamson" design, the basis of all the Fender and Marshall Power-Amps since the end of the 1940s. They use a new invention - a power transistor working as a "floating cathode resistor". The old Williamson design was used in the "early" MM Amps. These amps had a "normal" phase-splitting-design, featuring both triodes of a 12AX7 (ECC83). The splitted signals were fed into the CONTROL GRID of the EL34 (6CA7) or 6L6; this control grid had to be very negative (depending what type of tube was used) to control the "bias" (the current through the tube in idle state). The current through a 6CA7 or 6L6 in a typical "Williamson-Amps" is something between 30 to 40 mA. The new design is revolutionary different: The control grid is not used anymore. A positive voltage of +22 Volts is there (look at the 220 Ohm resistor, it is there for safety reasons). The signal is splitted by the two op_amps in IC8. The Motorola Power transistors JE 1692 act as "floating cathode resistors". The current through the Emitter-Collector path is "dancing" depending on the signal-voltage at the BASIS of these transistors. This was a VERY NEW design - possible because of the availability of these new transistors. The "bias" (the current through the power-tubes in idle state) is only between 6 to 7 mA (25 mA / 3,9). The "new design" is also found in amps with 6L6 power tubes - for example in my second MM Amp, the 2475-75 amp with two 12 inch speakers.

Very nice and educational video! It makes me feel like learning electronics :) Thanks.

I have this exact amp model and the original speaker had a blue/silver Music Man logo on the sticker, so the Celestion one is a replacement for sure.

I'm about to do some work on one of these that I purchased in November. Reverb doesn't work, needs recap, and I want to replace a bunch of the carbon comps. This is my first time working on an amp, but I've been researching amp electronics, practicing soldering, and studying the schematic for half a year at this point. So glad you posted this video. I've rewatched the one on Brad's guitar garage at least 10 times at this point.

Clapton played a Musicman HD-130 reverb modded for a bit more gain than stock. The early version had a 12ax7 phase inverter tube and no reverb, like a fender bassman. I have both, the earlier one sounds better to my ear. They came with sylvania 6CA7 output tubes.

I bought a really clean used. 112. 65 watt recently at a pawn shop for $150. Late 70s or early 80s. Speaker had been replaced with a cerwin vega. Loud and proud. A fender made better !!! Clean great for most styles. Clean lead amp

Joan Jett's choice too!

I had a 65 watt, 2X10 and it was the flattest sounding, most toneless amp I've ever owned.

What amp did you use for that Catfish Blues riff in the intro?

Outstanding job.

Hi Martin, I wish Kitty Hawk would have mounted the pots to the panel like Boogie did, they did get that right. It looks like the faceplates could have been made on the same machine as my M1s faceplate!, they are almost identical.

Excellent Tremelo sound! Freddie King led me here.

Have a late 64 early 65 vibro champ in collecting condition and a 1971 silver face I've modded the hell out of. LOVE THESE AMPS !!!!!! Lucky I got mine when they were cheap !! Hahha

I have a 2-12-65 pre amp was a Leo design his last one 8m gold. But I've never seen any literature on that model.

Heres another miracle - I have a mint 1965 Vibro Champ which is all original except for the same 1K 1W resistor. I only use the amp at home so I have not replaced the electrolytics as it is working just fine. Is this a mistake?? I like the fact that it is all original and I will leave it to my Son when I go. Mine is the AA764 circuit so the can cap is 20,20,20uf which is not easy to find in an original style. ( in the UK ) What would you recommend?? Great video by the way!

1950's national amp would not have ceramic Jensen, it would have P10Q Alnico. What model are you building with a 12AX7, most National amps that look like this, I know have 6SL7 or 6SJ7 preamp tubes. Of course, a few late ones have 12AX7. I see now you say 6616 but where is the second 12AX7 for the Tremolo? That said you did a very nice work on the cabinet but this would only fool a young man.

definitely not the original speaker

The Celestion is definitely not original. These came eminence custom order speakers.

There was one of these in a rehearsal space I used to frequent. Favourite amp ever.

My first real amp was a RP 100 head- wish I still had it

I remember when they came out nobody wanted them. Marshall ruled the day.

Very nice work valco’s can be a rat nest yours is nicely done almost like Hiwatt , very neat. Like and subscribed👍

I have a KH M1 100 watt head the reverb is weak. is there a layout schematic available for the M1? or an owner's/service manual? I have looked all over the net for info, it is very limited. I have found 2 wiring schematics, one of which seems to match my amp. I think the other is a redrawn copy of one by some else, that is similar, but different too. there are no pics or videos on the web of the guts or repair of an M1. everything else seems to work, except the weak reverb. they were supposedly not known known for strong reverb, but it used to have a lot more effect than it does now. Have you ever worked on an M1? is the output section board supposed to be cockeyed like that?

I owned the 2x12 version of this amp. The salesman at the music store talked me out of buying the Fender Twin Reverb that I’d always wanted. I regretted that decision every single day until I finally sold it to buy a Marshall JTM30 30 watt 2x10 combo amp which absolutely blew the door off this amp.

Peavey made hybrids before MM.

Great video. I wish you would have spent alittle more time exploring and explaining the circuit. The reason is documenting the past. Who designed these old Supro's and I'd liked to have seen a better overall view of the original circuit. I may want to build one of these someday, yes I can get a schematic but is the schematic true, and there are not alot of these around in there original state. I encourage you to make longer videos also. But I really enjoyed it. Thanks for the video.

This is so helpful… I don’t suppose you have link to the sort of resistor you used to bias?

First time viewer here, thanks for putting this up. Not many tube amp guys want anything to do with op amps or transistors.

That soldering iron I would use for rain pipes on the roof

I have this amp. Has a MM labeled Rola ceramic speaker.

The voltage across the resistor (the bias setting) on ​​that and other Music Man amps varies depending on the master volume setting.

I had 2 Music Man amps back in the day (mid 80's). A 65 Reverb head and an HD 130 head . Both were crazy reliable and sounded great thru my 4x12 marshall cabs. I wish I still had them.Today I have a Mesa Boogie V combo and a Fender Blues Jr.

To hell with Eric Crapton.

I had one of those in the early eighties. I loved it. Worked great with the few pedals we had then. Very loud. Durable, never let me down, not once. Very well made. Wanted a Marshall, got a Marshall. Loved that Amp though. 30 years later I got another one. It's here now next to my Marshall

Stanton-Gibsons were hybrid, 60's design I think. They're kind of neat, built in Maestro effect kind of phaser? Reverb tank too.

I have owned two MM amps...both the 212 HD model....and I believe both were either 120 watt or 130 watt....mine had a huge amount of headroom and were impossible to push into distortion because they were so FKN LOUD....I eventually bought a Soldano 2 channel foot switchable pre-amp and had an extra input that sent the Soldano straight to the MM's output section.....both MM amps had broken reverb when I bought them...the first had the entire reverb unit and enclosure bag removed from the bottom of the combo enclosure.....the second had the entire reverb still intact , but I discovered that the reverb pan had a small half moon cut into it for some of the circuitry wiring to pass through.....the reverb pan itself was being hung on springs , my guess is to lessen stage vibrations from transferring to the springs carrying the guitar signal , but when the amps were in a bumpy van with bad shocks on the way to a gig , or being mishandled by idiots , the reverb pan would shake like a hammock on a boat in a storm , and the sharp half -moon edge on the side would slice the circuitry wire because they were being thrifty and used short wires that had tension on them....a longer wire without the tension would just get pushed aside by the swinging reverb tank....I then understood why the first one I bought had the entire reverb unit removed ....I bought an Alessis microverb that I patched in after the Soldano instead of rescuing the original reverb.....both amps had Celestion Vintage 30's in them .....this rig sounded absolutely amazing !

My mate had a 50w 1x 12...cream tolex though. Lovely amp heavy as, but built to handle the back of vans... Joe Strummer used em too. Nice job mate!

Thanks for this! A MM RD210 2 x 6CA7 and square Eminence 10" were my first "real" amp and served me well through many recordings and occasional live performances. I often recorded in my flat and had to play quiet but the built-in distortion circuit did a great job to mimic a "swetting" amp, at least in my recordings.

Interesting, and effective testing. I've got a Music Man 112 RD. Nice sound, but I always thought it had a bit too much self noise. After hearing how quiet you got the Amp on your bench, I think there's probably something wrong with mine.

Wow, that phaser at 25:20 is just right! The sound of the 70s. <3

First time at your channel. Thanks for sharing. I hit the subscribe button too.

I have one with 2 10" speakers

Brilliant amps had this model just got to heavy over the years 👍