Marshall 4010 Turret Board Rebuild

[gldtp99]

This one came to me yrs ago with a modded PCB that was done so poorly that it barely worked at all----- I was in my AFD amp modding phase and this one got a #34 Mod and a Lar/Mar PPIMV---- I tried different versions of the #34 Mod and tweaked it in different ways----- It sounded like a #34 Mod: Highs and hi-mids boosted in a good way, extra noise from all the huge bypass caps, hard to get any usable clean tone from the amp whatsoever.
The PCB was in poor shape from all the work that had been done to the poor amp---- the PCB mount pots felt loose and cheap when turned.
So I decided to do a turret board rebuild using a near stock 2204 circuit---- I had already put in new F&T filter caps---- I kept the Lar/Mar PPIMV (but it doesn't seem all that useful after playing/testing the whole assembled amp tonight)---- added a Metro FX loop (always on, no bypass switch---simple is good).
V1 is an RCA 12ax7a, V2 is a new Ruby China 12ax7, PI is an RCA 12ax7a----- EL34's are the GT EL34M's that were in it before.
I had to make some changes to make it sound the way I wanted when testing with the 1x12 open backed cab and Mesa branded EVM12L vs initial bench testing with a 4x12----- the dist tone was great thru the 4x12 but had a buzzy edge thru the 1x12----- snubber caps on V1a and V1b and adjustment of the 1st treble peaker position values solved this.
I'm very happy with the wide range of tones possible now---- using a delay in the loop and a front ended OD pedal (with amp set to just breaking-up) gives me a huge improvement in tone range and overall tone compared to how it was before--- it's a lot of fun to play !!!!
Pics:
[IMG:800:600]http://i46.photobucket.com/albums/f112/gldtp99/Marshall%204010/IMG_4980_zps2b809396.jpg[/img]

[IMG:800:600]http://i46.photobucket.com/albums/f112/gldtp99/Marshall%204010/IMG_4975_zpsd379a31b.jpg[/img]

[IMG:800:600]http://i46.photobucket.com/albums/f112/gldtp99/Marshall%204010/IMG_4970_zps1182f34c.jpg[/img]

[IMG:800:600]http://i46.photobucket.com/albums/f112/gldtp99/Marshall%204010/IMG_4972_zpsa7a63190.jpg[/img]

Orig PCB:
[IMG:800:600]http://i46.photobucket.com/albums/f112/gldtp99/Marshall%204010/IMG_4978_zps1fd6c7c9.jpg[/img]

This isn't the prettiest rebuild I've ever done---- I re-used a good amount of Marshall's wiring (it was a messy build day at Marshall when this one was built)---- but i'm very satisfied with the Tone/Function of this one at long last----- the EVM I just put in helps, too----- this is the first circuit/speaker combination I've really liked in this amp ever since I've owned it----it sounds great without having to disconnect the internal speaker and plug it onto a 4x12.
Now on to the next project !! Just before Metro stopped selling kits I bought two 100 watt Master Volume Metro kits (probably two of the last group sold)---I put them into storage but I took the 1st one to my shop tonight to build it up------ this one won't be exactly stock: it will be modeled after a 25 watt 6v6x2 2204 circuit head I tried out some new ideas on (yes, stolen from some smart folks on the Metro board)----- the 25 watter has a Metro FX loop and this 100 watter will, too-----it should be a fun build.......................................gldtp99

[xtian]

That looks really great with the new turret board! Happy to see a photo of the Metro FX loop, too. I'm keeping that in mind. I also don't think the PPIMV is useful in the 2203/2204, because the existing, simple MV is good. My '83 JCM 800 2203 is the only remaining amp I own that was built by someone other than me!

[Reeltarded]

Ditto, ditto, and ditto! Looks great!

The loop is para only? I am always confused by the descriptions from people who have them installed. Aren't those more for pedals? (that don't effing belong in a loop!) hehe

the CF master and the simple master go really really really well together because you can stage how much you beat the PI. With both moderated you get lower volumes with control over response that you don't get anywhere else. I mean, if you really don't care for the PPIMV, and I really don't.

Another nice once! You do lots of great stuff!

[Reeltarded]

just tried to comment on your Mule 14 vids but Google tried to hand me over to Google+ and seriously pie their faces with molten wax.

Nice work!! Love that amp and I am not a lil amp guy at all! Sounds like business!

[gldtp99]

Thanks, guys !!!

What is the CF (cathode follower) MV you're talking about ?
The Lar/Mar has worked well on other higher gain modded builds.
The Metro FX loop is a useful addition for this amp because:

1) time based pedals sound great in the loop

2) it allows preamp out for some recording/reamping uses, if desired

3) FX Return can be used so that the amp functions as a 50 watt tube powered speaker.
I work with some local studios so modelers, rack preamps, prerecorded instruments/vocals---- really anything that needs more warmth in the digital recording process can be run thru the FX return and the speaker mic'd/recorded----- similar to the idea of a tube mic preamp, just different.
A friend is playing lead guitar in a local band and he is a die hard POD user---- he's very talented, has all his presets tailored, and makes it sound great----he wants to run stereo onstage so this 4010 might be perfect for one stereo side------ until I can build the tube stereo poweramp he's been talking about having me build for yrs------ I'm going to try to talk him into playing mono onstage but he probably won't listen-----his first show with the psychadellic band is Jan 3rd.

The Mule 14 is the only EL84 amp I've ever scratch built----- it sounds a lot like a much bigger amp, just quieter----- it was built with low cost parts, too---- a MPS Chinese PT190 PT, an OT pulled from a McGohan 10 watt PA head----it records very well and has been used by the studios I work with on several occasions------ I'm not a big EL84 fan but this one works.
I don't know what's up with YT---- the vids I have are listed as public access, no tricks on my end..............................gldtp99

[Reeltarded]

The CF master is known as the Jose.

10k and a .22uF off the socket at the junction of the 100k. .22 connects to pot, pot feeds tonestack entrance instead of the corner of that 100k CF resistor on a normal layout.

EL84s me too.. I am floored over the sound of your amp.

Youtube is a riddle. Google is fishing for more google+ users so they can jack ad rates. They made it mandatory for a while and I think half of everyone deleted their accounts. I did, and will everytime those stinking bastards try to commercialize me. It used to be a good search engine, that's all.

[gldtp99]

Yes, the Jose Master----- I know that one and have used it in a couple of builds------ I must have been having a bad brain day, I didn't equate it with the CF MV name----- I was excited about learning about another new MV but no such luck.

The Mule 14 was built at the same time as the 25 watt 6V6 x 2, 2204 (initially) circuit amp------ the 25 was the premium parts build (Heyboer iron, Sozo caps, etc) and the 14 was the budget parts build---- both low wattage 2204 circuits.
The cheapo parts 14 sounded better than the 25------ both amps have gone thru several revisions and now are quite different circuit wise.
I stopped tweaking/modding the 14 long ago----it's tone was happening and sometimes it's good to know when to stop developing an amp and call it "Finished".

Fwiw: the 14 and 25 now have these surplus .015/630V caps in most .022 positions----- I use a lot of these .015's in modded Marshall builds: http://www.ebay.com/itm/015uF-015-uF-63 ... 1c14fefa03

I don't know what company made these caps or even what their exact construction is----- but I do know that they can sound very good and they are inexpensive---- I think I have a lifetime supply of these put away----- but sometimes I use more conventional .022's like in my 4010 turretboard rebuild---- I don't want to get stuck in a rut....................gldtp99