Stage combo 50w

[M Fowler]

This is one of the models I'm going to try sell locally to the local bar playing guitarist hopefully.

Based on Marshall JCM800 2204 50w model using Mojo cab and WGS Veteran 30 speaker. Serial effects loop. Modulus chassis and plates.

Chassis photos will be posted later, I just got it together in the cab this afternoon.

Mark

[xtian]

Looks great!

In fact, looks really huge next to that baritone Les Paul on the left…

[M Fowler]

Yeah it does look huge, that is my little Lotus practice guitar.

Picked up all four of those instruments at an estate sale.

[Bob S]

Good looking amp Mark.
Can't wait to see the gutshots.
Especially since Mikey & me are planning to build 2204's this winter...
Not that we need any help while we fumble around in the dark.

Congrats on another beauty!

[M Fowler]

Thanks Bob I'll have to take it apart tomorrow because after that it goes to the Tone Syndicate store to sell.

This circuit layout is mirror image of a normal 2204 so not sure if your building heads or combos. The chassis on this one is a Watts 20x6 with Modulus mirrored faceplates.

The next one will use both Modulus JCM chassis with mirrored plates. What I like about Modulus chassis is that you can use standup PT no hole cut for laydown style PT, nice. I could even use Trainwreck iron for a nice 6V6 version 600vct PT.

Mark

[Reeltarded]

Nice Mark! And I bet IT WORKS TOO!

Rub my nose all in it!

Good amp. Good idea there.

[M Fowler]

Well I don't drop test my amps to see if the tubes will still work

Hope you get your figured out, it might take more coffee in the morning but you will find the problem buddy.

Mark

[rogb]

Looks great Mark!

Definitely looking to build a 50w Marshall after Christmas.
I have dealt with Modulus before and they were A1. Looks like I will be going there for my stuff too. I like the color choice of faceplates they have..
Also a 2204 turret board for not too much $$.

What iron did you run in this ?

I will build a combo cab with maybe gold faceplate and Bluesbreaker cloth.

[M Fowler]

Rogb,

Thanks, I used Magnetic Components Marshall JCM set with the 40-18058 small frame choke.

My new chassis are Modulus and new Modulus faceplates have the effects loop added. The next amp should be even easier to build. I'm going to go with different bias pot next time.

Mark

[Bob S]

Looks great Mark - inside & out!
Thanks for the insight.
How do you like WGS speakers?
Good Luck with the sale.

[Reeltarded]

Aha! Found my problem!

You should have built my amp.

Nice on both sides, in and out..

[M Fowler]

Thanks guys. There are some things I definitely will improve on with the next one.

Bob I like the WGS speakers I tried a pair of 12-65, two Retro 30's and two Veteran 30 so far. They have some others I would like to get. Some American and some British.

Miles, I'll read what you found to fix your amp.

Mark

[rogb]

Thanks for the pics and info Mark.

I was looking at the same MC set as it happens. I just got my MC 50w 102 set this week and they look and feel well made.

Reading I've been doing seems to point to a B+ of around 370v DC for the 2204 sweet spot. Later 2204s went to 420+ v.

What did you shoot for B+ wise? Dunno if it is worth zener ing down on the CT if the B+ is too high.

I would be interested to know the HT v of the Marstran for instance.

[martin manning]

Hi Rog, I'm using Marstran JMP 50 transformers and a 5H MC choke in my Jana 2204 https://tubeamparchive.com/viewtopic.ph ... 25&start=0 Voltages are 364, 362, 292, 258, 249 with a 122VAC line. The PT's HT is nominally 281-0-281. This tweaked 2204 is a fantastic sounding amp- check out the clip in the linked thread.

[M Fowler]

My voltage was 448vdc on the plates bias at 35mA.

JJ EL34's and three Sino-Chinese 12AX7's.

We just ran it this morning and this afternoon with a Wampler Pinnacle stomp box through the front end which sounded sweet.

Of course the guy wants a different speaker G12-80, I liked the tone of the Veteran 30, it handled drop D tuning, full on volume with no flub.

Oh well. No wonder they make so many different speakers.

Mark