Marshall - It's Alive & Kickin

[rogb]

Mmm -like the coco cab alot

My combo cab/chassis is finished - pics tomorrow.

In the middle of #102 build, maybe 15 hours work before fire up

When the Classictone multi tap PT is available in a few weeks, full steam ahead on the Marshall

[bal704]

I usually keep my PT and OT as far apart as possible. Do you have any noise issues associated with the PT and OT being that close to each other?

[rp]

...I tried just wiring them in parallel straight across the amp like the SLO style. Dead quiet and no twisting. Wiring filaments sucks

Aren't you totally freaked when you probe in there? I'd be terrified to hit the filaments to another pin or worse to ground.

Heyboer TW PT, Mercury JTM45 OT & choke.
Got to clear the bench before I start...

Did you use a TW PT? Not too low voltage?

Nice amp, Brit green is dope.

[Bob S]

The lower B+ is deliberate.
Some of the guys have built killer sounding JCM's with 370 - 400v on the plates.
The headphone trick for transformer placement really works.
Look at how close they are on a TW build.
Magnetic field induced hum between the PT & OT is virtually zero if you use the headphones for position/placement.
More pics this weekend...
I promise Miles.

[Colossal]

...I tried just wiring them in parallel straight across the amp like the SLO style. Dead quiet and no twisting. Wiring filaments sucks

Aren't you totally freaked when you probe in there? I'd be terrified to hit the filaments to another pin or worse to ground.

Haha, yes, that could get...smokey. In this case I used some insulation over the bare, parallel filament 'rails' connecting all of the preamp tubes. So as long as I stay clear of just pins 4/5 and 9 with the DMM, no worries.

[Cameron]

My least favorite thing - filament wiring.
1st attempt late last night.
This morning somehow it had transformed into the ugliest wiring job ever.
Re-did this morning - color coded to avoid phasing issues.
Still managed to get the phasing wrong - AAArghh.
Third attempt looks good enough - I really don't want to re-do it again.
I was intending to use a grounded CT.
Now I'm thinking elevated.
The wiring is quite close to the input jacks.
May end up with dc filaments.

I would move the tubes away from the input jacks...... you will have less interaction between the input and output of the tube. The tube placement in this chassis is not the best way to do it. If that 2nd tube(at the input) is the cathode follower..its in a very bad spot. Its just asking for parasitic problems. Also not good for the sound of the amp.

[rogb]

Here's my effort in BRG.

One question, I really like the tube rectifier/diode option on my AB763, so I was thinking of adding one to the 2204 build, it's not too much work and I have a Mullard GZ34, any thoughts on this?

[Reeltarded]

A tube rectifier will work but if you install one I will kill you.

lol

[Colossal]

A tube rectifier will work but if you install one I will kill you.

lol

Hahaha, oh don't worry about him...but seriously, he'll kill ya.

That Mullard will sound great! Lots of depth to the sound!

[rogb]

A tube rectifier will work but if you install one I will kill you.

lol

Hahaha, oh don't worry about him...but seriously, he'll kill ya.

That Mullard will sound great! Lots of depth to the sound!

Thanks, as Yogi said:
Tou can observe a lot just by watching

[rp]

it's not too much work and I have a Mullard GZ34, any thoughts on this?

Yes, because you can have your cake and eat it too. Wire up a socket then plug one of these in there.

http://www.mojotone.com/amp-parts/vacuu ... -Rectifier

Can't believe these are $10 now! These things should be like $3.50.

[rogb]

The diodes are already on the main board so I just need a socket and a switch to have best of both worlds

[Bob S]

Progress.
She's alive !
Still got some bells & whistles to do, but...
Sounds great to my humble ears.
Sustain !
Gonna get to know her before I make any changes.
I'll get a decent guitar player to make some clips.

Silent - very little hum or hiss !!!
This might get loud...

[ampmike]

Congrads Bob,Its a beauty.Nothin like a good old friendly marshall!!!Ill call you shortly Bro,Rock on Brother!!!

[M Fowler]

Looks great Bob, you used some nice components.

Mark