Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Champ_49 on May 07, 2015, 05:05:10 pm

Title: Wiring big filter caps for a Marshall 50W 2204/2203 type amp
Post by: Champ_49 on May 07, 2015, 05:05:10 pm

I had a question regarding lead dress or a proper wire layout for a Marshall 2204 type amp.

I am following this layout..

http://site.triodestore.com/JCM8002204V.2NEWlayout.pdf (http://site.triodestore.com/JCM8002204V.2NEWlayout.pdf)

So the first three big can capacitors.

My question is.. Would there be potential for problems if I grouped/bunched all wires coming from the main power cap, phase inverter/screen cap and lastly the preamp can filter cap?

It would definitely look neater but if this causes problems maybe not the best idea.  Would this be a potential for parasitic oscillation or unwanted double distortion?
I guess my options are as follows:

1) Bunch all of the wires coming off the can caps together.

2) Bunch the wires from the phase inverter/screen can cap & the preamp filter cap together while keeping wires from the main power cap as far from both as possible.

3) Separate ALL the wires from each other as far away as possible.

What are your thoughts on this?



Thank you.

Title: Re: Wiring big filter caps for a Marshall 50W 2204/2203 type amp
Post by: EL34 on May 08, 2015, 05:01:16 am

I have never had a problem doing that

Here's my Stout TMB with bundled cap wires in red
(http://el34world.com/projects/images/Img_8906.jpg)

Here's my Plexi 6V6 with a bundled caps leads in red
(http://el34world.com/projects/images/Img_9095.jpg)

Title: Re: Wiring big filter caps for a Marshall 50W 2204/2203 type amp
Post by: Champ_49 on May 08, 2015, 12:38:01 pm

Thanks for the pics!!

Nice looking amp! 

Did you bundle the wires of the power filter with the preamp filter? 

Btw,  I like how you wired the one end of the resistors and caps with a kind of diamond shaped wrap.  Are those grounds?

Title: Re: Wiring big filter caps for a Marshall 50W 2204/2203 type amp
Post by: EL34 on May 08, 2015, 12:47:43 pm

There is only one multi section cap so all the cap wires are bundled together


You can see what each of the laced bus's are for in the PDF build docs on the lbrary page


Here's the Plexi 6V6
http://el34world.com/Hoffman/files/Hoffman_Plexi_6V6-V2.pdf (http://el34world.com/Hoffman/files/Hoffman_Plexi_6V6-V2.pdf)

Title: Re: Wiring big filter caps for a Marshall 50W 2204/2203 type amp
Post by: Champ_49 on May 08, 2015, 12:53:35 pm

Thanks!

I'm still new to this so that is the first I've seen with 4 lugs on one cap. Interesting.

I think I will end up drilling a large hole near the preamp section to fit the preamp can cap nearer the preamp side of the chassis. I'm a bit iffy having the preamp filter near a power section. 

Title: Re: Wiring big filter caps for a Marshall 50W 2204/2203 type amp
Post by: EL34 on May 08, 2015, 12:56:44 pm

Look at all my builds on the library page to get ideas
http://el34world.com/schematics.htm (http://el34world.com/schematics.htm)

Title: Re: Wiring big filter caps for a Marshall 50W 2204/2203 type amp
Post by: Champ_49 on May 10, 2015, 08:05:25 am

Hi all.
I was wondering what your thoughts are on bundling the OT primary and secondaries like this. would this be an issue with oscillation?
Also bundled the black choke wires with it.