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Hoffman Amps Forum image Author Topic: Advise on wiring Marshall 18w TMB (Richies Schematic)  (Read 3155 times)

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Offline Oddvar

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Advise on wiring Marshall 18w TMB (Richies Schematic)
« on: June 19, 2018, 12:04:36 pm »
Hi.  I have enclosed a pic of this build.  I was wondering if anyone could tip me on the best way to wire the OT an PT cables.  They are coming into the chassis approx in the middle under the board, where should I put them for less noise? 

Offline shooter

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Re: Advise on wiring Marshall 18w TMB (Richies Schematic)
« Reply #1 on: June 19, 2018, 01:18:04 pm »
distance and angle are the key points.  coupling between wires is usually minimum when they cross at 90 degrees, distance is a squared kinda math, so 1 more inch away cancels more than 1.  You are also working in 3d, so anything "off plane" helps.
Ease n access helps when tweaking for minimum
Went Class C for efficiency

Offline sluckey

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Re: Advise on wiring Marshall 18w TMB (Richies Schematic)
« Reply #2 on: June 19, 2018, 01:34:50 pm »
I would move the OT closer to the PT. Center it on the chassis (front to back) and positioned such that it is half way between the two EL84s.
A schematic, layout, and hi-rez pics are very useful for troubleshooting your amp. Don't wait to be asked. JUST DO IT!

Offline Oddvar

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Re: Advise on wiring Marshall 18w TMB (Richies Schematic)
« Reply #3 on: June 19, 2018, 04:40:45 pm »
Good tis there, I think I'll do that.

Offline bnwitt

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Re: Advise on wiring Marshall 18w TMB (Richies Schematic)
« Reply #4 on: June 23, 2018, 08:02:23 am »
Here is a PDF of a Paul Ruby 18 watt chassis showing transformer postions
Guides on your quest for tone.
 Oh yeah, and I'm usually just kidding so don't take me too seriously.

 


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