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Hoffman Amps Forum image Author Topic: Fender Marshall channel switching idea  (Read 2436 times)

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Offline tubenit

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Fender Marshall channel switching idea
« on: March 01, 2015, 05:03:46 pm »
Not planning to build this.  Just thought I'd toss an idea out for anyone who might actually be interested in it. I am not sure how "smooth" the OD would sound with this?  It might be more of a heavier chimey/chunky somewhat distorted tone vs. smooth OD?

- use A/B/Y box to switch channels

- simultaneously switch Relay 1 and Relay 2 to all either a blend pot ............ OR  A/B channel switching

- an 5879 OD (which I've used on a couple of amps successfully)

With respect, Tubenit
« Last Edit: March 01, 2015, 05:05:49 pm by tubenit »

Offline kagliostro

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Re: Fender Marshall channel switching idea
« Reply #1 on: March 01, 2015, 05:14:06 pm »
Very interesting idea Tubenit :thumbsup:

Franco
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Offline Glennjeff

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Re: Fender Marshall channel switching idea
« Reply #2 on: March 01, 2015, 07:44:36 pm »
It just so happens I will be starting a new 50W 2 X 6L6 build in a couple of weeks.

My DC B+ will be about 470 - 480  Volts. Is that close enough.

I could have a go at this and see how it works out.
( I might prefer a slightly earlier Marshall model pre if they are any different - late plexi or master vol.)

I'm not real sure about switching the inputs section like that, looks like switching noise/thump.

Has anyone here used that method of switching guitar input to 2 different valve (tube) grids with success or otherwise ?

Could one replace the 1 MOhm grid - ground resistors to 1.8 or 2.2 MOhm each and leave both grids permanently connected.



« Last Edit: March 01, 2015, 07:56:39 pm by Glennjeff »

Offline tubenit

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Re: Fender Marshall channel switching idea
« Reply #3 on: March 01, 2015, 08:09:17 pm »
Quote
I'm not real sure about switching the inputs section like that, looks like switching noise/thump.
Has anyone here used that method of switching guitar input to 2 different valve (tube) grids with success or otherwise

http://www.musiciansfriend.com/amplifiers-effects/morley-aby-channel-switcher?pfm=sp

I made an A/B box maybe 12 yrs ago and don't remember any issues with switching noise, IIRC.

with respect, Tubenit

Offline MakerDP

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Re: Fender Marshall channel switching idea
« Reply #4 on: March 02, 2015, 11:37:51 am »
Quote
I'm not real sure about switching the inputs section like that, looks like switching noise/thump.
Has anyone here used that method of switching guitar input to 2 different valve (tube) grids with success or otherwise

http://www.musiciansfriend.com/amplifiers-effects/morley-aby-channel-switcher?pfm=sp

I made an A/B box maybe 12 yrs ago and don't remember any issues with switching noise, IIRC.

with respect, Tubenit

Same here. I made an ABY switch with a tuner bypass mode for my Matchless clone and it works great. No issues.

Offline kagliostro

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Re: Fender Marshall channel switching idea
« Reply #5 on: March 04, 2015, 05:33:26 pm »
Is an AB box circuit so simple, or there are other components to be added as to prevent pops ?



Franco

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Offline sgmezei16

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Re: Fender Marshall channel switching idea
« Reply #6 on: March 04, 2015, 09:26:32 pm »
I have used an A/B for channel switching on my Marshall 18watt (with a vox channel) and haven't had any noise issues either. Just used a 3pdt so I could have LED's show me what setting I am on.

Offline TubeGeek

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Re: Fender Marshall channel switching idea
« Reply #7 on: March 04, 2015, 09:37:25 pm »
Is an AB box circuit so simple, or there are other components to be added as to prevent pops ?



Franco


I built this design and was getting hum.  I never followed through with troubleshooting it further.  I'd be interested in seeing what designs you guys built and didn't have any issues.

 


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