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Hoffman Amps Forum image Author Topic: Dual 50 Plexi/JCM 800  (Read 44717 times)

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Offline sluckey

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Re: Dual 50 Plexi/JCM 800
« Reply #150 on: March 25, 2019, 07:24:02 am »
Probably not worth it since the two channels would be out of phase.
A schematic, layout, and hi-rez pics are very useful for troubleshooting your amp. Don't wait to be asked. JUST DO IT!

Offline shooter

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Re: Dual 50 Plexi/JCM 800
« Reply #151 on: March 25, 2019, 08:07:54 am »
 :think1:
it's still early  :BangHead:
Went Class C for efficiency

Offline DummyLoad

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Re: Dual 50 Plexi/JCM 800
« Reply #152 on: March 25, 2019, 09:01:09 am »
what He said;
if you're feeling froggy, un-do the select switch and replace with a blend pot for testing, it might be worth it


that won't work well - signals would be out of phase and cancel.


--pete

Offline purpletele

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Re: Dual 50 Plexi/JCM 800
« Reply #153 on: March 25, 2019, 10:53:48 am »
Glad you hung in there! You can probably cut some of the harsh ice pick by removing those two 470pF caps on the voltage dividers in the V2 circuit. Maybe remove the .001 from the volume pot also. The red head looks bold and daring!  :headbang:

Thank you Steve.

In classic Marshall form, the amp sounds really good when it is flush with volume. 

Thanks for the voicing advice, I'll work on that tonight.

BV

Offline shooter

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Re: Dual 50 Plexi/JCM 800
« Reply #154 on: March 25, 2019, 10:59:46 am »
since I failed the Captain Obvious  test  :icon_biggrin:
a simple quickie, put a 12AU7A in V2's spot. 
Went Class C for efficiency

Offline purpletele

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Re: Dual 50 Plexi/JCM 800
« Reply #155 on: March 25, 2019, 12:58:32 pm »
since I failed the Captain Obvious  test  :icon_biggrin:
a simple quickie, put a 12AU7A in V2's spot.



I'll try that, thanks for the tip

Offline purpletele

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Re: Dual 50 Plexi/JCM 800
« Reply #156 on: April 09, 2023, 11:07:48 pm »
Here is the first video that I could make of this really cool amp.  My friends latched onto it, which is great, in fact it's used on a new recorded EP.
I had Ben Fargen install a MV for me and it came out really nice.
Emmit the Gargoyle made it into another video.




Offline jojokeo

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Re: Dual 50 Plexi/JCM 800
« Reply #157 on: April 12, 2023, 09:49:50 am »
HI Brian! Long time, was wondering how you were doing?
To steal ideas from one person is plagiarism. To steal from many is research.

Offline purpletele

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Re: Dual 50 Plexi/JCM 800
« Reply #158 on: April 12, 2023, 08:12:05 pm »
HI Brian! Long time, was wondering how you were doing?

Hi Joe, doing well.  I'll send you a note later this evening

Offline KeithR

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Re: Dual 50 Plexi/JCM 800
« Reply #159 on: April 27, 2023, 11:56:18 am »
It's really good to see everyone putting time and effort into helping our fellow builder out in a nice civil manner. This, in spite of the obvious frustration bubbling just under the headlines. Good, informative stuff. Group hug! Ha.
Now that I've got time, part of the means, it's time to develop my chops!

 


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