50w Hot Rod Plexi AFD #39

[joeboo88]

Wow Mark, they all look great. I should try one, although I only have trainwreck sized chassis, I might be able to squeeze the stuff into it, if I used cap cans....
The cabinet is really sweet too.

[M Fowler]

My first AFD #39 was built from a Ceriatone Express and the owner loved that amp but sold it when his baby was born. Now he owns the first HRP 50w #1 amp.

Mark

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[joeboo88]

Thanks for that Mark. I guess it will fit.

[Mark]

Does your amp incorporate all the switching the Sir #39 is supposed to have?

[M Fowler]

It has the two switches the SIR #39 schematic from Darkbluemurder (Stephen) created.

I haven't gone back and looked at the original amp in a long time since I really like Stephen's schematic.

See photos of a Caswell modded amp.

Real Caswell #39 amp 03.jpg

Real Caswell #39 amp 01.jpg

Real Caswell #39 amp 09.jpg

[M Fowler]

Cab day so I can mount amp/feet and get it out to the customer.

Mark

Cab front view.jpg

Cab side view.jpg

[Colossal]

That looks real sharp, Mark. Your customer will be happy.

[M Fowler]

Thanks Dave, he is like a kid bugging me daily.

Just got done drilling for mounting. Having knob issues with CED so waiting on new knobs. Gold cap falls off defective glue and they do not fit 1/4" shaft.

Cab loaded front.jpg

Cab loaded side view.jpg

[statorvane]

Good looking cab! What kind of wood there, cherry?

[M Fowler]

Thanks, the cab is poplar stained red/brown to get the color I was hoping for.

The joints are old school cabinet style lots of glue surface but very hard to control the wood going through the router table.

My cabinet maker is a cabinet builder by trade.

[Guy77]

Great looking amp! I love working with popular too, its nice and light. The red paint came out nice.
I was looking at the schematic for this amp and noticed it has 5 gain stages before the phase inverter instead of the 4 usually seen in many of the Marshall style amps such as the Friedman Small Box and Dirty Shirley and other after market Marshall style amps.. I was wondering about the feasibility of placing the Diode clipping Mod and the extra volume control Mod on 2nd gain stage (as seen in the chupacabra amp) into the #39 amp.

The chupacabra amp schematic shows these 2 mods in detail. I am thinking all that would be needed would be to splice the extra controls in the circuit along with the extra gain stage of #39. In the schematic attached I have circled those mods in red, the Diode clipping Mod and the Extra volume Mod .
I am thinking of doing this for my next build and wondered if anyone else attempted this . I have also been looking at the BE50 and it seems like a very nice sounding amp.

Edit: After looking more carefully at the schematics I have answered my own questions in regards to adding the extra controls. I guess sometimes typing the questions makes things appear clearly LOL. Cheers

DiodeClip-CaliMod-Chupa.jpg

Cheers

Guy

[M Fowler]

I would just sit down look at the BE50 schematic and create a tone board layout then the power supply, bias and filter cap board layout. All on one long board or you can split it up.
I would use standup 50w Marshall type iron. The relay switching could be generic boards from Hoffman or others.

I might build a BE50w or BE100w some time in near future but the one I had on my bench I really didn't fall in love with but I didn't really give it a fair thorough test.

Mark

BE50 - Improved Clean v1.5.pdf

[Guy77]

Thanks for the input Mark. I have been wanting to build something high gain for a while now. Something different than a dumble and I think a high gain Marshall like the one you built here is what I will do. I may add the extra diode clipping mode to see if I like it.
I just picked up a 2016 Les Paul Studio T and would like to hear how it sounds with this amp.

Cheers

Guy

[M Fowler]

Guy,

Your going to have a lot of fun playing through a high gain amp like the SIR #39, enjoy.

Mark

[M Fowler]

Amp is finally finished and off to owner.

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