Stout Reverb Build / No Audio - Fixed

[jamaio]

For my 3rd Hoffman build I chose the Stout reverb. I was going to put it in a cabinet and chassis I had but it would have been a tight fit. I ordered a Mojotone Princeton Reverb cabinet with a 1x12 cutout. Doug sells the Princeton Reverb chassis and it is a good fit for the Stout Reverb.

I had to enlarge the PT cutout.




Installing the iron.




I had to use 8 pin to 9 pin plates, Doug sells these, I had to enlarge the holes for EL84s






The cabinet with the speaker mounted. I used the old speaker from my Blues Junior.

[purpletele]

Looks good!

I just cut in a PPIMV and it opened the amp up to a musical beast.  There are some component mods out there that Tubenit had put together that really enhance the amp.

I am really impressed with the amps after the mods.  You may want to review those mods, but the stock circuit is fantastic and it should be cool with the reverb.

I am looking forward to your report.

BV

[jamaio]

Looks good!

Thanks!!  I already ordered the parts for the gain switch mod with a gain pot. I like the idea of a PPIMV and I have an extra hole on the front panel for a pot.

[jamaio]

My board is all laced up and I am ready to start wiring everything.


I also ordered parts to add a PPIMV, my parts will be here tomorrow thanks to Doug's fast service.


Can one person have too many amps? This will be my 3rd amp and I have all the parts to build a Deluxe Reverb next, that should round out my collection nicely.

[purpletele]

Can one person have too many amps? This will be my 3rd amp and I have all the parts to build a Deluxe Reverb next, that should round out my collection nicely.

I have two nice Dr Z. Amps and I am building my fourth amp now.  Six is a bit excessive, If I can sell a couple for cost I would be thrilled. 

[jamaio]

I finally finished this build, everything went well but I have no audio output from the amp. I injected a 1 k tone at the input and I can follow the signal through the amp with my scope to the power tubes. I can see the signal at pin 1 on both power tubes so audio is going through the preamp. Not sure how to test from here. I have double checked all the wiring several times.

Here is the schematic: https://el34world.com/schematics.htm#Hoffman_Stout_Reverb_

[tubenit]

Try the obvious 1st ...................

Are tubes proven good?
Connect to a different speaker, is it good?
Different guitar and different guitar cord, are those good?

Are voltages correct?  This often gives a good clue.

Triple then quadruple check the wiring.  Are you using shielded wiring?  If so, any chance the signal wire shorted to shielding to ground?

Start bypassing sections.  Clip input jack to LTPI bypassing the preamp. Do this safely with insulated alligator clips.  Does that work?

With respect, Tubenit

[jamaio]

Try the obvious 1st ...................

Thanks for your help Tubenit. I had tried most of what you suggested before I posted.

As stated before I had signal all the way through the circuit to the output tubes so I was focused on the output section of the amp. In an attempt to add an external speaker out I used the same type of jack in both spots. The external speaker jack was shorted to ground when nothing was plugged into it. I removed that jack from the circuit and I now have audio. A simple rookie mistake.

The amp sounds great.

I had ordered parts for several mods but I wanted to get the amp working with the basic setup before adding mods. I may just leave it as it is for now.

On to the next project....

[tubenit]

Thanks for the update!  Glad you got it fixed.