Hoffman 18 Watt Stout TMB

[sluckey]

This is not a high gain amp.

[shooter]

overall volume seems low

this is where scopes n good meters comes in handy, we all have a pretty good idea of "what low volume sounds like"
scroll through your contacts, look for that one geeky dude that just might have a scope, barter your way there, amp, speaker, siggen app.
short of that, post a new set of VDC readings;
PS taps
preamp plate and cathode
the cathodes of the 84's


EDIT:
assuming this is the build?
https://el34world.com/Hoffman/files/Hoffman_Stout.pdf

[GarlandKelley]

Gotcha, I must have been mistaken. I had read that this a high gain variation of the classic Marshall 18 watt. Maybe just “higher” gain than the original. I’m sure it’s partly due to the fact that I’m playing single coils through a single 10” alnico but I’m getting more crunch and volume from that 5F1 Champ I built with an 8” ceramic. I have rolled all of the tubes minus the 5Y3 rectifier because I don’t have an extra right now. I watched a video of someone playing their 18 watt stout build and it was definitely way beefier and aggressive. Granted, they were playing through humbuckers but it seemed pretty significant.

Yes, that is the build. I’ll get new VDC readings posted ASAP.

[shooter]

this a high gain variation of the classic Marshall 18 watt.

once you get the amp sorted out, a simple "workaround", most every self biased amp i've built takes pedals well, throw a tube-screamer, or gain-pedal up front.

[sluckey]

I'd like to see a hi-rez pic of the amp with the new layout.

[Jalmeida]

Garlandkelly,

I won’t pretend to be an expert here. I am an amateur too. There are lots here that live and breath this stuff that can’t fathom what it’s like to not know what we don’t know. It looks like you’re getting some great advise and following which is making progress for you.

Here is some things that help me. This isn’t everything, but is a start:

Low volume could be several things. I would suggest starting by getting some wooden chopsticks and carefully poke around listening for pops and anything that may point/resistive to a bad solder connection. Check your pots for DC voltage with your meter. DC voltage can destroy pots which can cause low volume. Get a highlighter and highlight with your layout using one color for AC and one for DC so you know what is where. Having DC where you shouldn’t is good to know when chasing problems. And from there mark things you have checked on your layout. It’s easy to think you checked something but didn’t. Marking it helps to make sure you are checking things systematically and can recall on your prints.

[shooter]

Lots here that live and breath this stuff

I blame it on my upbringing, got paid 25 cents to hold the coil wire while Dad gave the starter rope a pull, learn't valuable lessons; money isn't that important, understanding the "power of GOD" is valuable knowledge

[WimWalther]

BTW, I just drug this '46 Philco cab to the curb last week. Gone by the end of the day.   

I had that exact model of '46 Philco, about 30 years ago, they were a fairly common model. I picked it up at an auction for around $15, and the cabinet was about like new.

Other than needing a re-cap, the only issue was a dry-rot speaker cone. It's an ED design, so my "hot fix" was to cut the magnet structure from the speaker, and screw it to the cab inside acting solely as the PS choke.

Then I replaced the speaker with a 12" PM paper cone type, pulled from a 60s console hifi. Worked dandy, nice sounding radio.

Iirc, it used a pair of 7C5 for the PA. Does that sound right to you?

[sluckey]

There was no chassis with this cab. The PA used P/P fixed bias 6V6s and had a bunch of loctals for the radio circuit. Schematic available at RadioMuseum.org. This 46-1209 model's speaker grill tilted out to give access to a turntable. I found it on the curb, brought it home and studied it a couple days. I had the idea of refinishing and putting one of my amps in it. I cleaned the cab enough to see that the wood was cheap birch and birch plywood so I came to my senses and drug it back to the curb. Not willing to put the time and money into refinishing a plain Jane cab. Besides, I don't have floor space for any more amps.

[GarlandKelley]

     Turns out my issue was a cold solder joint on the jumper from pins 3 and 8 of V2. I swapped that resistor for a 33k and it sounds awesome! I’ll be getting a couple NOS 12AX7s for V1 and V2. I just have some extra Groove Tube 12AX7s in there now which sound fine but nothing like a good set of RCAs or Mullards.
     I cannot thank you all enough for your help and guidance during this build. Sluckey, I wanted to thank you in particular for taking the time to draw that new layout for me and for taking the time to analyze my build and provide guidance. The amp is so clean and quiet and I am so happy with it both in terms of aesthetics and tone.
     I love the almost Vox chime it has with the EL84s and Weber Silver Alnico 10”. It also has that nice Marshall crunch of course. I’ll be getting more well equipped both with tools and knowledge and promise I will return more competent next time.
     The last question I have before I leave you all alone is, am I able to run two Fender style lamps off the heater wires while running the neon lamp from the line and neutral? I’m hoping to use the neon lamp on the rear of the chassis and use the fender lamps to illuminate the front dials of the radio itself in the original lamp positions.

[sluckey]

I'd like to see a hi-rez pic of the amp with the new layout.

[GarlandKelley]

I meant to attach the photo to that last post. I left the wiring I had on the pots to avoid having to require those. The soldering is still definitely not the prettiest thing.

[GarlandKelley]

There a couple of things I’m still going to touch up like the extra length of buss wire and some other wires that are longer than necessary. I wanted to wait on the final details until I figured out about the lamps. The. I’ll close up the chassis and mount it back on the cabinet.

[sluckey]

am I able to run two Fender style lamps off the heater wires while running the neon lamp from the line and neutral?

yes

[GarlandKelley]

Awesome, thanks! Typos from my autocorrect.

[jlaj]

I’ve built the Stout in an old Gibson GA15-RVT chassis and cabinet and can speak from experience that the TMB tone stack definitely wipes out a fair amount of gain compared to just a single tone control, however, I still do get a good amount now. Maybe it’s got something to do with voltages?

[kagliostro]

This council isn't about your present job, it is for the next time you go to build an amp using an old chassis that was planned for one other use

Dismant all from the chassis you want to use, use an aluminium sheet to cover all the top of the chassis, then drill new holes in proper position

The same you can do on the part of the chassis that are on the front and on the back side where you can drill the correct number of new holes for pot and other stuff

Doing that can save you from a lot of problems

Franci