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Tube Amp Building - Tweaks - Repairs / Re: Combining Stout TMB + Stout Reverb

« Last post by Lectroid on September 13, 2026, 11:56:01 am »

I made an 18W EL84 powered amp on a Hoffman Stout TMB board. I also went with a one-tube reverb and the post-PI volume mod.  I think it turned out well.  Nice cleans and power but with lots of growl on board when required.

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Tube Amp Building - Tweaks - Repairs / Re: Combining Stout TMB + Stout Reverb

« Last post by dogburn on September 13, 2026, 11:13:15 am »

I'd be inclined to add a one-tube reverb circuit to the Stout TMB, which would make a more simple circuit with one less tube. You can search the forum for designs along that line.

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Solid State / Need help troubleshooting crate amp

« Last post by Catman on September 13, 2026, 07:54:22 am »

Purchased a crate vtx200sh that seemed to work fine in the store,crackly but the cab was junk and cable wasn’t a speaker cable. Worked for 5. Minutes at home now it’s clearly giving me an error code, the tap button is flashing three times over and over,does anyone know what this means?

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Tube Amp Building - Tweaks - Repairs / Re: First amp build

« Last post by ac427v on September 13, 2026, 07:12:31 am »

12  12AU7 !!!
They used a lot more heater current than your design.
Check heater AC voltage on your build. If it's too high, you might have to use big power tubes or another alternative to use up excess heater capability.

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Tube Amp Building - Tweaks - Repairs / Combining Stout TMB + Stout Reverb

« Last post by martinman on September 12, 2026, 08:39:48 pm »

Hi all,

Long time DIYer here — I've built several amps over the years including a Hoffman 6V6 Plexi which I'm still running. Great platform and a great build experience.

My next project is an 18 watt EL84 build and I'm looking to combine elements from two existing Hoffman designs — the Stout TMB and the Stout Reverb — into a single build. Specifically I'm after:

• TMB tone stack from the Stout TMB
• Onboard reverb from the Stout Reverb
• Post-PI master volume added to the circuit
• Cut control added externally — I've done this successfully on my Plexi using a Lamarr design so I'm comfortable with that part

I'm comfortable with assembly and point-to-point work but I'll be honest — blending two layouts/schematics is beyond my current skill level. I'm looking for guidance on whether a combined layout exists anywhere, or whether someone can point me in the right direction on what's involved in merging these two circuits.

Rectifier preference is tube — 5Y3 ideally for the sag.

Any help appreciated. Happy to provide more detail on what I'm after tonally if that helps frame the conversation.

Thanks

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Tube Amp Building - Tweaks - Repairs / Re: First amp build

« Last post by Mongrel714 on September 12, 2026, 07:29:48 pm »

After trying the Hammond organ build with values from the old schematic, the voltages are still high with the tubes in, but I plugged one of my guitars in and got sound!!!!!!! not good sound, but guitar sound, I thought we had 300-0-300 coming out of the P.T. but it is 336-0-336, so higher than I thought, with all the other parts that were taken off when I took the organ apart, (it had something like 12 12AU7 tubes)  I don't know if Ill get the right voltages following the old schematics, so as soon as the new resistors get here (from Sluckeys schematics) Ill switch over to that build and see what happens.

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Tube Amp Building - Tweaks - Repairs / Re: AB763 clone reverb hum - Help!

« Last post by Helmholtz on September 12, 2026, 02:21:55 pm »

100Hz hum is power supply ripple.
A tube can only cause 50Hz heater hum.
What happens, when you disconnect the cathode resistor and its bypass cap from the recovery triode?

Apart from that, I don't trust phone sound spectra, because of the poor frequency response of the built-in microphone. In reality the 50Hz peak might be much larger.
Please post a scope pic of the output hum.

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Tube Amp Building - Tweaks - Repairs / Re: AB763 clone reverb hum - Help!

« Last post by Lectroid on September 12, 2026, 11:26:49 am »

I also built a faithfully stock DR ab763 close and it does have a small amount of idle reverb noise.  But nothing you can hear once the volume goes up.  Yours sounds worse.  ac427v's idea of upping up the cap value makes sense to me.  I'm going to try that--(being in pursuit of Perfect Silence like all builders.)

3. Lifting the connection from the .033 cap to the Reverb pot eliminates the hum

[deleted]

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Tube Amp Building - Tweaks - Repairs / Re: First amp build

« Last post by Mongrel714 on September 12, 2026, 09:56:34 am »

Just wanted to touch base, I'm still plugging away, trying to layout the old Hammond organ design power supply, Im understanding schematics better, but changing that into the physical build is still hard for me.
  If this doesn't work out I've ordered the parts to do the slucky power supply so I'll go that way if necessary.

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Other Topics / Re: Meme of the day

« Last post by shooter on September 12, 2026, 09:17:12 am »

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