The Amp Garage

bcmatt I did a very similar build, if I were to put together a schematic of my build it would look nearly identical to what you pieced together. On mine the switch to select or bypass the Dumbleator is actually a relay. I did this mainly to avoid long signal wire runs to a switch. Where I was able t...

Found a Gen 3 schematic and it matches the layout.

Something I noticed and am curious about. The green wire goes to the 220k OD entrance, then to a 33k then to OD1 input. The junction of the resistors is tied to ground on the layout. Is this really supposed to be grounded? With it grounded the signal is only passed by the 1m2 resistor.

Never mind...

Typically when I check voltages I have a dummy load connected to the output. Recently I had a speaker connected and when I checked plate voltages on the preamp I noticed a POP sound as I touched the probe to the point I was checking. Maybe you can use this as a method to narrow down where the signal...

I'm not real familiar with 2nd Gen. Is it supposed to have an OD entrance trim pot? Unable to see under the board but something seems off to me in that area. Where does the green wire land?

Thanks!

Looks like V1 pin 5 (heater) has no solder. Not sure this is enough to cause no signal. Still looking....

Quick update. Changed power supply resistors to Dumbleator tube and voltages fell into line. This helped the hum but changing the tube out helped a bunch more. Turns out I had a large plate in it, a lower gain tube really helped. I think putting it in a cabinet will help a lot more. The Dumbleator i...

What's the value of the resistor on your input jack? Check it with a meter. Best I can tell (small phone screen) color code is Brn-Blk-Red.

Will check all the resistors making sure they're the correct ones, easy to get mixed up.....so many choices... Brian, I received my electronics training in the '80's. I STILL verify each and every resistor with my meter prior to installing it because I suck at reading the color codes-its the multip...

You mean like this?

Yes I agree, it absolutely works great!

martin manning wrote: ↑Sat Apr 27, 2024 12:54 am You will not regret investing $120 in a Weller WE1010NA or Hakko FX888D-29BY soldering station.

+1

Time to move up from the $15 iron. You'll be amazed at the difference.

Martin got it right, it's a linear (physical) resistive element with the wiper on a screw (worm drive). 25 turns covers full range, in this case 500k. Doing the math 1 turn equals 20k, 1/2 turn equals 10k, etc... As you can see very fine adjustments can be made-much finer control than with a single ...

This is like asking what the best car brand is, everyone has their own preference. I recommend finding a good soldering station with temperature control. Higher wattage will help with warm-up time and overall temperature stability as you solder. A variety of tips is helpful, larger tips store more h...

For the Cap Can opening try these covers Sadly im based in the UK, my mate sent me some cracker barrel pancake mixture to my home in London once and I was hounded by FedEx to pay £37... the mixture was $9. UK and US trade is not great. Sorry to hear about the bad trade situation. Those plugs are fa...