Dumble 102 ODS testing

[desertmouth90]

Measures inductance, capacitance and resistance.
Mine lives in automatic mode - clip the leads on and it will work out what component it’s testing.

I got it originally as some very small capacitors have ambiguous labelling so it was impossible to be sure what you had.

Do you test individual components with it on the PCB for example?

[desertmouth90]

12B on the left and 12A on the right. You guys have saved me. I will be forever grateful!

Have a great weekend!

[timrobertson100]

Measures inductance, capacitance and resistance.
Mine lives in automatic mode - clip the leads on and it will work out what component it’s testing.

I got it originally as some very small capacitors have ambiguous labelling so it was impossible to be sure what you had.

Do you test individual components with it on the PCB for example?

In many cases you can’t because other things in parallel influence the measurement. I use it for things I want to check when placing parts.

[frusciante89]

Hello guys! Andrea here from AAE what this issue sorted? Let me know if there's any mislabeling in the layout!
Cheers from London
A

[desertmouth90]

The Voltages are really good now,

But there is no output when plugged into a speaker!

[timrobertson100]

Try plugging in to the effect return jack - it removes much of the circuit and can help to isolate the problem. Check wiring from there to the output.

[desertmouth90]

Try plugging in to the effect return jack - it removes much of the circuit and can help to isolate the problem. Check wiring from there to the output.

So I have been on holiday twice, injured my back in between, and now I have some flu or covid symptoms.

I have been thinking of rebuilding this 100w amp to make it up to the Aesthetics and functionality of the 50w build I have going on. The transformers for this will arrive soon.

for some reason I used ceramic sockets instead of Belkin Sockets for 8pin Tubes and all sorts of stuff I cut corners on with this build and I think I can do better.

what do you think? crack on and troubleshoot it, or rebuild with new chassis and faceplates?

Also I have a Tube Haul I found for £20 I will post pics of shortly

[martin manning]

I would take the time to get this one working. You are probably not far away, and you will probably learn something. Then you can decide if you want to rebuild it or just go through it and tidy things up, maybe replacing some parts.

[desertmouth90]

I would take the time to get this one working. You are probably not far away, and you will probably learn something. Then you can decide if you want to rebuild it or just go through it and tidy things up, maybe replacing some parts.

Everything you said makes sense so I will follow it.

Please see pics for my Valve (Tube) Haul.

[desertmouth90]

B+ voltages are 455v in standby, out of standby they drop to 350ish. And there’s a hum. Not sure what’s causing this tbh.

Could be because they are unbiased?

[martin manning]

Could be biased way too hot. In stand by, what is the voltage on power tube pin 5's?

[desertmouth90]

circa 360v. I have the Bias pot at max -V though

Edit: Sorry misread one moment

[desertmouth90]

Could be biased way too hot. In stand by, what is the voltage on power tube pin 5's?

its -17.7v on each pin 5

[martin manning]

-17V is much too high (not negative enough). You will need around -50V there.

Edit: above you had -50V available for biasing. Have you just not set the bias yet?

[desertmouth90]

-17V is much too high (not negative enough). You will need around -50V there.

Edit: above you had -50V available for biasing. Have you just not set the bias yet?

Bias not set yet.I tried that before I went away and ive completely forgetton how to do it tbh