Dumble 102 ODS testing

[martin manning]

Looks like you have a 12B for the main and an 11 for the extension, so you have no safety shorting contact, risking damage to your output transformer. You should use 12A for the main speaker (which includes the shorting switch) and 11 for the extension.

[desertmouth90]

I’ve checked I’ve never ordered at 12b. But what you are saying is very interesting and I’m keen to explore this further.

I have attached the 124 Layout that’s on here and the AA electronics layout for the 102 and take the outputs out of the chassis for closer photos.

[ijedouglas]

I’ve checked I’ve never ordered at 12b. But what you are saying is very interesting and I’m keen to explore this further.

I have attached the 124 Layout that’s on here and the AA electronics layout for the 102 and take the outputs out of the chassis for closer photos.

Looks like the jacks are correct in the AA layout but they are labelled incorrectly (swapped).

[timrobertson100]

You’ll find that from time to time, the wrong part will be put in by whoever is packing your order…

The 12b is for a stereo jack, with 3 connections for left, right and ground. That’s what you have with the black jumper wire.

The 12a is for a mono jack, also with 3 connections. It has a ground, and then the other 2 are a switch - without a jack inserted they are connected; in the speaker socket that is a safety in case powered up without load, in the effects loop it provides the through connection when not in use.

I think you should order two 12a’s. In the meantime, I’d suggest check that your effects loop connects through and that your speaker sockets are wired so the tips connect and the grounds connect together. Leave the ring connection unused and always have a load in when powering it up.

Cheers.

[martin manning]

I’ve checked I’ve never ordered at 12b. But what you are saying is very interesting and I’m keen to explore this further.

Your "Power Amp In" jack is also a 12B. The preamp output is connected to the sleeve lug so it is grounded out.

[desertmouth90]

This is my 3rd Gen 50w Build.

Do you think this is 12b too?

I can’t believe Mouser would mess this up so badly!

I’m not going to lie too, I cannot get my head around the difference so I’ll order more of both.

[martin manning]

Those are the correct types. For each pair 11 on the left and 12A on the right.

[desertmouth90]

Those are the correct types. For each pair 11 on the left and 12A on the right.

Well paint my pickle and call me Jeffry.

I will swap them over to my current project. And compare them too!

Many thanks for your help! You guys are worth your weight in gold!!! This amp is gonna slay!

[timrobertson100]

Those are 12A and correct. Stick a jack in and you’ll see the tip connect and the switch opens.

12B has the extra mechanical connection that connects the ring section of a stereo jack.

[martin manning]

Stick a jack in and you’ll see the tip connect and the switch opens.

Jack = female, Plug = male. Except for donkeys and kangaroos ;^)

[pottedplant]

This is my 3rd Gen 50w Build.

Do you think this is 12b too?

I can’t believe Mouser would mess this up so badly!

I’m not going to lie too, I cannot get my head around the difference so I’ll order more of both.

The stereo jacks have a second contact that sticks out from the fiber washer and touches the 'ring' contact on TRS cables. On TS cables (like speaker and guitar cables) this second contact touches the S part of the plug usually ground

[timrobertson100]

Stick a jack in and you’ll see the tip connect and the switch opens.

Jack = female, Plug = male. Except for donkeys and kangaroos ;^)

...or us Europeans. I had never known it was an abbreviation we'd applied to "jack plug" - around my parts they're generally jacks and sockets. Thanks!

I can’t believe <a supplier> would mess this up so badly!

Be aware it happens with parts like resistors and caps too and that can be a real nuisance to diagnose after a build. A good habit is to test everything as you're placing the component.
If you will build a lot, investing in an LCR meter can make the process easy (mine).

[dbharris]

...

A good habit is to test everything as you're placing the component.
If you will build a lot, investing in an LCR meter can make the process easy (mine).

I second this and the Peak LCR, it's fantastic.

-Dan

[desertmouth90]

Stick a jack in and you’ll see the tip connect and the switch opens.

Jack = female, Plug = male. Except for donkeys and kangaroos ;^)

...or us Europeans. I had never known it was an abbreviation we'd applied to "jack plug" - around my parts they're generally jacks and sockets. Thanks!

I can’t believe <a supplier> would mess this up so badly!

Be aware it happens with parts like resistors and caps too and that can be a real nuisance to diagnose after a build. A good habit is to test everything as you're placing the component.
If you will build a lot, investing in an LCR meter can make the process easy (mine).

Whats an LCR meter do?

[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.