Vox Cambridge 30 Reverb Twin keeps blowing TDA2050

[pecorporation]

whew!

[tom o]

I'd be tempted to give Korg some 'design credit', as major distributors often have a lot to say about the price point of any given product...thanks for the document; after reading it, I'm glad I've already twiddled the thing to my satisfaction. I'll pass the doc on to the buyer; maybe he understands Engrish better.

Cheers-

[afm_380]

Thanks Tom ... Yes, I found a resonable sweet spot (but there are SO MANY ... ;o). And the 3875 mod is the way to go on these sweet lil amps.

Thanks Enzo ... now I know why the recommendation is stated so simply.

[J M Fahey]

Maybe it got a little garbled after the Cantonese to Mandarin to Japanese to English translation
Any way, it seems to work.
Beware that they provide a failsafe option: "let me know if you have any vague things on this matter"
If only they provided some EMail address.
I'd *love* to read some back and forth mails, translated by Babelfish both ways

[Enzo]

I enjoy playing with babelfish. Write a message in English, translate to Chinese, then translate that back to English. HArd to believe it was the same sentence. Even more fun is to through two language changes.

Or fun like:

나의 이름은 저와 Spartacus, 흩뜨리지 않는다 이다.

[Robert M. Martinelli]

This reminds me of an old joke :

A man enters a fruit shop, and says :


"°?@@"£$%%&&/&/ STRAWBERRIES *^?é°ç@@#[!!!"

and the fruit shop clerk goes :

" Sir, you said you want a basket of....what? "

( sorry, I couldn't hold myself back )

Cheers

Bob

[J M Fahey]

Start mode:
You guys are fun !!
end.

[match]

Old thread, but assume I have the best chance here.

I have a Vox Cambridge Reverb 30
(Single 10" speaker)

Now I want to make the line out a line in jack.
So I can connect my preampprocessor and the Vox will play that by the power amp.
Anybody some guide how to modify the circuit board to achieve this?

Thanks in advance!

[Jazz P Bass]

Welcome to the Forum Match.

Etiquette dictates that you do not hang onto an old thread.
Especially one that has nothing to do with your request.

(upper left, click on 'New Posts'.
then off to the upper right, click on 'Forum'.
pick one (ie: Amplification: Maintenance, Troubleshooting & Repair)

Anyway, that is how to start a new post.

On to the question of a Line In jack: what is wrong with going in the front input jack?

[match]

Welcome to the Forum Match.

Anyway, that is how to start a new post.

You're right. Sorry for that. I was coming from a Google search to this page.
If you want me to start a new one, just say so.


But:...

Welcome to the Forum Match.


On to the question of a Line In jack: what is wrong with going in the front input jack?

Nothing wrong with that one, except I have a digital preamp/effects processor (Fractal Audio) which models the pre-amp already.
Way to go to amplify such is to stick it in a power amp.
So no extra soundcoloring of the Vox preamp in this case.

[Enzo]

Look on the schematic, upper right. Point C is the output of the preamp. You could tap in there with an outside signal input. The existing line out jack is wired to the speaker circuit.

[Jazz P Bass]

I don't know.

It's a TDA output IC with tubes in the preamp.

I would think that you would want the tubes.

It shouldn't be that hard to set up the preamp 'flat'.

[Enzo]

Philosophically you do not want the Vox preamp coloring your other thing, but in a practical sense, did you try plugging it in the front anyway, just to see if you could get good sound that way?

There is only one tube in this. I don't know what the B+ is, but the filter caps for it are only 250v. The tube is only in the dirt channel. There is a fixed tone stack circuit between the triodes, as well as a tone stack after the second.

I don't know how flat you can get it, but it takes only seconds to try going all the way through the amp to find out. If the tone is acceptable, it saves a lot of work converting the thing.

[The Dude]

^^^^ What he said.

A few thoughts (and I'm not trying to argue):

If you are monitoring the Fractal for purposes of wanting to know how it sounds through the PA system, then forget using a guitar amp. No guitar amp is flat and none will have the frequency response of a PA system. You need a full range speaker and amp or a powered monitor- something with a tweeter and some low frequency response.

If you just want to be able to hear what you're playing and aren't horribly concerned about matching main and monitor EQ, then it's not going to make a ton of difference whether you use the guitar input or install an "amp in " jack.

Or, just pipe the guitar back into stage monitors or in ears and forget about using a separate rig all together.

[match]

^^^^

You're all very right.
In the band I play FRFR etc for the purpose you mentioned.

I bought this Vox for another reason first and now it stays at home.
So I thought it could be nice to dial in some tones at home, or test some setups with the Fractal.

But as you say, the Vox is actually very flat by itself. So the input can be used for the purpose.

Colouring is for a big part done by the speaker cabinet as I can remember now.
Hooked the Fractal up once to the power amp of a Mesa Boogie. Any amp I choose had that "Mesa" blanket over it.

Thanks for the insights!
Solved