Solid State Guitar Amp Forum | DIY Guitar Amplifiers

That is what he means, but really, why not just insulate it like most installations, and then it doesn't matter if the heatsink gets grounded.   You can bolt the sink right to the chassis, which ads to the sinking.

We are technicians, we need to know what the problem is.  "Goes bad" doesn't help.

A.  I have been an authorized Peavey repair center for over 30 years, and I have never seen one of their products so defective they fail en masse.  For that matter I cannot think of any brand like that.  Besides even if there were some systemic failure, it wouldn't happen to all of them at the same time.

D.  No.  Any solid state amp will run cooler on 8 ohms instead of 4 ohms, it puts out only half the power that way.  So no issues there.  I suspect the difference in sound is not the ohms, but the brand and model speaker.

C.  Cables and carpet?  No.

B.  Not likely.

I choose E.


One of these amps if fully repaired, should run about forever.

Hello. New forum member here, and a proud owner of two of three Peavey Blazers. Why two of three? Well, I was so impressed by this little amp that I wanted another to use with for stereo delays. Unfortunately the second one I got for $12 didn’t work right. So recently I found a third for less than $50 which works fine...so far.

Unfortunately, the first one and the second one seemed to go bad at the same time which could be caused by:

A. Manufacturing defects...
B. Using them together in stereo without proper grounding. 
C. Unplugged cables lying on a static-charged carpet.   
D. Swapping the stock 4Ω speakers in both each with an 8Ω Jensen C8R.
E. None of the above. 

Can we rule out D?

The data sheet for the TDA2040 suggests it will work fine with an  8Ω speaker, and indeed I found the amp sounded better that way.

OR could the speaker dampening circuitry in Transtube amps make it susceptible to damage?

.05V across .33 ohms would be 150mA current through those output devices.
That sounds pretty hot.  I would not expect to see crossover distortion with that kind of idle current.

Hullo,

I'm from India and have bought the two module from Eight Audio, a company here in India. Since i've purchased the pre-assembled board their website conked out and there is no support from their side. It didn't come with any schematic or paper. Just plain board. I have the following questions. Both of them cost approximately 12 us dollars.

1. Since both boards utilised two ICs, When fitting a heatsink, do i need to used washers/insulation?

2. Since both can be used in bridge mode. How to activate this?

Thanks