my hybrid tube / TDA2050 amp build

[maiko]

Just sharing my Hybrid Tube (12au7) TDA2050 amplifier.
Well this thing is definitly louder than the tube cricket.    the preamp is a single 12au7 very similiar to the valve caster
the main amp is a GGG TDA20x0 amp.      Im using a dual powersupply after rectification its 32v for the power amp
and using a lm317 regulator and pumping 12v to the preamp and reverb.

Not sure if this is the proper thread to post.   



This pic shows the "verb" reverb circuit i always wanted to incorporate in an amp

Gut shots in all its glory hahaha 

Top view.  Counter sunk screws would have made for a clean flush look but all i had were cap screws

I made all of the parts in modules to make it easier to swap out modules that need modding/upgrading

[PRR]

Nice build.

> modules to make it easier to swap

Smart idea.

[runmikeyrun]

Looks great! 


Ham fisting my way through one build to the next since 2003. 

[cab42]

Looks very nice. I have just etched a board for a 2050 power amp and want to build something similar.

I like that you use the cabinet as heatsink, great idea.

Is there an effects loop?

[maiko]

Yup there is an Effects loop.     i like to play around with different preamps.     I had to use Mika insulators and bushings i wanted to make use of the aluminum to cool the ic.

Build update. :  I notice there is an awefully loud turn on thud when the circuit is powering up.   Ive researched about this and
it seems this is considered normal.      I however worry it might shorted the life of my speaker.   So ive come up with a circuit using a 555 ic to control a dpdt relay.   it diverts the output of the amp to a resistor(dummy load 10watt 30ohms) on the normally closed side of the relay and after approx 3-4 secs switches to the normally open providing continuity from the power amp to the speaker.   i have tested the "diverter module" outside the amp and will install it today.