• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

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Aikido preamp in a cheap plastic box.
PS used from another tube preamp (on the left).
 

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6C33 monoblocs.
6SL7 input, 6V6 driver and 6C33 power tube.
Hammond mains transformers, Sowter plate choke and Edcor OPT.

An externally hosted image should be here but it was not working when we last tested it.



Schematic:
An externally hosted image should be here but it was not working when we last tested it.


JanE

How does it sound and compared to what? I was looking at these tubes for possible build.
 
How does it sound

The bass sounds tight and well defined. I have chosen a 1k2 OPT that brings the output impedance down without feedback. My speakers start to sound muddy if the Zo from the amps are too high, but that's not the case here.
Output power is 12W+, noise level is ~190µV (mainly 50Hz) measured on the binding posts.
I have just listen to the amps for a few hours so I cant tell much more for the moment..
 
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Joined 2010
6C33 monoblocs.
6SL7 input, 6V6 driver and 6C33 power tube.
Hammond mains transformers, Sowter plate choke and Edcor OPT.




Schematic:
An externally hosted image should be here but it was not working when we last tested it.


JanE

Nice build,

It would be interesting to see a picture of how you sink 21.8 Watt in the chassis (Cathode)..Is it single resistor?

Regards
M. Gregg
 
Rk is 2 x 330R/17W resistors.

An externally hosted image should be here but it was not working when we last tested it.


The temperature on the surface of the chassis (near to the cathode resistors) is 56 C after playing for 2-3 hours.

Jan.

tidy work - any reason not to use Dale or equivalent aluminum/finned resistors bolted directly to chassis in such an application?
 
The bass sounds tight and well defined. I have chosen a 1k2 OPT that brings the output impedance down without feedback. My speakers start to sound muddy if the Zo from the amps are too high, but that's not the case here.
Output power is 12W+, noise level is ~190µV (mainly 50Hz) measured on the binding posts.
I have just listen to the amps for a few hours so I cant tell much more for the moment..

THanks. I eagerly await further listening results