4 watter high gain tube

high gain 4.5 watt using 2x 12ax7 and a single ended el84

secondary voltage 240--ct--240 which produce about ~290 after rectify. 3.15--ct--3.15 2.5A for the heater. not really loud ,can play in house but will scream if attached to 4x12 celestion or higher sensitivity speaker.. design to distort at low level due to high gian preamp.

enjoy the clips!

5150 EVH

5150 with no power supply came in , its a 120V wallvolt series.. 5 preamp tubes, 4x6l6gc..

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marshall JMP 100watter

old input jack

new input jack relpaced due to old part got leaking (ground)

stabalizing the bias section..

new chatode caps and dc blocking caps.

overall view

marshall jmp 100 at studio shop space suddenly got problem noise due to grounding issue.take about a week to debug and replace new part.

1960's VOX AC100 reconstruct!

twin reverb (2)

bias resistor change from 33k to 22k to increase the bias, bias hotter to achive better tone IMO..

increase the bias by reducing negative supply to grid(pin 5) from -40v to about -35v..

plate voltage (pin 3) - 460 v (all 4 tubes)

S.grid voltage (pin4)- 450v (all 4 tubes)

- bias ~ -35v

change all coupling caps for preamp and trem chatode ,change all filter caps due to old one already burst out...

marshall jcm 800 bass (printed board inside)

for power transformer replacement, supply by nik of ceriatone at a great price !

fender twin reverb 1960!?

stereo tube hifi

wooden box made out of pine..

my first stereo tubes amp design for hifi use.

2 x el84, 1 x 12ax7.

preamp plate voltage ~100v

el84 plate voltage 240v, screeen grid voltage 235v(both tubes) ,with chatode resistor 120R(chatode bias)

sounded great due to single ended config, but depends on speaker too.