Aria 6P14 makeover.

[audio1st]

Hi, I am new to tube amps and have bought a cheap Chinese amp as somewhere to start. I have been listening to it for a couple of weeks and I'm very pleased with the sound.

What I don't like is the nasty pcb that everything is mounted onto and would like to junk the board and hard-wire it. I have managed to draw most of the cct after a start from a cct that MOAMPS drew some time back.

What I would like to know is, what the (20k I think) trimmer from pin 7 to ground of the input valves is for and how to measure its effect?
Any other (non obscene) comments for any of the other parts in the cct would be most appreciated..cheers..

 

[Wavebourn]

The pot is AC balance, for maximum of 2'nd order distortion cancellation.

Nice drawing!

What software did you use?

 

[audio1st]

The pot is AC balance, for maximum of 2'nd order distortion cancellation.

Nice drawing!

What software did you use?

OK, so you would need an oscilloscope to set that?

I used express PCB (free) but had to draw the valves. (could not use eagle at all)..

A picture of the inside, I expect the large capacitors I fitted are showing my non understanding (ignorance) of tube amps...

 

[Wavebourn]

Are you going to restyle it for training purposes, or it don't satisfy you sonically?

 

[d2134]

Hi, audio1st

I have a question: is it a poor quality PCB or you like more point-to-point wire?
I'm curiouse to see a picture of the original PCB, can you post one?

 

[Svein_B]

This Aria Mini is almost identical to the Yarland FV-34C III described in a previous thread (incl. diagram) here

I agree that the small PCB make modifications more than a little difficult.

SveinB.

 

[audio1st]

Makeover finished, hardest part was removing the last bit of hum.
The 330ohm resistor where the feedback connects to, had to be earthed via the pot ground. My thanks to SY for his earth suggestion on another thread that allows me to connect the case to a safety earth without causing ground loop hum...PS sounds great..

 

[audio1st]

The finished diagram..

 

[maton00]

do you used a output transformer like the one in the Yarland FV-34C III?(specs)