Roger Mayer Octavia (without transformer) sounds gated....

[gigimarga]

I just build a Roger Mayer Octavia (without transformer) and, with the distors maximized, it sounds gated...it is necessary to bias the trannies?

If yes, which are the voltages?

Thx a lot!

[gigimarga]

nobody knows?

[hellwood]

I just build a Roger Mayer Octavia (without transformer) and, with the distors maximized, it sounds gated...it is necessary to bias the trannies?

its always a good idea to bias although i suppose you could get lucky.

If yes, which are the voltages?

what are your voltages?

[gigimarga]

the schematic and pcb was from tonepad: http://www.tonepad.com/getFile.asp?id=120

the power supply voltage: 9.60 V

the transistors voltages:

Q1 (2N3906 ): E= 4.46    B=3.10     C=3.04
Q2 (MPSA13): E= 2.11    B=3.05     C=6.05
Q3 (MPSA13): E= 2.85    B=3.30     C=6.60
Q4 (MPSA13): E= 3.66    B=2.28     C=9.60

thx a lot!

[hellwood]

that link at tonepad didnt work for me, but i noticed on my schematics that Q1 is oriented differently(180 degrees) than the rest of the transistors. could that be the problem?

[gigimarga]

if you enter on www.tonepad.com you can easily find the "RM Octavia" project.

you make me curious about Q1...can you send me your schematic?

thx a lot!

[hellwood]

if you enter on www.tonepad.com you can easily find the "RM Octavia" project.

you make me curious about Q1...can you send me your schematic?

thx a lot!

http://fuzzcentral.ssguitar.com/schematics/mayeroctaviaschem.gif

[gigimarga]

Thx a lot...i will compare it as soon as possible with the one from tonepad!

[gigimarga]

the 470pf input cap to ground is ok?
i saw on another schematic 47pf or 120pf...