Hi,
I'm new to the forum so I'm sorry if this one has come up previously.
I have just built a Tycobrahe Octavia on the GGG board.
The voltages on all three transistors are pretty much spot on with those quoted in the GGG instructions and the HFE of all three transistors is about 340. The cct is battery powered at present.
Everything seems to be in order. However, when I plug in I get a fair amount of hum and oscillations when the intensity is near maxed out.
The board is not boxed yet and I have left the wires fairly long (6-8 inches) until I get an enclosure.
Do you think the problems I am getting are a consequence of the cct not being shielded yet or the wires being too long (do I need to use shielded cable to replace some of the wires?).
Am I missing something.
Any help from you guys would be most welcome.
I think mine makes a little noise when it's turned up alot, boxing it may help...usually does, when there's gain involved
My wires usually go 4'' offboard, then get trimmed for the boxing.
I like to run short's' to and from volume control, input, and gain knobs, so I generally run them off one side of the board so theyr'e laid out in the box close to the board.
Having great results running long input and output wires [decided to try this and see/maybe replace with shielded I/O jack/switch wires] on the ZW pedal. they go from jack lug right against the box [across the whole box] to the switch, pinned/shaped to the shielded grounded box metal by the thick clear plastic I use to insulate the board mounting [between board and box], which also makes board as close as possible to the ground plane. This box is very low noise, I chose not to mess with shielding the I/O wires as a result. I ran them 'around' where the board is, away from most anything but ground [no I/O or PS or gain wires near...if near, crossing 'X' style...no parallel runs].
Thanks for the info.
I think I will get the thing in a box and follow your suggestions before I worry too much.
I have the "Body mod" and "Oct off mod" also on wires to switches, so there are lots of wires crossing all over the place at present whilst it is on my carpet unboxed
Thanks again...
No way to say exactly what's what with layout other than...
no parallel wires other than Gnd [something like that I guess...what I shoot for]
Try to layout the box And Board so all the offboard wires are 'tidy' and limited length.
I just figure if a wire is 'carrying' something like input output or V+ try...there's a chance that 'it' could get into something or 'something' could get into it...keeping 'separate' and short as possible and not 'back and forth'...try to put the offboard stuff mounted in the box close to where it hooksup to the board.