Monday, April 26, 2010

Epicenter Audio Valveboy



Got my hands on a Valveboy. Its a pretty decent pedal with lots of similarity to a Marshall preamp. Four gainstages cascaded into a passive TMB tone stack and a "prescence" switch. The Second gain stage can be switched in and out for more/less distortion. This thing has pretty good build quality, with orange drop caps and ceramic tube sockets. Double sided PCB too.

BTW. This is a realt tube circuit. B+ is around the mid 250VDC range.

Heres a Epicenter Audio Valveboy Schematic. I didnt include the switching for the optocouplers. Thats easy enough to figure out. K-map is for witch optocoupler switches on at what setting.




Tuesday, April 6, 2010

Turi's GAS day!

Hey guys! Its GAS day once again. Go and see cool gear from your local manufacturers and more!

Saturday, April 10, 2010. 2PM onwards. Mag-net High Street, The Fort.

Ill be doing a QnA in the afternoon. Ill be talking about gear in general.

See ya!

Thursday, April 1, 2010

Bass Preamp part 1

Ive been attempting to build another bass preamp. This is something ive been going at for years. The current incarnation seems to be the best one yet. Here's a little description and Progress report

- Opamp gain stages. Uses a James style tone stack followed by a parametric mid section. (SVT inspired). I'll try reversing the EQ order just so i can hear the difference. I'll have to build better gain stages.
- Thinking of what front end to use. Would like to use JFETS so i can get a little grind out of it when pushing it hard.
- Im liking the tone im getting out of it but its still to early to say. Its just a couple of days old. Im getting hissing noises from it but the gain stages are pretty basic. Can still add LPFs in key places plus try a few more tricks. Proper gain staging too.