More Skyripper shenanigans....

[digi2t]

Hi all,

More Skyripper fine tuning.

Firstly, it was really bugging me that I couldn't max my Bias knob, and be sure that all my tranny voltages were normal. Because my PS puts out more than 9vdc, and the trimmers spec'd in the original plan can't cope with the excess voltage, I was always cheating by keeping my Bias knob backed off. As a matter of fact, I had a dot painted on the enclosure to indicate where the max voltage for the trannies was. This really bothered me, so tonight I rolled up my sleeves, and rectified the situation.

First, limit max voltage, so that when the Bias pot was at max, the tranny voltages would be right as well. Solution, a 25K trimmer between the Bias pot and the input jack connection. I had extra room on the vero, so I simply ran 2 new wires, and soldered the trimmer and wires to the board. As for adjusting the voltage, start with the Bias turned down, and adjust the trimmer until your voltage (I used the Q2, -7vdc as reference) is maxed when the Bias pot tops out.

The other thing that was bugging me as well was the range of the Bias pot. The original plan calls for a B50K, but in my case I found the range really thin. I eventually settled on a B25K to open things up a bit. It was better, but I still only had about 40 or 50 degrees to play with on the pot before it would kill everything. A 10K wouldn't give me enough bottom end, it seemed as if I needed something in between. This makes it tough to dial in certain sounds consistantly. Finally, after a bit of mucking about, I found the a 100K trimmer soldered directly to the pot (poles 2 and 3) gave me a way to fine tune the range of the pot. It's kind of like biasing the Bias pot if you like. From 25K, I could stretch the range of the pot a little more i.e. making it a 17K pot. Now I can ultimately decide where the bottom end of the pot is as well, giving me a completely usable range. It doesn't affect the max Bias setting at all.

Insofar as tuning the range is concerned, once the max voltage is set, I just plugged everything in, maxed everything, put the Ripper on, and then started turning the Bias down. Basically, your starving the voltage here. By adjusting the balance between the pot and the trimmer, you can set where your minimum will be i.e. no more sound. This adjustment requires a bit of playing with the knobs, to make sure that your covering as much of the pedals output as possible.

These two mods really stand out when you dial in the stutter. It's clean and crisp, machine gun like. Also make the jumping octaves and arpeggios really stand out.

I'll be adding this to my DIY vero layout. If anyone is interested let me know, and I'll post the updated layout.

Cheers,
Dino