Thursday, June 4, 2009

Buchla 258 Sawtooth

Well after a lot of mucking around and changing the FET's quite a few times we have the "sawtooth" that looks pretty much like the one that was captured from the original.

This was a picture that is from the synthesis technology website. I tried linking directly to it but the Blogging software didn't work so I have copied it here. You can see all the original information at Synthesis Technology.

Mark Verbos, from who's design & PCB layout i used, has also done a more accurate clone from which he garnered this picture:

You can read his full blog posting here. Strangely I did end up securing the original FET that Don used, a 2N4339...


mark verbos said...

Looks to me like the only difference is that your waveshape control goes hotter than the others. The trim can be set lower.

Nice work! It's kinda finicky to get good waves without using the right FETs, but possible.

Hotlblack Desiato said...

I did fiddle with the adjustment a bit and came up with this setting as an attempt to get the best straight line between the bottom and the top.

I will give it a bit more of tweek once I have got it all mounted on a panel and sorted the tuning out.

Get Loose said...

I hope that you'll blog your progress in working out the tuning on the 258. Am following your results here on the 258 and 266 with much interest. Thanks for posting all this!