Sekova FA-II Fuzz NPN version with mods

[anders]

I've been tinkering with this forgotten old japanese germanium fuzz lately. I've built it according to the layout on the main site.:http://tagboardeffects.blogspot.se/2013/06/sekova-fa-ii-fuzz.html

But it really didn't cut the mustard, the output was to low and it sounded weak and gated no matter what transistors I put in. So I decided to twe new layout which ak a bit and draw a new layout (which is certinly not as elegant as Mirosols...)



I increased the level pot 500kB and added a clipper pot to the germanium diodes who dropped most of the output level. As for the gatey sound and low sustain....later version had different resistor values; all 27k resistor was subbed to 33k and all 5,6k resistor was lowered to 4,7k, and that did the trick! Now it's a loud, buzzy and quite a heavy fuzz with a cool tone control (Attack control, that is) in the vein of FY-2 Companion Fuzz.... but it has a different flavour and is not as unruly.

I used MP38A's in the 70hfe range for both transitors and D9E for the diodes, I tried D311 as well but they were to gritty.

Skål
Anders

[anders]

Udated the layout above, found some minor errors and added another layout with a scoop mod.

[velouriafx]

I built the pedal now. I really liked the settings with the clip full clockwised, but it's losing a lot of volume. Would silicon diodes not be a better choice? Another thing, how could increase the bass of the circuit? I found a bit of bass deficit.

[anders]

Yes, silicon diodes will make less volume drop, in fact it turns out that later versions of this circuit had silicon diodes. I recently built another one of these with red LED's, hardwired without clip pot. Sound pretty good. For more bass, I guess you can tinker with the tone section (which is a variation of  the Superfuzz tone section), 68k, 22k, 1nf, 100nF is the values to mess withl as the value of the attack pot.

I also swapped out the the 22k resistor between 33uF and 10uF capacitors for something much bigger, I think I ended up with something like 1,5M resulting in more volume and a bit more gain.

Cheers

Anders

[velouriafx]

Thanks for the answer. I swapped the germanium transistors for silicon, but did not obtain significant differences.
I had already thought of using LEDs as diodes because I really like LEDs as such. I also thought of bypass the clip pot because for me it is the most effective and cool setting. I like very much gated fuzzes.
I'll try some more changes soon.
 Today I will try to modify the Candy Apple Red Fuzz because I imagine it can have better results in these more gated settings and be more versatile in general.

Cheers.

Marcello