SD-1 Mod

[ildar]

Have any of you performed a mod on an SD-1 that included a germanium diode in D6? If so, did you experience a decreased output? I'm getting that, plus a weird compression on low strings when they're picked hard (think barre chords 5th fret and lower). Would it be due to the diode? I  also replaced a few resistors and caps, maybe they are to blame? Any insight would help.

[petemoore]

Socket them diodes...I do.
 Yes and Yes.
 Ge's lower the output, I find 'em a little too constricting sounding,
 Try two seriesed Ge's, both pointing >> er whatever in the FB loop, they'll still sound like GE's but the output will be higher than with just one.
 Two Ge's >l>l
 One Si     l<
 There are many ways to try diode configurations.

[ildar]

What do you use for diode sockets?
If I put two Ge in series, can I just join them lead to lead?

[RDV]

What do you use for diode sockets?
If I put two Ge in series, can I just join them lead to lead?

I sometimes take an 8 pin IC socket & cut it up into 4 sockets. Or you can order this from //www.smallbearelec.com & just snap off as many as you need.

RDV

[petemoore]

8 pin IC socket...rail a connection across each [4 pins in a row]  'side'...One is input the other side goes to pin2 {IIRC?].
 The diodes have a black line on one end of the body, orient them like

this   --->l->l---   for a higher clipping threshold [more output/less clipping].
pin1        -->l-->l-->l--
             --l<--l<---        pin 2
--------------------------------------
pin1      ->l-->l--
            -l<--l<--          pin2
------------------------------------
pin1     -->l--
          --l<--l<---    pin2
---------------------------------------
     Or any combination of diodes...pick your poison, try different value  high end clipping roll off caps across the ends of the diode connections to pin 1 and 2 [or is it 6 & 7]  ?...in the feedback loop at any rate.

[ildar]

Well, I'm about 50% through modding the pedal-still need some small 1uf caps (thanks RDV). Replaced- Caps: C2 with .047uf metal film;  C3 with .1uf metal film; Resistors: R6 with 2.2k metal film; R30 with 1kmetal film; daisy chained 2 germanium diodes in D6. Also put an RC4559P in place of the 4558DD.
Nice, slightly mid-boosted drive with a noticable bright edge. I still plan on soing some wholesale resistor and cap changes to metal film.