Bosstone diodes? 1N4001, 1N914, 1N34? WHICH?!?!

[superferrite]

Almost every schematic has a different set of diodes for the Jordan Bosstone.
Which is most sixties sounding?   I'd assume the Ge ones, but...

What are the other differences?  I'd like to socket them but the 1N4--- series is way fatter!

[newfish]

Not yet built a Bosstone - but would hazard a guess that the diodes are for clipping - which is where a whole lot of fun begins.

By putting different diodes (or combinations of diodes) in at the clipping stage, you can tailor your pedal to what you think sounds best.

LEDs, Ge and Si diodes - it doesn't matter what you use.

You could also try having two diodes in one direction, and a single diode facing the other way for asymetrical clipping.

If the different schematics all show different diodes - and you're after building an exact replica - that has to be frustrating though.

If you've already soldered your board, you could try running a wire from each end of where the diodes would be soldered.
Terminate these wires with crocodile clips, and dive in.

Best of luck auditioning doides.

[brett]

Hi
Most diodes have a very similar sized "knee" in their conductance curves.  This means that diodes with low Vf (Ge diodes) have the smallest unclipped part relative to the knee, and clipping is "softer".  LEDs have high Vf and the same sized knee, so they clip "harder".  For general purpose use, the 1N914/1N4148 is a good diode.  It has a gold-doped junction that makes the knee a little larger and the clipping a little softer than for a standard silicon diode.   

+1 for "You could also try having two diodes in one direction, and a single diode facing the other way for asymetrical clipping."
Asymetric clipping sounds good to most people.

The other thing with the Bosstone is to use transistors with low hFE.  (Around 150 is ideal.  Try a pair of BD139s or TIPs.)

Hope that helps.

[gigimarga]

I used a switch which selects between 2 Si diodes/nothing/2LEDs and sounds very well!

[jessetrbo]

I used 1N4001 diodes after trying many varieties (including germanium).  I was not considering what was originally used in the circuit but rather what sounded best to my ears...  Many people like the 1N914 and I found it to be alright... just liked the 1N4001 better.

For what it's worth, there are some great threads with  pictures of original Bosstones on the forum.  One of the pictures shows a California version (yes, there were more than one version) with 1N4001s in it...

Thread with discussion/nice pictures:
http://www.diystompboxes.com/smfforum/index.php?topic=57936.0

Nice picture from thread  posted by Dan N:
http://users.rio.com/senorris/jordanbt/P1010068.JPG

Mega pictures thread with different versions:
http://www.diystompboxes.com/smfforum/index.php?topic=48469.0

Cheers,

Jesse Trbovich

[Mark Hammer]

The brunt of the clipping in the Bosstone comes from the transistor circuit itself, not from the diodes.  The diodes simply add a bit "more".  I found the same thing with the Univox Square Wave circuit as well.

Because of that, I would recommend against using Ge diodes for this.  The principal reason is that the volume difference between the Si and no diodes is modest, but the difference between the Ge and Si, and especially Ge and no diodes, is huge.  Big enough to send you scrambling for the volume control.

If you need to mod it, far better to tinker with the input cap value (Aron first noted this and it was a real keeper of a mod), or place a cap in parallel with the diodes to roll off some top end buzz.  On one of mine I have a 3-way slide switch that gives me stock, added cap on the input for fatness (and weird octave-down quirkiness), and stock plus treble cut.

[alex frias]

I tried several possibilities and found the 1N4001 and 1N60 combination very interesting for some asymmetrical clipping.