Clock of Tone 50 - Modified COT50

briggs · Post by **briggs** » 21 Feb 2008, 12:51

I was playing with the COT50, came up with some pretty usefull mods, turns it from a OK/Good pedal to a really useful and versatile pedal

Try 'em out, you won't be disappointed

Scheme:
HERE

Blurb from my blog:

I tried a COT50 booster the other day - nice tone I thought, but it could be better! So I got my breadboard out and modified away until I was happy! More bass response was a must so I changed th input and output caps from 47nF and 100nF to 56n and 120nF, only a slight difference but it's enough to give your tone an extra thickness. Also I wanted to alter the clipping response slightly, it seemed a little harsh to me. I swapped out the 1N60 diodes used originally and went for some 1N270 Ge diodes, this softened up the top end a little - no more "Icepick"

Finally, as always, I wanted more versatility. This is where I came up with the "Nature" control to accompany the already present "Structure" control. The Nature control allows you to blend between a full on thick boost and a rangemaster style treble boost, a nice feature to add I thought. The Nature knob is fairly interactive with the Structure knob, for example with the Structure knob at min and the Nature towards treble boost you get a pretty high treble boost but with the Structure at min (and Nature still towards treble) the treble boost is much less pronounced and it just takes away a little bottom end from you tone and prevents a muddy bottom end.

Well with those mods the COT50 became a useful little pedal... Just got to send the finished article back to my buddy now, see if he likes it

seniorLoco · Post by **seniorLoco** » 22 Feb 2008, 02:58

Nice... Thanks!!

I built mine with a germ and silicon combo ...just wanted some bite.

Deaj · Post by **Deaj** » 22 Feb 2008, 08:03

I threw this one together on the breadboard today using a pair of Ge diodes I'd received in a GGG kit a little while back. This circuit can be dialed in to sound almost exactly like my Lovepedal COT-50 blue. I built it on perf-board and threw together an enclosure for it. I'll A/B them again tomorrow to be sure but I expect to be selling the COT-50 by tomorrow afternoon.

Here are a couple of pics of my build:

Thanks for another great circuit Briggs!!

seniorLoco · Post by **seniorLoco** » 22 Feb 2008, 09:25

how bout big mojo caps

briggs · Post by **briggs** » 22 Feb 2008, 12:49

Thanks for giving it a build guys. I'm pretty new to publishing my projects, I'm finding it pretty fun, I enjoy giving a little something back

I found that this build could sound remarkably similar to a COT50, but also had a lot more versatility too

Try playing with the transistor type, diode type and cap values, they are easy swaps and do change the tone a fair bit.

Wow Deaj! Great work, quick too!

What do you think to the "Nature" control? I was quite pleased how it turned out, you can alter it's response by altering the cap values.

Deaj · Post by **Deaj** » 22 Feb 2008, 19:11

briggs wrote:Thanks for giving it a build guys. I'm pretty new to publishing my projects, I'm finding it pretty fun, I enjoy giving a little something back

I found that this build could sound remarkably similar to a COT50, but also had a lot more versatility too Try playing with the transistor type, diode type and cap values, they are easy swaps and do change the tone a fair bit.

Wow Deaj! Great work, quick too!

What do you think to the "Nature" control? I was quite pleased how it turned out, you can alter it's response by altering the cap values.

I really like the 'Nature' control - very interactive with the gain/bias. It's flexibility belies its simplicity. Fantastic circuit - thanks again!

I'll be messing around with this one again as soon as I get another pair of Ge diodes like the ones I used for this build. I acquired them through General Guitar Gadgets with a kit a while ago but never used them. They sound remarkably close to whatever was used in my COT50. They're a clear glass with a smoke gray band and a little red coloring at one end. I post the part number once I have it.

gtrwrks · Post by **gtrwrks** » 22 Feb 2008, 20:24

What the hell is that, seniorLoco?

erikm5150 · Post by **erikm5150** » 22 Feb 2008, 20:45

Very nice build as always, Deaj.

Does anyone happen to have a vero layout for this circuit? Thanks!

Deaj · Post by **Deaj** » 22 Feb 2008, 23:24

I don't have a vero board layout but I am working on a perf-board layout. I'll post it when complete.

Deaj · Post by **Deaj** » 23 Feb 2008, 23:27

BTW: I used 1N270 Ge diodes for the clippers.

briggs · Post by **briggs** » 24 Feb 2008, 23:39

Interesting to see that you also used 2N270's, the diodes used do alter the character quite a bit. I thought they sounded the best. Soft but still with enough bite to cut through. It's a really useful little pedal with these mods - the next on my list is the "Woodrow", I'm on a mission to make all lovepedal's value for money

seniorLoco · Post by **seniorLoco** » 25 Feb 2008, 01:14

gtrwrks wrote:What the hell is that, seniorLoco?

It's an 18v electra using max1044 charge pump with fancy diodes and huge ass caps ...pretty cool aye. Those are japanese made by "Bam Basic" !!

https://www.freestompboxes.org/viewtopic.php?t=1253

Blues Lyne · Post by **Blues Lyne** » 25 Feb 2008, 06:48

I have a switch in mine to switch diodes. I have 1N270's and mosfets wired as shown in the second example here http://www.muzique.com/lab/zenmos.htm

You get less clipping with the mosfets and more output; makes it a bit more of a dirty boost, but it has a nice natural sound.

I'll have to give the nature control a try.

erikm5150 · Post by **erikm5150** » 25 Feb 2008, 17:06

Excuse the ignorance, but what is the 5088 in the schem?

Deaj · Post by **Deaj** » 25 Feb 2008, 20:50

erikm5150 wrote:Excuse the ignorance, but what is the 5088 in the schem?

It's a silicon NPN transistor. The common part number is 2N5088.

MoreCowbell · Post by **MoreCowbell** » 25 Feb 2008, 22:00

before i build this....

any reason to think that either a 2k pot or a 1k reverse audio pot would be better for the "structure" pot ?

how about the "nature" pot ? any possible better values ?

thanks...

erikm5150 · Post by **erikm5150** » 25 Feb 2008, 22:28

Deaj wrote:
erikm5150 wrote:Excuse the ignorance, but what is the 5088 in the schem?
It's a silicon NPN transistor. The common part number is 2N5088.

Ah, thanks a bunch!

...still looking forward to your layout.

briggs · Post by **briggs** » 25 Feb 2008, 22:42

MoreCowbell wrote:before i build this....

any reason to think that either a 2k pot or a 1k reverse audio pot would be better for the "structure" pot ?

how about the "nature" pot ? any possible better values ?

thanks...

I would say try a 1k rev log for the "structure". Unfortunately I don't have any to try at the moment. I'm quite happy with the "Nature" control, your could try a 1k log pot here though, it does alter the character somewhat....

Try a 2N2222 tranny in the circuit. It reduces the gain a fair amount, makes for an interesting change

MoreCowbell · Post by **MoreCowbell** » 25 Feb 2008, 23:34

briggs wrote:
MoreCowbell wrote:before i build this....

any reason to think that either a 2k pot or a 1k reverse audio pot would be better for the "structure" pot ?

how about the "nature" pot ? any possible better values ?

thanks...
I would say try a 1k rev log for the "structure". Unfortunately I don't have any to try at the moment. I'm quite happy with the "Nature" control, your could try a 1k log pot here though, it does alter the character somewhat....

Try a 2N2222 tranny in the circuit. It reduces the gain a fair amount, makes for an interesting change

Thanks... i might try the rev audio for the structure pot...i have a few sitting around....

MoreCowbell · Post by **MoreCowbell** » 26 Feb 2008, 00:46

This layout should be correct, but it hasnt been verified. Let me know if you spot any problems.

Also, the cap that is in parallel with the clipping diodes is listed as "47n" ...is this correct, or should it be "47p" ?