TT Cardinal "and then some" and a bigger Buzzy Fuzz

[midwayfair]

Someone wanted a Twin Peaks but they aren't buyable anymore, so I agreed to use one of the handful of leftover TT Cardinal boards and build him something cool. It's got a switched expression jack for either depth or rate (selected with the 3PDT) and a tone control based on the Garnet tacked onto the end, which works like a tilt tone for ~1KHz. It's a 20KW pot, a 47nF for the treble cut, and a 470nF for the treble boost. It's not 100% neutral at the center of the knob, but it's not too far off.

Problems encountered:
I had a bunch of ticking and was able to kill it by jumpering the power supply filter resistor and putting a 100uF from 5V to ground (that's what's going on with the cap on the expression jack).

Also had a dud vactrol, which was not fun to replace

Believe it or not the pedal worked before I took this picture. If you spot the problem, you win 2 interweb points.



Chris Freeland (the engineer at Beat Babies Studios I do all the Midway Fair albums with) took a liking to the Little Buzzy Fuzz (mini buzzaround) I left at his place but needed something more robust. (I think the LBF has one of those bad lumberg clone jacks in it) and asked me to make him a more robust one. So I made this. I added the volume control by replacing the 10K to ground at the output with a 10K pot, and then replaced the Timbre pot with a 100KC wired as a variable resistor and then used a 1uF instead of 100nF for the "big" cap. This makes it so that the output loading and cutoff frequencies are identical to the original without the volume pot and also corrects what would be a problem where the timbre pot would have less volume in the center of its travel than to either side. I'd actually highly recommend this in general as a way to build the pedal.

I also used the 10K bias pot, but dropped the 27K to 18K to get a slightly higher maximum voltage on Q3.

Q2 is a very low-gain button silicon transistor (2N5134, but it could be lots of stuff), which I've found can really really reduce the noise on this pedal without altering the tone or hunting for an impossibly low-leakage pair of Ge transistors. Interestingly the design is actually quieter with a germanium in Q1 than both being silicon. Q3 is an MP38A just like the previous build. These tend to have consistently good-but-not-too-much leakage (you need some leakage for Q3 to work right but it's not picky otherwise).

Overall it sounds pretty good. I don't have the little one to compare, and it's still not my favorite fuzz, but I think it's definitely a good sounding one.

I went a little more cartoony with the graphics this time. I still really like my other build's picture better, but this was cute enough.

[Orbis_Ignis]

Awesome man! I love the artwork. I really need to get a cardinal pcb. I still haven't built a tremolo yet

[m-Kresol]

Those look very good Jon. I really dig your Cardinal TT, it's very versatile and a great sounding effect.
Nice choice of colours btw.

[stringsthings]

Very nice.  Love the Buzzy Fuzz graphics !6

[Lubdar]

Great looking builds!! Love the colors and the clouds on the TT Cardinal. So bright and in your face


a dud vactrol ehh?  I recently learned that my lay interpretation of how vactrols should be oriented on a PCB and what the little colored dot that distributors put on some vactrols wasn't in sync.  I think i lost $5 or so removing it from the board sadly...

[Coda-effects]

I had a bunch of ticking and was able to kill it by jumpering the power supply filter resistor and putting a 100uF from 5V to ground (that's what's going on with the cap on the expression jack).

Thank you so much for sharing this! I had the same "ticking" issue with a tremolo design of mine ( http://www.madbeanpedals.com/forum/index.php?topic=21954.0 ), and I had many troubles removing it.
Jumping the power supply resistor killed it!