Kay Tremolo Build Report

somasix · May 23, 2006, 10:03:34 AM

Over the last two days I put together a Kay Tremolo from Dragonfly's veroboard layout. First and foremost, Dragonfly's layouts have definitely helped me build great sounding, classic pedals. Heck, the Tonebender tutorial taught me how to do stripboard in the first place. This one fired up immediately.

I once had the flimsy, blue plastic Kay Trem back in the mid-nineties, so I had a pretty good idea of what I was building. The specific things I was working for were the choppy, square wave sound and the SUPER fast, machine gun delivery. The machine gun is definitely there. Actually this thing skirts around the edges of Ring Mod territory at it's highest speed. On a recommendation of Steve Daniels on one of the Kay Trem threads I used the 1K Reverse Audio for the rate pot and would agreed that it makes dialling in sounds smooth and the trem speed doesn't bunch up at the end of the knob. It doesn't get super slow like the Vox Repeat Percussion though.

Regarding the Square Wave tremolo sound, my build isn't quite a square, maybe more of a trapezoid with a shallow bowl at the bottom. When ABed against a custom Square Wave trem from Death By Audio it did not compare. There was still some swell in the Kay circuit. Having said that, I will admit that I made a mistake of omission when ordering parts. Dragonfly's layout called for BC109C's and I ordered BC109's. Does anyone know if this might be the culprit?

As per the note on Dragonfly's layout, keep the rate lead really short. I had an inch and a half rate lead that was clicking at first, so I chopped the half off and it helped a bunch. So does the blend knob. When there's more gain in the signal before the Trem, it'll click a little. Just back off on the blend some and it clears right up.

The way I built it, the pedal is at unity with the amp volume when you kick it on, although it sounds slightly quieter because of the trem effect. It sounds AWESOME with the One Knob Tonebender in front of it. Fuzz + Kay Trem = More CHOP! It gets super fast and that is very cool. Unfortunately it's not as seductive as the Repeat Percussion when played clean. You guys working on Repeat Percussion out there, I wish you the best of luck. I'm rootin' for ya.

It's also my cleanest build so far. I'm happy.

Jason

syndromet · May 23, 2006, 10:35:42 AM

It's a great build, isn't it?
Think I'll have to box this up next week (I know, I'm slow at boxing things up.)

somasix · May 23, 2006, 11:16:57 AM

It's got a great sound. I got to play with it a little more and I have noticed at more pronounced volume drop that I noticed last night. I really wish I could crank it, but an infant lives two floors down (not that it seems to bother my landlord banging around in the unrenovated apartment between ours).

Did you have the same volume drop? Anyone out there have an idea how to bring the volume up to unity without the pedal breaking up in that oft mention Kay Tremolo fuzz way?

What transistors did you use for your circuit? I'm also wondering if the trapezoidal wave shape might be a product of my transistor choice. Thanks.

syndromet · May 23, 2006, 12:12:34 PM

I built mine with 2n5089's, but I haven't mounted a switch on it yet so I don't know if it's below unity gain. Guess I can check that for tomorrow. I haven't gotten to add a blinking led yet, but I remember someone told me how to a while ago.

somasix · May 23, 2006, 12:47:12 PM

I thought about a blinking LED, but I'm on the edge of getting a clicking noise with my one inch lead to the rate pot. I'm afraid a LED between that knob and the board would bring it to the front. Nonetheless, let me know how it goes, and with boxing 'er up too.

Dragonfly · May 23, 2006, 08:32:11 PM

glad you like it...

as for more chop/volume...you could try the aforementioned 2n5089's, or even the NTE47 (i'm going by memory here, but i think thats the right #)...the NTE47's tend to have hfe values between 700-900, so it might be worthwhile to get a few of those and try them in various combinations with the bc109's....

rock.

AC

somasix · May 24, 2006, 11:50:10 AM

Thanks for the recommendations Dragonfly. If I was to us 2n5089's or NTE47's in conjunction with the BC109, what positions do you recommend for the various transistors?

The Kay Tremolo is awesome for superfast trem sounds and I have enjoyed both of the builds I've made from Dragonfly layouts. I'm slowly putting together a Parallel Universe from your vero layouts, although it's going to be awhile before I have the bread to pay for all those pots.

Dragonfly · May 26, 2006, 11:00:43 PM

Quote from: somasix on May 24, 2006, 11:50:10 AM
Thanks for the recommendations Dragonfly. If I was to us 2n5089's or NTE47's in conjunction with the BC109, what positions do you recommend for the various transistors?

The Kay Tremolo is awesome for superfast trem sounds and I have enjoyed both of the builds I've made from Dragonfly layouts. I'm slowly putting together a Parallel Universe from your vero layouts, although it's going to be awhile before I have the bread to pay for all those pots.

SORRY IT TOOK SO LONG TO GET BACK TO YOU...I'M NOT ONLINE TOO OFTEN THESE DAYS.

anyway, try using a nte47 (or 5089) in place of the "furthest transistor on the right" ...that would be the first one i'd replace....

after that...trial and error....

hope that helps,
AC

edad · June 23, 2006, 06:43:55 PM

Im looking at my t-1 kay and it seems the trem pot sweep isnt used all the way,should it be? Id like to slow it down alot,as well.The fast is almost to fast and the slow isnt slow enough. Could a different pot be used?What other componets regulate the chop?
It has all three cb-c828-p transistors.I do have a 5089 to swap as well.
Has anyone put this into aother wah or volume case successfully?

somasix · June 24, 2006, 06:42:22 AM

I haven't owned the original version of one of these little guys in about ten years. On my build version I used a Reverse 1K Audio pot for rate, but that was really to keep the speed from bunching up at the top of the pot's throw. If I remember anything about that blue plastic case is that it was most certainly not an ideal design. A friend of mine (back in the nineties) pulled the wah rocker off his and put a big, fat knob on the side so he could roll it with his foot like a Maestro phaser.

That being said, I'm sure a rehouse is possible, but why destroy the little blue museum piece when he doesn't even really work to your exact specifications. Instead, I'd build a new board with the qualities that I'd want and house him in a wah shell from Small Bear.

Unfortunately I'm still too newb to be able to tell you what to replace to get a slower trem, but there's bound to be someone here who can. Dragonfly, are you out there?

Dragonfly · June 25, 2006, 03:38:37 PM

Quote from: somasix on June 24, 2006, 06:42:22 AM

Unfortunately I'm still too newb to be able to tell you what to replace to get a slower trem, but there's bound to be someone here who can. Dragonfly, are you out there?

i havent really tried to get a slower speed...if i think of any possibilities, i'll post the ideas...

AC

jmusser · June 25, 2006, 08:41:17 PM

I just got through perf boarding the T-1 off the schematic at GGG http://generalguitargadgets.com/diagrams/kaytrsc_original.gif The only part I subbed was the pot with a 5K, because I didn't have a 1K. I feel that if I was to use it much, I would have the speed pot as an outboard trimmer to be used with a screw driver, because it's so touchy to hold in a certain place. Other than that, I thought it generally sounded pretty good. It would be nice if it could be slowed down a little more, but I was just tickled it didn't distort. It seems to reproduce the note real well, and gives you some nice fast otherworldly sounds, like a Sci Fi B Movie.

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Kay Tremolo Build Report