A Quick note on the Kay Tremolo mod

[Colonel Angus]

I'm checking now.

Figured out the "subtle" difference between my depth knob and Lucifertrip's, I missed that little downward arrow that goes to a special place we like to call ground.

Ill see what that sounds like when I get home.

@deadastronaut, still checking, halfway through (I'm slow, bro). I  think 100K and 47K (R6,R7) need a jumper to ground.

[deadastronaut]

yep, missed that..i'll correct it.....cheers man!...

image updated!..

[Colonel Angus]

Cool, cool. Everything else looks good to me, however full disclaimer: I'm no EE , but as far as I can tell you're golden. Curious to see how it works out.

It felt like a caveman trying to make fire to search for the "flash" in the flashing LED. Kinda reminds of circuit bending - break it till it works - probing about the circuit with fingers crossed until "voila"

I'll fix the depth ground on mine and post a clip tonight, I guess I have to drill a hole for flashy flashy too

[deadastronaut]

ill bread it just to be sure!....

[Colonel Angus]

better bread than red brother

[Colonel Angus]

Thanks for the great mod LucifersTrip! Works alot better when grounded...

[LucifersTrip]

That's odd. You used 100K? I guess I left a resistor where the 68K is but brought it way down to 470R. My depth at min. blends in a bit of clean signal and seems to almost soften the  trem waveform. At full it is nice and square and choppy. I'm pleased with the max depth but more clean on the min end would be nice.

yeah, I have a 100K in there and completely removed the 68K...did you try larger than a 100K pot?

[LucifersTrip]

Thanks for the great mod LucifersTrip! Works alot better when grounded...

excellent!...and I have to build another without the distortion (most likely from the high gain Q's I used)

[Colonel Angus]

Mine has a slight distortion. I used all 2n3904s after experimenting with many combinations of 5088 and 3904, I even tried some NPN germaniums but that was too quiet. Any suggestions on how to split the difference, some SI tran that is milder than 3904?

Interesting about the rate LED, it is also a depth LED that flashes brighter at deeper depths.

[superferrite]

Thanks for bringing this one back.  My buddy has a real (plastic) Kay tremolo, and it is a fun mess of a pedal!
Any vero layouts around for this?  Where did you end up hacking in that LED, anyway?

[Colonel Angus]

The red LED on deadastronauts perf layout is the rate LED. It is connected to ground and the collector on Q4.

http://aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=11002&g2_serialNumber=2

[LucifersTrip]

Mine has a slight distortion. I used all 2n3904s after experimenting with many combinations of 5088 and 3904, I even tried some NPN germaniums but that was too quiet. Any suggestions on how to split the difference, some SI tran that is milder than 3904?

Interesting about the rate LED, it is also a depth LED that flashes brighter at deeper depths.

If you do a search here, you'll find a thread about the distortion...and usually the solution is lower gain transistors.

again, this is another case when builders are trying to duplicate a vintage effect with much higher gain modern transistors.

The original had 2SC828P. If you look up the 2SC828 or 2SC828A (I wasn't able to find the P), you'll find the min hfe is 65.
I asked someone in another thread about the original gains in a Univox Superfuzz (which also uses 2SC828) and the answer was average 100-150.

The 5088's are way too high and the 3904's (at least mine) are in the 200-250 range.

[Colonel Angus]

Thanks alot! Sounds like I need to order some 2sc828s. My 3904s are reading in the 150 ish range, the distortion isn't terrible. I did search, but wanted to hear your thoughts on the matter. Did you see the T-1's honorable mention in the worst pedals evar thread? Hilarious.  The vero I saw called for 4 5088s, I imagine that sounds... different. Anywho, thanks again, now off to drill the box for my Tri-Vibe (which sounds teats, BTW)

[LucifersTrip]

Thanks alot! Sounds like I need to order some 2sc828s. My 3904s are reading in the 150 ish range, the distortion isn't terrible. I did search, but wanted to hear your thoughts on the matter. Did you see the T-1's honorable mention in the worst pedals evar thread? Hilarious.  The vero I saw called for 4 5088s, I imagine that sounds... different. Anywho, thanks again, now off to drill the box for my Tri-Vibe (which sounds teats, BTW)

sounds cool...I'm definitely going to test a bunch of gains to see  what really happens. I don't believe until I hear for myself.  I'm guessing that the higher gains won't matter in all positions.

I didn't see that T-1 thing, but Kay probably deserves it for the cheap enclosure!

[deadastronaut]

The red LED on deadastronauts perf layout is the rate LED. It is connected to ground and the collector on Q4.

http://aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=11002&g2_serialNumber=2

mine is unverified...you have been warned ...if i get time i'll bread it soon and post my results...

and go through some trannies too.

[Colonel Angus]

It was definitely a process to tune the fuzzyness out of this one. The Perf I posted (not mine, just crudely modified by me) works and has an illustration of how to connect the rate LED. Note the Depth control is incorrect on mine however.

[deadastronaut]

hmmm ive breadboarded it got sound but getting no lfo......hmmmm, i've not been lucky breading this week...

[Colonel Angus]

Yeah, I hear you... My breadboard success rate is less than 50%. I had a struggle with this one it the oscillator section, dont give up!

[reverberation66]

i built this 5 or 6 years ago and I believe the transistors I used were a mix of 2n2222's and 5088's.  If you place 'em right you should get very little distortion w single coils.  I think those 2222's are lower gain than the 5088's and some others but I could be wrong about that.  I dunno but if you get it right it's a really great sounding tremolo, very natural sounding

[Canucker]

I added the depth mod, it is subtle but nice.
Also I tweaked with the rate knob until I came up with something that is:
usable across almost the whole range,
goes really really fast and
doesn't cut out at the highest setting. Also added Rate LED:

I built this using the original layout and since I wanted to finally do the depth mod this is what I worked on it from....I used the other layouts to wire my pots (the grounding issue was already addressed on this one)... I noticed that the 22ohm resistor coming from the rate knob is going to ground but in the other layouts/schematics it replaces the 33ohm resistor (R15 in this layout). No luck for me with the LED...tested it before putting it into the mix here so make sure its not defective....its not...but no light when I put it in the way shown here.