A Quick note on the Kay Tremolo mod

[LucifersTrip]

I built the original  with 2N3391's:



Then I added the depth mod, which does give you some more control:



But, I didn't understand why the 100k depth pot was put in series with the 68K resistor [especially if you want full depth control] so I simply replaced the 68K with the 100K pot...and it's far better. Now instead of the 68k "cutoff", you can drop to 0k and get some much sharper depth, which is excellent !

...just a quick note if you're goin' for this unique tremolo.

[alotawatts]

Interesting....
I just finished a GGG EA Trem. The depth pot is R13 -

http://www.generalguitargadgets.com/pdf/ggg_eat_sc_improved.pdf?phpMyAdmin=4a28f86a515b7883e7bc35a68d4e7b6d&phpMyAdmin=78482479fd7e7fc3768044a841b3e85a

[LucifersTrip]

Interesting....
I just finished a GGG EA Trem. The depth pot is R13 -

http://www.generalguitargadgets.com/pdf/ggg_eat_sc_improved.pdf?phpMyAdmin=4a28f86a515b7883e7bc35a68d4e7b6d&phpMyAdmin=78482479fd7e7fc3768044a841b3e85a

The EA was one of the others I was planning for the future. What happens when you lower R7 or R19 ?

[Renegadrian]

gotta try this out, thx for reporting!

[alarm]

Hi, I am just about to set off building one of these.
Can anyone tell me if the depth mod of replacing the 68k resistor with just a 100k pot turned out to be better than the fixed resistor and pot combination.
Also, would it be possible to add a volume pot to this and if so where? I was thinking a 100k pot wired to the output,the 0.22uF cap and ground.
Thanks for any help

[LucifersTrip]

Hi, I am just about to set off building one of these.
Can anyone tell me if the depth mod of replacing the 68k resistor with just a 100k pot turned out to be better than the fixed resistor and pot combination.

as I wrote above, for me it was much better and gave me more control...obviously. you can put any cutoff you like if you don't want it to hit 0K

Also, would it be possible to add a volume pot to this and if so where? I was thinking a 100k pot wired to the output,the 0.22uF cap and ground. Thanks for any help

yep, that's where you'd wire it...just like a standard one. experiment with the size.  though, don't think you really need one since there should be little or no increase in volume.

the biggest think to worry about (read other posts about it) is to avoid higher gain transistors or you'll wind up with distortion along with the tremolo. I wouldn't use anything higher than 200 hfe

good luck

[alarm]

Thanks LT I am working on a vero layout with on board pots. Good to know about transistor type problems, I was going to use bc109 as per Andy Carrells layout as I have some of these but from what you have said these might be too high gain. What type did you or anyone else use with success?

[alarm]

Ok so iI have finished my layout. Please let me know what you think/ If it should work?

[LucifersTrip]

Thanks LT I am working on a vero layout with on board pots. Good to know about transistor type problems, I was going to use bc109 as per Andy Carrells layout as I have some of these but from what you have said these might be too high gain. What type did you or anyone else use with success?

Seven64, who had the distortion problem
http://www.diystompboxes.com/smfforum/index.php?topic=92902.msg796666#msg796666

...wrote me a while later (I'm sure he wouldn't mind me sharing):
"hey, i found a thread from a while ago where i was asking about distortion in the kay tremolo.  you said you were experiencing the same problems.  just thought i would let you know today i was fussing with it again, and threw in some 2n3904's and now it works like a champ."

I was going to use lower gain ones on my next build. I always have 2N5550 and 2SC1815 laying around.

here are some voltages from an original (note the battery he used is low).
http://www.diystompboxes.com/smfforum/index.php?action=printpage;topic=16759.0

[Seven64]

confirming that i built the pcb layout with 2n3904's with hfe's around 200-210 and it works pretty well.  it sounds fine with my strat, but on my buddies schecter with semour duncan humbuckers and my esp with active emgs there is a little bit of distortion.  i am sure a simple resistor swap would fix this tho, as with the louder guitars the signal is quite a bit stronger than unity.

[alarm]

Thanks guys I'll have a go at building the layout that i've put together and let you know how i get on. The only lower gain trans i have are ge AC176's. I'll give them a try and order some lower gain silicon ones.

[Colonel Angus]

Awesome, thanks! I'm gonna try this mod tonight.

[deadastronaut]

@luciferstrip:   i'm doing a layout for the kay tremolo.

a couple of questions,

1:  did you remove the 68k totally...then have the 100k pot from the 2x33k's..?

2: how could i add a speed rate led to it?...

cheers rob.

[LucifersTrip]

@luciferstrip:   i'm doing a layout for the kay tremolo.

a couple of questions,

1:  did you remove the 68k totally...then have the 100k pot from the 2x33k's..?

yes, exactly....

2: how could i add a speed rate led to it?...

cheers rob.

sorry, didn't try to do that...I rarely work with tremolos, so I would've probably just used the trial and error method, anyway.

...and remember not to use high gain transistors.

[deadastronaut]

cheers man, i'll trial n error the led too....

[Colonel Angus]

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:

[deadastronaut]

cool, nice one brian!...

[LucifersTrip]

I added the depth mod, it is subtle but nice.

...my depth control is not subtle at all

[Colonel Angus]

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.

[deadastronaut]

@brian so the flashing led comes directly off the 2x33ks to ground then?...by the looks of it...

and you left the 68k there..?

heres what i have...any dodgy bits?