Kay Trem Build Report/Questions

[mydementia]

After building two EATrem's I decided to go for something with more chop.  Yesterday, I threw together a Kay Trem from Dragonfly's vero layout (http://aronnelson.com/gallery/album20/KAY_TREMOLO) - used 2n5088's for all 4 trannies.  At first it was tremolo-ing...but poorly.  I went over everything I could think of - then remembered when I was lying in bed that I stole a 47uF electro from one of my Ruby builds...not a 4.7uF!    Made all the difference in the world.  Now I'm getting good, choppy trem.  I have a couple questions that didn't seem completely addressed in the threads I found using the Search tool:

1) How can I counter the volume drop when the trem is on?  It's significant.  I haven't tried on my rig yet - but on my test amp it's significantly lower volume.

2) How can I clean up the low strings?  Unless I barely strike the low strings - the trem distorts. 

If I could solve these issues, this will be the trem that goes on my board (will likely package it with a TS808 clone in a 1590BB).  The range of speeds is more what I'm looking for.  The chop is also much stronger than the EA - still not quite square wave chopping - but pretty good. 

Here's a pic of my board for fun (just love how small vero layouts can be):

Yes, the pic shows 2n2222's in Q2 and Q3 - seemed to distort a little more than 2n5088's...

Thanks for looking.
Mike

[somasix]

I just recently finished this one myself.  I haven't tried to correct the unity volume issue yet.  As you probably found via the forum search, Dragonfly recommended to 'try using a nte47 (or 5089) in place of the "furthest transistor on the right"'  Until I correct it, I'm probably going to give it it's own signal chain with an AB box and a booster after it.

Regarding the notorious Kay Tremolo distortion, I actually don't get it that bad.  In my own newbie logic, I'm assuming it's cause I misordered BC109's instead of BC109C's.  No one has specifically affirmed this reasoning, although I'm sure I could if I compare the hfe of of the BC109 datasheet. 

I'm impressed that you got those homemade transistor sockets in there.  I had bought full sized sockets without giving much thought to how tight the layout is.  Those tranny sockets are eventually going to make it into another project as I was too lazy to whittle away at them.

Dragonfly's layouts have denfinitely helped my confidence as a novice builder.  My initial foray's into perf were intimidating to say the least.  It was hard for me to figure out what I did wrong as I stared down at all those criss crossing leads and blobs of solder.  There are more than a few vero layouts I look forward to building from his folder (I'm currently building the Parallel Universe and the Shin Ei is after that).  I've come to enjoy the ease and cleanliness of veroboard and the excitement of building some classics I used to own (but don't anymore) or that I've always wanted. 

I do think it's important for me to return to perfboard as my confidence grows.  I feel it will give me a better understanding of the transition from schematic to circuit.

[mydementia]

I started on perf - had some good success until I wanted to put multiple effects into small enclosures...vero and purchased PCB's are the way to go! 

I've been using SIP sockets for my trannies ever since I discovered them.

Last time I bought from Mouser, I got these:
http://www.mouser.com/index.cfm?handler=displayproduct&lstdispproductid=318912&e_categoryid=608&e_pcodeid=57508
also bought them from here:
http://www.allelectronics.com/cgi-bin/item/SIP-30/search/SNAPPABLE_30_PIN_SIP_SOCKET,_.1"#34;_CENTERS_.html

Maybe if we keep chatting someone will chime in with help on volume drop and distortion...

Happy building.
Mike

[B Tremblay]

No tips on the issues you're having, but I just wanted compliment you on the choice of background for the photo!

[mydementia]

Good eye...I always seem to test my circuits on whatever songbook is lying around - I was recently working on the Seek and Destroy solo...
This group would probably be REALLY good at a 'name that songbook' thread!

[somasix]

All right, here's an idea regarding volume unity.  Is the 33K resistor the output resistor and could a trimpot or volume pot be used in place of that resistor? 

[Dragonfly]

...using the nte47 should help it be slightly more "choppy".

...for the low strings' distortion, you could "try" adding a small value (maybe 10-15k ?) resistor to the front end of the circuit...may be handy with high output pickups.

...as for the volume issue...ive toyed around with the idea of tacking on a fet boost (like the fetzer valve or sparkle boost) to the end of the circuit...should boost it plenty...

as always,   ymmv....

AC

[reverberation66]

 I just built this myself, using 4 2n5088's and was having the same issue with distortion.  I did a forum search here on 'kay tremolo' and there's all kinds of suggestions for dealing with the problem.  I tried the easiest first, which was using a 2n2222a for Q1 and Q4 and that cleaned it up nicely.  I still get a little distortion on the low strings if I really hammer on the guitar but it's really not an issue any longer.  as far as the volume drop, I get that too but it's not a big deal to me at the moment so I haven't tried anything yet...cool tremolo though, very unique sound that I like a whole lot, spooky and can get really fast, reminds me of this old paia "synthespin" I used to have.

[mydementia]

...and it's finally finished...   - just needs a box...

I got rid of the KayTrem distortion by using a 2n2222 in Q1 and 2n5088's in the rest.  I added a sparkle boost (at Dragonfly's recommendation) to the Kay Trem output and it works GREAT - eliminates volume drop.  I put this trem after a TS808 clone that I'm going to package together - should be great.  The trem is nice and choppy.  With the Sparkle boost - I get unity volume.  I didn't have an NTE458 so I twisted around an MPF102 for the right pinout.  I also left the gain pot out and opted for a fixed resistor.  Is 5k max or min?  (I socketed this junction)

Thanks for all your input - this forum is awesome.
Mike