Fender style ldr/neon tremolo

[shzmm]

Hi,
I am building a stand-alone tremolo unit at the moment using R.G. Keen's mosfet design. It is based on a Fender neon/ldr circuit: http://www.geofex.com/Article_Folder.../sstremolo.htm
I am using an ldr of the following specification: 8k on 300k off http://optoelectronics.perkinelmer.c.../dts_vt400.pdf

My problem is that when the tremolo is engaged the signal is completely suffocated. My guess is that maybe the ldr simply isn't fast enough? Or the on resistance is simply too low?
Has anyone made their own "bug" before and encountered this problem?
Included is a copy of the circuit I am using. Any comments/concerns are greatly appreciated.

[jrfrond]

Your "Dark Resistance" spec is certainly high enough, but indicates a recovery time to peak resistance of 30 seconds! This is FAR to slow for a tremolo unit. My guess is that this is your problem. It's easy enough to measure this spec if you have a voltmeter.

[shzmm]

Ah ok thanks for the reply. That's what I assumed but it's so difficult to find any photo cell with appropriate specs. I've thought of maybe using a vactrol instead but I'll need to look into how to implement it.
Thanks again for looking...

[Enzo]

Where are you? Jameco used to have a good selection of photocels.

[shzmm]

I'm in Europe so ordering from the States isn't economical. I'm thinking of ditching the idea of using the neon bulb and trying a vactrol instead. I've heard that is the standard now but I haven't seen any schematics where they use one-- the contemporary Fender schematics appear to use the same "bug" style as always. I would think I will have to adjust the voltage down considerably to not fry the led.
If you know of any off hand please let me know. And thank you for your suggestion.

[Enzo]

LEDs run on current. You can put 250v on one end and find 249v on the other end. You have to arrange for the current to be limited to the 10-20ma or whatever that the LED wants.