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Subject: Re: “Vintage Vibe” Low Voltage 6111 Submini Tube Vibrato

From: "frequencycentral" <frequencycentral@...>
Date: 2009-02-18

Hi Andrew,

The LDRs I used:

Typical dark resistance = 1M Typical light resistance = 2K - 4K

The 6K8 resistor in series with the LED and Depth control sets the
maximum brightness of the LED. You could replace this with a 10K
trimpot if your LDRs are different to mine.

As I'm building this as a guitar pedal, there didn't seem much point
in being able to set the Depth pot to 'no effect' as the effect can
be bypassed by switch, so at it's minimum there is still a small
effect. Replacing the 47K pot with a 100K pot would allow you to
completely 'dial out' the effect.

You shouldn't have to change the 100K cathode resistors at all. These
are set up (together with the 100K anode resistors) to provide phase
cancellation (I think/hope!).

If your LDRs have a higher dark resistance than 1M you could just add
a parallel 1M resistor to limit them.

Have fun and please post your results/improvements!

regards

Rick


--- In tubesynthdiy@yahoogroups.com, "bbluthang" <jumpswine@...>
wrote:
>
>
> sounds great
> will try it with 6021s.
> Do I need to consider the on/off resistances of the LDRs and adjust
> the 100k resistors to suit?
>
> cheers
> Andrew