So THAT's where I left my nose!

[~arph]

Yes, and Mark then goes into talking about one pedal controlling both an increasing and decreasing resistance value and how they can be used in certain circuits. The link I provided shows that you can do the same with a regular pot arrangement without the need of specific hardware. It's just there for information purposes, I am not trying to be a smartass I just thought it might have been relevant to this thread.

Btw, I had some issues with that circuit too a few years back, but I accounted that to my lack of experience at the time. Funny to hear you having issues with ttg circuits too.

[Mark Hammer]

The reciprocal LED thing can work, and probably as per TTG expectations.  But as is probably true of all applications of photocells, you have to be picky about the LED, the LDR, the relatinship between pot resistance and LED brightness, the LED-brightness-to-photocell-resistance curves, the relationship between photocell resiostance and the parameters of the circuit under control, etc., etc.  Anything operated via a foot treadle will have a "feel" component to it, and the feel is a function of how the parameters of all the components tied to that treadle change.

It will work, and can be made to work.  It won't just "work" in plug-and-play fashion, the way that popping another dual op-amp into the socket will.

[armdnrdy]

Yes...I thought that I had a "problem solved" with the T.G. circuits....but it turned out....back to the drawing board!  

As I stated above, I was trying to implement an adjustable resistance (for different effects) expression pedal to control various parameters of pedals. From what I've seen so far, I think that the shutter/LED/ LDR combo is on the right track.

The shutter assembly can be fabricated without to much grief to fit a normal wha shell.

[armdnrdy]

The reciprocal LED thing can work, and probably as per TTG expectations.  But as is probably true of all applications of photocells, you have to be picky about the LED, the LDR, the relatinship between pot resistance and LED brightness, the LED-brightness-to-photocell-resistance curves, the relationship between photocell resiostance and the parameters of the circuit under control, etc., etc.  Anything operated via a foot treadle will have a "feel" component to it, and the feel is a function of how the parameters of all the components tied to that treadle change.

It will work, and can be made to work.  It won't just "work" in plug-and-play fashion, the way that popping another dual op-amp into the socket will.

I worked on it for a few days with a variety of components (LDRs and LEDs) and variations of this circuit found on the net.
I was trying to achieve a stable low ohms to 100K with a standard 10K expression pedal pot......never got there.

I've found the shutter to be more stable and adjustable.

[Mark Hammer]

My job involves development of web-based government surveys.  Given the multitude of problems we encounter related to servers, firewalls, accessibility standards, diverse operating systems, mobile devices vs desktops, programming skip patterns, and trying to keep things a legible size without requiring too much scrolling down, I am well-known in my work unit for mumbling "Paper is easier" through my fingers in an I-told-you-so manner at our meetings.

There are plenty of contexts in which what seems like the more cumbersome and backwards "old school" route to the desired goal actually ends up being the more expedient...much to the chagrin of those who prefer an elegant state-of-the-art solution.

Yeah, I would imagine that, once you know what you're doing, you could make a shutter to pretty much any spec in much less time than it would take to tweak the electronic components to arrive at the needed taper. 

[tubegeek]

Well, and this could probably not be MORE off-topic, I've been wrestling at work with trying to pull various bits of student data from paper records and also two or three computerized systems.

I have been wishing for a comprehensive database instead of all this - wonderfully relevant but scattered - paper I've got.

So there!

[deadastronaut]

5:35 onwards...morley pro volume shutter mod...and an interesting note on the power led..hmmmm...

[soggybag]

5:35 onwards...morley pro volume shutter mod...and an interesting note on the power led..hmmmm...

I love this guy he's so obnoxious. I can't help but think he's got it wrong about the LDR saving your tone vs the volume pot Seems the loss of tone on the guitar volume is due to the interaction between the tone and volume pots on the guitar.

I have an older Morley Volume pedal. It's similar but different.







http://www.super-freq.com/?p=1181

[Kipper4]

There it is


http://www.bbc.co.uk/newsbeat/24280766

[deadastronaut]

whoooahh...

now where did i leave my p...s