GGG EA Tremolo - half speed mod?

[sweetwilly]

Hi all.  Just about to build an EA Tremolo using layout from GGG.  I was going to use a 2nd footswitch and do the Booster Mod listed within the project documents, but was thinking a Half Speed footswitch would be a much more useable mod (considering I have a couple of preamp booster effects already!).

All of the project docs are listed under this link -

http://www.generalguitargadgets.com/index.php?option=com_content&task=view&id=142&Itemid=26

I'm pretty new to electronics and have only have a basic understanding of all this, so looking for a relatively simple way to use a footswitch to halve the speed.  I've read about a couple of methods to do this, but haven't been able to find anything specific to this project and what I'd like to do.

Any suggestions greatly appreciated!
Willy.

[jlullo]

dragonfly has a mod for this in his gallery:
http://www.aronnelson.com/gallery/main.php/v/DRAGONFLY-LAYOUTS_0/The-Mod-Zone-_/EA_rate_mod.gif.html

[fogwolf]

In that diagram, where on exactly on the board is the "From Circuit Board" wire connected? Looking at the way the Speed pot is currently wired, seeing that the diagram says to connect the switch to speed pot lug 3, which is currently connected to ground, I'm not clear on where on the board the switch connects.

dragonfly has a mod for this in his gallery:
http://www.aronnelson.com/gallery/main.php/v/DRAGONFLY-LAYOUTS_0/The-Mod-Zone-_/EA_rate_mod.gif.html

[jlullo]

It looks to me as though you'd take the wire that would originally be going to the RATE pot's third lug, solder that to one side of the switch, then the other side of the switch to the 3rd lug on RATE

[fogwolf]

Am I looking at the wrong diagram or is there something I'm reading wrong - https://www.generalguitargadgets.com/pdf/ggg_eat_lo.pdf?phpMyAdmin=4a28f86a515b7883e7bc35a68d4e7b6d - it looks to me as though lug 3 of Speed (Rate) is only connected to the ground lug of the Volume pot. Lug 1 of Speed is connected to a pad labeled S1 on the board.

It looks to me as though you'd take the wire that would originally be going to the RATE pot's third lug, solder that to one side of the switch, then the other side of the switch to the 3rd lug on RATE

[sweetwilly]

thank for the link jonathan.  a couple of cool ideas there.

[Alman]

Fogwolf, Usually the first lug goes to ground when used for a gain or volume. In this case it is probably reversed because it is used for a rate control, so the switch would go between the wire coming from the board to the first and second lug.

Allan

[sweetwilly]

Does anyone know if the resistor value shown on dragonfly's mod is going to be correct for the GGG layout, assuming, of course, I use exactly the same parts as listed?  If not, how would I figure out the correct value to use?  Excuse me if this is a bit of a dim question, still trying to figure out how this mod works exactly!

[fogwolf]

Ah, ok. Thanks for clearing that up!

Fogwolf, Usually the first lug goes to ground when used for a gain or volume. In this case it is probably reversed because it is used for a rate control, so the switch would go between the wire coming from the board to the first and second lug.

Allan

[sweetwilly]

I may be getting ahead of myself here, both skills-wise and seeing as I haven't got the board or parts yet, but have been thinking about what other speed mods can be done. 

Would it be possible to use something like RG's LERA circuit (http://www.geofex.com/Article_Folders/lera/lera.htm) wired to a momentary footswitch to cut the speed to half gradually when pushed, back to normal when released? 

Or is there a simpler circuit I can wire to a normal 3pdt/dpdt footswitch (I have spares) that would just slow the speed change down?

Many thanks!

[sweetwilly]

bumbity bumpity bumpity boo