Silly Feline Question layout question

[soggybag]

I just finished up up GEO Silly Feline, using a board from GGG which was a pleasure to work with. Looking at the layout there are two switches 1 SPDT and 1 DPDT (Not including the rotary switch). On the schematic there are three switches 1 SPDT and two DPDT. I'm a total amature, but it looks to me that the bypass switch has been left out of the layout and the DPDT shown on the layout is the Harmonic Mover switch? I figuring that I can wrap this in any of the common true bypass wiring schemes?

[optimus_prime_1985]

That is a good question! I just got my board for this project a week ago and am starting to populate it. I have the same question as you. Especially since the project makes mention that "you may want to add true bypass" Anybody know if this is indeed the harmonic mover switch?

[moosapotamus]

I'm a total amature, but it looks to me that the bypass switch has been left out of the layout and the DPDT shown on the layout is the Harmonic Mover switch? I figuring that I can wrap this in any of the common true bypass wiring schemes?

Yes, you got it!

Should be easy enough to figure yourself like this... Just pick a point in either the scheme or the layout, start tracing, then compare. Start with the center pole of the SPDT on the schematic, for example. Notice which components it connects to (C18 and the center pole on one side of the DPDT harmonic mover switch). Now, go look at the layout. See all the things the center pole on that SPDT connects to? It's the same as the scheme, isn't it?

DIY, y'all!

~ Charlie

[soggybag]

Thanks for the reply, that was very helpful.

While we're on the subject, let me also confirm that the two pots should be linear B50K. The layout shows B50K but the parts list says 50K Log. I searched up some posts about this and one post says the posts should be linear but there was no confirmation.

One more, I have my feline all wired up still and I find I do not hear the effect all of the time. It sounds like it is working correctly but the sweep doesn't come in all the time only when I play very hard or loud. Do rfba, rfbb or rfbc need to be tailored? I have used 4558's as the dual opamps and NTE 459 as the FET.

Speaking of which, the NTE FET has 4 legs? I had never seen that before. The package listed the fourth leg as can. I assumed this meant it was grouned to the metal exterior of the FET. I figured I'd be ok leaving it unconnected.

[moosapotamus]

Taper on the pots is not critical but as a general rule, log (audio) for level/gain type controls and linear for most of the rest. So, linear is good for the balance control and would be ok for the sds level control, too. But, a log taper for sds level might "feel" better.

You could try replacing Rfba with a 1M or a 2M. More gain up front should help to trigger the HM more predictably. I installed a switch in mine to go between the stock 470K and 2M values. Making Rfbb and Rfbc variable will give you lots of sweep-shaping capabilities. I added a 500Ka pot in series with each.

I always leave that can leg unconnected and, sometimes, even snip it off... after I've confirmed that I've got the pinout right, of course. :wink:

~ Charlie