AMZ pickup simulator -- vero layout?

[mordechai]

Hi...I am looking for a veroboard layout for the AMZ pickup simulator circuit (the first, simpler one).  I did a search through the archives, and if it's there, I missed it.  Any help would be appreciated.  Thanks.

[slacker]

There probably isn't a layout for it, it's just a transformer, a switch, a pot and a cap, there's no need for a board.

[wavley]

Yeah, I just foam taped mine next to the switch and built everything on the lugs.

[mordechai]

Alright, I'll give that a try. 

In your experience, does this add-on interact fairly well with the guitar volume?  In other words, with this engaged while using active pickups, will the fuzz still interact with the volume pot on my guitar as it would if I was using regular pickups and a regular fuzz circuit?

[induction]

I haven't tried that, so I can't say for sure, but I would think that as long as there are no buffers or other actives after the volume knob, it would probably work okay, assuming you're talking about something in the fuzz face family. If I recall Gus's explanations correctly, the gain of the first stage of the fuzz face depends on the series resistance of the volume knob. To make it interactive, the fuzz face has to be able to see that resistance, it can't be hidden behind a buffer.

[mordechai]

Well, that's what concerns me.  If I go from the volume out of my guitar into the pickup simulator, then isn't the front end of the fuzz (yes, a fuzz face circuit) seeing only what's coming out of the simulator and not my volume control?

[anchovie]

Well, that's what concerns me.  If I go from the volume out of my guitar into the pickup simulator, then isn't the front end of the fuzz (yes, a fuzz face circuit) seeing only what's coming out of the simulator and not my volume control?

Correct. That first circuit is just for tone-shaping - if you want the effect of varying passive pickup volume in performance, build the last circuit in a wah/volume/expression pedal shell with the tone control as a regular pot on the side.

[induction]

I'm not sure I agree. A passive pickup can be modeled as a resistor in series with an inductor followed by a cap to ground. The responsiveness of the fuzz face to the guitar volume knob is due to its dependence on the RLC circuit in the guitar, including the volume knob. The pickup simulator provides RLC elements, but your guitar volume knob also contributes series resistance. The volume pot is not hidden from the fuzz face input, it's in series with the pickup sim and there is no buffer to mask its impedance contribution.

The reason for putting a volume knob and tone control after the pickup sim is because the pickup sim is designed to come after a buffer, in which case the guitar controls are effectively decoupled from the fuzz face input, so the volume knob setting does not contribute to the impedance of the signal at the fuzz face input. This is not the case with active pickups as long as the volume pot comes after any active circuitry.

The biggest difference between a real pickup and a pickup sim following an active pickup is that the volume knob comes after the pickup impedance in the real pickup, and before the pickup impedance in the sim. With series components, order doesn't really matter, but the volume pot is a voltage divider, so it is connected to ground. This may or may not change the volume knob response, I'm not sure. But I wouldn't be at all surprised to find out that the volume knob cleanup in this case is very good. In any case, it's easy enough to try it out and see how well it works empirically.