Intersound IVP gyrator circuit output

[jimladladlooklike]

Cool! But in theory this should work?

[PRR]

There needs to be a DC block couple capacitor.

That drawing is so twisted and spread out that we can't clearly discuss it.

[jimladladlooklike]

I apologise for my schematic drawing skills (or lack thereof!). I tried to make the different sections distinguishable but theres a lot going on and this is one of maybe 3 schematics I've drawn.

I'll add that DC blocking cap and have a go at tidying it up.

Thanks a bunch again

[ElectricDruid]

That drawing is so twisted and spread out that we can't clearly discuss it.

Personally, I like the fact that it's nice and spread out, with the logical blocks separated.

What I find difficult about it is the switches that do the routing. I can't work that out at all. "Everything is switched all over the place" is what I take away from that.

[jimladladlooklike]

I did try and separate in a logical way to make clear where each circuit started and ended - as in Guv'nor / IVP Gyrator / MXR Dist+ (perhaps not that well, admittedly).

I agree the switching is far from neat. That's definitely the part I had the most problems drawing. The idea is to be able to send signal to/bypass each of the above 3 sections independently.

Cheers

[PRR]

I did try and separate in a logical way to make clear where each circuit started and ended ...

Then go around and figure-out HOW each stage/circuit start/end is DC-blocked and re-biased.

_I_ think you have a EQ stage getting both a mid-bias and a to-ground path. This plus DC gain in the EQ is throwing the output above the roof.

Not always, but "sometimes", it is better to separate the switching and the stages and connect them on the drawing with labels. This can go TOO far: the recent Toyota wiring diagrams are all labels and no function, or so it seems.

[ElectricDruid]

+1 agree.

I think keeping the two parts of that job separate would be a good idea. If each *stage* is sound, then the *switching* should be simple. At the moment, it's hard to pull one out from the other. Perhads Paul's suggestion of breaking out the different sections with labels and then using those for the switching is a good one. It would keep the "circuit making" part separate from the "circuit routing" part.

[Rob Strand]

Here's a revised version... I'm unsure of how I'm meant to bias U4A to be honest.

I'd move R41 (1M) to before R8 not after, there's no real reason to put it after.
R8 should be 20k not 10k, same value as R27 (20k)

For the Equalizer,  what's missing is an anti-pop resistor to ground after C20 (1uF) at the output of the Equalizer
Also an anti-pop cap and resistor on the input of the Equalizer.  Use 1uF in series with R8 then a 1M resistor to ground on the input side of the cap.

A bigger issue is the input impedance to the Equalizer is going to be very low.    That's going to be an issue when your select EQ only for sure.  However, it's also going to load down the relatively high impedance output of the first overdrive pedal.  You really need to add buffer to the input of the Equalizer, before R8.  Adding a buffer will change what I've said about the input of the EQ in the previous paragraphs - in fact with a buffer you don't need a cap between the buffer and the EQ nor do you need the 1M resistor (R41).

Your schematic is a little small and it's hard to read the values and part designators.  So some of the part values and designators I've mentioned might be off.

[jimladladlooklike]

Thank you all for your advice!

I've got the whole thing working as it should finally. Squeezed the AMZ basic JFET buffer onto the layout, did just the trick.

I will work on the schematic when I get some spare time and post here in case you're all interested!

Cheers again, this thing does exactly what I had in mind.