Revised Parallel Universe schem (with in/out buffers)

[curtissquare]

I'm going to be fixing up my PU that I made a little while ago . . . I love this thing, but yeah the input buffer should make a tremendous difference. I might skip the effect send/return as I'm going to be making a big true bypass feedback loop box. Anyway, thanks this is going to be awesome! I did the PU on perfboard and I think I'm still going to just perfboard this new version it doesn't seem too complex. If I was going to do it on stripbaord I would upload my stripboard layout for you andre . . . anybody have a perfboard layout done up for me to use?

-Curtis

[André]

A newbie question:

What kind of caps should I use? And those caps that don't have a + marked in the schem, are those caps that don't have poles (or how you say it) or doesn't it matter how they are mounted?

Thank's in advance:
André

[expanoncolin]

Caps marked with + should be polarized electrolytic, meaning the cylindrical caps with one end marked as -.  Caps without + can be anything unpolarized, be it polyester, ceramic, etc.

-Colin

[André]

Caps marked with + should be polarized electrolytic, meaning the cylindrical caps with one end marked as -.  Caps without + can be anything unpolarized, be it polyester, ceramic, etc.

-Colin

Thank's. I have my stripboard layout ready (probobly way more messy than necessary), now I just need something to house it in and find some cheap stomp switches.

[DreamSeller]

AWESOME, This one on the top of my list. Just wondering a couple of things.

I want to make this thing as tweakable as possible so im wodering a few things.

*I want to put a three knob tonestack in (marshall/fender/vox style thing) will it work just placing it where the existing tone stack is.

Also any hints on what mods are good to put in, I know you have made a PU with a lot of knobs (The most you put into an effect ever I think). Could you help me out with what mods you put in and maybe some schems.

Thanks Again

-Dream

[expanoncolin]

Good luck man.

If you are going to do a marshall tonestack, you'll have to replace the tone and volume control-they are very interactive in this schem.  So replace the tone with your tone stack, then the volume with some sort of audio taper pot, probably.  You know, center in, one lug out, one lug to ground.

The big custom PU had an LFO too.  The fun thing about the PU is that you can control the frequency with the V+ pin of the LM386-so an LFO with the right amount of resistance, with the right amount of resistance to 9V, too, can give you LFO control, too.  Those were the real big mods as I remember.

-Colin

[DreamSeller]

Thanks for your help.

Im just having a bit of trouble understanding the part about the LFO

This bit in particular - so an LFO with the right amount of resistance, with the right amount of resistance to 9V, too, can give you LFO control, too.

Also to make myself sound even more like a newb, How exactly do I figure out which part of an existing circuit is the LFO. Ive never really worked with chorus pedal etc so I never really tinkered with an LFO before.

Thanks Again

-Dream

[curtissquare]

I think what he is talking about is putting an LFO circuit (there's a good schematic of one in the archives here) between the postive 9v supply and the V+ rail on the chip in the normal PU circuit offset by resistors on both sides of the LFO circuit . . . if that makes any sense. I might actually try this when I make my new PU.

[expanoncolin]

Thanks for your help.

Im just having a bit of trouble understanding the part about the LFO

This bit in particular - so an LFO with the right amount of resistance, with the right amount of resistance to 9V, too, can give you LFO control, too.

Also to make myself sound even more like a newb, How exactly do I figure out which part of an existing circuit is the LFO. Ive never really worked with chorus pedal etc so I never really tinkered with an LFO before.

Thanks Again

-Dream

You've got it, curtissquare...

You need to build an add an LFO.  You can use a million circuits for that.  The LFO's output should be wired to a resistor whcih is wired to the LM386's V+.  V+ should also be wired through another resistor to 9v.  The values are something like 1k and 2k2 respectively, I'm not sure.

-Colin

[DreamSeller]

So if I use the simple dual LFO in the archives (is this a good one to use?) I will wire it up and then have the output of it go to a DPDT switch (so I can switch between normal and LFO) which then goes to the normal 9v on the PU circuit (which then goes to the starve switch)

The two resistors you were talking about, was the 1k on the out  put of the LFO (which is marked as a pot in the schem I am looking at) and is the 2k2 the resistor used in the starve switch?

Thanks Again

-Dream

[DreamSeller]

I guess I might as well put down the mods I hope to do so that I can get some opinions.

*3 Knob Tone Stack  - Replacing the single knob tonestack
*LFO - If I figure it out
*On top of the R8 gain pot I intend to add a gain pot (same as the one in the original schematic) to the LM386 between pins 1 and 8. I also intend to add another gain pot to control the input amp gain, this pot will replace R7
*Put the starve pot back in (Taken from original schematic)
*Also from one of my previous posts I remember Colin telling me that the PUs sound varies alot with your guitars input so Im thinking of putting an input volume in aswell, Is it better to have the volume pot at the beggining (before the input amp) or after the input amp or maybe even both.
*Also I would most likely put in switches that change the values of the frequency capacitors
*I also like whythisreason?'s idea which I will probably put in

I'm going to put a secondary volume control on the "osc" footswitch so that, when oscilation is achieved it switches to a second volume pot so you can match relative output level with your "normal gain" sound. I think it can be quite usefull into tapping into some more potential...

*I would also like it put in a momentary switch to reset the LFO but Im not quite sure how, Can anyone here help me with that

I will have switches to switch the LFO in/out, starve on/off, frequency on/off and im also thinking of putting in a switch to change the input cap for either a brighter sound or a more bassy sound.

Not sure whether to make this a stompbox or not, It will most likely be the biggest project Ive done so I dont know if I want to be stepping on it. I may look into a rack mount enclosure for this. Plus I dont know about fitting all of this into a stompbox

If there are any other ideas on how to be able to make this circuit as adjustable as possible then please let me know, Also please comment on the mods I have listed already as I would really like peoples opinions.

Wow, That is a long list. And alot of offboard wiring (for me anyway), 14 pots, 4 Jacks, 5 switches.

-Dream

[expanoncolin]

I guess I might as well put down the mods I hope to do so that I can get some opinions.

*3 Knob Tone Stack  - Replacing the single knob tonestack
*LFO - If I figure it out
*On top of the R8 gain pot I intend to add a gain pot (same as the one in the original schematic) to the LM386 between pins 1 and 8. I also intend to add another gain pot to control the input amp gain, this pot will replace R7
*Put the starve pot back in (Taken from original schematic)
*Also from one of my previous posts I remember Colin telling me that the PUs sound varies alot with your guitars input so Im thinking of putting an input volume in aswell, Is it better to have the volume pot at the beggining (before the input amp) or after the input amp or maybe even both.
*Also I would most likely put in switches that change the values of the frequency capacitors
*I also like whythisreason?'s idea which I will probably put in

I'm going to put a secondary volume control on the "osc" footswitch so that, when oscilation is achieved it switches to a second volume pot so you can match relative output level with your "normal gain" sound. I think it can be quite usefull into tapping into some more potential...

*I would also like it put in a momentary switch to reset the LFO but Im not quite sure how, Can anyone here help me with that

I will have switches to switch the LFO in/out, starve on/off, frequency on/off and im also thinking of putting in a switch to change the input cap for either a brighter sound or a more bassy sound.

Not sure whether to make this a stompbox or not, It will most likely be the biggest project Ive done so I dont know if I want to be stepping on it. I may look into a rack mount enclosure for this. Plus I dont know about fitting all of this into a stompbox

If there are any other ideas on how to be able to make this circuit as adjustable as possible then please let me know, Also please comment on the mods I have listed already as I would really like peoples opinions.

Wow, That is a long list. And alot of offboard wiring (for me anyway), 14 pots, 4 Jacks, 5 switches.

-Dream

Sounds cool man.

All of the input volume/gain pots will essentially be useless.  The one gain pot in there is doing all of those things.  You would just have numerous pots that do teh same things, with varied levels of intensity and taper.  The starve knob is also essentially useless-that is why it's removed.  In non-osc mode, it just functioned to add some fizzle to the top of the distortion, and in osc mode, it functioned as a second frequency knob.

You will not need a DPDT for the LFO switch.  An SPDT will work fine.  1k goes to the 1k pot on that schem you are looking at.  2k2 goes to 9v.  It could be the other way around, I'm not sure.  You are really going to want to breadboard something like this before you put it in a box, especially with so many changes.

-Colin

[DreamSeller]

I will leave the starve pot in, I likes them semi video game tones that I could get from using the starve pot on my original PU. I wont put the gain pot on the lm386 but I will keep the input gain and volume pot.

I am going to put this into a rack mount enclosure, I will draw up a template soon.

Also does anyone know how to go about putting in the LFO reset switch?

Thanks

-Dream

[expanoncolin]

I will leave the starve pot in, I likes them semi video game tones that I could get from using the starve pot on my original PU. I wont put the gain pot on the lm386 but I will keep the input gain and volume pot.

I am going to put this into a rack mount enclosure, I will draw up a template soon.

Also does anyone know how to go about putting in the LFO reset switch?

Thanks

-Dream

If you want gating from the starve knob, make it 5k and don't put in the switch... otherwise you won't really get any gating.  LFO reset might be possible with a normally closed switch between V+ and the LFO's V+ pin.

-Colin

[DreamSeller]

I would assume that you only hook up the LFO to the LM386 9V and not the input amp.

Am I Right?

-Dream