Multi LED on ross/dyna clone

[Jamiroking]

Hi,
I'm building a compressor from Tonepad but they dont have a forum over there so I figure I'd pick your brains again since you've helped so much  before. The comp has a mod that adds a 4pdt to swtich between the caps for a dynacomp or ross clone. I had a coupole of qustions just so I'm understanding exactly what its doing.

1.) Did this mod really need a 4pdt? Since the dyna settings are empty (I assume NC means no connection), isn't this turning a 4pdt into a 4pst? At that, couldn't the same effect have been achieved with a spst since all it is doing is breaking the caps' connection to ground? I already bought the 4pdt but I have a feeling its a bit overkill

2) Is there any way I could hookup a dual color led to this pedal for the indicator that would give me color 1 =dyna, color2 = ross, and off=off?

Thanks again guys

Pedal layout
http://tonepad.com/getFile.asp?id=9

Mod layout
http://tonepad.com/getFile.asp?id=24

[stecykmi]

They are using the 4pdt as a 4pst, but I believe you'll need 4 poles as not all of the extra caps are connected to the same node (that node being ground).

One solution would be to use a rotary switch instead of a rocker switch.

A 2 position 5 pole (at least 5) would work perfectly, including the LED mod. I have to run, but if you're interested, I could draw out a little wiring diagram later tonight.

[Jamiroking]

That would be great! I already bought the 4pdt a while ago but it would help me a lot to understand whats going on here. In the mod schematic, it looked to me that the switch was either connecting from the positive pads, through the caps, to the ground or there was nothing running to ground.

As for the LED mod, do you think it would be possible with the 4pdt I have?

Thanks again!

[stecykmi]

That would be great! I already bought the 4pdt a while ago but it would help me a lot to understand whats going on here. In the mod schematic, it looked to me that the switch was either connecting from the positive pads, through the caps, to the ground or there was nothing running to ground.

As for the LED mod, do you think it would be possible with the 4pdt I have?

Thanks again!

First off, please excuse the ms paint wiring diagrams. Anyway, after I looked at it a little more closely, it's possible to do with a dpdt switch, including the LED switcher! The reason for this is because all the caps are simply connected to ground, the same node (take a close look and you'll see what I mean).

Here's a wiring diagram done with a 6pole 2position rotary switch which is bigger, but probably somewhat easier to wire. Notice that one pole is unused.



and here it is done with a 4pdt (but notice that 2 poles are unused). This might be tricky to wire up since you'd have to solder 4 caps to one lug. If I were doing this, I would probably build a little perf-board circuit to hold the 4 caps.

[stecykmi]

It occurred to me in a dream that you owe it to yourself to call this pedal the dyana ross.

[oldhousescott]

Lifting the common ground of the four caps is not same as breaking each connection individually. In the original mod, the caps are completely out of circuit when the switch is open. When changed to break only the ground connection, the caps are still in circuit, and are connecting together points of the circuit that were not meant to be connected. For example, you would be providing a feedback path from the collector of Q1 to the base of Q1 through Cb, Ca, and Cd.

I would at least put Cb on its own set of contacts, and perhaps Cd as well. That would take up 3 of the 4 poles, and you'd still have one left for the LED.

My .02, YMMV, etc....

[Jamiroking]

Wow! Thanks a lot for the sketches! It helps explain a lot.

Lifting the common ground of the four caps is not same as breaking each connection individually. In the original mod, the caps are completely out of circuit when the switch is open. When changed to break only the ground connection, the caps are still in circuit, and are connecting together points of the circuit that were not meant to be connected.

Ah ha! I knew there was something I was missing! Otherwise I'd be pissed that I went through the trouble of buying a 4pdt when a spst would have worked. Although it still appears a 4pst would have done the job and saved me a couple bucks...

I would at least put Cb on its own set of contacts, and perhaps Cd as well. That would take up 3 of the 4 poles, and you'd still have one left for the LED

Since its a compressor I don't want to introduce any more noise into the signal than I have to so I may end up just wiring them all separately and sadly use an LED with one color The rotary switch sounds like it would have worked better. I wish I knew more about switches when I was ordering parts. Oh well.

It occurred to me in a dream that you owe it to yourself to call this pedal the dyana ross.

That is pretty amazing and is making me rethink my original idea of Dynasauross

[wasteofspace]

It occurred to me in a dream that you owe it to yourself to call this pedal the dyana ross.

Err.. No. It's a copy of a Dyna Ross, so it should be called a Jaxon (or Jackson, or Jaxxon, or something Jacko-related (RIP))

Good taste and I have never been close.