ross phaser (ropez) extra board switching quesion

[jmasciswannabe]

http://www.tonepad.com/getFile.asp?id=100

Just making sure I am getting this right. I am planning on making two additional boards. I read on how to do this with a 3 position dpdt but was wondering could I use a dpdt to switch on the first exta board (8 stages) and then use another dpdt to swirch on the next board (12 stages)? X and Y of the main board would attach to the two commons on the first dpdt, switched one way would gotto n and o on the first add on board and switched the other way the two remaining lugs would be connected together (essentially connecting x and y, right?). And the same from x and y on the first add on board to the 2nd dpdt and 2nd add on board. And all the other pads v, w ,u ,z would just run in series from main board to first board to second board. I definitly want to be able to switch because I plan on doing hammer's mods regarding the univibe mod and the low pass filter mod and this would be easiest in just the four stage setting.

[jmasciswannabe]

All right....didn't get any responses from that idea so let's stick with Mark Hammer's switch idea:

I think there IS a way but it means obtaining a less commonly found (and more expensive) type of toggle.  This would be a 3-position DPDT toggle with the following properties.  Let's start off by calling one set of contacts 1, 2, and 4, where 2 is the middle/common, and the other set 4, 5, and 6, where 4 is the middle/common.  Flicked to one side, the 1>2 contact is made.  Flicked to the other side, the 5>6 contact is made.  Set to the middle, both the 2>3 and 4>5 contacts are made.

IF you were able to find one of these, you could connect the free end (labelled point D on the recent Tonepad Ropez layout) of the 27k resistor that feeds the phase-shifted signal to the mixer/output stage to the two center contacts/lugs (2 and 5).  Then, contact 1 goes to the 4-stage tap, contact 4 (or 3) goes to the 8-stage tap, and contact 6 goes to the 12 stage tap.  Actually, the wiring is easy, the FINDING of the switch hard...but not impossible.

I was wondering if this switch from Mouser might do the trick. http://spec.e-switch.com/T-D/T126001C.pdf So, I should be able to send a wire from D on the main board to lug 2 on the switch and then send out lug 6 in position 1 to the 4 stage tap (d on the main board), out pin 4 in position 2 to the eight stage tap ( o on the first exta stage board), and out pin 1 in position 3 to the 12 stage tap (o on the second second extra stage board). And all the tonepad wiring would stay the same. Will this work?


http://www.tonepad.com/getFile.asp?id=99
http://www.tonepad.com/getFile.asp?id=100

[jmasciswannabe]

bump

[Mark Hammer]

I'm having a hard time following in the absence of all the other information, but my first response is that YES this is the exat type of switch I was referring to (with the added jumper removed).  My guess is that it probably costs about the same as a 3PDT stompswitch, right?

[jmasciswannabe]

Sorry Mark, I should have included this link:

http://www.elixant.com/~stompbox/smfforum/index.php?topic=38319.0

The switch was like 6.50 or so....expensive little booger, but I am going all out on this phaser project. I also got a rotary switch so I could go between stock, univibe, and lowpass filter values. And of course the switch for the vibrato mod. I guess I was more concerned that I had the stage tap points right and that all the other wiring in the tonepad layouts stayed the same. The "listening in" reference in the post above really helped me understand what was going on. As always , thanks for your time!

[Mark Hammer]

Okay, thinking more clearly now, though a few moments too late from the sounds of it.  This may NOT be the switch you want.  Sorry

If lugs 5 and 2 are jumpered together, AND the 4-stage tap goes to lug 6, AND the 8-stage tap goes to lug 4, AND the 12-stage tap goes to lug 1, you can get  a 4 and 8 stage tap in positions 1 and 2 (middle), but when you go to position 3, the 8-stage tap is still there.  Which presents a problem.

I'm pretty sure the switch I'm imagining exists.  And that would be one where the 2-3 connection is absent in position 1, and the 4-5 connection is absent in position 3.  Now THAT would work.  Is it possible to change your order at this point?

[jmasciswannabe]

It is too late, deborah the mouser operator said it was already being processed, but really it's all good!!! Hopefully something else will pop up that I might be able to use it for. What about my first idea, using two dpdt switches? Do you think that would work? I know I have some of those laying around! I sent an email to fp @ tonepad, on what he would suggest, but  I am sure he is busy....hopefully with that 9volt electric mistress!

[Mark Hammer]

Well, maybe the optimal thing is to start with 8 stages, and use the DPDT to select between 4 and 8, for the time being.  Truth be told, once you add on some of the other bells and whistles, you may not even care about having more stages or the capacity to select all possible tap points.

[jmasciswannabe]

And bells and whistles I plan on adding!!! I am very excited about working in the vibrato mod, regen resistor mod, sweep width control mod, univibe mod (will be experimenting with shin-ei values and traditional univibe values), swithcable lfo cap mod (maybe a higher one for the phase and lower one for the vibe), some sort of phasefilter mod (I am thinking allpass filter currently), and finally the additional stages mod. So leaving out another switch to change between 8 and 12 stages just wouldn't do this abomination justice! I am totally psyched!! Can't wait to debug!

As for the other switch I ordered, I think it can be used for a sansamp gt, which was next on my list!

If I still have my wits together after finishing this I plan on doing a nice built report including pics and links to where I got all the mod info from, cause there is quite a bit spread out over the forum!