PedalPCB 5-Loop True Bypass Switcher

[Robert]

We live in a world where diodes can be magical.

 

[benny_profane]

Silly me, I forgot. And a buffer is not a buffer.

 

[benny_profane]

What impact on impedance does CMOS multiplexing have?

 

[Giorfida]

What impact on impedance does CMOS multiplexing have?

Say goodbye to your high end. That was one of the big problems with the Craig Anderton electronic (CMOS) switch

 

[Robert]

The hiccup there is that the copy makes a point to discuss the switchable input/output buffers. Any transistor switch will amount to a buffer of sorts.

Yep, like I said, I'm not suggesting this is what's happening in the Fender gadget. I was just describing a method of switching that could be technically still considered true-bypass.

 

[giovanni]

Daniel from the GigRig discussed the fact that he wanted his switcher to never be buffered (unless you want to turn a buffer on) so I assume he has some sort of relay matrix in there? He didn’t go into details but I’m very curious.

 

[Robert]

Yep, I haven't seen one personally but I'm fairly sure GigRig states that the G3 uses a relay matrix.

 

[Barry]

I've only ever wanted to switch the order of my Wah to be honest, from first in line to AFTER the dirt.

I have a GuitarPcb board that has a double throw 4 pole switch, that you could make that easily. Be happy to send you one, I probably have the switch here too.

 

[CR0SSBL4DE]

My calculations are that for 100% mechanical routing and switching one would need:

[X = No. of loops]
No. of SPDT relays = 2 * X * (X-1) + X

1 loop --> 2 relays
2 loop --> 6 relays
3 loop --> 15 relays
4 loop --> 28 relays
5 loop --> 45 relays

I doubt that's what they are doing on the fender switcher. I wonder if jumping all the loops and measuring with input/output with a DMM would give you continuity. That's what I would assume for "true by pass switching". (also it has a volume control integrated)

I though of a way to do it with less relays:


(Sorry for the horrible quality, I don't have my phone around so I used my webcam)

This way the amount of SPDTs needed is a lot less. I didn't decompose the function, but it's basically L squared (5loops is 25 spdt relays. 8 loops is 64 spdt relays).

 

[Feral Feline]

I knew this thing was coming from a few posts elsewhere, but somehow missed there was this entire thread for it.


Only read first page, gotta hit the hay, but Carl Martin Octaswitch was mentioned as having dipswitches — it wasn't the only one!
Early GigRig switchers and Flex Reaction series switchers (4 loop, 6 loop, etc)...

I'll read the rest of the thread tomorrow and post something inane then.

 

[Feral Feline]

I once silently watched the big lebowski on a trumpet players IPad in the pit during a professional performance of West Side Story. Using it on a book isn't actually that far fetched.

Low brass gets a lot of rests and tacets in the theater world. Pay per note was off the charts.

Did you at least have captions/subtitles?

Or are you not only a good sight-reader but a good lip-reader, too?

---

Switcher-Looper options in the DIY realm beyond a bunch of 3PDT footswitches that I've looked at...

BYOC Super8, though Jimilee was not keen on it, I have one, too, and think it's cool in theory; there's also...
THCustom's "EFFECT CONTROL" 5-loop switcher. (been meaning to get this, but Robert's version would be preferred)
JMK's "EPIC BYPASS LOOPER", a project developed with THCustom above (and available there, too. (I have this one).
UK-Electronic's "8-WAY LOOPER", which has some minimal MIDI functionability. Been meaning to order this one, too.


So... yeah. There's only so many features you can pack into a 1032L enclosure or Hammond BX2...


IN / OUT order is important to get right (ie how I want it) — scoff at that statement but there's a number of smaller DIY loopers I've passed on because of the way the in/out jacks were configured....

 

[jimilee]

We're 8 pages in, I'm really chomping at the bit.

 

[Mentaltossflycoon]

Did you at least have captions/subtitles?

Or are you not only a good sight-reader but a good lip-reader, too?

---

Switcher-Looper options in the DIY realm beyond a bunch of 3PDT footswitches that I've looked at...

BYOC Super8, though Jimilee was not keen on it, I have one, too, and think it's cool in theory; there's also...
THCustom's "EFFECT CONTROL" 5-loop switcher. (been meaning to get this, but Robert's version would be preferred)
JMK's "EPIC BYPASS LOOPER", a project developed with THCustom above (and available there, too. (I have this one).
UK-Electronic's "8-WAY LOOPER", which has some minimal MIDI functionability. Been meaning to order this one, too.


So... yeah. There's only so many features you can pack into a 1032L enclosure or Hammond BX2...


IN / OUT order is important to get right (ie how I want it) — scoff at that statement but there's a number of smaller DIY loopers I've passed on because of the way the in/out jacks were configured....

The trumpet player offered me one side of his ear buds but I was terrified that I'd miss a cue. I think I said something like "I can recite 100% of that movie." Which was pretty close to true at the time.