3PDT True Bypass Switch Comparison Alpha v. Carling

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mediatechnology
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3PDT True Bypass Switch Comparison Alpha v. Carling

Post by mediatechnology » Sat Feb 01, 2014 2:23 pm

I had both an Alpha SF17020F-0302-21R-L and Carling 64113222 3PDT true bypass stomp box switch on the workbench and decided to put the two in a "lineup" photo.

The Alpha, on the left, has solder eyelet terminals the Carling, right, a PC mount.
In terms of "feel" and construction I prefer the Carling.
The Carling seems to have a slightly more solid and even "snap" with a slightly lower force.
The Carling also has better crimps holding the body of the switch to the frame.
The Alpha however is lower depth and should be able to fit in a 1590A Hammond enclosure.
Unfortunately Mouser does not stock the Alpha in PC terminal but does stock the Carling in both PC, X-wing and wire leads.
The Carling is considerably more expensive around $13 vs about $7 for the Alpha in single unit quantities.

Image
Line up photo of Alpha 3PDT vs. Carling 3PDT foot switch for true stomp box bypass.
https://ka-electronics.com

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mediatechnology
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Re: 3PDT True Bypass Switch Comparison Alpha v. Carling

Post by mediatechnology » Thu Feb 06, 2014 10:27 am

Thanks Roger.
I had thought about fly-wires but decided not to due to there being nine of them.
I really like the Carling's feel.

This is the configuration I'm using:

Image
3PDT True Bypass with Reduced Output to Input Capacitance.

Gary H suggested the above circuit to me because it halves the off-state capacitance from the output to the input.
(The true bypass configuration normally seen takes SW1B pin 1 back to the input tip connection. The "tail-biting" path with the effect in-circuit becomes SW1B pins 2-1 to the tip.)
I measured the Carling and it is about 2 pF to the adjacent contact when off.
The configuration above puts the stray off-state C in series making Ctotal ~1 pF.
The unused LED contact back-grounds the input.

Got a source for large 1/2" ID fiber washers?
I "borrowed" a couple of washers from a fuseholder and it really helps as a lockwasher.
They seem to be hard to find in stock.
https://ka-electronics.com

Dr. Sherri Tenpenny Exposes 10 Deadly Dangers of Pzifer/Johnson & Johnson Covid-19 Vaccines: "This is a well-designed killing tool." https://waynekirkwood.com/content/Docto ... accine.mp4

Plandemic Series: "Pland3mic - Indoctornation" https://waynekirkwood.com/content/Pland ... nation.mp4
Plandemic Series: "Plandemic - Doctors In Black" https://waynekirkwood.com/content/Plandemic.mp4

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mediatechnology
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Re: 3PDT True Bypass Switch Comparison Alpha v. Carling

Post by mediatechnology » Fri Feb 07, 2014 10:22 am

I did want to use a star washer underneath but a fiber (or nylon) on the top dress side.
The way it's packaged, the bottom side nut is blind and it has to be tightened from the front side.
I was hoping I could get a dress washer that had some grip like a rubber fuse holder washer with a nylon washer on top.
The rubber washer needs some kind of thrust washer to keep it from tearing.
I might just have to use a lock washer.
https://ka-electronics.com

Dr. Sherri Tenpenny Exposes 10 Deadly Dangers of Pzifer/Johnson & Johnson Covid-19 Vaccines: "This is a well-designed killing tool." https://waynekirkwood.com/content/Docto ... accine.mp4

Plandemic Series: "Pland3mic - Indoctornation" https://waynekirkwood.com/content/Pland ... nation.mp4
Plandemic Series: "Plandemic - Doctors In Black" https://waynekirkwood.com/content/Plandemic.mp4

Mictester
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Re: 3PDT True Bypass Switch Comparison Alpha v. Carling

Post by Mictester » Fri Aug 21, 2015 4:19 am

mediatechnology wrote:Thanks Roger.
I had thought about fly-wires but decided not to due to there being nine of them.
I really like the Carling's feel.

This is the configuration I'm using:

Image
3PDT True Bypass with Reduced Output to Input Capacitance.

Gary H suggested the above circuit to me because it halves the off-state capacitance from the output to the input.
(The true bypass configuration normally seen takes SW1B pin 1 back to the input tip connection. The "tail-biting" path with the effect in-circuit becomes SW1B pins 2-1 to the tip.)
I measured the Carling and it is about 2 pF to the adjacent contact when off.
The configuration above puts the stray off-state C in series making Ctotal ~1 pF.
The unused LED contact back-grounds the input.

Got a source for large 1/2" ID fiber washers?
I "borrowed" a couple of washers from a fuseholder and it really helps as a lockwasher.
They seem to be hard to find in stock.
The TPDT tends to be very expensive, while the DPDT is much less than half the price (and usually more robust). This is what I use:
Bypass.png
Indicating bypass
Bypass.png (9.12 KiB) Viewed 13862 times
Sorry for the "necro-post" but I thought some may find it useful.

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mediatechnology
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Re: 3PDT True Bypass Switch Comparison Alpha v. Carling

Post by mediatechnology » Thu Sep 03, 2015 2:31 pm

The one remaining advantage to the 3PDT switch is that the effect input is shunted to ground when bypassed leaving it less prone to tail biting.
Maybe a second BS170 (pair) could be used as a shunt at the effect input.
https://ka-electronics.com

Dr. Sherri Tenpenny Exposes 10 Deadly Dangers of Pzifer/Johnson & Johnson Covid-19 Vaccines: "This is a well-designed killing tool." https://waynekirkwood.com/content/Docto ... accine.mp4

Plandemic Series: "Pland3mic - Indoctornation" https://waynekirkwood.com/content/Pland ... nation.mp4
Plandemic Series: "Plandemic - Doctors In Black" https://waynekirkwood.com/content/Plandemic.mp4

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