ampage Tube Amps / Music Electronics	For current discussions, please visit Music Electronics Forum.

ampage archive

Vintage threads from the first ten years

Switching noise query

:

4/3/1997 9:33 PM

Switching noise query

A common complaint from people who use VOLUME!! as
a fundamental aspect of their sound is the
clicking noise that effects pedals create when
one steps on the switch. Another classic complaint
is signal loss and high-end loss. These latter
two problems can be easily overcome by use of
input and output switching instead of just output
switching (i.e., use a DPDT switch instead of
SPDT), but the noise problem is still an issue.

Over the years I've seen lots of different
switching arrangements, although I can't say that
I've ever taken examples of each and compared them
side-by-side. Assuming that we're comparing DPDT
footswitches against various sorts of CMOS and
FET switch arrangements (and the solid-state types
against each other), what do people provides the
"best" switch? I define "best" by including noise,
signal integrity, changeover time, immunity to
distortion, current drain (in the case of solid-
state), and anything else you'd like to include.

Feel free to depict switching arrangements in
terms of makes (DOD vs BOSS vs IBANEZ, etc.) if
that makes more sense to you. I'd also be curious
if people find 4016 or 4066 CMOS chips more or
less noise-susceptible than each other or other
solid-state switches.

4/4/1997 3:14 PM

Interesting topic. I have to admit that the BOSS FET design is my favorite because of load-less and noisless functionality; however, I dislike it because it has to many components and bipolars do draw excess current. I have yet to experiment with using some of the Maxim FET switching devices such as the MAX4526 which is a Phase-Reversal Analog switch and can operate from a single supply as well as a dual one. I hope I can do this soon so as to elaborate more on this subject. Good Topic. Christian

4/23/1997 6:46 AM

Mark,
I can sympathise with your problem. When I finished my first complete FX box with touch switching (Vibrato) I thought that the switching would be the easy part WRONG! I also use VOLUME!! as an effective way to communicate my music, and switching noise is a pain in the but.

There is a new chip that RS (Radio Spares) do you have them in US ? They probably started there dunno...
Anyway, it's called and Audio Switch (wow) I've got the part No. at home. I havn't got around to using it yet but it's meant to be completely noiseless and distortionless! You use it the same way as a 4016 or 4066. Only problem is that they sell for aound $20 (in Australia) dual or 4-way in one chip.

However, I have tried the mechanical dpdt switches and still use them on Big Muff & patch switching. They click & break occasionally, but I like 'em for the simplicity & no distortion. One problem I have had is the capacitance of the switch causing feedback when I switch between Bigmuff & TubeFuzz, but solved it by placing an ~500k load on the outputs of the fuzzes.(I think?)

In the vibrato I tried the 4016 & 4066 before settling on the BOSS style which took some tweeking to get working (diffr'nt cap values), but now works great! I've also got a good mechanical design for the switch mechanism using a microswitch that has a very short throw length.

I'd be interested to know how DOD & ibanez do their switching.

I hated trying to use the 4016 & 4066, my final conclusion was that both chips are inherently crappy, way too much switching noise.

I also spent some time investigating the use of fets in their linear reigon as voltage controlled resistors, this too was fruitless but I found a better solution (for a discrete VCA). Anyone else tried this with Fets?

Enough already...
See ya,
Richard

Page 1 of 1