Some comments on the "Squeezebox" Effect.

Hammerhands

Country Gent
Aug 26, 2011
2,464
Winnipeg
squeezebox.jpg



This Squeezebix capacitor is 0.022uf. There are at least two .,.


Guitar-Bass-Gear-28_10-12.jpg


Those long numbers are Fender style part numbers.

7708536000
7708537000

1619 and 1614 I think is a date or a lot number.

Here are a couple in .012 and .0039.

https://i1484.jp/2016/06/gretsch-guitar-2016-new-lineup!vintage-select-シリーズとは?/report-16365.html


DSCN9929.jpg


A capacitor for treble bleed for 500KA pots, maybe with an integrated resistor? P/N 7707987000
DSCN9930.jpg
 
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G5422T

Country Gent
May 24, 2012
4,115
usa
Last that I've heard, these Squeezebox caps are not available for sale from Gretsch/Fender.
 

Synchro

The artist formerly known as: Synchro
Staff member
Jun 2, 2008
26,380
Tucson
Paper in oil caps will not sound any different than pretty much any other capacitor, although ceramic capacitors are more sensitive to the effects of heat. Orange drops, or the caps I linked at Mouser, will,sound just as good.
 

LesB3

Gretschie
Aug 17, 2021
249
Philadelphia, PA
Paper in oil caps will not sound any different than pretty much any other capacitor, although ceramic capacitors are more sensitive to the effects of heat. Orange drops, or the caps I linked at Mouser, will,sound just as good.
Oh I know, its a vintage guitar, so just wanted it to "look right."
 

General_Lee

Gretschie
Apr 23, 2022
319
Manitoba, Canada
Paper in oil caps will not sound any different than pretty much any other capacitor, although ceramic capacitors are more sensitive to the effects of heat. Orange drops, or the caps I linked at Mouser, will,sound just as good.
With all respect Synchro, I do notice a significant effect in terms of taper with the PIOs. IOW, there seems to be a much wider ratio in effect, at the point where the tone pot begins to affect the full body of the signal passing through the tone pot. With most ceramic disc types, there is a much smaller distance from where the tone begins to be affected to where the capacitor seems fully engaged.

Also, for whatever reason, I find that there is more signal at the top and bottom of the tone spectrum that kind of bleeds through with the PIOs, giving the signal a kind of lovely fullness, even when the tone circuit is engaged (at least up to the point of full on). I've also noticed this same effect in the Telecaster I recently installed a PIO cap in. I'm not arguing the science, just the effect that my ears have noticed...
 

Synchro

The artist formerly known as: Synchro
Staff member
Jun 2, 2008
26,380
Tucson
With all respect Synchro, I do notice a significant effect in terms of taper with the PIOs. IOW, there seems to be a much wider ratio in effect, at the point where the tone pot begins to affect the full body of the signal passing through the tone pot. With most ceramic disc types, there is a much smaller distance from where the tone begins to be affected to where the capacitor seems fully engaged.

Also, for whatever reason, I find that there is more signal at the top and bottom of the tone spectrum that kind of bleeds through with the PIOs, giving the signal a kind of lovely fullness, even when the tone circuit is engaged (at least up to the point of full on). I've also noticed this same effect in the Telecaster I recently installed a PIO cap in. I'm not arguing the science, just the effect that my ears have noticed...
If you are noticing a difference, the only explanations would be if the inductive reactance, capacitive reactance or resistance (if there’s a tone pot) has changed. I’m not suggesting that you aren‘t hearing some difference, but the difference has to be explainable.

No component in an electrical circuit operates in Isolation. The various components interact. It’s also somewhat misleading to think of current moving down the length of a wire in an AC circuit. For all practical purposes, the current generated by your guitar pickups spreads all the way through the guitar circuit and the patch cord in a tiny fraction of a second.

Higher frequencies, shunt to ground if there’s a tone cap present and the exact cutoff frequency is a product of the inductive reactance, working at 180 degrees from one another, and the resistance, working at 90 degrees from the net reactance of the circuit. The result will be an RC circuit, with very predictable behavior.

There is interaction between the tone cap and the variable resistor of the tone pot, so tone pot settings can make a big difference, but keep in mind that with audio circuits, even fairly big changes are not always that easy to hear. Acoustics are logarithmic.

A properly functioning capacitor can do one thing, and that is to provide capacitive reactance. Now, various materials may react different to variations in temperature. There is no magic available to be had. Now, it is possible for a cap to malfunction, but that is not likely to have any positive effect.

A cap does one thing, and only one thing, it blocks DC and passes AC. The smaller the cap, the higher the frequency has to be before it can pass. There’s a curve of how much signal is attenuated with the change in frequency is well known, and strictly a product of capacitive reactance.

When I install a cap, I want one thing from it, and that is for it to be stable, so that the capacitive reactance does not drift over time, or with changes in environmental conditions. Film caps are the most bang for the buck, and mica is the ultimate for stability, but probably overkill for a guitar circuit.

One last thing that comes to mind, is that if PIO caps are somehow more variable, that is not likely to be a good thing. If PIO caps sound different from other, such as polyester film, or mica caps, that can only happen if the values are different, or the cap less stable.

A few years ago, people were jumping through hoops to install Orange Drops, which are good, stable caps, but now i hear of people removing Orange Drops for Bumblebees. That makes about as much sense as if I were to take the radials off my pickup and put on a set of bias belted tires from 50 years ago. PIO cpas hold no magic, no “mojo”, not any other esoteric goodness. They are an older approach, and if anything, far less precise than more modern designs. Saueezebox caps and Grease Bucket tone circuits are the words of advertising copy, and not the words of people with the theoretical background to understand what is going on.
 

Synchro

The artist formerly known as: Synchro
Staff member
Jun 2, 2008
26,380
Tucson
I stand educated...
I’m not saying that you aren’t hearing any difference, but I don’t think that the difference you are hearing is the paper in oil, aspect. The only cap I would suggest avoiding would be the ceramics, which are not bad, but they tend have looser tolerances and are more sensitive to variations in temperature, etc.

I‘ve without owning a capacitance meter, but have used them in the workplace, but I may pick one up for around the house, one of these days.


Earlier today, Amplified Parts sent me an email advertisement I visited their site and checked out caps while I was there. The selection was all but limitless, and a lot of them were inexpensive. Going out on a limb, ever so slightly, if you want a long lived cap, mica should be the best, and they were very cheap.
 

General_Lee

Gretschie
Apr 23, 2022
319
Manitoba, Canada
It's all good Synchro. I appreciate the exhaustive and informative posts. Perhaps there are other factors at work in my case - such as psychological perception. I do remember changing the pots out (CTS) for convenience sake, and to keep everything clean, and this may also be adding to my experience. In any case, I thank you for sharing your deep knowledge on the subject. I'll be keeping this info in my files...
 

Synchro

The artist formerly known as: Synchro
Staff member
Jun 2, 2008
26,380
Tucson
It's all good Synchro. I appreciate the exhaustive and informative posts. Perhaps there are other factors at work in my case - such as psychological perception. I do remember changing the pots out (CTS) for convenience sake, and to keep everything clean, and this may also be adding to my experience. In any case, I thank you for sharing your deep knowledge on the subject. I'll be keeping this info in my files...
The pots and the caps interact, so upgrading to better quality pots might have made quite a difference. Most audio taper pots are not truly a logarithmic taper. There’s a workaround that will fool pretty much everyone’s ear, but that taper is a bit off. So it’s entirely possible that the CTS pots had a different, and probably more accurate taper.

Psychology plays a roll, and I have fallen victim to this myself. The problem is, how does one define sounding better? It’s entirely subjective. Beyond that, our aural feedback can cause us to make unconscious changes in our RH technique. When I first plug in an electric guitar, I usually strike the strings and then quickly mute them, to gauge the volume and response of the guitar and amp. I’m certain that almost everyone does something similar, and I suspect that this “calibrates” our technique, to that setup.

But that’s not so bad. We are human, operate via human psychology, and we haven’t all gone deaf yet, so we must have at least some of it right.
 


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