D-Lite Rebuild....

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brewdude
Posts: 652
Joined: Mon Mar 31, 2008 6:26 am
Location: Napa, CA

Re: D-Lite Rebuild....

Post by brewdude »

tonestack wrote:
Bob-I wrote: You just opened a can of worms... Many of us have done tests on a variety of cap types and brands and find the it makes a significant difference in these amps. Even the orientation of the cap makes a difference. Some folks go so far as to use one type for the bass cap, and a different type for the mid cap.

Yep, there's a difference. :D
I will believe you when you show me spectral analysis plots from the same amp using two different sets of caps that have the same exact measured values. Any difference that cannot be measured doesn't exist. The difference is merely the result of acoustical phenomenon known as perceptual accommodation.

The orientation of a film-and-foil cap matters because the outer foil acts like a shield; therefore, it should be connected to the low-impedance side of the circuit to reduce coupling.
In my limited experience, I can definitely hear a difference in type of cap used--at least in some circuits and certain positions within those circuits. Perhaps, these caps have inherently different qualities other than capacitance, such as internal inductance (as you pointed out), which may be a result of different manufacturing techniques or materials employed by their respective manufacturers, etc. In which case, both premises could be equally true.

Anyway, it seems that half the fun is to find the best combination of ingredients, regardless of measured or unmeasured differences, to conjure the "magic" in the tonal potion that is each amp I build. Frankly, I don't really care why I like one cap over another, or whether others can perceive it. I just recognize they are subtly different and wish to learn how to use them to properly season my tone soup.
dogears
Posts: 1902
Joined: Wed Feb 01, 2006 1:29 pm

Re: D-Lite Rebuild....

Post by dogears »

Hey Tonestack, your comments abotu a film cap being a film cap are really off base.

Gary Johnson used his high end equipment to measure various specs of different film caps.

PS Series are a nonmetallized cap. These have a Q and a dissipation that is a magnitude different than metallized film caps.

So, not only does the dielectric matter, but the type of film cap. Metallized or not.

Big difference in testing.

So, completely reasonable that there is a tonal difference when the measurements are that different.
tonestack wrote:
renshen1957 wrote: I don't use Polyprops film caps as to my ear they sound harsh.
A film cap is a film cap. Polypropylene caps do not sound any different than polyester caps. As long as the caps that are being compared are not microphonic, any perceived difference in tone is the result of the caps not having the same value (the measured value, not the value that is printed on the component) or psychoacoustics (a.k.a. "perceptual accommodation").
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