Small Blue vs Blue Molded Fender Capacitors

[ModMan]

What is the difference between-
The small blue 200v caps with ITW stamped on them
and the longer blue molded ones everyone sells do these sound different/better?
Dan.

[Chuck H]

Wow... Maybe someone out there intrinsically knows just what you mean but I would benefit greatly from a link or photo.

In any case the difference is likely to be so small as to be ignored. I do think that there is a small difference in tone between caps of entirely different construction and materials but I'm a black sheep around here for it. And in blind tone tests no one can tell a fifty dollar cryo treated paper in beeswax cap from a plain jane two dollar jobbie. So don't buy into any hype. Be sure the caps you buy are from a respected MFG and be sure to get the right voltage rating for the circuit. I like polypropylene film and foil types because they have good thermal stability. That way my amps don't sound different at the beginning of a show at a cool outdoor venue in fall and the end of a show in a not air conditioned bar in summer.

[J M Fahey]

Short answer, no difference.

[Chuck H]

Well... JM, you and I are often on the same page at least but I'm going to disagree on this. If the two caps are of very different construction there could be a small difference. I say small but I do think it's a significant consideration at extremes. Anyone who can't tell the difference between two otherwise identical amps, but one is built with metalized polyester caps and the other with film and foil polypropylene, has tin ears. Especially after the amps get good and hot. It's subject to tastes as to which is better for a given circuit, and I don't expect there is really that much difference in the construction of the two cap types in question but that's why I asked for more info before giving an absolute poo to there being any significant difference.

[J M Fahey]

Fine with me.
To be more precise, I don't say that there is no difference between two capacitors with the same value printed on their cases; but rather that if there is an audible difference (which I don't reject in principle) , there must be a measurable difference in at least one parameter that explains it.
I also agree that using all caps from one type *or* another in a given amp , will add up all minute individual differences that may exist into a larger, more audible one; I only state that , in my opinion, that difference *should* be measurable in some way.

[Chuck H]

Good. I'm good with that. Maybe someday someone will take the time to measure the finite details of caps of different construction but it's not on my short list or even within the capability of my bench tools. I do know that the few accurate tests that have been done demonstrate a rather jagged line as compared to the typical rough -3dB roll off shown in specs. But these weren't comparisons. "I" think I can hear a difference. Also, the thermal properties are well within the environment of tube amps which is why I choose polyprops for builds regardless of the popularity of polyesters.

Sorry, but I won't be backing this with scientific study due to personal limitations. However, it's enough for me that I have heard the difference in person and am not the type to blow smoke up my own a$$.

[ThermionicScott]

Voltage rating?

[Pedro Vecino]

I use many types of capacitors new and old depending on the function in each amp, but I consider these two types equally to work with classic Fender. Both are made of polyester film foil (not metallized) and with the same voltage I d´ont have appreciated significant differences. I use them indistinctly

[dai h.]

I used to do a lot of cap swapping, and my own conclusion from all that is that I would not worry too much as long as the type of cap is similar enough (polyester to polyester or metal. poly, polyprop for polyprop, etc.). In general, it seems brand is overemphasized ("good" brand, "bad" brand) instead of looking at things like values and tolerances. I suppose there is a "coolness factor" for gear such as old (now valuable) vintage amps where you might want to favor a part that (more or less) "looks right" for aesthetics and potential ebaying. Kind of a situational and subjective thing where maybe relatively speaking there is a "correct answer", but not absolutely (if you take subjective preferences into account). Also, there seems to be this idea about attaining vintage sound through "exact (same) parts", but a lot of things, whether PAFs(from what I understand), Tube Screamers, old Marshalls, or whatever, they didn't exhibit an unaltering uniformity, so while that exact paid dearly for (on ebay or whereever) part might have been "vintage exact (mojo buzz word--"JRC", "Lemco", etc.) correct" on some units, it may have been different for other vintage units (the reality was probably that the manf. just used what they had or could obtain readily and easily instead of rigorously testing for the best nuance between two cap brands of the same value, different maker ICs or whatever 'til their ears bled from their tone fanaticism).

[J M Fahey]

In general, it seems brand is overemphasized ("good" brand, "bad" brand) instead of looking at things like values and tolerances.

Amen

Also, there seems to be this idea about attaining vintage sound through "exact (same) parts"

Curiously, being the "no bullshit" guy, I fully agree with this one.
Do you want the exact sound of a 1959 Bassman? ...... buy one !!!!!!!!!!!!
It will have *all* the right parts !!!!!!!!!!!!!!!
Do you think that your just built clone, with modern iron, many modern parts, modern chassis, wood, solder, switches, jacks, etc. , with *some* vintage parts will be the same?
No way !!!!!!!!
Even if you found a moldy box in some guy's garage with a full kit of parts , it would be closer, but not 100%, because it will lack the 50 year (or more) maturing/cooking/smoothing by playing on stage, vibrating with the music, cooking with those 70 or 80ºC for hours on.
I'm sure an electrolytic capacitor will change when charging/discharging , because that's an electrolytic action (duh !!) which causes chemical changes, both in plate material and electrolyte; I'm sure something similar happens in paper in oil capacitors, because paper ages (a lot) and oil composition/properties must change too, although in a lesser degree.
Bottom line?: don't obsess too much (a little is fine) about *some* parts you use, when many more are not being taken care of at all.

[Bruce / Mission Amps]

I have found that the players that really dwell so heavily on this subject, ... I mean live and breathe it to an extreme, are usually the most novice and unfortunately, sometimes the most annoying soul-less players.
Green amp techs can apply here too...

That in no way was meant to discourage anybody from experimenting with or asking questions about the use of one kind of part over another.

[TheElectricMoron]

What with the massive slop in tolerance on those parts you would have to measure every piece and compare the pieces that matched (when you started anyway). Some kinds seem to sound better (I can't hear it) but inside a collection of low tolerance components, none of which you really know the value of, how are you going to tell the critical piece because even clones side by side can sound different.
If you like the way something sounds leave it alone. If you don't like it then get out the soldering iron and have a good time looking for the right stuff.

I use orange drops cuz I think they look cool and are seemingly a quality product. But the old blue ones, both kinds, are cool too. I have a bag of dog turds that I'm gonna use exclusively in a rebuild soon and I'll bet they sound OK too. but I am gonna measure them first hahaha

JMO of course YMMV

Charlie

[greekie]

I agree with Bruce. I buy the components that I feel are good quality, and that I have had good experience with in the past. Sometimes one of those "know-it-all" customers comes along, I'll use one of the fancier brands like SoZo, which are good as well. Some people play into that, and a big part of how we feel about playing a certain guitar or amplifier is all about psychology. Make a guy feel good about an amp, and he'll love it and recommend you to his friends. No hurt in that!

JMO

Jake

[1ampman]

No 50 yr old cap is going to sound like a new cap. 2 different animals... ESR is a factor.... Also those little round pea size caps in a Peavey Classis 30 do NOT sound good. I've heard that. Everybody has their own take of what sounds good. If you want to try different sounds, buy a Boogie with 10 thousand swiches & knobs on it. I get the biggest kick out of Boogie owners, they don't even know what all the things do? I got yelled at for turning a knob on their amp. NOT to mention the 12 button ft. switch..... Oh Lordy!