Orange Drop Caps vs. Ceramic Disk?

[Chuck H]

Ok... I'm actually in the camp that believes different capacitors DO sound different. And I've even gone so far as to use a specific type for a specific type of amp. I think I've just done enough mods and tweaks on very similar circuits to become familiar with certain consistencies in changes due to capacitor type. On paper, as per the specs, there is no significant difference in the film type caps used by most builders. But I still think I can hear it. However, to give an idea of how small the difference "I" percieve is... I actually prefere the sound of polyester caps. But I build my own designs with polypropylene. Why??? Because polypropylene caps have better temperature stability. Some of my early mod experiences included the observation that some mods sounded good initially, but not so much as the amp got hot. Changing the cap type seemed to help. Now... I Can't promise that the for the purposes of evaluation the cap value was tested for an accurate compare. But I can tell you that there is definitely less tonal difference between a cold amp and a hot amp when polyprops with a good spec in this area are used instead of any polyester cap. So, for me, designing with polypropylene just gets me to accurate results faster than other types of caps because I don't need to wait an hour to know what a particular tweak actually sounds like.!.

[kleuck]

Interesting, i know some amps for which the sound changes with time during a gig, but i thought it was more due to the tube. BTW, my comparisons have been made with caps within 2%, that's not the tolerance thats leads to audible differences.

[lowell]

What I'm really saying is that, aside from swapping in a cap here or there, the remaining variables (wire, other components, guitar etc) are so large and unknown that how can one really discern between them. I accept that these minuscule variables matter to some people. They just don't matter to me. It's akin to a guitarist coming in after their electric guitar has had a fret level, or even a setup, and they play it without plugging into an amp and they are SO focused on fret buzz that they sit there and nit pick the tiniest bit of buzz. (all guitars have some fret buzz if you play them hard enough) "see this string here, at fret 7 kinda buzzes... do you HEAR that?" And I wanna say, "If you plug the thing into an amp and PLAY, you're not going to notice that... you're just SO focused on it now that you WANT to hear it."

All I'm saying is that I feel there are more important variables in an amp's sound than cap types. JMHO.

[soundmasterg]

If it was me I would leave those ceramic caps in place if they are working fine....especially on a vintage, somewhat collectible amp. I very rarely see ceramic caps go bad, and they have benefits in certain locations when compared to other dialectric types. In any case, in a trem circuit, the cap type doesn't matter to the sound.

Greg

[Steve A.]

Ceramic disc caps are often replaced by silver-mica types.

That is true with ceramic caps in the pF range. For the ceramic tone stack capacitors that Fender sometimes used- like 0.1uF or .047uF- you probably want to replace them with polyester caps like the Mallory 150's.

[Steve A.]

So one would have to use the SAME amp and a substitution box with capacitor "types" to immediately switch them... so as to avoid a time gap.

I have done that and yes I can hear a difference between some types of caps like polyester and polypropylene, or ceramic and silver mica.

All I'm saying is that I feel there are more important variables in an amp's sound than cap types. JMHO.

For modern high gain circuits that might be true since the circuit itself can contribute more to the sound than the actual components used but you should be able to notice a fairly big difference in the classic Fender amps if you go from all polyester coupling and tone caps to polypropylene. (Polyester is a bit warmer and smoother, polypropylene is a bit brighter and sharper.) Sometimes you can hear a difference changing just one of the caps. Capacitors have parameters besides capacitance and maximum voltage; differences in ESR (Equivalent Series Resistance) can have a big effect on the sound.

Steve Ahola

[Steve A.]

You got me on that
Although, to be precise, I was referring to "real" Books, not "Guru" babbling transcriptions, printed, bound, and sold as the real stuff.
But, of course, I see your point. Probably many swear by them.
It's just that I have never wasted a cent or a minute in one of those, so they fly under my radar

If you have never read them how do you know that they are crap? Although Dan Torres doesn't understand electronics as well as someone like Kevin O'Conner, there are some good tricks in his book and in his Vintage Guitar articles. (Many of those tricks have become common knowledge among amp techs since he first published his book in 1995.) Gerald Weber has some cool tricks in his books, too. So what do you want- good sounds or technically correct explanations?

Steve Ahola

[Chuck H]

I'll actually back Dan in defence of my own inference. Whether Dan's "literature" is specifically accurate or not doesn't change the fact that his circuits consistently sound good! It's true. I think it's important to allow some leeway since Dan was a fore runner in the publicly visible amp mod game. He designed all of his circuits by trial and error. My BEST circuits have been done that way. I worked in close relation with Dan at the time when he was between his shop in Saratoga (which he sold) and opening his store front in Menlo Park (some twenty years ago). He is a true believer. He loves good tone. And he's very saavy with what he knows to implement. He was the only game in town (in a very big town) at one point. A ground breaker to be sure. Dan was my amp tech for two years before I decided to learn this stuff for myself. An inspiration of sorts. And I've NEVER run across a Torres installed mod that was bad sounding. All his amps and mods that he does himself do indeed sound good.

But it's also true that Dan doesn't have the same level of sheer tech that is available to a first year EE student on line. His book reaveals that clear enough. Still, he is a fore runner in the game and deserves his kudos. I enjoyed his mods for years. If not for him the whole process of information to the gen pop might have been slower. And I would even say that any decent player would be satisfied with his amps.

I could honestly walk into Dan's house tomorrow, slap him on the back and call him an a$$ho!e and he would laugh it off. Seriously. It's only because some of his info isn't STRICKTLY accurate that I used his name.

To be certain, I've had my relationship with Dan. I meant no offense.

[Steve Conner]

I want both. Good sounds and technically correct explanations.

[kleuck]

All I'm saying is that I feel there are more important variables in an amp's sound than cap types. JMHO.

Yep : speaker, design, design of the power supply, but caps are more important to the overall sound than the tube themselves imo.
As pointed out by Steve, i'm talking classic simple amps, not Soldano or modern amps, i have no experience with them

[Steve A.]

I'll actually back Dan in defence of my own inference. Whether Dan's "literature" is specifically accurate or not doesn't change the fact that his circuits consistently sound good!

I got the impression that Dan's hearing is impaired to some extent- my guess is that he doesn't hear high frequencies well. Because of that some of his designs can be a bit bright or harsh. But I think that he has been having more ears listen to his circuits in recent years to compensate for that.

I remember seeing Torres tweed champ amps at Leo's music in 1982 when I was getting a telecaster there. At least I think that Torres was the name on plate. Not a lot of people were build tweed clones 30 years ago. (I remember that the price was $200 but I didn't want to pay more than $100 for an amp that was so small. Darn!)

If you compared Dan's circuits to anything designed by a first year EE student I think that his would sound better at least 9 out of 10 times.

Steve Ahola

[Steve A.]

I want both. Good sounds and technically correct explanations.

I'm not sure that I want or need technically correct explanations but I do want circuits to be technically correct (within the specs of the components and no glaring error in design... like JCA omitting the grid leak resistor on one of the preamp stages in their Picovalve- the resistor was on the original design drawn up by Andy Marshall.) Or a lot of the internet mods created by people who know absolutely nothing about electronics.

Steve

[Chuck H]

If you compared Dan's circuits to anything designed by a first year EE student I think that his would sound better at least 9 out of 10 times.

Agreed. It's his sheer level of experience and tweakery for years that put him in any status. Dan and I parted ways when he was starting to build his own amps. He ran out of time for obsessive, compulsive players like me wanting their amps tweaked twice a month. I became frustrated and, like other things that I either couldn't afford or suddenly became unavailable, I decided I had to be able to do it myself if I was to be in control of my personal circumstance on the matter. So I stopped going to Dan and started tweaking. I found this forum about a year later. It's been the best thing that could have happened. I guess that was about ninteen years ago!!! But the very first things I learned was by studying Dan's circuit mods and listening to the changes. I continued to study his circuits for a while. He had built me a custom Traynor Guitarmate that he put into a combo cab with an EV 12". It had the most complex and smooth distortion tone of any amp I've ever heard... I sold it to get a Marshall head Just more my style I guess. But to be sure, Dumble had nothing on the OD of that bastard combo amp. It was the definition of tone nirvana for the fat country /jazz guys.

I was just trying to excuse my indiscression. I've had Dans back here before (aginst all odds). So I feel a little bad having slammed his authored work. But it did suit the subject matter. So there you go.

[J M Fahey]

Well, I'm quoting respected Techs who say so, plus some snippets I've seen online here and there plus some shameful videos on Y.T.
Proof enough for me.
But of course my mind is open, I'd *love* to see some original, classic circuit and then some, say, "[insert Guru name here] Mod" which makes it sound better.
Preferrably 3 or 4 examples, so as to show that 1 was not just a lucky chance.
I'm all ears

[exclamationmark]

I think most of the tonal differences from ceramic capacitors comes from people using the high k dielectric types in coupling cap positions (everything but the NP0/C0G ceramics fits this description). These types are bias sensitive, and with a bias voltage of something like 150+ volts, the capacitance is often cut by huge margins (I've seen graphs that go up to 80%!). So that 0.022uf ceramic cap might only turn out to be a fraction of that value. Less bass would make the amp seem more shrill, and of course these types also tend to be piezoelectric, on top of having huge distortion figures.