(Archive) Coupling Capacitors

[radar01]

I have seen small 50's era amps using chocolate drop and orange drop capacitors for interstage coupling.  Fender used disk ceramic coupling capacitors in their 60's and 70's era amps that I have worked on.  Everybody has their own opinion, but I'm interested in hearing those opinions about what type capacitor gives the best overall tone?

[TubeGeek]

It is a subjective thing.  Some say that orange drops are better, I have heard people say that they are more "hifi" sounding as compared to mallory 150 series caps.  Orange drop 715p series has a polypropylene dielectric and mallory's have a metallized polyester dielectric material.  Can we hear a difference? Maybe but there are many other variables that could essentially affect their sound.  I am testing this out for myself instead of listening to what other people say.  I have been working on listening to differences between orange drops and mallory's.  What have I found? I hear less high frequency response when I use mallory's. It is not so much as a filtered sound but more of a warmer, softer tone.  If I am building a 2 channel amp, I use the mallory caps in the clean channel and the orange drops in the dirty channel. It is a never ending evaluation.

So what is your definition of "best overall tone"? I suggest that if you really want to know for sure then build a project where you can switch between the caps and evaluate it with your ears.

[phsyconoodler]

What i would suggest you do is get a bunch of different capacitors and swap them until you get the tone that sounds best to you.Actually I do the two channel amp thing differently.I use the orange drops for clean and the mallory's for dirty.Fender's seem to sound better with orange drops and marshall's with mallory's.There are many others to choose from like Cornel Dublier and Aural tone,solen,and the list goes on.There are many opinions aboout this as well.Buy a bunch and get testing!

[EL34]

Actually most amps older than say 1950 used a tubular cap that looks like it was dipped in a thick wax.
Jukebox amps, radios, etc all had these caps.

Fender used yellow Astrons in the 50's and early 60's.
Fender used the blue tubular mallories and just a few ceramics in the 60's amps.
Fender used the brown blob caps late 60's and early 70's.

[SoundmasterG]

Gibson used lots of those yellow Astrons and some bumblebees in the late 50's also. Every one of them that I've seen (Astrons and Bumblebees) has been really leaky. The blue Mallories that Fender used seem to be usually ok though for leakage so I leave them in place. For new stuff, as the others said, experimenting and deciding for yourself is best. Good choices would be the Mallory 150's, Orange Drops (they have 715P and 716P as film/foil polypropylene, and PS series and 225P's as film/foil polyester), Sozo's, AES's yellow polyester caps, Xicons, Solens, and then hi-fi stuff like Auricaps, Hovlands, etc.

Greg

[HotBluePlates]

I used to put a lot of stock in what cap type to use in the past, but that was only because I bought into Gerald Weber's vintage amp hype.

Changing the value of a cap from say .022uF to .047uF or .1uF will make a much, much bigger difference than changing cap type. What I would suggest doing is taking your "guinea pig" amp, and going through first tweaking cap values to get the sound where it should be. Once all values are dialled in, you should get those values from a number of other cap types, and swap them wholesale to compare the differences.

I will say that I do hear distinct differences in the tone of different caps, but that the value will make a bigger difference. That said, polyester caps usually sound warmer or more midrangey to me, where polypropylene sound crisper, clearer with more lows and highs (or less accented mids).

That said, either can work in any amp, but if you were to totally tweak the sound for 716p orange drops (polypropylene), then the amp may sound either warmer or downright muddy with Mallory 150's. The same is true going the other way.

Marshall's have values that are geared towards a bright sound, which is probably why people like 150's in them to get more warmth, where a lot of Fender amps have a full, sometimes muddy sound (to compliment single coils), where the orange drops may bring more clarity.

And by the way, there are also polyester orange drops (225p). The only other consideration is that polypropylene caps are physically larger for the same capacitance and voltage rating, and may not fit as well in smaller tweed chassis.

[Voxbox]

Anybody any idea why they sound different?

[SoundmasterG]

It is probably due to the different materials that they are made with and the way they are made. Orange Drop 715P and 716P are film/foil polypropylene, and Mallory 150's are metallized polyester. I think Sozos are metallized polyester also, but can't recall. Different dialectrics will affect the signal in different ways, as will the size of the cap. The Sozo site has some info on this that is interesting. Maybe others can chime in too.

Greg

[tubenit]

From Bigsbybender on another thread about coupling caps.

On the amp that I tweak the most, I used Orange Drop (Sprague 715) in the preamp/tonestack..Then used the Mallory 150's in the PI. I tried various caps in about every position but this is what I liked the best....not saying that anyone else will like it..but it is worth it to mix and match. I like the bright orange drops but the Mallory 150's sort of "smoothed" the tone at the PI versus the OD's.  
 
On new builds I usually stick to one kind of cap in the whole amp just for aesthetics. I am usually a fan of Orange Drops but have been using M150's alot lately.  I've used some expensive caps  like Solen (only down to 0.1uF) but really the OD's and M150s  are what I keep coming back to.
 
Now if I could only find a truckload of those blue tubular Mallory caps that Fender used in the 60's.  
 
Also from Bigsbybender:

I use Xicon E-lytics all the time...they're good.   I've use their poly caps here and there with good results, but never done an entire amp with them. I do believe the "normal" channel of my twin is Xicon...compact little blue ones at least, but I'm thinking they were Xicon. well whatever they are, they sound a little closer to the Orange Drops than to the Mallory 150's. (got orange drops in the Vibrato channel to compare)
 
j.

[Greasehorse]

One amp guy I talk to once in a while rolls his own small amp caps. He takes teflon caps from Fleabay, unwinds them, reuses the teflon and rolls his own caps to whatever specs he needs...likely pfs or smaller ufs...

[Jim Coash]

I have replaced a lot of caps and I tend to prefer the "Hi-Fi" sound.  The only caps I never touch, unless I have to, are the Cornell-Dubilier caps I commonly find in Ampegs.  They seem to sound especially good to me.  Others have suggested I not change them unless I must.  Jim

[Voxbox]

I've had a good experience with Jupiter yellow caps in a 1960 Vibrasonic rebuild.

Some of the anode caps had been replaced by Sprague orange drops, however there were some of the original black spragues present and working ok.

I did a lot of A/B testing with the original black Sprague anode caps vs. the Jupiters and the sound was identical.

I also did A/B tests with Sprague Orange Drops. To my ears, the Jupiters were preferable. The ODs sounded a bit edgy, or harsh compared to the Black Spragues and the yellow Jupiters.

Of course there is no "right" choice - just the one you like!

Cheers, VB