Testing out some tone caps...

[Steve A.]

Many thanks to Possum for bringing up this topic since I'd been meaning to experiment with some of the premium caps around.

No mythbusting in this thread- just some opinionated and subjective observations.

I ordered some Hovland Musicaps and some Luxe Bumblebee clones over the weekend and the Musicaps arrived today.

I replaced the generic brown .022uF tone cap in my PRS SE Singlecut II (w/ a Burstbucker 2 in the neck and a Burstbucker Pro in the bridge). And gave it a spin in a few of my amps.

My impression was that it was definitely worth the ~$12 since it did open up the middle range of the tone control- lots of good sounds in there that I wasn't getting before in the 14 months that I've had this guitar.

Would it be worth it to spend $24 for two caps for one of my Les Pauls? I'd have to think about that...

As for the custom guitar builders out there, I doubt that you could justify the added expense and many of your customers might not really appreciate the difference (I doubt if you can hear much of anything going through one of those modern multiprocessors! ) But I would suggest offering an upgraded cap or two as an option.

I'll try out the Luxe Bumblebee when I get it and post the results here. And I repeat that these are just very subjective experiments- nothing scientific at all. It is just something that you hear and feel when you are playing. So the next time that you are suffering a G.A.S. attack, don't buy another guitar that you don't need, but spend a small fraction of that on some upgraded caps that you find on eBay or Google and make your own tests. Or not...

Steve Ahola

P.S. The local electronics part dealer just got in some Orange Drop caps! When I asked the previous owner for some Orange Drop caps about 15 years ago, he told me "caps are caps- these are just as good!" So I replaced the tone caps in my BF Pro Reverb with some of those "little greenies" that he sold me and it made the amp sound like crap. I put the original caps back in and it sounded much better (so its not like I screwed something up). While the technical explanations and theories can be interesting, what I really care about is what works for me. And I know from personal experience that all caps were not created equal...

[mark]

Dear Steve

Good to hear from you again.

Yours Sincerely

Mark Abbott

[outtahear]

Would it be worth it to spend $24 for two caps for one of my Les Pauls? I'd have to think about that...

How about $10??

http://www.thegearpage.net/board/sho...d.php?t=463490

[Steve A.]

How about $10??

http://www.thegearpage.net/board/sho...d.php?t=463490

You tell me this now that I already ordered some Luxes...?

Speaking of which, I wonder why I have not received them yet...

Steve

P.S. Can you PM me with information to purchase your caps?

[jack briggs]

As for the custom guitar builders out there, I doubt that you could justify the added expense and many of your customers might not really appreciate the difference (I doubt if you can hear much of anything going through one of those modern multiprocessors! ) But I would suggest offering an upgraded cap or two as an option.



Steve Ahola

Steve,

I ship my guitars with Hovland caps. My Reserve Stock instruments usually have NOS Vitamin Q's. Nowhere to go from there!



Cheers,

[dai h.]

I have found that the best capacitors for guitars are Mullards. I have tested the Hovlands and PIO VITQ's and everything in between. The cheapest upgrade is Orange Drop. The best upgrade in TONE is to use Mullard Mustard Capacitors NOS. There is a reason why Marshall used them in the original plexi's. They happen to be on to something back in the early days. If you can get your hands on some I would suggest you try replacing some capacitors with Original Mullard Mustards and it will blow your mind.

if one bothers to actually look at Marshall chassis pics, it is easy to see that the "mustard" caps were one of a number of cap brands used by Marshall. They also used different resistor brands as well as types (carbon film and carbon comp). The first JTM45 chassis in the Fliegler book for one, doesn't show any Philips mustards. Knowing the facts, I think it'd be very hard to argue that mustards were some sort of special specification.

[David Schwab]

Companies used the parts that were available at the time. Now they are vintage, but at the time they were just caps.

Same with magnets. Alnico was used because it was the new magnet material at the time, and better than cobalt-steel magnets. They didn't pick alnico because it was better than other choices, because there really weren't any other choices! Same reason some guitar companies went to ceramic magnets in the 60's. They were new and cheaper than alnico.

It's easy to look back and to over think these things, like Marshall tried a bunch of caps until they found some magic formula, except that didn't happen. They were manufacturing amps, so they went with the good parts for the price they wanted to pay and with adequate supply to meet their needs. Mullard was a big name in electronic parts, as were others.

For a guitar tone control, anything other than a ceramic cap works just fine. I have some little green mylar film caps from RadioShack in my guitar, and they sound great. Other than changing cap values, I do not believe you would hear a difference between any quality cap used in a tone control circuit.

That's been my experience anyway.

[Joe Gwinn]

Testing caps for audible differences

I have no opinion on the audible difference, if any, between capacitor types. However, I've been following the traffic, and see that a lot of the tests that have been used could prove misleading. What is needed to make a valid test? Here is the minimum:

1. Capacitors to be tested to determine differences between construction types and/or dielectric type must be matched in capacitance to within 1%, or any effect due to type will be swamped by variations due to difference in capacitance. Capacitance tolerances can be quite loose, +/- 20%, which makes a lot of difference. All else in the circuit must be unchanged.

2. Capacitors to be tested must be installed in the test guitar (or amp) with a mechanical switch that allows immediate A-B (or A-B-C...) switching, as the memory for tone is fleeting.

3. In the strongest form, during listening tests the people doing the test cannot know which capacitor is which, to prevent subjectivity and expectation biases from invalidating the results. All testing is done in terms of A, B, C, et al, with written evaluations provided. Only after the tests are complete and all evaluations received is the study "unblinded", where the identity of A, B, C et al are at last revealed and the results analyzed.


In Medicine , a single-blind study is where the treating doctor knows which treatment or drug the patient received, but the evaluator does not. A double-blind study is where neither treating nor evaluating doctor knows which drug is which.

The classic music test with an audience of musicians who are prevented from seeing the player by a curtain is a single-blind study. It isn't obvious how one would make a double-blind music test, unless the player were blindfolded. Which would give blind players an unfair advantage.

In test involving a guitar or amp, the double-blind approach is for someone other than player and evaluator to install the test hardware but to not reveal which letter selects which component.

[David Schwab]

The classic music test with an audience of musicians who are prevented from seeing the player by a curtain is a single-blind study. It isn't obvious how one would make a double-blind music test, unless the player were blindfolded. Which would give blind players an unfair advantage.

In test involving a guitar or amp, the double-blind approach is for someone other than player and evaluator to install the test hardware but to not reveal which letter selects which component.

There was a similar double blind test done to see if there is a difference in two buffer circuits, one using an op amp, and the other a JFET:

Lutherie Myth/Science: A Listening Evaluation of Discrete vs Integrated Circuit Audio Preamplifiers in Stringed Musical Instruments

They had a switch on the bass labeled "A" and "B"

Abstract
Audio preamplifier circuitry is increasingly used in electric guitars and electric bass guitars. A general preference for circuits built using discrete solid state components vs integrated circuit operational amplifiers appears to be building within the user community for these instruments. A double blind experiment was conducted to determine if users showed a preference between a JFET discrete component preamp and an opamp preamp following a listening evaluation. Results indicate no clear preference for either type.

In the end, some thought one sounded better than the other, and others had no preference.

Results
The experiment was unblinded and the questionnaires tabulated with the following results. Two (2) subjects found the tone of the discrete FET preamp preferable. Two (2) subjects found the tone of the opamp preamp preferable. Five (5) subjects found the sound identical in both preamps. Five (5) subjects found the two preamps sounded different but that neither one was superior in tone. As the data are so obviously distributed normally about the mean no additional statistical evaluations were performed. Subjects that indicated a preference also indicated that perceived differences were very subtle.

[David Schwab]

No one here has a degree in electronic engineering...

How do you know this?

[Mike Sulzer]

1. Capacitors to be tested to determine differences between construction types and/or dielectric type must be matched in capacitance to within 1%, or any effect due to type will be swamped by variations due to difference in capacitance. Capacitance tolerances can be quite loose, +/- 20%, which makes a lot of difference. All else in the circuit must be unchanged.

Joe, that is a good point about matching the cap values. But there is something to be considered first before one can proceed with the kind of careful tests you have described, because they involve a lot of care and effort: what is the best setting for the tone pot to give the most sensitivity to the capacitor characteristics? This is not so obvious. On 0, the upper midrange frequencies that the ear/brain is so sensitive to are much attenuated. On 10, the capacitor has a large resistor in series. Although most people are not convinced that the degree of isolation is as large as I think, no one seems to be denying that there is such an effect. I suspect that the best position is somewhere in between. Any ideas on a test to determine what that position is?

[dai h.]

here's what was said:

The best upgrade in TONE is to use Mullard Mustard Capacitors NOS. There is a reason why Marshall used them in the original plexi's. They happen to be on to something back in the early days. If you can get your hands on some I would suggest you try replacing some capacitors with Original Mullard Mustards and it will blow your mind.

For this reason, I hate posting anything on this fourm. Everyone thinks they have all the knowledge when they have no ground to stand on. These replies are for suggestions or advice. No one here has a degree in electronic engineering and designed capacitors for 20+ years. People trying to under cut the suggestions of others just bring out their ignorance and lack of respect of others peoples voices. That's whats wrong with this forum. Shit guys EGO'S ASIDE. WE ARN'T GODS!

how in anyone's reply are they showing ignorance or pretending to be a god? Anyone with an internet connection can look for individual (or a collection of) chassis pics and check out the variety of caps themselves. There is no special effort or skill required. If you like them or think they are special, great, but stating they were especially chosen by Marshall due to their special tonal qualities doesn't really stand up to scrutiny.

[David Schwab]

I'm not here to play GAMES.

Well you sure sound like a little kid to me.

You made a statement, and people pointed out it had flawed logic.

You also made the assumption that no one here has any formal training in electronics, without any proof.

So maybe you don't like to post here because you don't think before you post?

Some of the people here do indeed have degrees and know what they are talking about. Others just have a lot of experience.

No one said they were gods, but a lot of us know what we are talking about.

Oh and it's "WE'RE NOT GODS." not "WERE NOT GODS."

[David Schwab]

We all have a right to speak our ideas and opinions with out the scrutiny from other peoples EGO's.

That's what we were doing... however we voiced an opinion that you don't agree with. So that makes us egotistical?

No one is trying to start an argument with you, but as I said before, I don't agree that Marshall picked a particular capacitor for the tone of it. I'm sure you wont find any reference to them doing that either. They did pick a good quality part, but that's about it.

[David King]

Mustard caps?
Personally, I prefer Ginseng caps but I'll admit that pure cocaine is a lot faster.
Anyone here ever smoked a resistor?