Non-electrolytic replacement caps, Orange Drops, etc - Your thoughts please?

[olddawg]

I have found myself recapping a few amplifiers lately. Many people recommend "Orange Drop Caps", Torres Engineering even has them with his name on them as "the best" orange drop caps . Fliptops recommends a different yellow axial cap that looks more like the old red Astrons. Recently when an old amp of mine suddenly quit I replaced the non-electrolytic caps with new 630 volt brown NTE brand Mylar/Film caps. They were available locally in 10 minutes and cost $1 each. They seem to work fine. There are botique UTV Ultratone replacement caps for $50 apiece. I figure any modern cap has got to be better than the 40 year old paper caps that were in the amp. Is there really any discernable advantage to using specific brands of film caps or is it all hype and attitude? I know people who sware that they can hear a difference with their botique speaker cables. Heavy guage copper lamp cord has always sounded the same to me. Is it like that?

[soundmasterg]

If you're looking for differences in sound, then you'll notice much more difference from changing speakers, tubes, and transformers, or modding the circuit to change voltages than you will from changing caps. That said, there are subtle differences from changing caps. The brand doesn't really matter though as long as any brand you are using is good quality. What matters more is the composition of the cap. Orange Drops come in film/foil polypropylene (715P and 716P) and film/foil polyester (6PS, 225P). Torres's "Orange Drops" are probably very similar to the others and I wouldn't bother honestly. Mallory 150's are metallized polyester. Sozo's are film/foil polyester, etc. Polyester caps tend to sound rounder and browner than polypropylene, with less highs. For a guitar amp, polyester are usually better to my ears, but for bass or hi-fi, polypropylene can sound better in certain places. The old paper caps tend to leak DC, and if they don't now will eventually, but they can sound really good too. Theres also paper-in-oil, military NOS sealed paper caps which will probably outlast all other paper types.

Best advice would be to get various composition caps and try them out yourself and see what works for you.

Greg

[dai h.]

I think it depends on a bunch of things like what is being done? ("exact vintage restoration"? cost-effective repair? Experimentation?, etc.), Who is doing the listening (hypersensitive ultra-obsessive Eric Johnson-type ears guy/gal, casual hobby player, 70 year old with massive hearing damage, etc.), how much effort and money you want to spend obtaining a part(super rare vintage hard to find and expensive, super high tech and expensive, etc.), what sort of function in the circuit and effect on sound(coupling cap? snubber?, etc.).

[olddawg]

So in your opinion there will be a noticible positive tonal difference (closer to the original voicing of the amp) in using Orange Drops when compared to the mylar film caps I used in the coupling and phase inverter circuits? I used the NTE mylar film caps because they were convenient and I wanted to use the amp. It's not a big deal or expensive to order some and put them in. I just wonder if it is worth the trouble. I guess I'll find out. What is your opinion of mylar film caps for this application?

[TD_Madden]

Topic variant.....Electrolytic replacements

how about a variant of the question...

Anybody using polyprop film as repacements for electrolytics? There's been a lot of progress in reducing their size in values large enough to handle power-supply filtering), but I can't find any evidence of folks using them for that purpose in guitar amps.

R.G. Keen had a comment-stream running over at the Vox forum in PlexiPalace, and I'm interested in using them in my AC50 (replaced the original 32mf/450 caps with paralleled 20mf/600 since the B+ was about 511v...

[bob p]

i think we'll have the definitive answer to the cap question as soon as @mykey finds this thread.

[TD_Madden]

oh hell, that's JUST what we need!

[soundmasterg]

So in your opinion there will be a noticible positive tonal difference (closer to the original voicing of the amp) in using Orange Drops when compared to the mylar film caps I used in the coupling and phase inverter circuits? I used the NTE mylar film caps because they were convenient and I wanted to use the amp. It's not a big deal or expensive to order some and put them in. I just wonder if it is worth the trouble. I guess I'll find out. What is your opinion of mylar film caps for this application?

Mylar is a Dupont trade name for polyester. There will be a noticeable difference if you use polypropylene Sprague Orange Drops (715P and 716P) in place of the mylar/polyester ones you have in there, but it will be a subtle difference. Orange Drops, to my ears, tend to have a big bottom and somewhat harsh highs depending on the application. The mids in polyester caps usually sound more interesting to me too, but again, those are my ears. You might hear differently. If you use the polyester Orange Drops (6PS or 225P) in place of the mylars, there won't be much difference, though there will be some. Whether this will be a positive change or not depends on what you're going for? What kind of amp is it? What do you want to change about the tone as it is now? Changing caps are a subtle change to the tone....sort of like the creme on top of your hot choclate. It isn't necessary for the drink to taste good, but sometimes it can take it over the top and make it just right....and that is what the caps do, but you have to have your amp right before that with the circuit design, arrangment, voltages, etc.

Greg

[olddawg]

Mylar is a Dupont trade name for polyester. There will be a noticeable difference if you use polypropylene Sprague Orange Drops (715P and 716P) in place of the mylar/polyester ones you have in there, but it will be a subtle difference. Orange Drops, to my ears, tend to have a big bottom and somewhat harsh highs depending on the application. The mids in polyester caps usually sound more interesting to me too, but again, those are my ears. You might hear differently. If you use the polyester Orange Drops (6PS or 225P) in place of the mylars, there won't be much difference, though there will be some. Whether this will be a positive change or not depends on what you're going for? What kind of amp is it? What do you want to change about the tone as it is now? Changing caps are a subtle change to the tone....sort of like the creme on top of your hot choclate. It isn't necessary for the drink to taste good, but sometimes it can take it over the top and make it just right....and that is what the caps do, but you have to have your amp right before that with the circuit design, arrangment, voltages, etc.

Greg

The amp is the 1960 Ampeg Rocket I discussed in an earlier post. I replaced the filter can and found the tremolo was weak. In repairing the tremolo I discovered the phase inverter caps were leaking. Since I needed to use the amp soon, I used the NTE mylars that were immediately available. I am trying to get a concensus because I need to recap my 1963 Blonde Tremolux and a couple of other amps also. I have an AS degree in electronics and worked as a bench tech on solid state audio/video equipment for many years. For that application one usually uses OEM parts. My experience in repairing tube equipment is somewhat limited so I am trying to get up to speed on the various nuances and idiosycracies. In the past I let someone else service my guitar amps. Now I want to do it myself, save some money, and do it right.

[dai h.]

as long you replace with something similar enough and as long as the value is not too far off I would not expect a particularly noticeable change. So if the original was polyester, then one might at the least try to find polyester caps. But things like this can be subjective and some techs might try to find an exact period correct replacement, or something they feel is close or they hear is close or thought to be the best replacement by users and techs, etc. Some (dishonest) techs seem to replace things that don't need replacing either from sheer ignorance or just to charge more money (not suggesting anyone here is but just examples of the variety). There seem to be all sorts of situations out there from what I gather, so I guess you have to make the best judgment for your particular situation.

[olddawg]

as long you replace with something similar enough and as long as the value is not too far off I would not expect a particularly noticeable change. So if the original was polyester, then one might at the least try to find polyester caps. But things like this can be subjective and some techs might try to find an exact period correct replacement, or something they feel is close or they hear is close or thought to be the best replacement by users and techs, etc. Some (dishonest) techs seem to replace things that don't need replacing either from sheer ignorance or just to charge more money (not suggesting anyone here is but just examples of the variety). There seem to be all sorts of situations out there from what I gather, so I guess you have to make the best judgment for your particular situation.

The caps I am concerned with are mostly paper caps. Nos caps are usually a bucket of worms, possibly being as bad or worse as the ones you are replacing IMO. I am not worried about achieving a pristine restoration on the Ampeg which is a beater amp. I will be more concerned with the Tremolux since it is in excellent cosmetic shape, has never been worked on, and has two original cabinets. So it is potentially quite valuable and how I recap it may effect that value. However, I do use the amp. It is not a collector piece. Any advice is appreciated.

[dai h.]

like you say NOS can be problematic. Some do seem to be reliable and hold up for a long time, while others can be leaky, usually go leaky, or even shorted sometimes. I observe techs doing different things. One might sort through a bunch of old ones and try to find non-leaky ones (this could be cost-prohibitive where the old ones have gained value on the NOS market and have become too expensive to buy in bulk and sort through. One might also wonder how such caps would hold up over the long run). Another might not use old ones at all to eliminate any sort of risk. Somebody else, maybe they try to find something new that sounds the same or similar. You could try different things like for example for oil cap replacement, maybe you could use the hermetically sealed "Vitamin Q" type for replacement since those are oil and seem to be quite reliable. There is some info on the net here (archives) as well as other sites (not necessarily amp sites--could be radio/TV oriented) about specifics on the observed reliability of old caps. Regardless of what you do, if you do have a bad leaky cap you will need to change it for the amp to work correctly, so you'll have to do something... unless it's one of those Nigel Tufnel amps that you can't play or look at.

[soundmasterg]

I'm not sure when Fender started in with using the blue Mallory "Molded" caps, but it should be right around when your Tremolux was made. The older Fenders were using Astrons a lot and almost all of those caps are leaky from what I have seen. On the other hand, the blue "molded" Mallorys are great caps and still usually work just fine. I wouldn't replace any of those unless one was non-functional or was leaking DC. For ceramics, I'd probably replace those with new good quality ceramics or silver micas, depending on what sound you're after. A lot of people who are looking for old Fenders have learned enough about the insides of the amps to really be looking for those old blue "molded" caps, so changing them out wouldn't be suggested unless they are bad. My 2 cents anyway.

Greg

P.S. Those old blue "molded" Mallorys were paper and polyester/mylar caps.

[olddawg]

I'm not sure when Fender started in with using the blue Mallory "Molded" caps, but it should be right around when your Tremolux was made. The older Fenders were using Astrons a lot and almost all of those caps are leaky from what I have seen. On the other hand, the blue "molded" Mallorys are great caps and still usually work just fine. I wouldn't replace any of those unless one was non-functional or was leaking DC. For ceramics, I'd probably replace those with new good quality ceramics or silver micas, depending on what sound you're after. A lot of people who are looking for old Fenders have learned enough about the insides of the amps to really be looking for those old blue "molded" caps, so changing them out wouldn't be suggested unless they are bad. My 2 cents anyway.

Greg

P.S. Those old blue "molded" Mallorys were paper and polyester/mylar caps.

Yeah, those were Astrons I was replacing in the Ampeg Rocket. Fliptops recomends these: http://www.fliptops.net/catalog/prod...roducts_id=284 There seem to be a few posters on this site who own they're own shops. Would any of you guys be willing to give a rule of thumb cap replacement guide such as, replace the Astron paper caps with this kind, replace the blue molded Mallorys with this kind? Even a chart guide would be nice. These years of Fender amps use this replacement, etc?

[Enzo]

Dammit, I typoed my whole response away.

There is no wrong part to use. And who knows who made those caps for NTE anyway?

Modern film caps will all work fine in this amp, and differences will be subtle tonal ones. It will make less difference than brand of guitar string. Can you listen to a recording and hear D'addarios from Fenders? When you get the golden ears, then worry about brand.

REstoring the amp to original specs is a myth. Back then 20% tolerance parts were common. Leo Fender was not going to spend extra for 5% parts when 20% was good enough. That means your 100k plate resistor could be anything from 80k to 120k and be within spec. ecaps were spec'd at +80/-20% most of the time. Your coupling caps were no more precise. Today 5% parts are expected, and 2% parts are quite common too. Not so back when your amp was made.


SO to try to "match" the original sound with some particular brand, is to me wasted effort. Two amps side by side off the line didn't sound the same. There is nothing to match. SOme guys have their favorites, and involved rationalizations for every choice. But not everyone prefers the same tone, so the guy who likes shrill amps will chose different parts from the guy who is after smooth sound.