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Wasn’t dismissing, I just already knew it could use ground lugs, and was attempting to make a thread to find out what people’s favourite caps were. It’s kind of turned into someone asking for pickup recommendations, and people replying that it doesn’t matter what pickups you use, because you need to change your strings.
Fair enuf (though I don't think it was quite that belaboured and, frankly, trivial).
 

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All else aside, I do hope you will post about your choice and how you like them. :)
 

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For my two cents, those Mojo caps I see in the Princeton pic should be absolutely fine as far as good functioning of the amp. I have them in several builds, 5 or 6 years old, and have never known one to cause a problem. I do agree with the poster who said that Sozos or Jupiters are preferred when the "image" of vintage amp preservation needs to be preserved for somebody who cares about such optics (like a few fussier customers I've had over the years). Both are good brands but needlessly expensive. In terms of functionality, the Mojos (sold by tubestore), Mallory 150s (sold by NextGen), and ETR (sold by Just Radios) all do a fine job for a much lower price.
 

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I did a restoration a few years ago, a late '50's Tremolux and I was glad when my customer (and friend) pulled the trigger on the red Astrons. They look right and the amp drips tone, good tone.
Oh and never fucking ever buy CHINESE caps or anything else CHINESE if you can avoid it.
 

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Discussion Starter · #28 ·
For my two cents, those Mojo caps I see in the Princeton pic should be absolutely fine as far as good functioning of the amp. I have them in several builds, 5 or 6 years old, and have never known one to cause a problem. I do agree with the poster who said that Sozos or Jupiters are preferred when the "image" of vintage amp preservation needs to be preserved for somebody who cares about such optics (like a few fussier customers I've had over the years). Both are good brands but needlessly expensive. In terms of functionality, the Mojos (sold by tubestore), Mallory 150s (sold by NextGen), and ETR (sold by Just Radios) all do a fine job for a much lower price.
That’s for the input! I will agree the amp sounds fine and this is nothing more than a potential fun project, and there are absolutely no issues with the amp ‘as is’. In other project news, I hear you make cabs, and I have a tweed champ chassis that needs one!
 

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Discussion Starter · #29 ·
I did a restoration a few years ago, a late '50's Tremolux and I was glad when my customer (and friend) pulled the trigger on the red Astrons. They look right and the amp drips tone, good tone.
Oh and never fucking ever buy CHINESE caps or anything else CHINESE if you can avoid it.
I have a tweed tremolux that I would think about recapping with those after these ones stop working.
Circuit component Audio equipment Electronic component Hardware programmer Beer
 

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Discussion Starter · #31 ·
Nice! Yellow Astrons, in my experience, are notorious leakers.
These ones would have been tested a little While back and were fine, I dint really plan on testing them again unless something happens or it starts not sounding awesome.
 

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1965 Fender Mustang, Ampegs, anything to test an amp.
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Most players won't realize the coupling caps are beginning to leak, especially if they use the amp regularly...it's usually a very gradual process, until your buddy says WTF with the tinny sound from the speakers.
 

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The solder connections to the chassis are not fully bonded. The heat source used was insufficient to create a proper bond...some may refer to it as a cold solder joint.
All the terminations are tacked to the chassis....there is no mechanical connection; the properties of solder does not allow a strong mechanical connection.
It may be acceptable for proto-type work but not for a commercial product.
For the record Paul. Those ground terminations are OEM. In my experience, the ones on the chassis from the factory rarely go as they were using a substantial iron to solder them with. Personally, I can't recall seeing any of the solder joints on the main chassis come loose from the factory and I've seen dozens if not hundreds of old Fender amps....I have seen where folks get in there with a solder gun that doesn't create sufficient heat resulting in poor contact. That said, the ones that can be a problem are the grounds on the brass sub plate under the pots. They usually stretch the wire to those points and over time, expansion and contraction due to heat causes the joints to crack.
 

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You misunderstand - I meant that one of the reasons is NOT the vintage amp value thing (that some others mentioned) - not my concern here at all. Personally I wouldn't be arsed to preserve the original cap cans as you describe (but valiant effort) because a) I have some vintage amps but nothing super valuable (if I sell the buyers are players not collectors, and they value proper working order above originality when it comes to consumables like filter caps and bias resistors), and b) it can be construed as misleading (if not disclosed) upon sale (and sure you may disclose but the next guy will probably forget - I'd put money on it actually). I am also not certain what that link to a cap selling site you included is for/trying to demonstrate.

Further, based on all the dfifferent caps I have used in various devices (not just tube amps - I'm newish to building those) I have serious doubts that anyone can hear any real difference between brands/types of the same actual value (especially if, as it appears you are now suggesting, you replace one or two here or there randomly in an uncontrolled fashion, in an amp with 10+ poly film caps in it). See also what @jbwelder said about value tolerances just above your last post - at the very least, if you want to have a valid experiment, control the variables that you can (measure the old cap after removing, and the replacement before you put it in - betcha they're not that close in value at all +/- 20% is a lot of swing - even 10% - how much makes a difference depends on what the cap is doing). Then there's the fact that they're all (minus PiO - which is a whole other problem) the same type of cap - Mallory, Orange Drops, Sozos (some of them - they have a few lines but you're not going to be using Micas as coupling caps), even vintage Mustards etc are all metalised polypropylene film (Orange Drops have a few types/product lines, but are all poly-something films; close enuf). The same thing (except in axial format and higher voltage rating) as those 40c box films in any guitar pedal. In fact Vishay (itself already an umbrella), Sprague (Orange Drops), Mallory (and a few others) are all brands owned by the same manufacturer - Cornell Dubliner. You think the boutique best-for-your-amp brands are rolled in house by the sole proprietor of whatever brand you care to look at (Sozo, Mojotone, Emerson etc)? The legacy of Mustards being awesome comes from the fact that they were one of the earliest precision mass produced NON PiO (or wax vs oil; same problems) caps - their true legacy is not tone so much as reliability (and tighter tolerances). That's why Marshall and Traynor etc used them so religiously. Same goes for Orange Drops in the US for Fender (Traynor is physically closer to the US, but at the time being part of the Commonwealth, British parts were sometimes easier/cheaper to get, Pete may also have just preferred Mustards - they were smaller). Eisenhower didn't give Sprague the exclusive military supply contract because they sounded better in their communications gear - it was all about tolerance and reliability (which can affect tone, eg 10% off a standard value tone cap will change the rolloff point of the filter a bit; some may notice).

If you really want to check the effect of different caps, build or buy (though if one can't build perhaps they're not qualified to run the experiment) a small uncomplicated device (a basic tube buffer or preamp only with no bells/whistles), buy a bunch of caps of each type desired to be tested and select the ones that are all closest in value (both to each other and to spec for the device ), put them on a multiway switch so it's not half an hour between tests, use a source that is consistant (recording or loop of you playing from a loop pedal). Don't just trust your ears (there's a reason proper experiments are double blind - not feasible here, fine, so do what you can), use the spectral analysis in your DAW. That's not a complete list. Otherwise you're just falling victim to various cognative biases, and, most likely simple variance in actual Farad values.... and especially with NOS or PiO stuff, significantly larger leakage resistance.

Lastly, rolling caps for fun when there are actual concerns with the amp (the grounds soldered to the chassis) is just ass backwards priorities (I really hope @RBlakeney is not dismissing that in post #14 above - little vague). The amp may have intermittent grounds (or variable resistance to ground if not cutting out all the way) and making those more solid will actually imnprove tone more (as well as prevent possible costly failures).

It is his amp and he can do what he wants, but the point is that if he does this, in such a wildly uncontrolled fashion (as so many already have - with the youtube vids to document it, no need to repeat) proves nothing - you can convince yourself of all sorts of things in the process though. All that will result in is an upwards price spiral for the 'special' stuff.
A guitar amplifier is like a horse to me. I don’t need one, but if I had a horse I’d feed it diamonds just to make their poo sparkle.

That’s the logic I use to approach buying pretty capacitors and needlessly installing them into needlessly expensive needless luxury items like guitar amplifiers that I don’t need because I will never become a successful musician.
 
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