Are Mallory caps essential?

[Roe]

I just tried TAD's audio caps, made in Germany, in two twins. the caps formed very quickly and reached about 0.5-1v voltage drop over a 100k, something that is great. they sound very punchy comparred to some other caps (TAD standards/asian, ceriatone holy grail). also they may sound a little brighter but not in an unpleasant way.

I'm very impressed with the sound and response of these caps, but they are somewhat expensive. will do more tests and report back

[Scottie]

As to the original question about Mallory's, I'd agree and say no.

I've used quite-a-few different brands of AL caps, and like Ken Moon, between the two I'd just as soon go with Nichicon over Xicon, as they are easier to get (esp. in repairist/smalltime amp hobbyist quantities) and the quality seems to be there.

I haven't tried the Nichicon Muse series, but for pedal mods and upgrades I seem to have good luck and tone with the Nichicon PW series, where they are used for coupling, and likely have an higher impact on tone.

PW's are shown as one of Nichicon's 'low impedance' lines, FWIW, and they do spec impedances on the data sheet.

I've used them in amp and old radio power supplies, too. I'm not sure I would be able to hear brand-to-brand differences in caps used in power supplies. It'd be interesting to set up a switch circuit to do some A-B-C testing... or just use a reasonable quality cap and go with it.

Aren't there some amp builders that add films across AL electrolytics? That would take care of some of the possible ESR issues. One wonders if K. Fisher ever thought about this, given all the opinions he had on the tonality of various components.

Scottie

[renshen1957]

As to the original question about Mallory's, I'd agree and say no.

Aren't there some amp builders that add films across AL electrolytics? That would take care of some of the possible ESR issues. One wonders if K. Fisher ever thought about this, given all the opinions he had on the tonality of various components.

Scottie

Hi Scottie,

The film caps across Elytics is for my 2 cents is either a Hi Fi influence (I used the "H" word) in some builds, or in other builds I have seen the film caps (with a few resistors added) were used as "hash" filters to eliminate SS diode/rectifier noise.

The benefit of bypassing electrolytic caps with film cap is typically in improved high frequency response because the lower value film cap will pass higher frequencies better than the higher value one, and vice versa. There's a counter argument about phase shift. Phase shift and hi frequency response in a guitar isn't worth worrying about. However, some Trainwrecks (Komets) have a reputation of being a little "noisy" at those higher frequencies, bypassing the elytic caps, would accentuate this. (I know, I am speaking heresy in the Trainwreck forum).

I use UF4007 (not as noisy as 1N4007) diodes and still add film caps/resistors in amps that do not use a tube rectifier.

I have also used Solen PP film caps in place of Al electrolytic caps in 22uf 630V (lower values and larger values.).

In this case the film caps in the power supply do not have the distortion characteristics of Al electrolytic caps. Some builders use a either ceramic disc across the Solen caps to capture the classic sound or add another tube gain stage.

Currently the Solen Caps aren't any more expensive than Atoms from my distributor, but these caps are physically larger in size. However, these caps will last the life of the guitar amp (and are self healing). One reason to consider this type of cap is you don't have to worry about replacing them after 2,000 or 10,000 hours. Downside is you have less distortion in the power supply, and thus have to resort to other means to achieve "a classic" sound.

Best Regards,

Steve

PS My experience with the Atoms have been very good, and I do test all my caps with a tube capacitor tester at the cap's working voltage.