Sozo electrolytics, interesting!

[geetarpicker]

I recently got two of the recently released Sozo electrolytic 100uf @ 350v caps for my '68 Superbass 100. So fare these are the only electrolytics in the line. These caps are supposed to be made to similar specs and to have tonal qualities simliar to the Erie/RS caps used in late 60s era Marshall plexi 100s. Thought I'd try them just for grins in one of my two personal wreck clones, and guess where they are staying?

Yep, not even the truly correct values but wow they really smoothed out that slight bit of extra brightness and high end harshness of my clone vs my original. Not that the clone wasn't the closest I've played to my original (and darker than most if not all of the clones I've played) but I still did find myself avoiding my bridge PU on my strat a bit or at least rolling off the treble control on the bridge PU just a tad. Close enough for live gigging I'd say, but to nit pick in the studio yes the clones are just a tad brighter and harsher even after a year of break in compared to the real deal...

I put two of the Sozo electrolytics in series for a net resulting value of 50uf @ 700v. The series effect on the caps performance probably even added to the tonal effects of the caps above what they normally would have. It was both noticable that the amp was a little darker, but even more noticable was how the caps gave the amp a more broken in feel and less harshness. In my clone I had prior swapped the 50pf PI cap to 250pf to get the amp more in the range of my original EQ/brightness wise. But with the Sozo cap setup I put the 50pf PI cap back in and the amp is still warmer and smoother than ever. Yes, since the net uf in the main power supply is now lower @ 50uf instead of 80uf the amp now ghosts just a tad more than before but I think it's worth it. I currently simply mounted them near the preamp, still leaving the first two original caps mounted but not hooked up. I went back and forth about half a dozen times listening to the tonal differences between using the two Mallory 40uf caps as the first filters, and the Sozos. The low end was actually quite similar between the two type of caps. However it was the smoothing of the extreme treble that I noticed right away. Not exactly just a darkening, but both a darkening and smoothing of it.

By putting the caps in series I'm sure that also adds just a tad to the darkening effect. As folks know I always prefer these amps with the 500pf bright cap engaged, but it's takes some work with cords/PUs/speakers to mellow it out just enough to balance it all out. That said, I think these slight details need to be looked into. Perhaps the electrolytics and signal caps that are "still available" today are actually not made the same way they were 20 years ago? I built my amps with original spec Mallorys and Pacifics, but it all makes you wonder just what really is the same these days and what is not...

It would be very interesting to do some side to side comparisons of other brands of power supply caps in these amps.

[RobBozic]

That is interesting. I didn't know that Electrolytics could effect the tone at all.

I thought that some brands were probably more reliable and had more consistent values than others, but not tone.

What about their coupling caps, what do you think of those? Would you use them in a tweed or blackface type amp?

Rob

[geetarpicker]

In my amp changing the power supply caps (just the 1st set right off the PT B+) made more of a difference in EQ tonality than changing the PI "fizz" cap from 50pf up to 250pf. And possibly more tonal difference than say going from one brand of power tube to another. Still, it wasn't that the amp is now that much darker. It's more a combination of a little darker but also with a little less hash on top when distorted for lack of better terms.

I talked with the owner of Sozo about this. He says he really prefers power caps in series when possible in his Marshalls. He says it adds to the richer tones, as opposed to parallel cap setups used in the later amps with the dual 50s. Still I may try his dual 50s when they come out but with the two sections in paralled they may not be as sweet but the amp will probably ghost a little less with a net 100uf of filtering. Sozo is also working on some axial 32uf caps. None are exactly what supposed to be in a Wreck, but if it sounds good I don't care what the specs say. I may try his 32uf axials when he finally get's them to market, in the wreck with a 32uf for the screen and maybe one at each preamp point. It may be too much, but maybe worth a try.

We'll see when I get the amp out on a gig. I have a show specifically using my clones in a couple weeks, so I'll see how they do then. One is still left with the stock Mallory cap setup.

As far as I know Sozo is the only one I've seen attempting to reproduce the "tone" of the old electrolytic caps. He said that the foil in these caps (and the older ones from the 60s) is way thicker than any modern electrolytic cap, and that he electrically measured these caps (and vintage ones) during development at many different frequency points not just 60hz. Apparently even in the power supply it can effect how the amp responds not just dynamically, but also tonally and EQ wise. It seems there are some high end electrolytic caps made these days, but they seem mainly aimed at the pro audio market that are going to want an amp that goes flat up to 20k or even alot more. For a guitar amp, you may actually want a cap that rolls off some of the highs. Probably one reason an old Plexi is a mellower amp than the later metal face amps even when the amp is basically setup the same preamp wise.

I'll admit Ken wasn't building these amps in the 50s or even the 70s. However maybe even back in the 80s, and early 90s the off the shelf caps were still made better than today? When I mean "better" I mean perhaps they added more color to the tone? Just one more piece to the puzzle perhaps.

I may try adding a couple 220k bleeder resistors across my two 100uf Sozos to balance the voltages across them, as some sources point out this is required when running in series. However with two 350v caps in series on just 420 B+ they would have to be way off value to get an over voltage situation on either cap. Old plexis had series caps without bleeders and plenty of those amps are still going with original caps. I'll check if this changes the tone any. I still wired the bleeder resistors to ground like in the stock TW setup, just not on each separate cap now that they are in series.

[Roe]

I gonna try these sozo electrolytics as soon as 32uf (and other values) are ready. I'm gonna test in a early 67 jtm45/100 clone with el34s and the 1202-119 first.

I suppose the 32uf would work well for the PI and screens in an express.

dual 32uf caps might works for the mains. or perhaps two 100uf in series (50uf) in parallell with a 32uf for a total of 82 uf

[Andy Le Blanc]

Its an impedance relationship of the power supply, and you are right that it
really does effect the tone of the amp. Most Hi-Fi trends seek to extend the
presentation of the amp, guitar is quite different. Were did you source Sozo caps?

[M Fowler]

The sozo filter caps weren't out there but I did put all sozo on my boards in the express combo I built.

When these new electrolytic caps hit the market I will switch my filter caps out as well. Nice

[NowFender]

Thanks for the review, ordered 2 for my Express that's still a little harsh after cap changes to Mallory pvc's, spragues electrolytics, ts output, tubes..
but sounding alot better, just not there yet.

[Dai H.]

a "filter cap" can be directly in series with the signal, so it can effect the sound(they don't just necessarily filter ripple). I've tried a film for a preamp filter and it did (does) sound a bit different. Also the bias filter in series with the grid load/bias return R is in the signal path.

[rfgordon]

On the subject of caps changing in production over time, I have to agree with that. Last year I did a cap job on a Peavey Classic 50 that was about 15 years old. I ordered the same brand/value for the E-lytics, and the new ones were much larger than the stock caps. In fact, the locations on the PCB were sized for the originals. I had to do some aggie-engineering to make it all work. So, clearly, that brand/value of cap was vastly physically different than the originals.

Who knows what kinds of changes have gone on inside the various brands over the years? I would guess KF's ears found the magic ones from among what was common.

[Structo]

Did you guys buy these direct from Sozo?

Looks like $20 each?

Says they are 1 3/8" in dia.

[NowFender]

Direct from sozo....

[geetarpicker]

Yes I got my caps direct from Sozo.

I just got done adding two 220k 1 watt bleeder resistors across each of the series caps, just as a safety margin. I may experiment at a future date with 100ks there instead to see if there is any audible difference.

I hope Sozo does well with these and can get to work on the other values he has in mind for future release. Dual 50s, and single axial 32s I think are his next projects.

[Zippy]

If you are changing the value of the capacitance as well as changing to "Sozo" caps, how 'bout seeing if you get a similar effect with other brands of caps using the same values?

[hitchcaster]

thanks for the tip glen... im a little turned off by some of the negativity surrounding sozo's but i don't doubt they sound good, maybe i will get some anyways.
heres some other mallory's you could experiment with as well that might fit better too at 450v $3 each
http://www.mouser.com/Search/ProductDet ... h9AQ%3d%3d
i find the bleeder resistor value effects the tone FWIW

[Zippy]

i find the bleeder resistor value effects the tone FWIW

Which way? What are the trends?