Solen Non Polorized caps for filters

[jmohr58]

It has always been my understanding that filter caps after the rectifier are to be polorized Electrolytic, with the negative side going to ground. But I have seen several layouts since joining the TAG forum where Solens are used as filter caps. So other than figuring out the outer foil side to attach to the lowest potentinal point I.E. - Ground, what are the pros and cons of using Non-Polorized Solens as Filter Caps?
Or was I dreaming and I'm not in Kansas anymore but in Solen Land? And Toto is licking electolyte off my face as I wake up.

[Cliff Schecht]

There is no requirement for capacitors to be polarized or electrolytic in these applications, or any that I can think of. The fact that the caps are polarized is just a downfall of the technology, or better said a caveat. The reason we deal with polarized caps at all is because these technologies allow us to get very large capacitance per unit area as opposed to film and ceramic technologies (both of which are always improving as well). But if you need a large value in a small size, polarized caps are almost always the answer (but there are more and more exceptions to this rule nowadays).

One thing to keep in mind is that electrolytics have a certain ESR associated with them that actually plays into how fast an amp can react to quick dynamics. Solens are film caps with much lower ESR and occasionally you hear people complain that these caps react too fast and don't allow for as much sag as us guitar players want. In most applications lower ESR=better but us musicians tend to ignore what is technically correct in lieu of what sounds good, for better or for worse.

[jmohr58]

Thanks Cliff,
Appreciate the response and explaination.
Kind of like the SAG factor they speak about in the small SE Class A amps
and the Tube rectifier kits that are out there to replace the SS rectifiers.
But being such a small amp you will never experience the SAG effect so you are basically throwing your money away so you can have another pretty tube glowing in the chassis.
I guess that about sums up what you are saying about the Solens and fast response time.
And as long as SAG isn't an issue for you then they are a fine choice.
With that said, as for using Solens, just test them for the outer sheild and run with them accordingly, correct?
Or does the orientation of the filter caps matter as much in the filter area?
Thanks,
Jerry

[surfsup]

jmohr, RE: testing Solens. No need see last post here they are standardized at manufacturing:

https://tubeamparchive.com/viewtopic.ph ... 6f42619330

[jmohr58]

As some of you know I am going to use the big Solen Fast Cap - metallized film caps for a X10 clone build. I thought it would be appropriate to ask them if there was a side with the outer foil marked. Here is their response:

Les valeurs en haut de 39uf ont le "Outside Foil" indique avec le fil le plus long. Pour les valeurs en dessous il sont du cote du logo "S"

This says the values larger than 39uF it is indicated by a longer lead on one end. The values smaller than 39uF, the outside foil is on the side marked with the S logo. (maybe this will help someone one day)

Yes, that helps alot. Thank you surfsup.
Plus I am glad you can read French!

So now that you have used them, and have had time to see and hear how they respond, do you like they way they sound and function in your amp?

[surfsup]

I am not quite done with that amp yet but stay tuned...

[John_P_WI]

IMHO Solens are brighter, faster, more clear. You lose a little grit / dirt that the electrolytics have. The trade off is the film caps will sound the same today, 1 year or 20 years as they will not dry out like the electrolytics do.

BTW you can put a 10 ohm or higher resistor between the cap and ground to simulate a more vintage electrolytic cap esr.

[jmohr58]

Thanks John and sursup,
Good info, I think you are convincing me that the Solens are the way to go. Especially with your trick of adding resistance to ground for the vintage vibe John. Plus I am sure you can loose a little brightness by tweaking other points in the circuit and get some of the lost grittyness and dirt back.

[Structo]

Where did you buy the Solens?

[jmohr58]

from the Tube Depot website:
http://www.tubedepot.com/solen.html

[diagrammatiks]

film caps definitely sound a bit different then electros. It's not quite a sag thing so much as a response thing. It's hard to explain but the amp will feel faster overall whereas sag is something that you have a little bit of control over.

Like everyone else has said above me, there is no requirement that caps be polarized or electrolytic in the amp. They just happened to be convenient at the time.

From what I've been able to gather...there's actually not a lot of companies producing 500vdc electrolytic in axial lead anymore. Although film caps are far more advanced then they were 40 years ago.

Solen actually makes a big 100uf 630vdc cap in a radial leaded aluminum can that can be top mounted. It's 2.5 inches in diameter though.

[davent]

Where did you buy the Solens?

I've always bought the Solens directly from Solen.

http://www.solen.ca/pub/cms_nf_catalogu ... 0zJmZ0PW5m

dave

[jmohr58]

Thanks diagrammaticks,
You are correct, seems finding low voltage electros is pretty easy, but not with larger voltages.
The Tube Depot site only carries the Solens up to 47uF 630V, where do you find them at 100uF 630V?
Not that I need one but am always looking for part sources.

[jmohr58]

To the True, Wize, Honorable and Just members of "The Amp Garage Forum".
Thank you for clearing up this issue that has been on my mind since I joined the forum. I had never seen non-polorized caps used anywhere else as power supply filter caps. You, Gentle People of TAG are blessed with the gift of Knowledge and I thank you for sharing your knowledge, ideas and time so generously.
Jerry
"Viva Solen!"

[diagrammatiks]

Thanks diagrammaticks,
You are correct, seems finding low voltage electros is pretty easy, but not with larger voltages.
The Tube Depot site only carries the Solens up to 47uF 630V, where do you find them at 100uF 630V?
Not that I need one but am always looking for part sources.

http://www.partsconnexion.com/

and percyaudio have them.

pcx is in canada but seems like a bunch of people here have ordered from them b4.

I'm planning on using all film caps in a future build...

up to about 10/15uf you can kinda wrangle them in there as replacements...

the 47uf 630vdc film caps are the size of a half roll of toilet paper.