Solen Non Polorized caps for filters

[jmohr58]

diagrammatiks,
Thanks for the links.

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

Yes, I bet they take up a good chunk of the inside of your chassis.
Thanks again,
Jerry

[XgamerGt03]

400+ V caps are difficult to find because the demand for them is very low compared to the demand for low voltage caps. I rarely see larger than a 200V cap in most stuff I buy.

[Structo]

It seems Solen has come to the conclusion with their "Fast Caps" that if they make the roll shorter in length but larger in diameter that they can make them have very low dielectric absorption and minimal ESR.
The problem is fitting them into a design where in many cases they simply won't fit in a power supply.

The low ESR is what I think makes them feel different in an amp if you are used to electrolytic filter caps.

I saw one forum thread where it was recommended that the user install 10 ohm or larger resistors on the caps to simulate ESR to give the amp the feel of electrolytics.

The Hi Fi guys have been going to plastic filter caps more and more in the last few years with many using the motor run film caps for their large reservoir caps.

[bancika]

I like to use motor run caps but they are huge. Here's a preamp I did with no electros at all
[img:800:600]http://diy-fever.com/wordpress/wp-conte ... l_guts.jpg[/img]
Btw, ESR is supposed to be a bad thing, why simulate it? I know we're not after hi-fi, but still...

[rdjones]

Are the Solens a higher tolerence ?
They seem to have a lot of "in between" values.

I looked at them on Tubedepots site in a recent order but haven't jump in yet.

I think it was Bane's "no electrolytic" design that started me thinking about going this route.
I've since found some 2.2 films that I used in place of electros in a mod/rebuild. No complaints yet.

rd

[surfsup]

I'm using 15uF 630s in this build. I got em from AES I think.

I used 400v for the first tube (the cap to the left) since 630 wasn't needed. It was smaller.

[img750]http://www.chicagocadcam.com/ChrisHahn/ ... ogress.jpg[/img]

[renshen1957]

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.

Hi I have purchased Solens at CEdist.com (the wholesale arm of AES at www.ubesandmore.com); currently they stock only 47uf 630V as the highest,too.

I use the 22uf 630 volt, they take up more real estate than the radial Electrolytics, something to consider.

As to adding some E-lytic "grit" some builders will bypass the cap with a ceramic cap, others just a tube stage, and one can simulate ageing in a cap (the resistor method works here using a military spec pot).

I am about to start a build using smaller film caps (lower voltage) and MOSFETs as a capacitance (and voltage withstand) multiplier. However, this will be rather clean as it is for a hi fi circuit, but I can see if the above methods will render a lo fi, traditional effect.


Best Regards,

Steve

PS I hate to think what the prices will be in the future as the dollar is sinking fast.

[renshen1957]

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.
Jerry

Hi Jerry,

I agree about the hot recto tube comment and throwing money away, SE Class A amps are by nature already pre-sagged as the power tube is on all the time (running hot), there isn't very much dynamic current variation to come into play or to play with to cause sag.

Same can be said of High biased class AB push pull amps (Vox AC30). I couldn't find any difference between 5AR4, 5U4, or 5Y3 tubes other than the voltage drop measured on the plates, the changes did not make the amp "squeese like a tube of toothpase" going from a 5AR4 to a 5U4.

There was a sonic difference, but not the decrease in the attack transient time associated with sag.

It is easier to add a resistor elsewhere in the PP class AB power tube circuits (and keep the SS diodes), however it still won't work in a SE amp.

Best Regards,

Steve

[davent]

Parts Connexion carry the 100mF's 630v as does Solen of course but, Solen have them listed as back ordered.

dave

[diagrammatiks]

bigger film caps will go in price soon.

high voltage electrolytics are being replaced with dc link capacitors.

the big solen, mundorfs etc were precursors to what's being rolled out now...

unfortunately...they aren't really being made with amps in mind so for the time being they are huge.

1.8-2.5+ diameter....but you can grab one in 500uf 1200vdc.

[Ken Moon]

I used Solens in th e preamp of this Talon, and it made the amp too brittle sounding for my taste.

I'd used them for the reservoir cap before (using a CLCLC filter, I've used reservoir caps as small as 3.3uF), and it sounded great.

Adding them to the PI and preamp nodes all at once made it sound too brittle. I haven't gone back and tried to find out which one(s) made the big difference.

[IMG700]http://i514.photobucket.com/albums/t346 ... t_done.jpg[/img]

[diagrammatiks]

I used Solens in th e preamp of this Talon, and it made the amp too brittle sounding for my taste.

I'd used them for the reservoir cap before (using a CLCLC filter, I've used reservoir caps as small as 3.3uF), and it sounded great.

Adding them to the PI and preamp nodes all at once made it sound too brittle. I haven't gone back and tried to find out which one(s) made the big difference.

[IMG700]http://i514.photobucket.com/albums/t346 ... t_done.jpg[/img]

I've had that problem too with using all of the same type of film cap in the power filter stages or the coupling stages.

I think generally half the value in a film cap is a closer match for the sound of the electro it replaces.

[jmohr58]

I agree about the hot recto tube comment and throwing money away, SE Class A amps are by nature already pre-sagged as the power tube is on all the time (running hot), there isn't very much dynamic current variation to come into play or to play with to cause sag.

Same can be said of High biased class AB push pull amps (Vox AC30). I couldn't find any difference between 5AR4, 5U4, or 5Y3 tubes other than the voltage drop measured on the plates, the changes did not make the amp "squeese like a tube of toothpase" going from a 5AR4 to a 5U4.

There was a sonic difference, but not the decrease in the attack transient time associated with sag.

It is easier to add a resistor elsewhere in the PP class AB power tube circuits (and keep the SS diodes), however it still won't work in a SE amp.

Thanks for the info renshen1957,
A Blackheart amp has a 5V tap off the PT so you can be enticed to do the Recto Tube Mod. I wouldn't doubt that several other SE Class A's do the same. And there are places on the net that will sell several different Mod kits so you can swap out the PCB and install a Turrent Board and make it look more like a hand built, and I don't doubt it sounds better, but why spend so much money on Tranformer replacements, Turrent board upgrads, recto tube mods etc. when in the end, you've still got basically the same amp with the same limitations. Unless you plan on complete modification and adding more stages etc.

To those of you who have built an Express, Rocket or Liverpool using Solen Caps, do you find it an improvement, or is just Taboo to mess with the classics?
Thanks to all who have joined in to share their knowledge, opinions, ideas, thoughts and time.
Jerry

[renshen1957]

. A Blackheart amp has a 5V tap off the PT so you can be enticed to do the Recto Tube Mod. I wouldn't doubt that several other SE Class A's do the same. Jerry

Hi Jerry,

The 5V taps is a great resource for 6.3V DC powered heaters for the preamps (or to add extra preamp tubes as well) to power switching relays (or transistor based switching), to make bias supplies (using step up transformer), or to power indirectly heated rectifier tubes (for an automatic stand by switch or a circuit to slowly heat the power the screen grids and preamp tubes) to prevent cathode stripping.

A center tap on the 5V tap (not too common), is the foundation for a great circuit which Kevin O'Connor wrote up in his The Ultimate Tone series Vol. 3. It taps the rectifier output for the B+ from the center tap. The idea is to neutralize the noise from the usual asymentric connection of the heater winding used with rectifier as usually found on every schematic with recto Tubes.

Speaking of Rectifier tubes, I have used UF4007 SS diodes connected to the plates of tube rectifiers (Dave Funk's bombproof the rectifier) method, to give extra reliability in case a non-vintage rectifier fails. The amp continues to work through a Gig if half the tube fails, and the $100 output transformer doesn't protect a 50 cent by shorting out before the fuse blows.

Best Regards,

Steve

[jmohr58]

Thanks renshen1957,
Under the use you describe the 5V tap is a useful addition,
It seems most just consider the use of the 5V tap for the addition of a Tube Recto so they can get the SAG factor. Which really won't happen like they think.
For a tube recto as a redundency factor, then yes, that would be a logical use for the tap. Adding extra preamp stages would be a great use for the 5V tap.
Some very useful information you have added

(Dave Funk's bombproof the rectifier) method, to give extra reliability in case a non-vintage rectifier fails.

Very good idea.
Thanks,
Jerry