Which capacitors give the most pleasing vs cost effective results in charge coupled crossovers?

[Deang]

lol.

[karlson3]

with bipolar electrolytic, I'd assume the junction of the two caps would be plus to plus and battery voltage applied at that point.  Can the supposed effect on cap soakage also be thought as something other than "biasing" ?  Risch said its not RC time constant dependant but rather something which may take several days to stabilize (and that higher values of R may make that stability worse.  Risch also indicated the resistor value must be around 3 orders of magnitude higher than driver impedance to minimize effect upon response) 

 

If one figures charge coupled technique to not have real provable merit (ABX), then perhaps one might also say most of "high end" audio, fancy $ capacitors beyond a certain measurable ESR, etc.  may also be either imaginary in value - or worse - detrimental compared to simple - cheap (and mass produced) ways of doing things.   I like the "purist" approach of minimal gain devices in the path and those not being "push-pull" but will also apply processing* to some commercial CD with eighty-skate electrolytic caps, op-amps, to make something "sound better to myself"  (* Aphex Aural Exciter - DBX 3BX) 

 

FWIW, read this page from a JBL data sheet.  (hopefully there's better info somewhere)  Does application of a voltage reduce some memory effect in capacitors? 

 

 

[glens]

I agree that the notion of preventing current reversal sounds attractive, but only one of any series pair is so affected.  The other is still acting the same in that respect as a single non-biased unit would be acting in that circuit location.  I'd consider it less than a wash in the case of two equal-value (twice as large) caps.  If you used one small-value cap and one ultra-value cap to arrive at the desired pair-value, and biased the huge one I could see maybe deriving some non-current-reversal benefit, but at what cost/performance ratio?

 

In terms of the expansion / contraction, if the cap "breathes" with current flow, I don't see how biasing can do anything about that.  It'll just take a further swing in whichever direction than the other. 

 

"Nay," says I on this one.

[Marvel]

While companies spend silly amounts of money on designs, some with questionable gains, I would actually tend to side with JBL on this idea. They do have some smart engineers.

[PrestonTom]

6 minutes ago, Marvel said:

While companies spend silly amounts of money on designs, some with questionable gains, I would actually tend to side with JBL on this idea. They do have some smart engineers.

 

I agree with Marvel on this one. They have apparently discovered something and found the benefit is worth the cost. 

Yet here we are quibbling about imagined things (fancy caps etc)

[glens]

I've been a fan of JBL since I bought my first pair in the '70s.  But you're talking about models that only sell at a rate of a few pairs per year, and largely in Japan, right?  Still, I'd like to know just how sonically notable doubling up on the capacitors and biasing one each pair really is.

[karlson3]

I'd try it on the highpass and probably worth a try with simple networks like PWK's "Type A".    One problem is selecting cost effective caps.  It seems like cheap Solen have been used a lot.  (I briefly ran old but healthy ESR Russian MBGO, PETP, and Obbligato motor run film/"oil" caps. all with 9vdc)

 

For type A and looking around, some DC-link type would come in around $40 - maybe there's a cheaper/better option.

 

25uF 500vdc DC-link  4 needed for stereo @ $7.65 each = $30.60
EZP-E50256LTA  Panasonic EZP-E50256LTA  $7.65 each
Mouser #: 667-EZP-E50256LTA Mfr. #:EZP-E50256LTA
ESR - 8.8 mOhm
Description:
Film Capacitors 500VDC 25uF 10% MPP L/S=37.5mm

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
4uF 800vdc  DC-link  4 needed for stereo @ $2.03 each = $8.12
 KEMET C4AQIBU4400A1XJ
Mouser #: 80-C4AQIBU4400A1XJ
Mfr. #:C4AQIBU4400A1XJ
Description:
Film Capacitors 800V 4uF LS=27.5mm 5% AEC-Q200
 

[Marvel]

8 hours ago, glens said:

I've been a fan of JBL since I bought my first pair in the '70s.  But you're talking about models that only sell at a rate of a few pairs per year, and largely in Japan, right?  Still, I'd like to know just how sonically notable doubling up on the capacitors and biasing one each pair really is.

 

We went through this a few years ago, ad nauaeum, and dean has made some. Don't know how many, but they a more work. I haven't tried them.

[Schu]

Cheaper is better?

 

[glens]

6 hours ago, karlson3 said:

(I briefly ran old but healthy ESR Russian MBGO, PETP, and Obbligato motor run film/"oil" caps. all with 9vdc)

 

Please describe the result.

[glens]

1 hour ago, Marvel said:

 

We went through this a few years ago, ad nauaeum, and dean has made some. Don't know how many, but they a more work. I haven't tried them.

 

Before my tenure here (I was likely molesting tree work or Harley forums if I was "foruming" at the time).  They wouldn't be terribly much more work, but as we've recently learned, double the zip ties means at least quadruple the trouble...

[karlson3]

I think in general the subjective impression was "smoother" "more relaxed" less "veiling" - know those are pretty much useless terms - but at least more compact description than those old "audiophile rags" using flavors and colors to describe sound.   I never tried the Obbligato CC with my K-horns as did not have enough.  I didn't like those Obbligato motor run caps as much as the charge coupled MBGO but the Obbligato setup was Type AA and the MBGO, type A .  My main amp (Crown XLS 2500) isn't "audiophile quality" but has been dependable.  I've AlephJ clone, Monarchy Audio, Chinese SE EL34 ,Mesa 400 and a little Chinese JLH1969 (which is fun)