ML HV doubler cap recommendation

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Hi community,

i am thinking about to change/upgrade the brown caps in the HV doubler circuit in my ML Ascent. Obviously these caps could upgrade the SQ.

Some members change the brown caps to Wima FKP1. Any thoughts about that?

BTW, is the 630V for the 0.1 uF AC or DC?
 
FKP1 is foil PP capacitor. Max slew rate is 11kV/us. This number translates into (11V/nS)*100nF=1100A of peak current. Whether or not multiplier produce such a current, it's up to you to decide. In reality it's possible if you short charged capacitor. Assuming 30 Meg resistor in series with the circuit of yours it's not gonna happen, period. It looks like ceramic HV caps can be unreliable, especially older ones, and do decrease capacitance if you raise DC voltage across. Moreover higher value cap will yield less ripples in such circuit. If you want to throw out EU1.5 per cap you are free to do so. That's said any good quality PP film cap rated @ 630VDC having capacitance of 100nF will do starting as low as eu 0.26 each.
 
Yes DVB after TYU's comments over at the bias snubber thread, this got me thinking also.
My Odyssey have been modded using the Ascent XO almost all components have been upgraded. Btw you'll be real surprise the change of power resistors greatly affects the sound, tried 5 variants & the best of the lot are Powertrons grainless.

Cheers
 
Try not to be so negative Alex. If one has been tweaking a system for yrs & listening to the same music that is too familiar, I can assure you that you'll be able to identify the difference be it an improvement or going backwards. Sarcasm does not help if one is into diy with a close mind.

Cheers
 
I do apologize for off-topic.
The cure is to visit opera once a while. With lead sopranos and/or tenors from Bolshoi or Mariinsky or Berlin or Vienna... Preferably 3rd to 5th row somewhere at the middle. It does not happen that often where I can comfortably travel to but 2 to 3 times a year provides me with enough immunity.
 
Hi,

Obviously these caps could upgrade the SQ.
Sounds like tales of mystery and imagination to me ;)
Obvious in this case is only, that a upgrade in SQ is solely due to knowing that a change has been made.
There's not the slightest hint how there could be any change at all, as the membrane in a symmetrical ESL is -so to speak- taken off of the equation of the system.
Only the amount of charge/bias voltage counts.
Because of the high resistance diaphragm coating and high ohmic resistors in the bias supply the charge can be regarded as almost constant.
At the same these high resistances would iron out any differences between different caps -if there were any in first place.
If there were differences in bias voltage due to differing capacitance values one could as well still use the old caps and just tune the bias voltage.

jauu
Calvin
 
Hi Calvin,
Thanks for your thoughts. Yes I've experimented a little on adjusting the bias voltage. One does hear a difference in Sq but the issue at hand like my Odyssey is a hybrid, go to high a bias voltage you'll get an imbalance in sound. if speakers are full range esl upping bias voltage within sense should be the way to improve sound.

Thank again
 
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