[wazza]

I have noticed in several forums/tweaks circles that they mention replacing D1 with a Schottky diode.
If anyone has done this could you please post with details/part numbers and or thoughts or impressions about the benefits of doing this.
Regards
Warren

[AKSA]

Hi Warren,

Sorry about the delay;  I have tried this, couldn't pick it.     Others however have tried it, and two to my memory have said it is superior.

There's probably more mileage in changing C3 for a Black Gate, however.

Hope this is helpful.

Cheers,

Hugh

[fred]

Has anyone tried a black gate at C3?  If so, which black gate (FK? PK? Standard)? and what were the results?

[Regis B]

Has anyone tried a black gate at C3?  If so, which black gate (FK? PK? Standard)? and what were the results?

Just did it in my 100 watter with the nirvana upgrade ( + Mill MRA-5 emitter resistor, + D1 Schottky and Mill spec Teflon cap ( Huge 600volt beast    )  for C8/C9 ).  

I Am trying the FK series ( 100uF at 100V ). The result are positive ( So Far they have less than a week of break In ) as they just straightened the sound of the AKSA.. They add air and refinement to the top end,  without losing any bass frequency. Bass seem to have gain in detail too as time pass .


I also tested The N series in the Super-E cap ( 2 Non-polar in reverse to each other ). configuration  , they where even better  top end and bit better bass .

I will report back in a while for full review of the Mod.

[fred]

Interesting.  In the Michael Percy catalog, I see the Black Gate you mention selling for $21.50.  Keep us posted as to the sound as they break-in (I understand BG's take a long time to break in).

[Possum]

the Michael Percy catalog, I see the Black Gate you mention selling for $21.50.

From what I've seen, that's about the typical price for the FK series at that value.

Is there any particular Schottky brand/type that should be used, or in this case, is a Schottky a Schottky?

Thanks,
Greg

EDIT: Speaking of C3, is the 100uF value critical?  I happen to have 4 220uF Panasonic FC's available, and was wondering if I could use these in place of C3.

[Regis B]

For the schottky  i have use a 11DQ10

[cmscott6]

I notice that c3 on the Aksa 55 is rated 63V.  Michael Percy offers Black Gate FK series in 50V and 100V ratings.  Would the 50V work?  Or is it better to go with the 100V and be safe?

[PSP]

Question for Hugh:  I have the same question as cmscott... the 50v 100uf Standard Polarized Black Gate diameter is 12.5mm (and would fit on the AKSA PCB without too much ugly surgery) while the one rated for 100v is 16mm, while this is not a lot larger it is kind of a tight fit.  Thoughts??

Many thanks,
Peter

[AKSA]

Hi Chris, Peter,

No problem at all using the BG on the 55W AKSA, since the power rail is only at about 38V max.

As a general rule, electrolytics should not be run at more than about 80% of rated voltage.  This gives you maximum life and reliability;  it is not good practice to run them at the rated voltage.

Accordingly, it would not be wise to run the 50VW BG at 51V or so on the 100W AKSA.  It would not last more than a couple of years, and failure would likely be traumatic, endangering other components.  

Hope this is helpful,

Cheers,

Hugh

[Regis B]

Hi Chris, Peter

Has far value  for the 55 watts AKSA  the 100uF 50V N series would be a tad better than a FK series  I tried N series for a while ( I got them for my DVP-S9000ES as coupling cap), STD black gate and now I have the FK IN.  In provement in sound is that way N , FK and STD.

The properly rated N series for a 100 watt AKSA would cost 28.75.

For mounting those large capacitor . You just bent the led at 90 degres and solder it under le board . A bit of blutack or hot met glue will hold it in place.

PS: Black gate unlike other capacitor tend to blow both way ( open or short ).