Is this worth the trouble?

Lost81 · « **on:** 4 Nov 2004, 02:50 am »

Anyone considered the possibility of using Black Gate FK Series 100uF 100V for C11 and C13 for the AKSA 100W?

The BG 100uF 100V FK Series(18mm x 35mm) is a significantly larger capacitor than the BG 100uF 100V Standard Series (16mm x 25mm).

Fitting the FK caps will require that I desolder the 7.5A fuse clips, the +ve and -ve rail spades, as well as the output spade, and re-solder them on the copper side of the PCB, in order to free up PCB real estate.

Is the performance difference of the BG FK over BG Standard worth this amount of surgery?

I also have 4 pieces of 1uF 100v Siemens stacked film and foil caps.
I am wondering if they are superior to the stock film bypass caps (C12, C14).

And, oh yes, the BG FK costs about 4 times more than the BG Standard.
Each

Thanks!

-Lost81

Red Dragon Audio · « **Reply #1 on:** 4 Nov 2004, 02:53 am »

why not use the Elna Certafine?

Welbourne labs swear they are almost as good as BG caps.

http://www.welbornelabs.com/elna.htm

Lost81 · « **Reply #2 on:** 4 Nov 2004, 03:00 am »

Quote from: heavystarch

why not use the Elna Certafine?

Welbourne labs swear they are almost as good as BG caps.

You are the 2nd person to say that

The 1st guy who said that believed in them so much he sent me 4 pieces of Elna Cerafine 100uF 100V, along with 4 of those Siemens stacked film and foil 1uF 100V, for free

I guess I can ask Welborne Labs if they were pitting the Cerafines against the BG Standard or the BG FK...

-Lost81

cmscott6 · « **Reply #3 on:** 6 Nov 2004, 01:56 am »

Just my two cents worth, but I replaced Elna Cerafines in the signal path of my cd player with BG Standards and found a noticeable improvement: better bass and treble extension, and just a more musical presentation (not sure how else to describe it - with the Elnas everything sounded kinda' harsh and brittle and "fatiguing".) Anyway I'm hooked on the BG Standards

Chris

jeffreybehr · « **Reply #4 on:** 6 Nov 2004, 05:56 am »

Lost, I think I'd concentrate on improving the quality and quantity of the bypass caps before I replaced main PS caps. I'd consider some fairly inexpensive, big, bypassed 'propylenes (maybe SCR/Solen/Axon or North Creek Zen 'propylenes bypassed by North Creek Harmony 0.22/625s) in the current bypass positions and some smaller, higher-quality (TRT DynamiCaps? MultiCap 'styrene RTXs, available in a 1/100*?) in positions closer to the output devices.

* and then bypass those!

Rhythm Willie · « **Reply #5 on:** 6 Nov 2004, 11:33 am »

Yes I have tried them, virtually no difference - large capacitors(100v) - had to mount them below(on the copper side) of the PCB.

The larger difference I noticed was on Power supply bleeder resisters (15k) & incresasing bias slightly to around 62 mv(better/quicker base) 0 cents.

Rhythm Willie · « **Reply #6 on:** 6 Nov 2004, 11:44 am »

I tried some large metalised polypropolenes caps(mounted on the dc inputs of hhePCB board & was disappointed with the results - quickly remoed them. If the power supply caps are of good quality i.e. the Nichicon's supplied with the Nirvana or especially as supplied with the 100w+ version, then in my experience power supply bypass caps may only decreade performance(especially in the base region).

Rhythm Willie · « **Reply #7 on:** 6 Nov 2004, 11:44 am »

I tried some large metalised polypropolenes caps(mounted on the dc inputs of hhePCB board & was disappointed with the results - quickly remoed them. If the power supply caps are of good quality i.e. the Nichicon's supplied with the Nirvana or especially as supplied with the 100w+ version, then in my experience power supply bypass caps may only decreade performance(especially in the bass region

Occam · « **Reply #8 on:** 6 Nov 2004, 06:35 pm »

Quote from: jeffreybehr

Lost, I think I'd concentrate on improving the quality and quantity of the bypass caps before I replaced main PS caps. I'd consider some fairly inexpensive, big, bypassed 'propylenes (maybe SCR/Solen/Axon or North Creek Zen 'propylenes bypassed by North Creek Harmony 0.22/625s) in the current bypass positions and some smaller, higher-quality (TRT DynamiCaps? MultiCap 'styrene RTXs, available in a 1/100*?) in positions closer to the output devices.
* and then bypass those!

Jeffrey,

I believe (because you don't have Hugh's brilliantly designed amp board in front of you

) you are slightly misreading Lost's question. Both the electrolytic and film caps he referred to are local rail bypass on the amp board itself, not the main resevoir caps or their bypass cap. As the film cap (which bypasses that local electrolytic) is mounted with a lead spacing of 5mm, the limitation due to lead and inherent inductance severly constrain one's alternatives. Lost's choice of a Epcos (now Vishay) stacked polyester metallized radial cap make substantial techinical sense. I certainly agree that the RTX would make a great bypass cap, but its use on the amp board, in the discussed role, is not pratical.

Occam · « **Reply #9 on:** 6 Nov 2004, 07:35 pm »

Lost81,

I think your choice of the stacked metallized PET caps is a very good one. Are they the 'nude' (unencapsulated) 7.5mm spacing, or the encapsulated 5mm [B32529D1105]? If they're the nekk'd ones, bending the leads to 5mm is a royal pain as they tend to break....
If you want additional levels of bypassing as Jeff suggested, a Vishay polyprop foil cap, KP1830 is technically and anecdotally very attractive. I'd solder the KP thru the pc board on one side, and solder the stacked Epcos to the KP's leads on the other side of the board. $1.35*/pair/rail total, for the 1uf Stacked cap and the PolyProp&Foil .01uf cap.

How would it sound? BTFOM.
.

* a shameless plug for my Lab Circle sticky - " Looking for a specific component?"
http://www.audiocircle.com/index.php?topic=14139

andyr · « **Reply #10 on:** 7 Nov 2004, 07:23 am »

Quote from: Rhythm Willie

I tried some large metalised polypropylene caps(mounted on the dc inputs of the PCB board & was disappointed with the results - quickly removed them. If the power supply caps are of good quality i.e. the Nichicons supplied with the Nirvana or especially as supplied with the 100w+ version, then in my experience power supply bypass caps may only decrease performance (especially in the bass region

Rhythm, ma man,

Maybe you used the wrong caps?

C'mon, all you gurus out there (the list is too long to list here!!

), I thought the "holy grail" as far as power supply caps is concerned is to minimise ESR? IE., it doesn't matter whether they're Hitanos or Nichicons ... bypassing a PS cap with, say, a 1/100th value will do good - BUT ONLY if the bypass caps are of the right sort? I thought ceramics or "film" (whatever they are!) are supposed to be the ones to use?

Regards,

Andy