advertisement


Supertech or ???

S-Man

S-Man

StrivingON
I recently recommissioned my Leach amp... and damn fine it sounds. However I noticed that the smoothing caps, which are 4700uF 63V Kendeils (2 per rail, 8 in all), are bulging slightly at the top.
I had noticed this a few weeks ago and thought it was maybe the way they were made. However yesterday I noticed that in the centre of the top there seems to be a white deposit which looks like fine salt grains. I have no idea how this has got through the plastic insulator/top but I am now deeply suspicious that these caps are nearing their end.

So the question is, what to replace them with?
I don't need to stick with the same can size although it makes life a bit easier.

Has anyone tried Supertech ST4-020?
Is it worth going all out on something like SIC SAFCO CO39s?
Or maybe:
http://intuneaudio.co.uk/index.php?route=product/product&product_id=190
I'm tending towards 8 of these, but maybe I should try somethiing a bit fancier:
http://uk.farnell.com/vishay/mal205658472e3/cap-alu-elec-4700uf-63v-snap-in/dp/1165584

No more Krappy Kendeils for me though!
 
Pesky little Kendeils have been removed. All measured ~70 mOhm ESR and ~3,900uF so EOL. Date code 2004, so probably ready to be replaced. These are the shortest lived caps I've come across.
They have been replaced for now by some BHC ALS10s which are 1991 vintage and measure very close to new spec!! Not bad for 27 yo caps.
 
Continuing my monologue...

... very disappointed with the sound of the amp with the BHCs fitted. Sounds, dare I say it, like a bad Naim amp - all praty and forward.

A quick toe-dip into the vast impenetrable oceans of DIYAudio seems to indicate that BHC 4-terminal caps favour the upper frequencies. This along with my own BHC disappointment (although it could be because they are so old) rules them out. Supertech is a complete unknown and the datasheet inspires minimal confidence.

Looks like I might have to order some "short-life" Kendeils.
These seem to be hard to find - any suggestions on where to buy them?
 
Expectation biased and feeble minded sighted subjective impressions....

The BHCs seemed to mellow out a bit and actually became rather good sounding, seemed to be very good at 3D soundstage (not something I'm that botherred about) and clear and dynamic.
Anyway, they got replaced with a set of Kendeils. Intially these sounded dull and bland, very disappointing :(
After a few evenings' use the sound suddenly opened up and now the system sounds wonderful. Not quite as clear and dynamic as the BHCs, but better harmonic richness and all round coherence. Actually the system just sounds more musical o_O with the Kendeils n use.

Happy again :p
 
David
I totally agree with you and plenty of other people on PFM have shared similar experience with caps changing dramatically during the first week especially with a complete new build amp
Its very noticeable with an amp you are very familiar with
I have just had a similar experience with a set of Avondale 821-A boards that I have been modifying all the caps, when I fitted them they sounded thin and weedy and just plain wrong?, after 3 days of being switched on 24/7 they now sound superb and bass is back

Alan
 
Funnily enough, I had a very similar experience recently - when I built a total-overkill split-rail offboard psu for my favourite headphone amp* .
V nice 100VA transformer, spare hackercap board, Qspeed 6A diodes and 6 spare kendeils K05s. I built the thing up and checked with the scope for snubbing reqts - none, utterly spot-on damped rectification as it turned out (and it has stayed that way) Anyway - connect up, and yeah it's quite nice (vs the finessed but only 1/2wave onboard rect, designed to generate split rails from AC input)


About 10days later after a couple of hours a day I started on a film, then moved to music, and suddenly realised the whole-in-head soundfield and perception of musical intent had changed and grown, immensely: the gestalt was fundamental altered, expanded, I thought improved: not unlike the famous dolly-zoom moment in Jaws. This is at total variance with my expectation. Still trying to work-out the what and why.


*a McCormack Micro Integrated Drive - bloody great thing I've had over a decade, and this was 'pointless ott' project I'd long postponed on grounds of on-paper diminishing returns. The lump has good internal decoupling and regulation strategies all over the place inside from new, and only two other v minor sensitivities easily long- fixed.
 
You must log in or register to reply here.


advertisement


Back
Top