• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

300B B+ PSU caps

I use Kemet DC Link caps, together with Kemet electrolytics (550v).

Kemet DC Link are the last in the chain and a little smoother. The electrolytics are possibly a touch more detailed. DC Link for all the cathode bypass caps - very happy with those.

I also have a couple of Vishay DC Link caps which I use as cathode bypasses. They're very good too.
 
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TBM

Member
2005-05-10 8:57 am
Norway
I use Kemet DC Link caps, together with Kemet electrolytics (550v).

Kemet DC Link are the last in the chain and a little smoother. The electrolytics are possibly a touch more detailed. DC Link for all the cathode bypass caps - very happy with those.

I also have a couple of Vishay DC Link caps which I use as cathode bypasses. They're very good too.
Thanks for the tip! Much appreciated!! :)
 
I like all tube regulated power supplies, a friend of mine uses my boards for 6B4G/2A3 SE, These sound different from the normal choke loaded supplies, and he prefers stabilized supplies now.

My point is, that once you start regulating the filter capacitors dont matter that much to the sound any-more.
 

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My current project uses motor run 40uf for C1 (tube rectified), then electrolytics for middle l/c (or r/c) filters, then a DC Link film in the last r/c filter. My thinking is this... Your air conditioner, furnace or table saw motor throws out huge demand on a capacitor, so I use that for C1 since it is located in the most "violent" position right after rectification. At the tail end of the filter chain is closest to the signal, so I want a film cap there DC link has both high capacitance and voltage and pp film is supposed to sound better. For all the filters in the middle they are just good low esr high ripple rated electrolytics.

When the signal passes through the power supply its only going to "see" that last capacitor, which will be a nice film DC link. The power signal (music) current isn't going to crawl up the chain any farther, that last film cap is its path. At the pulse charging end of the chain the motor run is just plain rugged, that soldier is on the front lines taking fire. All the C's in the middle are electro smoothers, their life is limited, but the outer C's are film, long life. The motor run and rectifier junction is kept as a tight loop, this point is fed only once to the next loop which consists of the electrolytic smoothers and the final DC link cap for the music to pass through. Sorry for the Newby language.
 
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There appears to be a lot of DC-link in the surplus (outlet?) market. Like https://www.ebay.de/itm/313677716252?hash=item4908a61b1c:g:1wsAAOSwK9VhREze

Good price if they are genuine (??). Shipping to the UK for me makes them more expensive, but in the EU that's a nice price.

A word about motor run caps. I compared the usual type as shown in pic and they were audibly worse than Kemet electrolytics and DC Link caps. Not much good at all, in fact. Just being polypropylene doesn't guarantee good sound, as I found out to my surprise when I compared them.
 

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There appears to be a lot of DC-link in the surplus (outlet?) market. Like https://www.ebay.de/itm/313677716252?hash=item4908a61b1c:g:1wsAAOSwK9VhREze

Good price if they are genuine (??). Shipping to the UK for me makes them more expensive, but in the EU that's a nice price.

A word about motor run caps. I compared the usual type as shown in pic and they were audibly worse than Kemet electrolytics and DC Link caps. Not much good at all, in fact. Just being polypropylene doesn't guarantee good sound, as I found out to my surprise when I compared them.

My post was referring to the vegetable oil ones, but for the C1 position. I've wouldn't trust these dry motor run caps either for audio.