PSU for Caiman with Pics

[MartinT]

Thanks Marco.

[chrism]

Bit worried about exceeding 15.5v into the Caiman. The diode does reduce the voltage by 0.7v so the input cap would see around 14.8v leaving some margin of safety for a 16v rated cap. This ideally should be nearer 20% though to leave a little headroom.

If you feed 18v to the Caiman the cap will see 17.3v and I think that this would be quite a risk and you are relying on the manufacturer giving a generous factor of safety.

I suspect feeding 18v and taking the diode out could be the last straw.

Regards

Chris

[MartinT]

I'm keeping to 16V exactly, putting about 15.4V or so across the main electrolytic which should be ok. I have now modified the Caiman with Elna Silmic electrolytics to replace many of the tantalums and smaller electrolytics, although not the big 10,000uF one as that is impossible to source in that size (it's a Beresford special).

See post here http://theartofsound.net/forum/showt...229#post118229

My thanks to Carson for a great post on the electrolytic mods.

[UV101]

Chris, if you are worried about a constant voltage on the cap being above the 16v rating for the std cap, replace it with something like a dumpy 35v 10000uF TSUP.

If not, you could use a conventional height TSUP cap in the psu and remove the 16v one in the dac. Its only the one pre the reg you need to be worried about.

Personally i'd try and fit something different in the dac itself

[Covenant]

Here is my Beresford home made power supply jobby working at last. It will probably get some Teddyreg upgrade work done soon.
Bet your wondering why there is a 2p piece stuck on my headphones.

[MartinT]

Nice one Jerry. What's the regulator module in there?

[StanleyB]

Bet your wondering why there is a 2p piece stuck on my headphones.

Because you are short of a penny?

[Covenant]

Its this one:
http://kikitronic.blogspot.com/searc...r%20DC%200-24V
Puffin has had a look at it ( and fixed a problem), thinks it needs some noise supression.
The headphones are Superlux HD681's and have been modded to death. The 2p's were a suggestion for adding mass and therefore reducing vibration. Heavy aluminium rings will eventually replace the coins (I hope)

[chrism]

Chris, if you are worried about a constant voltage on the cap being above the 16v rating for the std cap, replace it with something like a dumpy 35v 10000uF TSUP.

If not, you could use a conventional height TSUP cap in the psu and remove the 16v one in the dac. Its only the one pre the reg you need to be worried about.

Personally i'd try and fit something different in the dac itself

Hi Ian,

Stuggling to find a higher rated cap that fits under the casing as it's a bit snug.

Been thinking about a linear multi-style power supply a bit more feeding regulated voltages straight into the Caiman. Think that 15v, 12v and 2 x 5v is needed. I can then strip out the diode and 16v cap. The Spower regs will be quite expensive though even though good.

Regards

Chris

[UV101]

you can get Panasonic TSUPs at 25v/ 10000uF that are 20mm high and 35mm diameter and 35v/ 10000uF 25mm high and 35mm diameter. Problem is, I can't find that physical size on Farnel or RS!

I'll see if I can source them! but i'm fairly sure that they will fit. Otherwise you could try something physically larger on its side??? Not ideal but would work if space permits