Caiman PSU

Hi Gaz,

My maps linear benchy (XM22Y) is a stop gap but very surprised how good it is. I went for it as it's linear rather than switching. I have seen it on the scope and it's a bit noisy by more expensive comparisons. So, on this basis currently developing a new PS based on a nice well built traffo, couple of decent smoothing caps and a well built regulator.

Will let you know how I go on.

Regards

Chris

Cheers Chris,
be interesting how you get on!

I never really thought about the linear vs switcher for the dac, be interesting to get some other thoughts?

Some time ago Stan said that linear supplies were not as effective as switched supplies but I cant remember the reason why!

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Originally Posted by Covenant

Some time ago Stan said that linear supplies were not as effective as switched supplies but I cant remember the reason why!

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Which is interesting, because linear supplies are generally thought of as better than switching supplies for audio purposes. Just passing along what I've understood to be conventional wisdom on power supplies. But as usual, I'd have no problem seeing conventional wisdom turned on its head....:eyebrows:

For most low current apps linear usually is better, less noisy etc, majority of regulated linear supplies based around say LM317 do not like to see high capacitance on the output though, they are slower to start up etc, performance tends to be worse imo if theres honking great big capacitors on the output, you've seen whats inside the 7520/Caiman dacs for the input supply;)
A SMPS with a faster start up capable of driving heavier loads is far better suited at keeping that large cap topped up, Stans gone through various options and offered something proven to work very well with these dacs at a great price

This is not to say all linear regulated supplies would be worse here of course, I've recently tried something linear based here which is excellent but would cost nearly as much as the dac itself

Hi Leo,

I have measured the current demand of the Caiman (under load) and found it is quite small compared to what most linear PS can deliver.

I do agree that good linear supplies will be at considerably higher cost than Stan's switchmode one. Even the one that I am working on will cost me around £80.00 in bits and I am aiming for 14.5v and duty 3A (well over the top).

Regards

Chris

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Originally Posted by chrism

Hi Leo,

I have measured the current demand of the Caiman (under load) and found it is quite small compared to what most linear PS can deliver.

I do agree that good linear supplies will be at considerably higher cost than Stan's switchmode one. Even the one that I am working on will cost me around £80.00 in bits and I am aiming for 14.5v and duty 3A (well over the top).

Regards

Chris

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Hi Chris,

In this case its not so much the current demand but how the Caiman/7520 supply is designed , the usual LM317 based regulated psu's neither works well or gives the best sound imo when theres 10k uf seen on their output

Regards,
Leo

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Originally Posted by leo

the usual LM317 based regulated psu's neither works well or gives the best sound imo when theres 10k uf seen on their output

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That's exactly what I found, which is why I did this to my 7510:

http://i609.photobucket.com/albums/t...k/DSCN4294.jpg

Taking out the power supply caps made a massive difference to the sound I got from the DAC using my linear PSU. On top of that, having the extra space in the case allowed me to put in some nice output caps and bypass the op-amps altogether. I decided I'd had enough of faffing around with different op-amps (plus being SMD on the 7510, you weren't going to get many chances at it) so after fitting a Wolfson DAC, I thought I'd try and get an unadulterated signal out of it using some of Maplin's finest 'Audio grade' caps straight to the Vout left and right on the Wolfson. I had wondered for a while whether op-amps were really that necessary on a Vout DAC. I guess mileage will vary depending on your amps but to me, the answer is no, you don't really need them. Of course, my 7510 now no longer has variable output or headphone capabilities - and yes, the linear PSU cost almost as much as the DAC itself, but boy does it sound good.

Top work Rich,

I might give this ago on my well battered 7510. Is Stan taking a well earned rest from us as he has not posted for a while?

Incidently tried 13.8, 14.4 and 15v on my Caiman and Maps bench supply. I think it sounds best at 14.4v and I detected a very slight distortion to the sound at 15v. It is probably because the Maps supply is out of it's comfort zone.

Regards

Hello Stan are these new power supplies still available ?if so what sthe difference from the one supplied with Caimen? and how do i go about ordering one

Thanks Mark