Caiman passive output mod revealed

[StanleyB]

Far too early indeed. But hopefully it will be in many stockings next Christmas .

[Reid Malenfant]

I don't see why a more accurate clock couldn't be fitted, there are enough of them out there after all The only problem might be the power supply as the Caiman appears to only run off of a single rail DC supply & i'm not sure about aftermarket clocks I'd have thought 5V DC would be the order of the day though.

Something tells me this is probably a no go Just took a look inside & unless i missed something (though i didn't look underneath the PCBs) it looks like the clock is on board one of the ICs & probably can't be bypassed

Time to check out the specs on the chips Not until i can be bothered though

[HighFidelityGuy]

I wondered about the possibility of upgrading the clock a while ago but couldn't see one on the main PCB's. There's nothing under the PCB's either. Perhaps we should move discussion of this to the main 7520 mods section HERE to avoid confusion, or create a new thread.


EDIT: I've made a new thread on this subject HERE.

[vid]

Hi there....

I want to install this passive mod to my caiman.
my rotel RA 1062 specs are:
Preamplifier
Frequency response: 10 - 100kHz at +-3dB
Signal to noise ratio: Line level: 95dB
Input impedance: Line in: 33 kohms +/-5%
Input sensitivity: Line level: 160mV
Preamplifier output: Nominal output level: 1000mV

which caps would be useful? 47u rubycon or other?
thank´s a lot :-)

greets
vid

[chrism]

Hi Vid,

Start with the 47uf Rubycon bipolars and work from there (they are not bad)! Those big yellow ones were from eBay and I can sell you mine if you want to try them.

You can spend some serious dosh on different caps if you wish.

Regards

Chris

[HighFidelityGuy]

You could use any capacitor value between about 2.4uF and 47uF. The exact choice will depend on your budget and whether or not you care if the caps are too big to fit in the case. Some people don't mind running the DAC with the lid off and massive caps sticking out the top. There's a good calculator HERE for working out the values. You need to put 33000 in the Ohms box and then pick a -3db Frequency based on what the info on the page says. Personally I choose much lower values of around 1Hz to ensure phase anomalies are kept well away from the audio range of 20Hz-20KHz.

If you want to spend as little as possible and still be able to put the lid on I'd recommend THESE. They have been proven to be some of the best sounding bipolar electrolytic caps that are easy to get hold of. Many people believe polypropylene or polyester film caps sound better but these are bigger and more expensive. The ClarityCap SA range seems to get a lot of praise for being excellent value for money. So they could be a good entry into poly caps. If you want to try the ClarityCaps I would check the dimensions of the 2.6uF version and see if you think that will fit, then work your way up the uF range until you find the highest value that will fit or that you can afford.

If you fit them as shown in the photo you attached then the mod is easily reversible.
Make sure you discharge your self on something earthed at regular intervals while working in the DAC as the Wolfson DAC chips are very susceptible to static electricity damage. Also if you use bigger caps make sure the cap's legs don't short against anything else inside the DAC. Some insulating tape will prevent that.

Good luck.

[StanleyB]

I want to install this passive mod to my caiman.

which caps would be useful? 47u rubycon or other?
thank´s a lot :-)

I recommend the yellow caps as in the picture. I have a few spare that you can have at cost if you email or PM me.

[vid]

well...
thank you very much! I will test some of my mundorf´s and the rubycon.

greets from austria :-)
vid

[vid]

Hi!

I am not sure how to connect the caps into the caiman
would it work´s with this parts?


thank you

greets
vid

[HighFidelityGuy]

If you're just going to connect them as the yellow ones are above then you can just push the capacitor leads into the holes. You don't need any special connectors or anything.

This image explains better: