Caiman passive output mod revealed

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06-07-2010, 23:21
Shanedudddy2

Just wondering..what is the normal output impedance of the Beresford caiman and does this mod change the output impedance? Please let me know, cheers.
07-07-2010, 01:31
James G

Quote:

Originally Posted by HighFidelityGuy

I've just finished my passive mod with some Nichicon Muse caps. They were a bit tricky to fit around the Elna's but I got there in the end. I must say it was worth the effort. I'm hearing improvements across the board. Most notably in the clarity/detail and dynamics which have both improved but also in the stereo image. I'm finding I can hear the leading and trailing ends of notes and beats more clearly, with drums having noticeably more attack and punch. Bass also drops lower. It was a real struggle to tear myself away. :eek:

The best bit of all though is that I've got the day off tomorrow and Thu, so guess what I'll be doing. :eyebrows:

I can also confirm that with this mod in place (providing you don't need the variable or headphone outputs) you can remove the entire opamp board. So that's a whole bunch of components removed.

The only downsides I've found are that I've now got a little harshness in the treble and the fixed output level hasn't been reduced by quite as much as I'd hoped. The harshness is similar to what I found after I'd first installed the Elna caps but this gradually subsided over a couple of weeks, so hopefully the same will happen here. As for the output level, I think I need to reduce this by about 3dB, so has anyone got any suggestions on how to achieve this with an internal mod?

I'm curious to hear your impressions when trying this with a film cap (not a crazy Mundorf). What are those ugly yellow ones from China? They are cheaper than Muse and I bet they would do better for this type application.
07-07-2010, 07:21
StanleyB

The harshness in the treble is an obvious sign that that cap needs burning in. You can speed up the process by swapping them over with to on the aedio PCB that are already burnt in. It will also give you a chance to experience right away why I recommend that the DAC undergoes a burn in period from new. Few believe in burn in, but my DACs are possibly prime examples that demonstrate the process.

Anyone with a high end DAC or CD player and who have done this mod on the Ciaman? It might be worth your while doing a side by side comparison. I doubt you can get better from any opamp or discrete output stage based DAC or CDP in a direct shoot out with the Caiman.
07-07-2010, 07:21
Ali Tait

Crazy Mundorf? They were only about £3.70 each.
07-07-2010, 07:37
StanleyB

I hope to start work on a mod that will go directly from the passive output to the headphone amp chip, and that I can use to get even more out of the headamp section. I have tried it on my externally mounted headamp PCB with some seriously amazing results. My Sennheiser HD800 and Denon AH-D7000 are really singing now. The HD650 and K701 are now beyond recognition. Unfortunately my lab has been knocked down and the builders are busy building me a new and bigger office and lab. So I am reduced to using a bit of space in a corner of the warehouse. What a way to treat nearly £3K of headphones just to find the latest burning hot mod :lolsign:.

http://www.homehifi.co.uk/images/mods/testing.jpg
07-07-2010, 09:07
Puffin

Can anyone who has done the "wire" mod tell me what they think of having the 5v direct to the chip pin.
07-07-2010, 10:41
DSJR

Quote:

Originally Posted by Shanedudddy2

Just wondering..what is the normal output impedance of the Beresford caiman and does this mod change the output impedance? Please let me know, cheers.

I'm bumping this for you because I reckon it's important too. Not so much with the 47K+ available on many valve input impedances, but many modern ss aux/CD inputs with only 10 - 25K available.

I've a sneaky suspicion the output impedance may actually be lower, but await Stan's reply please....
07-07-2010, 12:02
StanleyB

1K. Yes. Don't install the mod if you are concerned about the impedance change.
07-07-2010, 12:09
Shanedudddy2

A bit more information would be great. What does it change it to? a rough figure would be great, is there anyway to lower this...I am guessing not?
07-07-2010, 13:14
StanleyB

Quote:

Originally Posted by Shanedudddy2

A bit more information would be great. What does it change it to? a rough figure would be great, is there anyway to lower this...I am guessing not?

I haven't got a clue mate. If you are unhappy about the lack of more information, don't attempt the mod. Stick to what is known.

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