Caiman passive output mod revealed

[Carson]

Hi James,

How's the new case for the Caiman doing? Unless I've missed it, I don't believe you've posted any pictures of it completed

Marco.

Hi Marco,
Unfortunately I have not been able to progress any more on the case yet. I have 90% of the parts sitting here waiting to be assembled.
All I really need to get going is the front and rear panels for the case. Am just waiting for enough spare money in the kitty to get these made as they are likely to be the most expensive parts of the build by quite some distance.

Am also thinking of holding back a little longer so I can perform another mod at the same time the Caiman is transplanted across, but this mod will likely cost ~£100-£150 so am waiting a tad longer so I can do it all in one go.

Am off on holiday in August so priorities are elsewhere at the moment, after that though things will progress.
Will keep you posted.

[Ali Tait]

Thinking about it (not tried the mod yet), it seems that the results should sound a lot better with the left op-amp removed from the board. Otherwise would there would be a combination of active and passive output?

Andrew

No,because the pins connecting board to rca's are cut.

[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.

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

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?

[Marco]

Hi James,

Am off on holiday in August so priorities are elsewhere at the moment, after that though things will progress.
Will keep you posted.

Please do, as I am very interested in this, and so should Stan be, as I've always said that the Caiman should have a quality case to match its quality internals!

Enjoy your holiday when it comes

Marco.

[Clive]

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.

Does this mean the 12V reg is not required any more or are there chips on the main board that need it?

[HighFidelityGuy]

Does this mean the 12V reg is not required any more or are there chips on the main board that need it?

I wondered that as well. I honestly don't know. Perhaps Stan could shed some light on this?

[StanleyB]

Does this mean the 12V reg is not required any more or are there chips on the main board that need it?

Are you suggesting there are no other ICs on the various PCBs that need power?

[Clive]

Are you suggesting there are no other ICs on the various PCBs that need power?

Well.....now that I think about it the 12V presumably feeds the 5V so it will be needed. What I was thinking was that all the remaining chips may just need 5V but of course the cascaded regs will remove a lot of noise so even if only 5V is needed the 12V will improve noise performance.

[StanleyB]

Which inputs are you guys using on your amp? The CD or an AUX? And how is the mod affecting the turn on the volume dial compared to the unmodded volume level?

[HighFidelityGuy]

Which inputs are you guys using on your amp? The CD or an AUX? And how is the mod affecting the turn on the volume dial compared to the unmodded volume level?

I use a passive "preamp" so all it's inputs are the same. I've found that I can turn the volume dial up a bit higher with the passive output mod. But not as high as I could when I used the active output in combination with a 10dB attenuator. So at my usual listening level my volume control is now at about 11 o'clock. With the active output and attenuator it was at 12 o'clock. So I could do with loosing a few dB to get back to that optimum setting.