CLS II music sensing power switch

[CLS owner]

I have a pair of CLS II speakers. I do not have a manual. I have downloaded CLS and CLS IIz manuals. The CLS IIz manual states that the dc high voltage disconnects after a few minutes of no music so the panel will not collect dust. The CLS manual (only two pages) doesn't mention this feature. What about the CLS II? Mine were manufactured in 1994. Anyone out there know if that music-sensing switch was incorporated into the CLS II models? Thank you!

 

[JonFo]

Having not looked into this for the CLS, I'm not 100% sure whether the orginal II's had music sense. For sure the I's did not.

Music Sense started showing up in 1993 on models like the Sequel IIb, which I have and bought new, and I recall the big deal they were making about this feature.

So it's a 50/50 chance of it being there based on timeline, but if the manual does not state anything, then probably not.

In any case, it's probably best to plug the speakers into a switched power controller and turn them on and off at the same time as the amps.

 

[nsgarch]

The IIz has signal sensing. The II and IIa I'm not sure. The original I does not. Email Jim Power [email protected]

 

[kmanusa]

The CLS 1 has a signal sensing circuit but it is not used to switch off the high voltage. Instead, when no signal is present, a resistor in the high voltage supply is switched into the circuit that lowers the HV by 50%--

This from Jim Power:

"Indeed. Actually all of the original CLSs has a simple shut down
circuit. It turns off after 7 seconds and instead of full turn off, it
powers down to half the voltage...sort of a hot idle. It works quite
well."

 

[Retro]

kmanusa

Great info..., i have not yet had my printboards dismantled from the housing, but when i get to it i will increase the values of the C1 and C2 caps.

Ps. i did manage to alter the single filtering cap in the LF section by placing it above the original cap which of i did cut one lead to remove its connection