This is topic Dolby CP65 mute/fade time modification in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.
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Posted by Carsten Kurz (Member # 5396) on 02-18-2010, 04:39 PM:
There is rumour that the CP65 mute/fadeout time can be modified (probably on CAT NO 443) by changing a resistor or capacitor. Does anyone have detailed info on this?
- Carsten
Posted by Christos Mitsakis (Member # 143) on 02-19-2010, 12:30 PM:
On Cat243 its the R34 resistor value that controls the mute fade time. It should be the same resistor on cat443. It has been developed from cat243 and I don't think they changed that part.
C.
Posted by Carsten Kurz (Member # 5396) on 02-22-2010, 06:41 AM:
Thanks - I'm going to check this out.
- Carsten
Posted by Carsten Kurz (Member # 5396) on 02-22-2010, 05:49 PM:
I found R34 on CAT443, but on first sight it doesn't seem to have anything to do with the Mute Timing. I will have to have a closer look at the circuit, though. Does anyone know how the Muting is accomplished on these cards? I have seen a few op-amps and Multiplexers on the 443 card. As far as I know, VCAs are used for leveling in the CP65. So I assume that the volume and Remote fader pots should lead into the same circuit area as the Mute circuit?
- Carsten
Posted by System Notices (Member # 2357) on 02-26-2014, 07:48 AM:
It has been 1464 days since the last post.
Posted by Christian Hove (Member # 6743) on 02-26-2014, 07:48 AM:
Hi,
Not being able to PM or email Carsten I revive this old thread.
Hi Carsten,
I would also like to modify the fade time of our CP65'ers.
Did you find a way to do this?
Posted by Carsten Kurz (Member # 5396) on 02-26-2014, 09:41 AM:
Hmm, seems there is temporary trouble with the PM function. However, I just saw your PM in my profile. And no, I did not modify our CP65 for a longer fade time.
But I guess we should be able to find the necessary information. There are quite a few Dolby buffs on the forum.
Only info I have so far is that resistor R34, changed to 500kOhm, would produce around 7s of fade. On which CAT I don't know, but there are not too many choices ;-)
- Carsten
Posted by Carsten Kurz (Member # 5396) on 02-27-2014, 11:50 AM:
Sure it is CAT. No. 443
Did someone contact you privately about this?
Oh, wow, there is an excellent zoomable picture of a CAT. No. 243 on ebay, readable down to component number.
http://www.ebay.com/itm/DOLBY-CAT-243-CONTROL-LOGIC-spare-card-for-CP-55-Processors-/390371034623
Now who's able to find R34 or pinpoint any other regions that deal with the mute function/mute timing??
Hmm, strange, I can easily pinpoint R32,R33 (top middle), R35,36,37,etc. (bottom left), but I can't find R34...
Ooops, I found it, right side, around a third from the top, R34,R94,C5,R12, IC3 in a row from left to right. I'll have a look at our real 443 later. I have never seen the two side by side.
- Carsten
Posted by Sam D. Chavez (Member # 1841) on 02-27-2014, 01:16 PM:
The fade up time affects the fader. If too long the knob will turn faster than the audio can follow.