Film-Tech Forum ARCHIVE: CP65 / DA 20 output level difference

This is topic CP65 / DA 20 output level difference in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Bernie Anderson Jr (Member # 410) on 02-23-2012, 12:06 AM:

I'm still playing around with my CP65 and DA 20 combo at home. When I set up the 65 last year, I didn't have the DA 20 yet. I set the output to 85db on the stage speakers and the split surrounds at 82db. When I use the DA20, the digital output is louder than analog. The amp that I'm using is a Yamaha receiver with 6 channel inputs. I usually run the CP65 at 5 with the Yamaha at -10 (it's max is +2). When the DA20 is running, I have to turn the Yamaha down to -20 or -25.

Am I missing something? I don't see anything that has to do with specific digital input gain for balance between analog and digital.

Posted by Robert Minichino (Member # 3495) on 02-23-2012, 08:23 AM:

Stupid question perhaps, but how did you set up the CP65? Did you use the Cat 85 to set your levels?

Posted by Sam D. Chavez (Member # 1841) on 02-23-2012, 09:51 AM:

The setup of the b-chain sounds right if you used a pink noise generator in the 65.

The analog audio input for the processor is part of the A chain. Dolby level needs to be set using Cat. 69 test film.

Posted by Pete Naples (Member # 761) on 02-23-2012, 10:45 AM:

What Sam said^^,

Every time I've heard this said, I've found that the A chain alignment was lacking in some way, often a good clean of the glassy bits and set Dolby level properly was all it needed.

Sometimes people confuse tonality and quality with volume, what I mean is you have a DA20 playing SRD, sounds lovely. Then it reverts, and you have analogue SR reproduced by a sound head incapable of anything over 8kHz, or with such poor slit illumination it's distorting and clipping/compressing loud passages... Distortion is often mistaken for volume.
You can't expect SRD to precisely tonally match analogue from a 1940's Kalee/British Acoustic rep set, is my point.

Posted by Bernie Anderson Jr (Member # 410) on 02-23-2012, 12:49 PM:

Yep, used CAT 85 to set up levels (digital does sound great) and I'm running with a CE reverse scan. I'll have to go through the whole thing again and check it to see what's going on. I'd figure I ask just to make sure I didn't miss anything.

Posted by Sam D. Chavez (Member # 1841) on 02-23-2012, 02:33 PM:

It is possible the Dolby meters on the 222 are off a bit for one reason or another. To double check, use a meter and measure the L and R level coming out of the 240 running cat. No. 69T. It should be around 300 mV and both the same if the meters are showing Dolby level.

Posted by Bernie Anderson Jr (Member # 410) on 02-23-2012, 04:20 PM:

Good point. I'll take a look at that too. Shouldn't the output to amps also be at 300mV too to properly set output level?

Posted by Louis Bornwasser (Member # 3063) on 02-23-2012, 05:46 PM:

Remember to set Dolby level in MONO.

If set correct and well, there should be minimal difference between high quality analog and the DA-20. Louis

Posted by Sam D. Chavez (Member # 1841) on 02-23-2012, 05:56 PM:

To Bernie's last point:

The output level of the 65 has nothing to do with what we were discussing before as I'm sure you know.

Output levels have been discussed many times in the past. I tend to run the output higher, closer to 700 mVolts. This minimizes any hum or noise induced on the wiring between the processor and amplifier.

There is no real point to setting them exactly for any specific number, either before or after doing the EQ.

Posted by Steve Guttag (Member # 268) on 02-24-2012, 10:09 AM:

Point of Information...on the CP65 using the Cat 85 (or CE SG-1)...the surrounds should be set to 85dB/Side, not 82...the Cat 441 boosts optical surround by 3dB and one is in the optical mode when setting the surround levels.