Topic: PMD660 Firmware V1.17 ALC

[Javier Cinakowski]

I noticed a manual/auto hybrid level control feature on the last few firmware updates.  I assume it is similar to a rockbox'd iRiverH120 in which you can set the levels manually, then if the signal clips, the auto circuit turns down the gain slightly.  Unlike traditional ALC, it never turns it back up...   Being the 660 is 16bit, I always want my levels as high as possible, perhaps this would help me achieve that, especially in situations when you can't keep a close eye on the rig. 

Too bad Marantz doesn't let you change the ALC parameters manually.  It would be nice to be able to adjust the response time and level of attenuation. I don't want a random short drum spike activating the circuit. 


Anyone using this feature on a 660?    Perhaps the 661 has something similar that you may have experience with?

[Javier Cinakowski]

hmm, how does the ALC auto/manual circuit handle gain, since the knob on the front is not motorized.  If the ALC circuit gain reduced too low how would you turn it up, if your knob was already the entire way up....  perhaps to reset you would have to hit stop and play again?  that could be a problem... 

[Javier Cinakowski]

ok, I updated the firmware and did a test recording.    "ALC+Manual" mode is interesting.  There isn't anything in the manual about it and I can't find any other mention online.  Anyway, the test recording indicated to me that the ALC circuit is activated in direct proportion to input level and/or gain.  As the source gets louder, or you turn up the gain knob the ALC circuit attenuates stronger.  In other words, if you turn the gain up slowly the ALC barely works at all.  Crank the gain up real quick and ALC attenuates dramatically.  I was surprised to find that the ALC was not audible even though it did clip slightly several times in my test recording.  I would love to know what is really going on in that circuit though...  Perhaps I'll email marantz...   

[newplanet7]

Christ. I didn't even know there were firmware updates for the 660. 

[Javier Cinakowski]

One more bump before I email oade/marantz. 

[T-90]

One more bump before I email oade/marantz.

Pls do email them...I'd love to learn more about this also