Topic: Taping with a Marantz 661 and and MP2 Pre

[grindstone2]

I am new to taping, new to the 661 and MP2 and I have run into some trouble with this setup:

Here's the gear:  AKG C-460/ULS61 > SD MP-2 > MARANTZ PMD-661 OADE CONCERT MOD

Here's a description of my trouble:  I recorded a Keller Williams show on Friday night, I may not have needed the MP2 but I ran the mics to it's XLR inputs and then out XLR to the XLR/line in on the PMD-661.  Once I realized I had a problem, I ran different gain levels from the MP2 ranging from nothing which still put out a signal to about -15db average max on the MP and on the 661 I stayed at -12db adjusted for whatever was coming through from the MP2.   The recording brickwalled every time.  I bypassed the MP2 and went directly into the 661 for the rest of the show and it came out great!

The only time that I was able to achieve success was recoding the piano concerts since the audio is very soft in the church.    Apparently I really need the MP2 in that setting.

The guy I bought from responded to my PM as follows (the second reply after I finally revealed I was using A 661):

Reply 1: The MP-2 puts out 6dbs of gain throught the tape out even when turned to Zero and 16db throught the XLR out when at Zero.  That is how it was built and not a problem.  The MP-2 works fine you can check my many recordings on LMA and see it has great results.  The MP-2 puts out a really hot signal and my guess is your recorder can't handle the signal and your recorder input is distorting.  Try turning down the gain on your recorder.  I don't know what you use, but I'm positive that is your problem. 

Reply2: It's the 661!!  I have read posts of them brickwalling even if the levels look good.  I think most people run the 661 at -18.  Also I would try to have your peaks around -6 tops if not lower.  You can always boost the levels in the post.  If you had a successful recording then obviously the MP2 works perfectly.  Sounds like user error and you might want to check the team 661 thread to find out how to set your recorder for rock music.  I ran a Sony D50 and M10 and never had a problem.  The MP-2 does send a really hot signal so you have to be careful.  I would suggest doing some reading on TS to find out more since I have never run a 661.   

So here I am, I may not be the best at doing searches because I found nothing on the 661 coupled with the MP-2 so I have decided it is time to post!   I am really looking for some advice from someone who has experience using MP2 and PMD-661 together so I don't mess any more recordings up - especially at the church concerts; it appears that for rock and other high amped events I may not need the MP2 at all but I would like to figure that out with some guidance.

Truly, Bob

[bryonsos]

I'm not 100% sure, but I think the MP-2 uses the same internals as the MixPre which has input transformers to allow for really long cable runs. I bought a pair of -23db attenuators from Naiant and it cooled the signal down nicely for both my M10 and 661, and gets the MixPre settings about optimal (~11:00).  Having said that, when I run the 661, I seldomly bother with the MixPre. I would say that setting the 661 to attenuate at -12 or -18 is generally what you'll need at loud shows. Hope that helps!

[DigiGal]

If the MP 2 is putting out a line level signal you'll need to set the PMD661 to line level xlr input instead of mic level.

MP 2 manual here: http://www.sounddevices.com/download/guides/mp2_en.pdf

PMD661 manual here: http://taperssection.com/index.php?topic=140025.0

[grindstone2]

Line level - yes, never thought about that!  You must be right - it does after all label "Line Outputs" under the XLR outs!

Thanks!

[datbrad]

If the MP 2 is putting out a line level signal you'll need to set the PMD661 to line level xlr input instead of mic level.

X2

I run almost the exact same setup, except I am using a pair of monoblock MP-1s into an Oade warm modded 661. I have never had a single brickwall incident on the 661 for the 2+ years I have used it. I do know that the Oade mod extends the headroom substantially and if yours is stock, that can be an issue running hot mics straight in. However, if you are running a pre with the switch set to mic in at the XLRs, that is your problem.

If you set the input to XLR line in, and the gain knob on the 661 between 6 and 7, then bring up the gain on the MP-2 until you get good levels, even hitting zero there will not be any distortion or brickwalling.

[grindstone2]

DATBRAD, OK great to see your setup is similar.  I will try liune in setting.  One question about the MP2.  Why does the meter only have 2 positions below 0db, -30 and -15 while there are 4 posiytions above 0 up the 12db before the clip indicator would flash.  When whould I ever want to push the signal that high?  Wouldn't it just distort?  or would there be ann application with a very soft signal - like a distant unmicd instrument (ie at my chruch concerts), or recording wildlife (a beetle eating a 50 ft??) 

[grindstone2]

Actually now that I check the preset I was using, it is on Mic/Line but it was that swtich on the end of the 661 that only switrch on the darn unit!  Got it now.  Indicates line on the display instead of Mic!
Wow.  Now I can venture out with renewed confidence!   Thanks to both of you!!

[datbrad]

DATBRAD, OK great to see your setup is similar.  I will try liune in setting.  One question about the MP2.  Why does the meter only have 2 positions below 0db, -30 and -15 while there are 4 posiytions above 0 up the 12db before the clip indicator would flash.  When whould I ever want to push the signal that high?  Wouldn't it just distort?  or would there be ann application with a very soft signal - like a distant unmicd instrument (ie at my chruch concerts), or recording wildlife (a beetle eating a 50 ft??)

Remember that that gain indicated by the meters on the MP-2 is not the same as what is indicated on a digital recorders peak meters. Trust me, pay more attention to using the 661 starting with the gain knob between 6-7 (XLR line in), and just bring up the gain knobs on the MP-2 until you are getting nice strong levels on the recorder's level indicators, and you will be golden.

[JasonSobel]

DATBRAD, OK great to see your setup is similar.  I will try liune in setting.  One question about the MP2. Why does the meter only have 2 positions below 0db, -30 and -15 while there are 4 posiytions above 0 up the 12db before the clip indicator would flash.  When whould I ever want to push the signal that high?  Wouldn't it just distort?  or would there be ann application with a very soft signal - like a distant unmicd instrument (ie at my chruch concerts), or recording wildlife (a beetle eating a 50 ft??)

while your primary question has been answered (run Line-in on the PMD-661), the answer to the above question is all about the db scale.

It sounds like you are thinking of dBfs, which is the dB scale used for digital recording.  with dBfs, 0 dB is the hard limit, and anything above 0 dB is hard clipping.
but the scale on the MP2 is measured in dBu, not dBfs.  dBu is an analog dB scale, and there is no hard upper limit.  When you would want to run things at +16 or +20 or whatever dBu all depends on the gear you are using downstream, and how sensitive the downstream A/D converter is.

For example, take the Sonic AD2K+ (Benchmark AD2402-96).  that A/D converter has an adjustable sensitivity.  i.e. you can choose a sensitivity of +14 to +24 dBu.  if it's set to +24 dBu, then an analog signal of +24 dBu = 0 dBfs.  you would NOT want to run that setting with the Sound Devices MP-2, because the MP-2 pre-amp overloads at a level lower than +24 dBu.  so if you were watching your digital levels, you'd never see clipping (because the input signal is always less than +24 dBu), but the pre-amp could be overloading horribly.  Instead, you always want to have an A/D with a sensitivity that clips before the pre-amp overloads.  If you set the AD2K sensitivity to +14dBu, you wouldn't have to worry about the pre-amp overloading, because you'd get digital clipping (0 dBfs) at +14 dBu, well below the point that the pre-amp overloads.

Now, most gear, unlike the AD2K, does not have an adjustable sensitivity.  So you need to know the specs of your gear and know at level each piece of gear overloads.  Or, follow the recommendation of other people here, who have run similar gear in the past.  As DATBRAD says, the PMD-661 can take a very hot signal when running line-in, so that should definitely take care of your problems.  As another data point, I've run Sonosax SX-M2 > PMD-661 (XLR line in), and DATBRAD's advice to set the PMD-661 to 7, and adjust levels on the pre-amp worked like a charm