Get in touch with Ted!
http://taperssection.com/index.php?topic=133186.0
Yeah, he made me a AES>SPDIF cable in anticipation of my getting a MixPre-D... It is a work of art...
Terry
How are you guys going with your Sound Devices Mix Pre-D / Mix Pre to Marantz PMD661 recorder set ups? What have you found is the best way to preserve the Mix Pre or Mix Pre-D's superior dynamic range and signal to noise ratio? I've bought a mix pre-D and Marantz PMD661 and I'm currently running the mixer from the XLR outs to the XLR ins of the Marantz set to 'Line in'. My concern is that discussions here suggest even using 'line in' on the Marantz, either through the XLR ports or the 'Line in 2' RCA socket, the signal runs through at least one set of pre-amps (and then another if you have the recorder set to 'Mic in'). The Marantz has lower signal to noise ratio and less dynamic range than the Mix Pre-D. Here's a summary of the pro's and cons of the different routing options as far as I can work out from the limited info in the manuals of the two devices, discussions here and experience with my current set up. I love these two devices. I'm just trying to get the best out of using them together. If I can crack it, the combo would be a good low-price alternative to the Sound Devices 702 (as the Mix Pre-D shares the same pre-amps and input circuitry).
Set Up 1) Run 2 x XLR mono cables from the Mix Pre-D's XLR outs to the Marantz's XLR ins, with the mic/line switch set to 'Line' and 'Mic/Line' recording selected in the menu. This is my current setup and it sounds pretty good.
Pros: Strong XLR connectors, hot line level signal seems to be preserved well.
Possible cons: Signal may be running through one set of the Marantz's Pre-amps. These have inferior SNR and DR. It appears to me that these pre-amps are only used to trim and not for gain when the recorder is set to line level in. It appears that setting the gain to max gives you the un-amplified signal. I called Marantz and the tech said he thought that was right but he didn't sound sure. Even if the pre-amp is only attenuating if anything and not adding gain, would it's inferior DR affect the signal, ie compress the dynamic range somehow or with the gain set to maximum on the Marantz' line in are you sending an unadulterated signal to the Marantz's A/D converters? A further con (although nothing major) is I suspect the Marantz's A/D converters wouldn't be as good as the Sound Devices'.
Set Up 2) Run from the Mix Pre-Ds XLR outs to the Marantz's 'Line In 2' via a twin XLR mono to RCA stereo cable.
Pros: I read on this forum that this RCA input may be 14DB more sensitive than the XLR. I can't test it without the cable but I'm guessing this might mean better SNR because of the hotter line level? Does it matter at line level? The signal coming out of the Mix Pre D is so hot anyway. I'm a bit confused about this part. The Sound Devices' levels have massive headroom and are marked from -30 to +20. They start going orange at -4DB. The Marantz's levels go from -60db to 0db. I sync the two recorders by flicking the Tone switch on the Mix Pre-D, sending a 0db, 20Khz tone to the Marantz. I then set that tone to 0DB on the Marantz (at about 8/10 on the Marantz). This means though that a signal at 0DB would be using only half the maximum levels of the Mix Pre-D but would peak out the Marantz.. To allow for any more gain on the Mix Pre-D, I have to trim the Marantz. Seems like a shame to unecessarily add gain (and therefore noise) at the mixer end that is going to be trimmed at the recorder end. Seems to me that the Marantz MUST be adding gain to the line in signal when at 8/10. I just don't know at what point gain kicks in. Does anyone?
Cons: It's been suggested in discussion here that the Line in 2 port routes the same as the mic/line in, ie via the first set of pre-amps in 'line in' mode, so no DR/SNR advantage there. Also, the RCA connection obviously isn't as secure as XLR.
Set Up 3) This one looks really promising. Run a digital out from the Mix Pre-D to the Marantz's digital in. Problem is that the Mix Pre-D uses AES format and the Marantz uses the consumer grade S/PDIF and they're not mutually compatible. There are converter boxes (
http://www.hosatech.com/product/0/CDL-313/_/Digital_Audio_Interface%2C_SPDIF_Coax_to_AESEBU), although these look heavy and don't seem to be battery powerable. Alternatively, conversion cables are available, one of Ted's AES to S/PDIF cables (
http://taperssection.com/index.php?topic=133186.0), or alternatives, including adapters to correct for the different impedence, here:
http://www.gearslutz.com/board/so-much-gear-so-little-time/12214-aes-spdif-adapter.html.
Pros: this should completely bypass all of the Marant'z pre-amps and so should give superior SNR and DR at least at this stage? It would also use the Mix Pre's probably superior A/D converters.
Possible cons:My concern here is that S/PDIF is generally 20 bit with 4 bits preserved for metadata. Some manufacturers use the full 24 bits but the Marantz manual's don't say what the bit rate is. Does anyone know? 4 bits may just be dropped! Also, obviously the RCA connection is not as solid as XLR.
I'd be very interested in your thoughts on the above or what solutions you have found for preserving the superior SNR, DR and A/D converters of the Mix Pre-D when connecting to a Marantz PMD661.