Standalone mixer into interface into Mac?

[Beedster]

Folks, still getting to grips with this whole digital thing! I've been using mic into RME interface into my Mac, I now want to use my mixer (SSL) that does not have an interface but has very high quality preamps, likely higher quality than those in the RME. Strikes me that I'm running high quality preamps into high quality preamps before A/D conversion and that the pres in the RME are to all intents redundant. That's not the end of the world as I'd like to know I have backup in case I ever had a problem with the mixer, but are there any problems with doing this, for example greater potential noise or other undesirable. Should I/can I bypass the pres in the RME and run straight into the converter? 

Thanks in advance

Chris

[Beedster]

PS I have both BabyFace Pro and FireFace 400 units, I guess I'm asking whether using the preamps on this will add anything to the signal already run through the preamps on the desk, and if so whether setting to zero gain on the RME would resolve this, and if the answers are YES and NO respectively, whether I can bypass the preamps on either RME unit? 

[BigRedX]

Do the pre-amps on the interface have any controls other than input gain? If not then you shouldn't be adding any extra "colour" to the input signal by running it through two sets of pre-amps. 

Pre-amps for recording devices should be doing anything to your input signal other than setting the optimum signal level, unless they specifically have controls for the features. 

[Beedster]

12 minutes ago, BigRedX said:

Do the pre-amps on the interface have any controls other than input gain? If not then you shouldn't be adding any extra "colour" to the input signal by running it through two sets of pre-amps. 

Pre-amps for recording devices should be doing anything to your input signal other than setting the optimum signal level, unless they specifically have controls for the features. 

Thanks mate, given your consistent responses re recording I think I need to put you on a consultancy contract!

I've done quite a lot of reading around and I posted here because it's clearly one of those issues that divides opinions. But, even people who argue that ideally you should not run pre into pre seem to agree that as long as they're both decent quality and you've got the gain structure OK you're probably not going to hear much difference, this for the point you make, a decent interface isn't designed to colour your signal, just get it to the optimal level and convert it (and neither of my RME units have anything other than gain on the input side). 

[linear]

Would using a dedicated line-in input on the interface maybe avoid a redundant gain stage?

Or would that just result in the signal being boosted up to line level at the mixer and then attenuated back down at the interface, before A/D conversion?  Rather defeating the object of the exercise.

 

[Beedster]

32 minutes ago, linear said:

Would using a dedicated line-in input on the interface maybe avoid a redundant gain stage?

Or would that just result in the signal being boosted up to line level at the mixer and then attenuated back down at the interface, before A/D conversion?  Rather defeating the object of the exercise.

 

Thanks linear, I was aiming on using the line level inputs yes, but assume that there's a preamp between these and the converters also, I'm pretty sure I've been able to increase the signal level on the RMEs when I've plugged bass straight in. Might be wrong so will check

[TwoTimesBass]

On 02/11/2020 at 13:16, Beedster said:

Thanks linear, I was aiming on using the line level inputs yes, but assume that there's a preamp between these and the converters also, I'm pretty sure I've been able to increase the signal level on the RMEs when I've plugged bass straight in. Might be wrong so will check

Yes, you're on the right track and what @linear says is true. By using a line-level input on the soundcard from a line-level output on your mixer, you've got a strong signal that won't suffer any additional noise or need amplification in the soundcard. Yes, you can turn up the level on the soundcard, but if your gain structure is good through the desk you shouldn't need to. I've not used the Babyface, but on the FireFace if you use the rear line inputs then you're not going via the mic preamps which are mic/instrument rather than mic/line on the front. RME are anal about signal quality and design very very clean sounding kit, so you should worry too much about the interface affecting the sound. Good quality balanced cables, as short as possible also help.