Topic: 722 a/b low/high gain?

[scb]

just got a call from curtis, who said he's been running the 722 at low gain with the 4022s and said he'll never run it with high gain ever again.  he said there is a big difference in sound


has anyone messed with both low/high gain and seen this?

i haven't, but i think i'll try low gain next time i'm out...

[MattD]

I've only switched out of necessity. Try running an AB test at your speakers with one channel on high and the other on low. The range is individually settable.

[nickgregory]

I have run it at low gain all the time, with the only excpetion being glen phillips, and that was because I needed the little boost...never noticed a difference though

[JasonR]

I've compared them about as thoroughly as I care to, and from 20-20k they're identical in terms of frequency response and noise floor.  I do see some differences though:

1 - there seems to be little if any correlation between the normal gain and low gain level displays.  ie: on the low end of the scale (say 25dB to 30dB), the two are within about 2dB of each other.  But as the levels go up, so too does the display disparity.  For example, at 38dB, the two are nowhere near the same level.  If I put the Normal Gain at 38dB and the Low Gain at 51dB, the L/R levels are actually identical.  This seems like a bug that probably hasn't been reported yet, but given the stereo work that us TS.com folks do it's not a big issue for us I would think.

2 - beyond 20kHz, there is a difference between the gain structures.  Using the above settings (with the display disparity), I get an interesting result.  Here are the frequency response curves without any analysis on my part (cuz I really don't know what to make of them!)

FYI - I repeated the tests reversing which 722 channel was low/normal gain, and reversing the CD player source L/R and saw identical performance following whichever 722 channel was set normal/low.  The CD I used was mono white noise (20-20k random) with a low enough level to keep from overloading the 722 input section.

In these images:
Blue - Left Channel -  Normal Gain Scale - +38dB
Red - Right Channel - Low Gain Scale - +51dB

[JasonR]

FYI - I just spoke with Justin at SD who confirmed that there should be zero sonic difference between the gain scales as this is all done in the digital domain.  However, he was somewhat surprised at the gain display differences that I had between the two scales.

Just to clarify, the LEDs were reading identical on the L/R when showing this disparity on the display.  The LEDs are behaving just fine.

- Jason

[JasonR]

Good question, and I'm not certain.  From speaking with Justin, it seemed pretty clear that going mic-in, the two gain scales have the exact amount of analog gain, and the only difference is the available digital gain... which means it really should sound the same.

[Brian]

i also run at low gain all the time.

as for how much gain is digital and analog?  i'd like to hope that the converter that's receiving the analog signal is or is like a "+4" line input and and lets the preamp give most or all of the gain.

i'm not a very technical minded person when it comes to these things really, but that seems like a logical design to me.

[prof_peabody]

Hey guys - sorry to rehash this thread.  I'm new to the 722 and just wanted to check if low gain was best with the DPA402X (arena rock show from the floor).  Seems like the consensus is low gain.  Thanks

[CQBert]

I run low gain for everything that is not acoustic... the acoustice stuff sometimes needs a little more than low will provide...

The stats may show no difference but my ears/mind thinks that there is a slight difference... nothing tesed or proven...just thoughts...

CQBert

[F.O.Bean]

I run low gain for everything since I dont record acoustic/unamped stuff too much at all. most rock/jamband shows, I am pretty damn close to teh stage, and even for moe last saturday, my gain was on 'low' as usual, and the 722 gain knob was at like 8 o'clock, which is a LOUD moe show for sure..... I would think with the 48x running 'high' gain at all, it would be WAY too much and overload the 722 quickly. doesnt answer your 402x question, but i would def recomend low gain for rock shows.

[prof_peabody]

Low gain is the answer... Thanks, I was kind of panicking/overthinking. 

[F.O.Bean]

+T and welcome to the team What mics are you gonna run thru the 722 The AT's? if so, I would like to hear the mini AT's>722 for sure as I have never seen or heard of a mini mic>722 recording....

good luck and welcome. the 722 is the easiest piece of gear to run ever. Just hit power and record and lock the buttons

also, here are some tips bud:

http://taperssection.com/index.php/topic,85482.0.html

Linked gain is BAD-ASS and essential once you start using it If you have never used linked gain before, you are going to fall in love with it for real top gain knob is for gain, and bottom gain knob( both on front panel) is for the panning to left/right balance SOOOOO easy to dial in your levels its almost a childs toy

what else? hmmm. set gain to low. I have my headphones set to '1,2' for when monitoring live since (1,2) has the monitoring set to live monitoring without any delay. For playing back the files after theyve been recorded to the 722's recording medium, I have its et to 'A,B' because that is what ahs been written to the HD in a true monitor setup. If you have A,B set while monitoring your setup live, it is setup so that you hear what is being recorded to the 722's medium and there is a SLIGHT delay since its reading from the INHDD/CF Card/etc. 1,2 during your live monitor I think is teh way to go since its a true live monitor, and not whats being written to the 722.

so, if you cant speak Bean's rambling Language volume 2, to sum up what I said:

Headphone monitoring:

1,2 - A direct monitoring feed. Not being fed from the CF Card/INHDD.

A,B - A monitoring feed that is coming from the cf card/INHDD. Live, it is letting you hear what exactly is being written to the INHDD/ETC. Thios is the onlyw ay its a true monitor I guess since you can hear any errors while its being written to teh HDD. the 1,2 monitoring isnt as great as a monitoring tool if you are worried about truely monitoring whats beingw ritten to teh INHDD/ETC. The only downfall(which I doubt anyone could actually tell in a loud PA show) is the slightd elay in the A,B monitor mode.

hope you can understand my rambling. sometimes I just cant put the words I have in my ehad down on the computer screen just right

Anyone have any other tips?

[prof_peabody]

Back at you...

ATs into a 722 would be pretty interesting, like going for glory, but you only have cash for one part of the rig...  Someone lent me theirs to use, some else lent me some DPAs to run into it - now I'm going to have to make a concious effort not to read the yardsale. 

I read the instruction manual pretty quick, but didn't think until I was at the show to realize seperate gain was going to be a pain.

The DPAs are great (smoking), and I like the 722 more than the HD-P2.  For most of the recordings I do, I think I'm going to have to upgrade to the Aerco MP2 and run it into my R-09.  Mic upgrade will follow.

Here's what I made out with:

http://www.thetradersden.org/forums/showthread.php?t=39847
http://www.dimeadozen.org/torrents-details.php?id=152677