How come there's so much noise "on gains"?

zoofar · Post by **zoofar** » Mon Jun 02, 2003 11:31 am

When using A16 ultra & Z-links, it's impossible to get a clean Mic-signal. This is the chain:
Mic SureBeta58 -> balanced in A16 Ultra
If using -10dB the nosie:signal ratio is a little better than using +4dB, but not by far comparable to when using a preamp of some sort between mic and A16 ( like a mixer

). To get a decent signal without pre-amp I have to crank up the gain to about +20, wich introduces an incredible amount of noise ( think about -40dB noise floor, don't remember exactly, but LOUD ). I'm not an expert on pre-amps and stuff, so this might be perfectly normal. I was wondering though why there's so much noise generated with SFP mixer gains, and so little noise with external mixer gains?

Music Manic · Post by **Music Manic** » Mon Jun 02, 2003 11:43 am

Yes they pick up a lot don't they,that's how sensitive they are.Your picking up noise from cicuit.Try a gate.

King of Snake · Post by **King of Snake** » Mon Jun 02, 2003 11:43 am

I'm no expert but I think this is normal. By cranking up the gain you're also cranking up the noise. If you use a decent mic preamp you won't have to boost the gain so the noise will be much lower.
I don't think you're ever supposed to plug mics directly into an A16 without a preamp (most outboard mixers have mic pre's built in I think)

<font size=-1>[ This Message was edited by: King of Snake on 2003-06-02 12:44 ]</font>

rodos1979 · Post by **rodos1979** » Mon Jun 02, 2003 11:51 am

I am afraid I cant reply to your question because I dont know how mixer gain works; however, cranking up the gain on a hardware mixer makes the signal noisier as well (the more gain, the less S/N ratio). And dont forget that the gain and faders etc on SFP mixers are all digital, which means that whatever you do it happens after the audio has passed the AD converters. For the best S/N ratio you need to feed the AD converters with the loudest signal possible (without making them clip though!).
To the best of my knowledge, the A16 Ultra is just a bunch of good ADA converters...so in your case you need a preamp!

Post by **garyb** » Mon Jun 02, 2003 12:23 pm

you need a mic pre(preAMP) to raise the mic to line level.this is normal.what you are hearing is the noise on the cable.the mic signal is very very low level,especially a dynamic like the 58.this is the whole reason for the existence of mic pres.a hardware mixer usually has them built in.for recording,however,it's best to use the finest mic pres you can afford.(obviously.if a cheap mixer of 8 channels was $200 and a cheap mic pre with just one channel was $200 one would expect the single pre to be better than the eight-plus-mixer.)

zoofar · Post by **zoofar** » Mon Jun 02, 2003 12:33 pm

Thanx. Always nice to know you're normal

Follow up question:

I frequently use my system for live playing, and I usually have need for everything from 1 to 10 mic's . Is there a budget-quality multi-channel pre-amp out there ( say 300-400$ or so ), or might I just as well buy a cheap mixer?

Post by **garyb** » Mon Jun 02, 2003 10:07 pm

there are some very high quality used mixers out there for cheap.the store i work in just sold a ramsa 20 input board(a REAL studio quality mixer with high quality pres)for $600.that board was over $4000 in 1980.look around,they're out there.

zoofar · Post by **zoofar** » Tue Jun 03, 2003 4:51 am

Do you think line boxes would do the trick? As mentioned, it's only for live use, and my main goal is to reduce noise to a level acceptable at live performance, where noise is pretty high anyway. Then again I can always try instead of keep asking

grotools · Post by **grotools** » Tue Jun 03, 2003 6:21 am

http://www.tfpro.com/products/info/2.php

seems to be made for the a16....

zoofar · Post by **zoofar** » Tue Jun 03, 2003 6:33 am

Yes it does indeed!
That's infact exactly what I would need to complete my live-setup-case. Good tip!

bassdude · Post by **bassdude** » Tue Jun 03, 2003 8:06 pm

On 2003-06-02 23:07, garyb wrote:
there are some very high quality used mixers out there for cheap.the store i work in just sold a ramsa 20 input board(a REAL studio quality mixer with high quality pres)for $600.that board was over $4000 in 1980.look around,they're out there.

Ramsa Da7 over here.

Bought it second hand over buying a new Tascam Dm24 for the same amount. Liked it better at 48 kHz over trying the dm24 at 96! Shame they went the way of the dodo. Good gear!