Mic Pre-Amps
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Posted on Feb 09, 2005 06:17 am
ILLbizzel
ILLbino - one of WA's finest
Member Since: Feb 10, 2004
On my mixer, if I turn up the GAIN on my mic, I hear a hiss the louder I turn it up. Is this the result of cheap pre-amps within the mixer? Or is this typical for any GAIN increase? I want to boost my vocal levels with little or no hiss added. I'm guessing I need a stand alone Pre-Amp?
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pjkPrince CZAR-mingMember
Since: Apr 08, 2004
Feb 09, 2005 08:55 am It may not be the mixer, it may be the cable, or the mic itself. I would think if you had nothing plugged into the mixer, can you turn up the gain and still hear hiss? then it would be the mixer preamp. If there's no noise, then I would think the hiss is coming from upstream (mic and/or cable).
I went through this with my PC / mixer. I thought the mixer was noisy, when it was noise coming from the PC (on my monitoring side).
Feb 09, 2005 08:56 am it might be a ghost in the machine...
ILLbizzelILLbino - one of WA's finestMember
Since: Feb 10, 2004
Feb 09, 2005 11:23 am yes, if I unplug my mic and turn up the GAIN, the hiss gets louder the more I turn it up. I have a Behringer Eurorack UB802 which is about the cheapest mixer you can get. I was looking into a pre-amps and I seen a Behringer Pre-Amp for $50. But I'd hate to buy that pre-amp if it did the same thing as my mixer pre amps now. Suggestions?
pjkPrince CZAR-mingMember
Since: Apr 08, 2004
Feb 09, 2005 12:12 pm ugh, seems the writing's on the wall there.
I did the same thing with my yamaha mixer - unplugged and turned the gain / trim all the way up, and it was dead quiet.
Don't have any advice on the pre-amps, sorry.
Feb 09, 2005 01:38 pm Every mixer has noise that becomes more apparent when you turn up the different gain stages. If you put on a pair of head phones and monitor your main outs at Unity with all other gain stages (Mic pres, EQ, Faders) turned down. Listen as you turn the other gain stages to unity and beyond. This is probably one of the biggest reasons that people have noise in their recordings. They have a gain stage turned up some where on their board on a channel their not using. If your tracking make sure everything on your board is turned down except the channel your using. Just a simple thing, but I thought I'd mention it.
Your mic pres should be pretty quiet up till the 2 o'clock position.
Feb 09, 2005 03:54 pm HA!!! and everyone thought i was beein' anal, by turning every trim, and fader all the way down before hittin' record! thanks Recordinc Chick, i'm gonna show this post to them.
ยง=o)
ILLbizzelILLbino - one of WA's finestMember
Since: Feb 10, 2004
Feb 09, 2005 11:15 pm So are you saying that a dedicated pre-amp wouldn't make much of a difference? Or are you just saying that all mixers carry noise, and that you have to fine tune everything to get desired results?
I want to record loud warm vocal mixes, but without any hiss from the pre-amps. My settings are better now because I've found a mixture of GAIN, mic level, and Master main mix volume that has somewhat low noise. Also, I've turned off all unused channels so they have no GAIN and no volume so that helped a little too. So do you think it'd be worth it to get a dedicated pre-amp?
Feb 10, 2005 12:45 am ILLBIZZEL-Glad your achieving optimum gain structure. I don't know what mic your using, but some mics are hotter than others. The hotter the mic, the less you will have to turn up the gain stage on the mic pre on the board, and the noise will be lower. What is your mic pre turned up to now. More than 2 or 3 O'clock? What mic are you using?
An AT4050 will put out a stronger signal than say a SM57. With a SM57 you will have to turn up the mic pre gain stage more on softer sound sources amplifying the noise of the pre. An SM57 is fine for sound sources that put out high spl, like snare, guitar cabs, screaming metal vocalist.
It's hard to say if it would be worth it to get another pre. A hotter mic might make it so you don't have to turn up the mic pre as much, and it would be quieter. It depends on what fidelity is acceptable to you. As your ears improve, they could demand higher fidelity. You might be out growing your gear. For me it would be worth it. Do you think there is a fidelity difference between a Behringer mic pre costing about a dollar or less and a Grace designs (I'm just throwing Grace out there. There are many fine pres depending on the budget.)costing 1,800 or more for 2 channels? You could audition it, and then return it if it isn't an improvement. I don't know if Behringer is known for warmth, if anything they would be more neutral I would think.
WHOSYOURDADDY-Yeah, I'm very anal, and a perfectionist which is a very expensive way to be. I'm seeking therapy :)
ILLbizzelILLbino - one of WA's finestMember
Since: Feb 10, 2004
Feb 10, 2005 02:16 am I'm using a Behringer Ultravoice XM 8500: cheap dynamic mic that received great ratings. My gain is set at about 75% (or 3 o'clock). My level is turned up 100%. My main mix is at about 10% (7 o'clock).
Feb 10, 2005 03:44 am No gain stage should be turned up 100%. There will be noise. Turn the level from 100% to unity (0 mark, 12 O'clock). Turn the Main mix from 7 O'clock to Unity, 12 O'clock. This should produce about equal gain with less noise....I hope. I think you might be in the neighborhood of optimum gain structure with these settings. Let me know. I'm curious. also Eq settings at unity.
I'm not familiar with that Mic, but I'm betting a large diaphram phantom powered condensor will put out a hotter signal than that dynamic you have. Mabey an MXL mic in the 100 dollar range. 3 O'clock seems high on that mixer for the mic pre. 12 or 1 O'clock would be better.
WaltChief Cook and Bottle WasherMember
Since: May 10, 2002
Feb 10, 2005 10:10 am RC has this one nailed for sure.
Normalize your board first! Everything in gain stages down to zero. All eq's to to normal or zip effect. And yes condensers have a preamp in them viola the phantom power. I should be a little carefull about the word preamp. It does not replace the preamp in the board. It is engineered to hit the board at a good level for the board's preamp to work with.
And yes a Behringer tube pre (forgive me RC, I know that's a bad word, and it's ok, honestly) will warm a mic, but there are more considerations to take into account than say a Grace. This is where the home recorder has to work a little to overcome budget restraints. A Grace is very convenient and will work under most any condition. Grab the know turn up warm...you get warmer. With the Behringer you have to watch your mic placement, your mic chioce to ensure you are getting enough drive into the preamp for it to work well.
Last vocal recording I did, I was able to achieve a 75dB down noise floor. That was in a room with a 42dB down ambient noise level. It took a couple of cubie divider pannels in a 'V' shape behind the singer, using an Oktave 319 through an 1953 Behringer tube pre into an MX9000 line in. Singer to mic placement was critical as well. A Neuman mic, with a Grace pre and a soundcrafter and I would have had a lot less work to do getting everything 'just right' to get the same results.
That's kinda where things balance out. A production studio can charge $150/hr and still beat $50/hr in some cases as there is much less work and 'fine tuning' to do.
A lot of it is all about you. What do you enjoy? I dig all the little adjustements, room prep, getting recordings with 'least possible' equipment. It's a challange. If you don't dig that stuff it will be simple frustration. That frustration will come out in the recording; guranteed. Get more forgiving 'better' gear.
Feb 10, 2005 01:37 pm Actually Walt, I did a gig in Sandiego, and the engineer used those B-tube pres you mentioned, and bypassed the pres on his Mackie board with them. I thought the recording sounded pretty good. I was referring to, I didn't think Behringer was known for warmth on their boards.
ILLbizzelILLbino - one of WA's finestMember
Since: Feb 10, 2004
Feb 10, 2005 04:10 pm That "Grace" pre amp is a lot more money than what I want to spend. Looks cool though. I do have a condensor too, but until I can build a near sound proof box for my PC, I can't use it because condensors pick up every little sound in the room. I'm sure it could pick up the sound of two flies mating, lol. I also live next to a freeway, so that noise gets picked up as well. I've been trying to move to a new place for almost a year now, but my financials haven't been where I need them. So I have to share a roommate for the time being.
Anyway, I'll probably give that behringer Pre-Amp a shot. If I don't like it, I'll return it.
drakeMember
Since: Apr 13, 2004
Feb 11, 2005 04:43 am simple solution to the ambient noise from your environment would be to apply an expander to your vocal chain. this acts like a gate in that it applies gain reducation once the sound source goes below a certain threshold (the quitest part of your voice). and when you are singing it doesn't matter much what outside noise there is... your voice is louder. this will get rid of that bzzz from your PC when you aren't singing.
another trick i've seen home recording people use is to analyze the noise from your pc with a simple spectrogram plug-in. then just kill those indeivdual fruencies in the vocal track. this will kill the noise, while leaving the vocal tone more or less in tact.
also, make sure the mic is set to a polar pattern and point it away from the PC.
