Topic: Mixpre gain setup

[Chimney Top]

I've read a few threads discussing issues with the gain on the mixpre.  Haven't really come across a direct answer/solution to how hot the gain is...  I've had to either use the filter or limiter, neither which is going to work for me if that's what it comes down to...

at the LOWEST possible setting it lights up two green lights, then a slight adjustment the red clipping lights are lighting up... what is the solution? or use something else?

There really is no setting that works without using the limiters.  I turned the highpass off for the last 30 minutes last night, and the red lights were coming on every 5-7 seconds, the recording is ok, but the wav files brickwalled.  Tascam DR-100 line -10db  I just bought one and I've used it a few times now.

Thanks

[kirk97132]

(COMMENT BASED ON THE FACT THIS IS NOT MIXPRE-D)I was also assuming it was the recorder being clipped.  I found on the MP-2 that I alsmost always had to run the gain knobs turned all the way down and then depending on the music source, I sometimes had to use the line output rather than the XLR outs.  The XLR outs run hotter. 

[bryonsos]

Use the pads on your mics if they have them. If not, get some attenuators. -12 should be enough. I got mine from Naiant and they work great.

[Chimney Top]

Use the pads on your mics if they have them. If not, get some attenuators. -12 should be enough. I got mine from Naiant and they work great.

Neumann km184's... I don't want to add more equipment.

The preamp sounds great, but this gain issue is rediculous.  It isn't set up to handle SDC mic's/rock shows.

[bryonsos]

Use the pads on your mics if they have them. If not, get some attenuators. -12 should be enough. I got mine from Naiant and they work great.

Neumann km184's... I don't want to add more equipment.

The preamp sounds great, but this gain issue is rediculous.  It isn't set up to handle SDC mic's/rock shows.

Not quite true. Its input transformers provide gain for long cable runs. Granted this is a minor PITA if you're running short cables.

[Chimney Top]

Input transformers do provide gain, but that's not to offset cable loss.  Losses to cables at audio frequencies are negligable, a tiny fraction of a dB.  Step-up input transformers have two major jobs:  excellent common mode rejection (that is important for long cable runs; it eliminates induced noise) and very low-noise gain.  The latter is more important for dynamic microphones.

The downside is that step-up gain becomes a minimum gain figure for the amplifier unless the design provides for an input pad or a transformer bypass.  That minimum gain could be too much for condenser mics used on loud sources, where no gain might be required.  In that case, the solutions are to use the pads on the mics, use inline pads, or select a different microphone or amplifier.

If the preamp has sufficient headroom for the amount of minimum gain at hot input levels, but the recorder cannot handle that output level, then the pad is best placed between the preamp and recorder rather than mic and preamp.  However, if the preamp is clipping at minimum gain, you've got to do something to reduce input levels.

If the preamp doesn't clip and output levels are adequate at minimum gain, then use minimum gain.  That could be proper gain staging for that situation.

Thanks.

Will the pads add any effect on the signal, other than reducing the gain?

[phil_er_up]

Have a MIXPRE-D and use them with sensitive mics and found the same as you I could not turn the gain up at all without it going into the red. At a very low setting you get 2-3 green lights then a slight adjustment it goes into the red. This was at a very loud RR show. I got it to work and did not clip anything. Even though I turned down one channel off twice....arggg. The high end was really pushed though.

To solve this problem: I went to a local free  festival with the MIXPRE-D and jons inline pads that I bought about a year earlier for this exact situation. So what it does it move the position of where the gain starts. The gain still increases rapidly from the new position using the inline pads though - it is easier to control somewhat. In other words, if the first gain position is zero (6:00 o'clock) the new position is about 12:00 o'clock.

I did not put that recording up though I still listen to it to this day on well the mixpre-d works if you have the gear to match it and right position in the venue. Though many time I use one of LB/BB/V3 preamps due to its easier to control the gain with my sensitive mics and I run them on stage a lot and that is LOUD. Or if you have a multi-channel recording unit you can run many different mics/pre-amps in different configs to figure out which ones work best in what situation.

[DigiGal]

A gain trim would certainly have been a welcome addition to the MixPre-D when they updated the product.  I use the attenuation switches on my mics for loud shows. 

My mics will take 12V phantom power and MixPre-D can be set for P12, haven't tried it myself but I wonder if that would help.

[hi and lo]

I'm confused. Are folks here experiencing clipping/overload when running at minimum gain or only when they try to run above minimum gain? This is a fairly common concern for PSP-2 owners, which has input transformers and a very high minimum gain, however 95% of the time it's not an issue.

[F.O.Bean]

I'm confused. Are folks here experiencing clipping/overload when running at minimum gain or only when they try to run above minimum gain? This is a fairly common concern for PSP-2 owners, which has input transformers and a very high minimum gain, however 95% of the time it's not an issue.

I saved toned ears ass on 9/21/12 because his psp2 was clipping hard at 0db. I switched it to -6db and problem solved

[Fried Chicken Boy]

The issue is that the MixPre is a very sensitive microphone pre, very capable of capturing the most subtle of nature sounds with the proper mics.  Not only is the output very hot but the gain knobs are really sensitive to adjustment.  Personally, I've never been able to run mine without engaging the pads on the mics.  With the pads on I've had no issues with my recordings clipping and that's been at some very loud shows including a stage lip recording.

[cd2go]

The issue is that the MixPre is a very sensitive microphone pre

Indeed, especially with hot mics--I have to run mine below 9:00 for most shows and below 8:00 for some, but I love it!

[DSatz]

I don't have a MixPre and frankly, the present discussion would tend to make me think twice about getting one since I mostly use rather high-output condenser microphones. But I feel that something essential is being left out of this discussion: The pad switch on most condenser microphones makes their signals (in effect) noisier by the same amount as it reduces their output level. So the use of that switch is almost always a last resort.

The one time the pad switch on a microphone MUST be used is when the sounds are so loud that the microphone's own internal electronics are being overloaded, or are likely to be. In that case, nothing else will help and the microphone's own pad switch must be used.

But if the microphone itself is doing fine and the problem is that its output is overloading the input of the preamp or recorder that it's connected to, the thing to do then is use a resistive pad at the input of the preamp or recorder--not the microphone's pad switch.

This isn't a question of ideology or opinion. Every microphone--and BTW, this includes microphones that don't have any internal active circuitry, such as ribbons and other dynamic microphones--has some amount of noise in its output. Some is generated within the transducer, and then if active electronics are also a part of the mike (as in condenser microphones), some is generated in the active electronics as well. The pad switch on most condenser microphones is placed at the input to the active electronics of the microphone. Thus it reduces the microphone's sensitivity while (unfortunately) not affecting the noise caused by the active electronics (which generally predominates at higher frequencies where it's more readily audible). Voila, the signal-to-noise ratio is reduced by 10, 12, 15 dB or whatever else the amount of the pad is.

A resistive pad at the input of the preamp or recorder, on the other hand, knocks down the level of both the microphone's noise and its useful signal by the same amount at the same time--it can't tell the difference, obviously. So that approach is preferable by far, and hugely outweighs the inconvenience of bringing a couple of in-line pads along to the recording.

--best regards

[F.O.Bean]

I don't have a MixPre and frankly, the present discussion would tend to make me think twice about getting one since I mostly use rather high-output condenser microphones. But I feel that something essential is being left out of this discussion: The pad switch on most condenser microphones makes their signals (in effect) noisier by the same amount as it reduces their output level. So the use of that switch is almost always a last resort.

The one time the pad switch on a microphone MUST be used is when the sounds are so loud that the microphone's own internal electronics are being overloaded, or are likely to be. In that case, nothing else will help and the microphone's own pad switch must be used.

But if the microphone itself is doing fine and the problem is that its output is overloading the input of the preamp or recorder that it's connected to, the thing to do then is use a resistive pad at the input of the preamp or recorder--not the microphone's pad switch.

This isn't a question of ideology or opinion. Every microphone--and BTW, this includes microphones that don't have any internal active circuitry, such as ribbons and other dynamic microphones--has some amount of noise in its output. Some is generated within the transducer, and then if active electronics are also a part of the mike (as in condenser microphones), some is generated in the active electronics as well. The pad switch on most condenser microphones is placed at the input to the active electronics of the microphone. Thus it reduces the microphone's sensitivity while (unfortunately) not affecting the noise caused by the active electronics (which generally predominates at higher frequencies where it's more readily audible). Voila, the signal-to-noise ratio is reduced by 10, 12, 15 dB or whatever else the amount of the pad is.

A resistive pad at the input of the preamp or recorder, on the other hand, knocks down the level of both the microphone's noise and its useful signal by the same amount at the same time--it can't tell the difference, obviously. So that approach is preferable by far, and hugely outweighs the inconvenience of bringing a couple of in-line pads along to the recording.

--best regards

Great read, thanks DSatz. And a Merry Christmas to you, too!

[Popmarter]

Intresting point from Dsatz.

Correct me if I am wrong. I am using Milab VM44-Link > Mixpre-D > recorder. It's very hard to set levels without having the -20db switch on.
Now, i want these in-line pads, any suggestions on what to get, so i can place in in the chain? (mics have xlr connection). Preferably short en simple.