Topic: MixPre (or MP-2?) users

[SClassical]

I've recently been using my MixPre and would like to ask the MixPre users in this forum if they find it difficult to adjust the vol due the highly sensitive knob...A few mm turn will increase the signal to from -30dB to 0dB. So I was wondering how most users especially recording loud rock concerts deal with vol adjustments. I understand the top 75% of the high end of the knob will never be used - why did SD build this preamp like this? I tried turning the knob to half way max without mics and the red lights starts flashing (indicating clipping).

Why did SD make the vol control so sensitive??? Anyone use the top end of the vol knob? I very doubt anyone will turn the knob pass the halfway mark.... Why did SD make the MixPre so user-unfriendly? The V3 vol control is so much better and user friendly. Just want to know that it is not only me who is experiencing this vol adjustment issue.

Is there a way to MOD this to make the vol more user friendly? What really bothers me is a small turn (maybe 1 or 2 mm turn) will make the signal from -30dB to > 0 dB and 75% of the upper end of the knob is never ever used.

[Brian Skalinder]

why did SD build this preamp like this?

Because their target audience was not tapers recording very loud PA systems.  Think more along the lines of the ENG market, in which sound sources are far quieter and more gain may be desirable.

I tried turning the knob to half way max without mics and the red lights starts flashing (indicating clipping).

FYI, the red lights indicate -3 below clipping.

I adjusted fairly quickly to the sensitivity and made minor adjustments without too much trouble.  Removing the black plastic caps on the gain knobs (mine just pulled right off, and pushed back on as easily) seemed to help, too, enabling me to make finer adustments.

[OOK]

put a -30db mic pad in line.  That might help you.... Shure and AT make a model that does this....

[SClassical]

why did SD build this preamp like this?

Because their target audience was not tapers recording very loud PA systems.  Think more along the lines of the ENG market, in which sound sources are far quieter and more gain may be desirable.

I tried turning the knob to half way max without mics and the red lights starts flashing (indicating clipping).

FYI, the red lights indicate -3 below clipping.

I adjusted fairly quickly to the sensitivity and made minor adjustments without too much trouble.  Removing the black plastic caps on the gain knobs (mine just pulled right off, and pushed back on as easily) seemed to help, too, enabling me to make finer adustments.

But the strange thing is even when you are recording nothing turning the knob pass half way causes clipping. So really >50% of gain range is never used even for people recording very soft stuff.

I'll try and pull off the knobs from my MixPre like you said. Didn't know you can just pull them off.

No one ever done any MOD on this preamp to make it taper friendly?

[jeromejello]

i know when i run the mp-2 in to my iriver i only have my dials set about 8 - 9 o'clock and bump the rest on the iriver (about +6dB - if necessary)

i do this b/c
(1) the mp-2 can get a bit rough with high gain (and i think this has a lot to do with as Brian pointed out the targeted audience of the item) applied.
(2) the more gain on the mp-2, the more likely i will pick up noise from touching the mic cables... and when stealthing, the cables are wound all over the place.

[BayTaynt3d]

Agreed, this is essentially an ENG preamp/mixer. That said, I have an FP24 (same as MixPre) and sometimes actually tape the pots down with gaffer's tape (especially when stealthing) -- or remove the pot handles like mentioned above. I leave the tape right there but not covering them at the start and once things are looking good I wrap the tape over the pots for the rest of the night. If stealthing with it, I usually try to guess low on the gain and fine-tune using the gain on the recorder (I use a H120 when stealthing) -- but the initial guess requires knowing your gear and having experience with it obviously.

[jlykos]

I ran an MP-2 for a while and liked the unit, especially when I ran it in front of a modSBM-1, but you are correct, the gain is insanely sensitive.  I didn't use any special method; I would raise or lower the levels by placing a finger on the side of the pot and pretty much think about the direction I wanted to move it in, which would raise or lower the level the appropriate amount.  With the SBM, I was able to set the gain in one channel of the MP-2 at 0, and then adjust with the other pot to even out the levels; sometimes this worked, sometimes it did not.  It did give me one less thing to worry about though.

Use the Force, it is your only hope.

[SClassical]

Would attaching this between the mics and MixPre (MP-2) help? Just wondering if this will effect the sound quality in anyway apart from reducing the vol.

http://cgi.ebay.com/HOSA-ATT-448-Input-Attenuator-XLR-M-to-XLR-F-NEW_W0QQitemZ260104702942QQihZ016QQcategoryZ23783QQrdZ1QQssPageNameZWD1VQQcmdZViewItem

What is the down side using attenuators between the mics and preamp?

[Roving Sign]

Here's a good post from DSatz that seems to address your issue...

If the input gain trims on the board can't be set to where they are overload-proof for a given microphone, then the best remedy is a resistive pad (attenuator) at the board's mike input. Such pads reduce the noise from the microphone's circuitry to the same degree that they reduce the wanted signal levels, so they prevent overload distortion without making the recording that much noisier. Resistive pads are inexpensive and reliable, they don't color the sound, and they don't interfere with phantom powering. Every engineer who does live recording should have some on hand, both as trouble-shooting devices and as real-world problem solvers. And then they can leave the microphones' pads switched off when their use isn't strictly necessary.

As a final note, sometimes what's overloading a microphone is air currents or breath noise, so a simple wind or pop screen should always be tried before deciding to turn on the pad switch. Similarly, solid-borne sound (physical vibration) can occur at such low frequencies that you don't hear it over your monitors, but it can overload the microphone's circuitry especially if the microphone has an output transformer. So a good shock mount is another thing to try rather than habitually reaching for the pad switch. (Unfortunately I have to add that good shock mounts aren't generally cheap, and cheap ones aren't generally good. The ones which I've seen offered as accessories for many recent Chinese microphones seem almost completely ineffective at preventing vibration from reaching the microphones.)

[sanaka]

Scyue wrote, in part:

But the strange thing is even when you are recording nothing turning the knob pass half way causes clipping.

Clip light with no mics! Doesn't anyone think Scyue's particular unit is defective?

[Nick Graham]

A little late on this, but when I ran MP2>SBM1 a few years ago I ran the gain on the MP2 at 12 o' clock and adjusted everything with the SBM1. After a few accidents of barely touching the MP2's gain knobs and having levels go through the roof I just left them alone....

[George2]

Use a Pad at least a 20db pad between the mics and preamp.

Put a 150ohm resister accross input XLR pin 2 and 3 before turning the preamp gain up with no mic connected. You need to have a load on it.
Phantom off.

[landshark]

Hi Scy -

I have the rebranded Shure, and was having the same problems feeding into my MR1.  I had gain set at about zero, and was still getting a very strong signal into the MR1 from my AKG 460's and 391's.  I ended up putting a 20db pad between the mics and the Shure, and another 20 db pad between the Shure and the MR1.  As many have commented, the MixPre is for lower volume situations, and expects to be able to pump out a pretty hot, full professional line signal which can easily obverload the max +6 db signal the MR1 will take.

I haven't tested it live in a venue, but initally the result seems to be a significant improvement.  I run the gain knobs at about 50-60% of the way to maxiumum, and I think that using a larger amount of the gain is giving me a better ratio of signal to noise.  With the gain turned all the way down, I always wondered if the noise floor inherent in the preamp's output was too close to the insanely low level of signal coming out. 

FYI, my pads are fixed 20db pads, not the adjustable, but the adjustible seem like they would be more convenient.  It helps that the mics have a built-in -10db pad if things get too hot. 

Good luck!

Mike

[Jamos]

landshark, are you using the "tape out" of the mix-pre, or the XLR line outs?

The tape outs have 10dB less gain and would be much better suited to feeding a signal to your MR-1.

[landshark]

Hi Jmos -

Yup, using the XLR line outs - no reason to go through the headphone amplifier stage and add that noise.