Clipping/Distorsion SP B1, Audio Buddy + M-audio 2496

J

Jonas Hammar

New member
Hey fellas!

I experience clipping/distorsion when the mic damper is set to -odB, i have the audio buddy set to juuuust above zero gain, just enough to get a signal through, and when singing normal singing i get clipping and distorsion. Worth mentioning is that the clipping is not due to high input-signal to the soundcard, input sits at around -15db with normal singing with these settings - i can clearly see how it clips the wave-form as if i had a compressor running in the signal chain

i can fix this by setting the mic to -20dB and rais the preamp-gain but at that point the noise-floor is soo damn high it sounds like i have a fan or something running in the room right next to the mic, it's virtually impossible to get a good balance between noise-levels and actual signal-levels without experiencing clipping.

The preamp is measuring 40.2 volts without load, and 26.4 with the mic plugged in, i dont know if this is the problem.

i did a test-recording and with the preamp left unchanged i have the exact same noise-floor on all three (-0dB -10dB -20dB) levels of damping. the signal/noise ratio is acceptable with the -0dB mode but even at the lowest gain-setting on the preamp it still clips.

I know the audiobuddy is a piece of crap, i just wanna know if im doing something wrong or if there's a way to beef up the power supplied to the preamp to rais the voltage under load or something..
 
"The preamp is measuring 40.2 volts without load, and 26.4 with the mic plugged in, i dont know if this is the problem."

^ Could well be. The spec for that mic gives the current draw as less than 2.5mA. That would leave 31.5V from the 40V supply (which is already 4V low of specc)
The fact that you only get 26.4 V indicates to me that the phantom power has collapsed and that 26 V is just not enough for correct operation.

You can test the phantom power by connecting a 6k8 resistor from pin 2 to pin 1 and a second from pin 3 to pin 1. If the spook source is right (even tho' low) you should get 20.2 volts.

I have to say how refreshing it is to get a question backed up with some voltage readings.

NOT that hard you know peeps..Get a freakin' meter!

Dave.
 
thanks a heap for the quick answer mate!

Guess im gonna haveto bite the bullet and buy something that matches the mic, the audio buddy i a toy, found a post that mentioned it's internal chip-design and appearently it's a laugh.. oh well! better to learn than to moan!
 
You are very welcome Jonas.
The Audio Buddy might be cheap, discounted here at around £70, but M-Audio kit is generally pretty good and I would have expected that pre amp to work and be quite acceptable with a capacitor mic even if a bit noisy with a dynamic?

Before you condemn the pre, do try the 6k8 resistors test as it is jeeeust possible that mic is faulty. Best way is with a spare XLR M chassis socket and solder the resistors to that and plug the mic lead in.

How do you monitor from the 2496 card? If you do decide to replace the Buddy a mixer would be the best solution in this instance. I still use a 2496 in conjunction with an A&H ZED 10 mixer with good results. Before the ZED I used a Behringer Xenyx 802. Was not at all bad!

Dave.
 
One thing you've not said - has it always done it, or has it suddenly started.

I wonder if the issue is gain staging - you have the gain turned almost fully down on the pre-amp, and the mic pad off? You really should be seeing the preamp gain control somewhere either side of centre in most normal applications, and if the mic is being sung into at a close distance, then -10 or -20 dialled in there, so the clip light is nearly about to light, but doesn't on the preamp. If this setting on -10dB is still a bit too anti-clockwise, then, try again on -20dB.

I'd bet the mic is too hot and is crushing the pre-amp front end, creating the distortion. It's also common for these small units to be unable to supply 48V - the mics usually cope, but you lose a little dynamic range.

Give it a try?
 
You must log in or register to reply here.
Back
Top