VO-BB - 20 YEARS OLD!

Rob Ellis · M&M Joined: 01 Aug 2006 Posts: 2385 Location: Detroit

Chasing my own tail here....need a reality check.

As you may know, I have been trying out a new pre-amp/Brent Averill 1073 and detected a hum in the signal. Otherwise I luv this pre-amp.

They sent a replacement and I honestly can't tell if any hum that is there is significant or if I just need to get over it and get back to work Rolls Eyes

Please listen to the sound files as carefully as you can and tell me if it would bother you, and more importantly, would bother an engineer. I have included a comparison of the same audio chain with my Mackie 1202 for A/B purposes.

I have become lost in the woods and at this point can't see the forest for the trees. Some fresh ears would really help. Thanks,.

http://WWW.ROBELLIS.INFO/images/Mics_into_BAE_replacement_unit.mp3

http://WWW.ROBELLIS.INFO/images/Mics_into_Mackie_1202.mp3

Mike Sommer · Posted: Mon Dec 13, 2010 2:19 pm Post subject:

It's really hard to listen to the background when you're continually announcing over it. Just slate the file and give us 15 seconds of silents.

Also your levels really sound hot, I don't think you need to be that hot.

In the first file the BAE, there is just a little bit of hum, but I really think it's because you're too hot on the levels.

There wasn't enough dead air to listen to the background on the second file. THough I could hear the beginnings of what could be hum on the Makie.

Have you replace the firewire cable?

The Apogee breakout cables are know for their problems.

Have you shut down the whole house (like I suggested) and just powered the circuit to your recording space??
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Acoustics are counter-intuitive. If one thing is certain about acoustics, it is that if anything seems obvious it is probably wrong.

Mike Sommer · Posted: Mon Dec 13, 2010 2:43 pm Post subject:

Also understand the Avalon had 30dB's output.

The BA is close to 80dB's

Try setting the the big red switch to 20 or 25 dB and set the output gain full- this would be a pretty normal setting.

The red switch drives the transformer and gives the amp its color. The output gain blanches the amp's out put. So if you want more color (distortion) you over drive the transformers. But when you do that you increase the pres volume output, so that you don't overload the device your going into, you must reduce the output gain on the BA.

You want a steady output- no more no less. If you increase the input you must reduce the output.
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The Blog:
http://voiceoveraudio.blogspot.com/

Acoustics are counter-intuitive. If one thing is certain about acoustics, it is that if anything seems obvious it is probably wrong.

Eddie Eagle · M&M Joined: 23 Apr 2008 Posts: 2393

From what you posted I didn't hear any hum and I turned it up pretty loud.

cyclometh · Posted: Mon Dec 13, 2010 3:17 pm Post subject:

Compared to the one you posted before, I can't hear any discernible hum. I'll listen again when I get home on better equipment, but it was pretty blatant on the previous one, here not so much.
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Mike Sommer · Posted: Mon Dec 13, 2010 3:53 pm Post subject:

I can, it's there.

I called Rob and I think I narrowed it down, to the Apogee and the levels going into the computer.
_________________
The Blog:
http://voiceoveraudio.blogspot.com/

Acoustics are counter-intuitive. If one thing is certain about acoustics, it is that if anything seems obvious it is probably wrong.

Rob Ellis · M&M Joined: 01 Aug 2006 Posts: 2385 Location: Detroit

I can tell you this---thanks for the call BTW Mike------

I think the Output knob is the culprit here (not the gain)

If I run the gain at about 45 db and turn back the Output to about 12 0 clock the hum disappears, and I don't get clipping.

The reason I didn't turn back the Output knob earlier is that all the BAE literature and the people I spoke with there said to crank the Output knob (not the gain) all the way.

But I'm telling you when I dial it back this hum almost completely goes away.

Mike Sommer · Posted: Mon Dec 13, 2010 4:19 pm Post subject:

I sensed you were a little unsure when I told you that about the output. But it's a detail a lot of folks forget to supply, or they assume people know.

It's all a balancing act with the front end gain and the output of the pre.

I sent you an email regarding the Apogee
_________________
The Blog:
http://voiceoveraudio.blogspot.com/

Acoustics are counter-intuitive. If one thing is certain about acoustics, it is that if anything seems obvious it is probably wrong.

Eddie Eagle · M&M Joined: 23 Apr 2008 Posts: 2393

Cool you guys nailed that one. I thought about getting an Apogee a few years ago but I'm PC based.