PGA2500 Project Finally Finished

[ricardo]

They only make sense if you have a need for remote control of preamp gain, or perhaps perfect recall of gain. In the context of a digital live-sound console, they're the solution. For a typical studio, I don't see the point.

Can you tell us what quality issues you've found with PGA2500 preamps?

 

[JohnRoberts]

They only make sense if you have a need for remote control of preamp gain, or perhaps perfect recall of gain. In the context of a digital live-sound console, they're the solution. For a typical studio, I don't see the point.

Can you tell us what quality issues you've found with PGA2500 preamps?

While I can not answer for Andy, it sounds top me like he was talking about the digitally controlled gain feature not sound quality. While I can imagine some utility for this (digital control) in the studio too, this is a premium feature. 

JR

 

[Andy Peters]

They only make sense if you have a need for remote control of preamp gain, or perhaps perfect recall of gain. In the context of a digital live-sound console, they're the solution. For a typical studio, I don't see the point.

Can you tell us what quality issues you've found with PGA2500 preamps?

It has nothing to do with the quality of the preamp, which I think is really good.
It's just ... I don't see why you need remote gain control in the typical studio.

-a

 

[ricardo]

It has nothing to do with the quality of the preamp, which I think is really good.
It's just ... I don't see why you need remote gain control in the typical studio.

Here's one NEED.

I design ambisonic microphones.
http://www.core-sound.com/TetraMic/1.php

They NEED 4 channels of preamplification with gains matched to better than 0.1dB.  This is difficult & expensive to do.  You need expensive high quality switches and complex wiring to the critical LN parts of your circuitry.  A small amount of intelligence (like JR has in his magic boxes) allows you to control the gain in a nicer manner and still have good LN layout with PGA2500 .. better for EMI/RFI than using even an evil gain pot.

I believe PGA2500 is used in many of the highest quality soundcards like the Metric Halo.  Expat Audio shows how the competing THAT devices achieves excellent performance in their very simple Eden preamp.

Du..uh!  Expat are TI gurus.  Their remote controlled preamp uses PGA2500 I think.  It's not Eden.

The THAT devices are 1570/5171 and used in http://www.diyrecordingequipment.com/projects/innersonix-lucidity-mic-preamp/

 

[Rochey]

Our digitally controlled front end is basically a momentary to latching converter, allowing sexy backlit switches etc.

Expat Audio has no publically available PGA2500 design at this time

/R

 

[Andy Peters]

I design ambisonic microphones.
http://www.core-sound.com/TetraMic/1.php

They NEED 4 channels of preamplification with gains matched to better than 0.1dB.  This is difficult & expensive to do.  You need expensive high quality switches and complex wiring to the critical LN parts of your circuitry.  A small amount of intelligence (like JR has in his magic boxes) allows you to control the gain in a nicer manner and still have good LN layout with PGA2500 .. better for EMI/RFI than using even an evil gain pot.

Ah, excellent.

I've built demo preamps out of both the THAT and the PGA2500 parts. I think they sound fine.

-a