Can Anybody Identify This Meter???

[laatsch55]

Looks like a high quality LED in an analog setting, pretty intense meter drive on the back..
The only numbers on the boards are 3839 JLB and 3831.

 

[laatsch55]

That didn't take long, thanks Ed.

 

[mlucitt]

Well? Can we have some info?

 

[laatsch55]

Oh, that was rude, sorry. Ed has some experience in live concert mixing. He used to man the boards for various venues in and around Seattle in the 70's and 80's.
He tells me these are out of a high end "Quad Eight 2082" mixing console.

 

[mlucitt]

Oh a 32 track mixing board. I wonder where the other 31 meters are...

 

[laatsch55]

Don't know, but there are facets to Ed that are very interesting.
I have a pair of them. So we're down to 30.

 

[Gepetto]

All that would be done in one small IC these days, one microcontroller

 

[laatsch55]

Really? That's progress I guess. Therein could lie that IC versus discreet argument.
Joe, have you looked at that am,p I put a link too. State of the art it says and it makes a special point to say it is THROUGH HOLE assembly instead of the unreliable SURFACE MOUNT components. Are things turning around here or what???

 

[Gepetto]

The Dagostino amp link Lee?

 

[laatsch55]

Yes Joe.

 

[Gepetto]

Note he uses the word "usual" to describe the surface mount. There are many very high rel SMT board assemblies out there in the wild (and in space). If compared to consumer grade SMT, then yes, agree with that statement.

Each technique has its pluses and minuses. As is accurately pointed out, high quality, audio grade capacitors are "generally" more readily available in through hole vs. SMT. It also says however that there are no capacitors in the audio path so...

It is a nicely styled amp, following in the Krell tradition.

 

[laatsch55]

42K for a pair they better be. That's 70 dollars a watt. I think I picked up a pretty good amp for 43 cents a watt.

 

[Gepetto]

No doubt Lee.

 

[laatsch55]

Seems strange breaking down that kind of gear in a dollar per watt scenario, don't know where that came from.
Is the Carver Mosfet Joe?? I haven't even looked. It does sound good though. Needs some tuneup on the bottom end, doesn't have the crisp, sharp bass the wopl's do. Close but noticeable.

 

[Gepetto]

No it is a 3281 and 1302 based bipolar design Lee. It is much more complicated than the Phase Linear designs as it was designed to be relatively light weight, high power for professional PA reinforcement type applications. It will not be as faithful as the simpler designs that Bob C put into his early amps because it is a different market. I think he carried this mode switch power supply approach over into the later Sunfire designs.

 

[laatsch55]

OK, if it's bipolar, where is all the heat going, it has a small fan that goes constantly, and the heatsinks are tiny. Guess I'm gonna have to open it up finally and take a look. Then the question begs can the switchers be replaced with toroids., Gotta be swinging some serious voltage, hell on the 8 ohm test it was outputting 81.5 volts, that's a lot of output voltage.

 

[laatsch55]

In an AB design, how do you have a dominant pole cap that is not in the signal path?

 

[Skratch]

May be interstage transformers ?