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I vote for an active bus matrix with auxes.  ;D 

We already have so many choices of pre's. Some great comps and a few eq's are here as well. I think having some kind of card that ties it all together would be a great addition for those of us wanting to build a modular mixer. I know I'd plunk down a sac of gold for that.

It could integrate with Igor's master volume control too. What do ya think?

 
What about a new discrete opamp PCB/kit? Currently the only ones we have to choose from are 2520 clones which gets boring after a while. A higher slew rate alternative would be great.
 
Igor said:
Helios EQ is not a bad idea at all. At least there's no any diy-able here.....
Well, let's go for Helios EQ. I will check what is possible to do with inductors and Elma switch.
The make-up amp on Helios card is not capable of driving the 600 ohm line. So, unbalanced? Line receiver/driver chips? Nope...
And....just as a thought, it can be done with Neve class A make-up amp (second half of BA-283) and 31267-like line input trafo....
I thinking about fully automated summing mixer based on PGA2320 chips insteaad of faders. Bit complicated and costy...
Well, Helli've... Nevious....whatever....
Hi, guys. Igor has built an incredible mastering controller for me which uses the PGA2320 for gain control and I must admit it sounds amazingly transparent to my ears. Soon I intend to do a very careful blind shootout of it against my Cranesong Avocet, which as you may know uses relay-controlled switched resistors. Texas Instruments is particularly cagey about what sort of switches they are using to switch their resistors, but they certainly are a lot better than your "classic" 4066. Has anyone else here built any circuits using the PGA2320 and got sonic comments about this remarkable chip? It seems to me so far you'd have to have a VERY transparent monitoring chain to discern any issues with this chip. That's what I've got here, so I just have to switch between the Avocet and the PGA-based box and compare their sonics.
 
bobkatz said:
Igor said:
Helios EQ is not a bad idea at all. At least there's no any diy-able here.....
Well, let's go for Helios EQ. I will check what is possible to do with inductors and Elma switch.
The make-up amp on Helios card is not capable of driving the 600 ohm line. So, unbalanced? Line receiver/driver chips? Nope...
And....just as a thought, it can be done with Neve class A make-up amp (second half of BA-283) and 31267-like line input trafo....
I thinking about fully automated summing mixer based on PGA2320 chips insteaad of faders. Bit complicated and costy...
Well, Helli've... Nevious....whatever....
Hi, guys. Igor has built an incredible mastering controller for me which uses the PGA2320 for gain control and I must admit it sounds amazingly transparent to my ears. Soon I intend to do a very careful blind shootout of it against my Cranesong Avocet, which as you may know uses relay-controlled switched resistors. Texas Instruments is particularly cagey about what sort of switches they are using to switch their resistors, but they certainly are a lot better than your "classic" 4066. Has anyone else here built any circuits using the PGA2320 and got sonic comments about this remarkable chip? It seems to me so far you'd have to have a VERY transparent monitoring chain to discern any issues with this chip. That's what I've got here, so I just have to switch between the Avocet and the PGA-based box and compare their sonics.

Hi Bob(cat): If you are going to do a proper listening comparison, it would be nice to include the new THAT corp digitally controlled mic pre offering.
http://www.thatcorp.com/datashts/THAT_1570_Datasheet.pdf
http://www.thatcorp.com/datashts/THAT_5171_Datasheet.pdf

A friend of mine, has bench tested it, and the numbers suggest it should be arbitrarily transparent.

Regarding the technology, these are way beyond simple 4066 TG stuff, as IC manufacturers have been making digital pots for years. I don't want to presuppose the results of a listening test. I suspect both (chips) are very transparent. If there are any audible differences I would be more suspicious of the glue circuitry around them (input impedance, phantom blocking caps, etc). Bad glue can mess up any art project.

On paper at least THAT gets a small edge for breaking up the switched resistor matrix into a different chip than the preamp proper which allows them use more optimal process technology in each. The most obvious difference is the higher signal swing of the THAT, but this is all moot, when the output gets sent to a A/D running on 5V or 3.3V rail.

I would be very interested in an honest shoot out (between TI and THAT), while I would expect a tie if well controlled.


JR

PS: how's the system clock?
 
Yes, there's a....little difference: PGA2320 is level control chip, and THAT combo is digitally controlled micpre.
 
:-[

OOPs... I thought it was  the preamp chip..... never mind.


That TI part looks very clean...  with distortion products down 100+dB, once again the glue around it will matter, but properly done it should not have any sound of it's own.


JR

 
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