Master mixer balanced out using THAT1646?

[RRR]

Hi,

I'm putting a mixer together comprised of 24 preamps feeding into 4 summing mixers (attached) and I want to feed the output of the 4 summing mixers (L1 - 4 Out/ R1 - 4 Out) into a master mixer with L/R gain control and a balanced outputs, and was thinking of using the THAT1646 for the master mixer/ balanced output section.

I was wondering what people thought of doing this, to essentially feed the THAT1646 with the 4 outputs of the 4 summing mixers and include a master gain control, or, do you think it would be better to sum the 4 outputs of the summing mixer into another NE5532 with a gain control, and use the output of the NE5532 to feed into the THAT1646?

Many thanks!

 

[JohnRoberts]

Get your signals squared away and volume controlled before sending to the 1646... I think they want to be driven by simple low impedance sources.

I didn't review your entire schematic, but in passing it is not generally a good idea to put pots in negative feedback loops. For one reason wiper bounce can momentarily look like infinite gain.....

JR

 

[RRR]

Get your signals squared away and volume controlled before sending to the 1646... I think they want to be driven by simple low impedance sources.

I didn't review your entire schematic, but in passing it is not generally a good idea to put pots in negative feedback loops. For one reason wiper bounce can momentarily look like infinite gain.....

JR

Thanks! So shall I get rid of RV9 and RV10, and instead have gain control pots coming off pin 1 and 7 of U2A/B going to ground, with the signal coming out of pin 2 of the pots?

Also, in that case do you think it would be better to sum the 4 summing mixer outputs into another NE5532 with master gain control, and take that output into the THAT1646?

 

[RRR]

I've redone the summing mixer and put together the master mixer part and plan on running L1 - 4 out/ R1 - 4 out of the summing mixers into C13 and C14 of the master mixer - can I run ML1 Out/ MR1 Out directly into a THAT1646? What do people think of this design so far?

Thanks!

 

[k brown]

You're getting some of the basics quite wrong.

As a start, I'd study the basic building blocks of this project, and adapt as needed:

https://sound-au.com/project94a.htm