Search found 5447 matches

by mediatechnology
Wed Apr 15, 2009 2:07 pm
Forum: Pro Audio Design
Topic: NE570-based NR compander (P-522) by JR
Replies: 34
Views: 70331

Re: NR compander (P-522)

If you are talking about that diode break where above a P-P voltage another feedback path becomes active, that will was done to sound better that hard clipping, and IIRC with the 570- series gain cells the could get nasty if they are overdriven. So it was a lesser evil decision ands only expected t...
by mediatechnology
Wed Apr 15, 2009 9:44 am
Forum: Pro Audio Design
Topic: An Improved Servo for the THAT1510 and THAT1512
Replies: 32
Views: 88399

Re: An Improved Servo for the THAT1510 and THAT1512

Thanks everyone. I fired up the desk lamp and temperature probe. With the global servo defeated I looked at the offset drift in the 1510 output op amp with it operating at 6 dB gain. At 69 degrees F the output Vos was a trimmed -0.11 mV. At 129 degrees -1.15 mV. It took about a 34 degree C rise to &...
by mediatechnology
Wed Apr 15, 2009 7:31 am
Forum: Pro Audio Design
Topic: An Improved Servo for the THAT1510 and THAT1512
Replies: 32
Views: 88399

Re: An Improved Servo for the THAT1510 and THAT1512

Thanks Crusty. The switch I used is indeed break-before-make. Between every gain step there is a brief return to unity gain. The temperature drift of the THAT1510 isn't characterized in the data sheet. My concern would be with the Vos of the internal output op amp and the OP07 driving the ref pin. D...
by mediatechnology
Tue Apr 14, 2009 1:04 pm
Forum: Pro Audio Design
Topic: An Improved Servo for the THAT1510 and THAT1512
Replies: 32
Views: 88399

An Improved Servo for the THAT1510 and THAT1512

I see a lot of questions here and elsewhere asking about servos for the THAT1510 and THAT1512. This post will discuss an improved servo circuit which has the goals of reducing switching clicks during gain change and eliminating a large value Cgain. An added benefit of this circuit is that output of...
by mediatechnology
Mon Apr 13, 2009 4:52 pm
Forum: Build
Topic: 4 Gang 24 Pos Silver Rotary Switches on eBay
Replies: 4
Views: 22455

4 Gang 24 Pos Silver Rotary Switches on eBay

I stumbled on this listing the other day and thought of our mastering engineers and preamp builders:

http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... FP:US:1123
by mediatechnology
Sun Apr 12, 2009 3:02 pm
Forum: Pro Audio Design
Topic: NE570-based NR compander (P-522) by JR
Replies: 34
Views: 70331

Re: NR compander (P-522)

I use an EMU-0404 internal. Apparently Asus Xonar D2's are testing well at RMAA but I've never found the summary for it. The product "specification" page is here: http://usa.asus.com/products.aspx?l1=25&l2=144&l3=0&l4=0&model=1769&modelmenu=2 This is the chipset informa...
by mediatechnology
Sun Apr 12, 2009 11:34 am
Forum: Pro Audio Design
Topic: NE570-based NR compander (P-522) by JR
Replies: 34
Views: 70331

Re: NR compander (P-522)

It seems you could cover a lot of the features you asked about with a decent computer sound card and some software. Probably some freeware out there that does some of that. Crusty - Take a look at Visual Analyser for basic tests. http://www.sillanumsoft.org/ And RMAA: http://audio.rightmark.org/pro...
by mediatechnology
Sat Apr 11, 2009 1:33 pm
Forum: Pro Audio Design
Topic: Mid Side M-S Matrix Uses No Precision Resistors
Replies: 271
Views: 619463

Re: Mid Side M-S Matrix Uses No Precision Resistors

Guys - Roger did a great job on the layout. I'm ordering boards today with delivery expected in about two weeks. I'll be sure to announce when they become available. MS boards can be ordered from this web page by sending an e-mail: http://www.ka-electronics.com There will be plenty of boards availab...
by mediatechnology
Wed Apr 08, 2009 6:01 pm
Forum: Pro Audio Design
Topic: Mid Side M-S Matrix Uses No Precision Resistors
Replies: 271
Views: 619463

Re: Mid Side M-S Matrix Uses No Precision Resistors

Thanks Miko!

Got it built. Now for some electrical tests...

Image
by mediatechnology
Wed Apr 08, 2009 10:42 am
Forum: Pro Audio Design
Topic: Mid Side M-S Matrix Uses No Precision Resistors
Replies: 271
Views: 619463

Re: Mid Side M-S Matrix Uses No Precision Resistors

Thanks for joining us Brock! I just got the test run with silkscreen and solder mask. Great work Roger! https://www.ka-electronics.com/Images/jpg/MS162_Photo.JPG We rotated the insert connectors 90 degrees. I've dry-fitted the Phoenix connectors to check the mechanicals. After I've built this one we...