Search found 5477 matches

by mediatechnology
Sun May 10, 2009 1:50 pm
Forum: Build
Topic: Mid Side M-S Matrix Construction Information
Replies: 121
Views: 453781

Re: Mid Side M-S Matrix Construction Information

https://www.ka-electronics.com/Images/jpg/MS162_Photo_1.JPG EDIT: If I understand your question correctly, no. Take a look above. The bottom-most rows are Ground. The jumpers link vertically from insert send to insert return. To disable them just remove the jumper or store it on one pin. Look at BL...
by mediatechnology
Sun May 10, 2009 1:20 pm
Forum: Document
Topic: Valley People TransAmp, ECG-101 VCA, TA-103 Documents
Replies: 1
Views: 10741

Valley People TA-101 TA-102 TA-103 Documents

Valley People TA-103 Application Note https://www.ka-electronics.com/images/pdf/Valley_people_TA-103.pdf https://www.ka-electronics.com/images/jpg/Valley_People_TA-101_TA-102_TA-103_Pinout.JPG Valley People TA-101 TA-102 TA-103 Pinout Note the thermal coupling of the transistor pairs. TA-101 4 NPN ...
by mediatechnology
Sat May 09, 2009 12:25 pm
Forum: Pro Audio Design
Topic: Mid Side M-S Matrix Uses No Precision Resistors
Replies: 271
Views: 641540

Re: Mid Side M-S Matrix Uses No Precision Resistors - Boards 5/1

Thanks for joining us Andy! Couple questions though, is there a schematic?! Not a complete one yet. That was a goal for last weekend which turns out to have been one without power for about a day due to lightning strike. I'm a little behind. You can piece all the bits together and can't go wrong usi...
by mediatechnology
Fri May 08, 2009 9:51 pm
Forum: Build
Topic: Mid Side M-S Matrix Construction Information
Replies: 121
Views: 453781

Mid Side M-S Matrix Construction Information

This is a clone of the post in the original thread. We might want to put build questions in this thread. MS Mid Side Encoder/Decoder PC Boards: https://ka-electronics.com/shop/index.php?route=product/search&search=Simple%20MS Update 5/12/2015: PDF Assembly Instructions are here: https://www.ka-...
by mediatechnology
Fri May 08, 2009 8:57 pm
Forum: Pro Audio Design
Topic: Mid Side M-S Matrix Uses No Precision Resistors
Replies: 271
Views: 641540

Mid Side M-S Matrix Construction Information

I've gotten a little behind on creating and posting documentation. Wayne is stretched thin. I've cloned this post in the Build Subforum. We might want to discuss build questions here: http://www.proaudiodesignforum.com/forum/php/viewtopic.php?f=7&t=262 Here's a preliminary bill of materials: 13)...
by mediatechnology
Thu May 07, 2009 3:04 pm
Forum: Pro Audio Design
Topic: Old: A Direct-Coupled Input-Capacitorless Active Mic Preamp
Replies: 212
Views: 414415

Re: A Direct-Coupled Input-Capacitorless Active Mic Preamp

No problemo and a great question. IIRC correctly I measured the peak current into the 1510 it was around 8 mA vs. the >>3A when input caps are present. I tried just about every way I could to blow up a 1510. I failed, it didn't. That particular fault, when input caps are used (one input pulled up, t...
by mediatechnology
Thu May 07, 2009 12:27 pm
Forum: Pro Audio Design
Topic: Old: A Direct-Coupled Input-Capacitorless Active Mic Preamp
Replies: 212
Views: 414415

Re: A Direct-Coupled Input-Capacitorless Active Mic Preamp

OK, here’s what I measured, although unexpected: AT 4033 serial 39XX DCR=~740K offset=6.8mV AT 4033 serial 90XX DCR=20K offset=0.3mV AT 4033 serial 95XX DCR=22K offset=0.7mV TLM103#1 DCR=9K5 offset=0.8mV TLM103#2 DCR=9K4 offset=0.9mv Schoeps CMC5 body DCR>2M offset=15.7mV (wow, checked it 3 times) ...
by mediatechnology
Thu May 07, 2009 11:29 am
Forum: Pro Audio Design
Topic: Old: A Direct-Coupled Input-Capacitorless Active Mic Preamp
Replies: 212
Views: 414415

Re: A Direct-Coupled Input-Capacitorless Active Mic Preamp

I found that with some cap-coupled inputs it can indeed take awhile to settle, particularly the common mode voltage.

If the preamp has been off awhile it takes ages for the capacitors to re-form.

What sort of differential (pin 2 to 3) offsets are you seeing?
by mediatechnology
Thu May 07, 2009 10:12 am
Forum: Pro Audio Design
Topic: Old: A Direct-Coupled Input-Capacitorless Active Mic Preamp
Replies: 212
Views: 414415

Re: A Direct-Coupled Input-Capacitorless Active Mic Preamp

Glad I thought to ask. When you get a chance you might try it with a couple of 6K81s pulled up to 48V.

If you don't have an easily obtainable 48V supply you can get 45V from the IP27-18 by stacking all three or use the dual 20V and a 9V battery in series.

I'm curious about Bruno's TLM103s....
by mediatechnology
Thu May 07, 2009 9:05 am
Forum: Pro Audio Design
Topic: Old: A Direct-Coupled Input-Capacitorless Active Mic Preamp
Replies: 212
Views: 414415

Re: A Direct-Coupled Input-Capacitorless Active Mic Preamp

Wow, cool - thanks! What we're looking for is the offset developed by the microphone when phantom is applied through the customary 6K81 pull-ups. It cannot be loaded by a transformer but an active input, or just the pullup resistors as load, will tell us how symmetric the current draw is. The DC pot...