Search found 5471 matches

by mediatechnology
Tue Jan 05, 2010 7:15 pm
Forum: Pro Audio Design
Topic: Old: A Direct-Coupled Input-Capacitorless Active Mic Preamp
Replies: 212
Views: 413497

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

Thanks Ilya. I think you could use the circuit you posted as-is or with one TL074 section eliminated or this one: https://www.ka-electronics.com/images/jpg/Level_Det_Two_Color.JPG The above gives you off, signal present and clip though it's only negative peak detecting, You could combine the two for...
by mediatechnology
Sat Dec 26, 2009 12:02 pm
Forum: The Peabody Lounge
Topic: Texas White Chrsitmas
Replies: 3
Views: 7428

Re: Texas White Chrsitmas

Thanks Roger.

JR - It snowed earlier in the month as far south as Houston.
by mediatechnology
Sat Dec 26, 2009 6:06 am
Forum: Pro Audio Design
Topic: PSU design assistance needed
Replies: 35
Views: 52936

Re: PSU design assistance needed

Heres' the LM317/337 regulator board schematic we sold for the Picos. They are no longer available but it may help you out: http://www.proaudiodesignforum.com/PicoComp/PCB-Kits/Documents/PSU/PSU_Documents.htm I had forgotten that there were links to Sam Groener's PSU calculator spreadsheet and to th...
by mediatechnology
Fri Dec 25, 2009 8:57 am
Forum: The Peabody Lounge
Topic: Texas White Chrsitmas
Replies: 3
Views: 7428

Texas White Chrsitmas

We estimate it's been about 52 years since the last white Christmas...

Image
by mediatechnology
Thu Dec 24, 2009 11:32 am
Forum: Pro Audio Design
Topic: PSU design assistance needed
Replies: 35
Views: 52936

Re: PSU design assistance needed

Thanks John! I'm archiving some physical databooks for our member crazynightowl as well. I think I have the VR handbook. Let me see which edition I have...

BTW The National Audio Handbook edition I have is 1977. I think I have an earlier one as well.
by mediatechnology
Thu Dec 24, 2009 7:55 am
Forum: Pro Audio Design
Topic: PSU design assistance needed
Replies: 35
Views: 52936

Re: PSU design assistance needed

John - The NSC Audio Handbook I have is the series with the dark blue bottom and - IIRC - a tan color bar at the top. Unfortunately the NSC books of that era were printed on newsprint and they haven't aged well. I'm not sure where we discussed the TS-1 but I do have the sch here: http://www.proaudio...
by mediatechnology
Wed Dec 23, 2009 7:41 am
Forum: Pro Audio Design
Topic: PSU design assistance needed
Replies: 35
Views: 52936

Re: PSU design assistance needed

This is a very good reference for you to start with. It should be on everyone's virtual bookshelf:

http://www.proaudiodesignforum.com/imag ... Design.pdf

National Semiconductor Audio Handbook Chapter 6 Power Supply Design
by mediatechnology
Thu Dec 17, 2009 10:01 am
Forum: Pro Audio Design
Topic: Sum bus theory and practice
Replies: 37
Views: 55507

Re: Sum bus theory and practice

For now, jump here: viewtopic.php?f=6&t=26&p=101

And here: http://www.ka-electronics.com/Images/pd ... pdf#page=4

JR - What browser do you use? Do the pdf page arguments work in Safari?
by mediatechnology
Thu Dec 17, 2009 4:02 am
Forum: Pro Audio Design
Topic: Sum bus theory and practice
Replies: 37
Views: 55507

Re: Sum bus theory and practice

Paul - Use a "derived" filter so that they re-combine properly. The old NSC audio handbook has a discussion on that in active speaker crossovers. We should probably start a thread on that.

Wayne
by mediatechnology
Mon Dec 14, 2009 3:31 pm
Forum: Pro Audio Design
Topic: op amp gain; vary Rg or Rf, and why?
Replies: 28
Views: 42160

Re: op amp gain; vary Rg or Rf, and why?

An assumption definitaly not to make is to assume that the carbon comp resistors really are the correct value in 2010.

I just threw out a bunch of 5% carbon comps that were off in the 20-30% range. Others from the same period, depending on value manufacturer etc., were spot on.