Search found 5449 matches

by mediatechnology
Wed Mar 11, 2009 9:32 pm
Forum: Document
Topic: HB for Sound Engineers
Replies: 4
Views: 10605

HB for Sound Engineers

Guys - The 4th edition of "Handbook for Sound Engineers" became available last November and I recommend that you get a copy if you don't already have one. It's available from Amazon. https://www.amazon.com/Handbook-Sound-Engineers-Fourth-Ballou/dp/0240809696 Here's a small section on Analo...
by mediatechnology
Sun Mar 01, 2009 11:49 am
Forum: Test, Measurement and Repair
Topic: For Those Needing Test Equipment - My eBay Picks
Replies: 4
Views: 13105

Re: For Those Needing Test Equipment - My eBay Picks

Heathkit did make some very affordable 'scopes. Used, on eBay, they'd be my last choice these days the reason being that Tek, Leader etc are just so cheap. With any used Heathkit the risk is how well it was assembled to begin with. My Dad built virtually all of mine - he enjoyed building them more t...
by mediatechnology
Sat Feb 28, 2009 3:54 pm
Forum: Pro Audio Design
Topic: Mid Side M-S Matrix Uses No Precision Resistors
Replies: 271
Views: 620317

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

An update on this. Roger has sent me a new layout and I'm looking it over to do another proto run.

Paul - That extra inverter in there did add phase shift so your hunch was right on. That's why the crosstalk I was measuring was always asymmetric.
by mediatechnology
Sat Feb 28, 2009 3:44 pm
Forum: Test, Measurement and Repair
Topic: For Those Needing Test Equipment - My eBay Picks
Replies: 4
Views: 13105

For Those Needing Test Equipment - My eBay Picks

While there is certainly the Soundcard option for performing a lot of tests there's a lot to be said for older knob-based instrumentation. I got the idea to start a thread series on the test equipment of yesteryear that can be bought today at low cost. First up is Heathkit. There are three or four p...
by mediatechnology
Thu Feb 26, 2009 9:00 am
Forum: Pro Audio Design
Topic: OTB Mixer Using Current Summation
Replies: 137
Views: 214274

Re: OTB Mixer Using Current Summation

Thanks audio hammer for both joinging us and posting in this particular thread!

Maybe JR will check in and we can see what the status is. I can build his pan circuit to test if he thinks it's ready.

Wayne
by mediatechnology
Tue Feb 10, 2009 1:30 pm
Forum: Pro Audio Design
Topic: Help with parallel & summing with THAT IC's
Replies: 13
Views: 25336

Re: Help with parallel & summing with THAT IC's

Hey you're welcome. Figure 10 and the post here are the same circuit. This trick can only be done with the 1240: With the 1243 or 1246 the resistors are of unequal value.

I edited your link to add the pdf session argument #page=7 so it jumps to the figure. Hope that's OK. It's a neat trick
by mediatechnology
Tue Feb 10, 2009 12:56 pm
Forum: Pro Audio Design
Topic: Help with parallel & summing with THAT IC's
Replies: 13
Views: 25336

Re: Help with parallel & summing with THAT IC's

syn

That's what the top circuit does here: http://www.picocompressorforum.com/foru ... 12&start=0

"Mid" is mono is L+R. Just use the top 1240 and call the two inputs left and right.
by mediatechnology
Tue Feb 10, 2009 8:58 am
Forum: Pro Audio Design
Topic: Mid Side M-S Matrix Uses No Precision Resistors
Replies: 271
Views: 620317

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

This is one case where a 1640 would be useful. Unfortunately it's not possible to resistively pad the matrix output and use the unbuffered pad to drive the 1646. The 1646 requires low Z drive.... Two 1246 in a - 6dB attenuating non-inverting connection would work fine and be more gain-accurate than ...
by mediatechnology
Tue Feb 10, 2009 8:48 am
Forum: Pro Audio Design
Topic: FPGA Design...
Replies: 23
Views: 40338

Re: FPGA Design...

Since the charge injection is going to occur at a frequency equal to the timebase, wouldn't it be removed by the following low-pass filter stage anyway? It would seem to since it's far out-of-band. Would the charge injection also introduce in-band errors? It seems time to revisit an old SIliconix d...
by mediatechnology
Mon Feb 09, 2009 7:38 pm
Forum: Pro Audio Design
Topic: FPGA Design...
Replies: 23
Views: 40338

Re: FPGA Design...

Hmm... For some reason I recalled it to be faster than that.