Search found 5471 matches
- Fri Oct 16, 2009 9:25 am
- Forum: Pro Audio Design
- Topic: The 48V Phantom Menace Returns
- Replies: 11
- Views: 24621
Re: The 48V Phantom Menace Returns
We figured that input and output phantom protection of line-level stages was a lot to throw in. There may be a sequel. To answer Roger's question, the published 1646 protection using bridge to rails, works fine. One thing I have found with the 1646 is that OutSmarts makes the part tolerant to stored...
- Wed Oct 14, 2009 4:14 pm
- Forum: Document
- Topic: SSL Phase Meter Schematic
- Replies: 16
- Views: 32157
Re: SSL Phase Meter Schematic
John - I edit a lot of commercial modern music (head/tail trims, normalization etc.) You'd be surprised at the number of entire mixes, or elements in mixes, that have it upside down on the CD. We may now agree that pin 2 is really hot, but that doesn't solve the problem. The other day I was listenin...
- Wed Oct 14, 2009 1:58 pm
- Forum: Document
- Topic: SSL Phase Meter Schematic
- Replies: 16
- Views: 32157
Re: SSL Phase Meter Schematic
John - Unless they have a 'scope or are working on a DAW I don't know how they would have a visual indication of absolute polarity in the studio.
- Wed Oct 14, 2009 10:56 am
- Forum: Document
- Topic: SSL Phase Meter Schematic
- Replies: 16
- Views: 32157
Re: SSL Phase Meter Schematic
I did it with log amps and ratios. I don't think it would be too hard in DSP. At some point in the chain you have to define the electrical polarity from the correct acoustic polarity using a measurement mic to define "right-side up" as pressure. If the speaker drive is "waveform posit...
- Wed Oct 14, 2009 10:12 am
- Forum: The Peabody Lounge
- Topic: Are These Two Soundfiles the Same?
- Replies: 1
- Views: 5567
Are These Two Soundfiles the Same?
Here's the first one: http://www.proaudiodesignforum.com/Content/Renee_Olstead-Someone_To_Watch_Over_Me_Cut_1.mp3 Here's the second: http://www.proaudiodesignforum.com/Content/Renee_Olstead-Someone_To_Watch_Over_Me_Cut_2.mp3 Do you hear any differences? No peeking. Resist the temptation to open them...
- Wed Oct 14, 2009 10:01 am
- Forum: Document
- Topic: SSL Phase Meter Schematic
- Replies: 16
- Views: 32157
Re: SSL Phase Meter Schematic
I'm still thinking about when I would want a correlation meter. The scenarios are few. In broadcast about the most obvious application is in machine room/content ingest applications where you occasionally get stereo content delivered with the polarity flipped on one channel. I think it makes sense i...
- Wed Oct 14, 2009 9:39 am
- Forum: Pro Audio Design
- Topic: The 48V Phantom Menace Returns
- Replies: 11
- Views: 24621
Re: The 48V Phantom Menace Returns
Thanks John. The observation about transient interfering with PS rail may explain one difference between my (low) failure experience in mixers and your bench.. I suspect the consoles may have more rail capacitance to soak up the current. (Also I typically used 22 uF). I agree. And there's a lot of o...
- Wed Oct 14, 2009 5:11 am
- Forum: Pro Audio Design
- Topic: The 48V Phantom Menace Returns
- Replies: 11
- Views: 24621
The 48V Phantom Menace Returns
Here's a paper Ros Bortoni and I recently wrote about the phantom menace. Ros has just presented it at AES 127. http://www.thatcorp.com/datashts/AES127-000183.pdf We managed to discover a differential fault mode that's particularly destructive. Previously, the diode bridges to the supply rails have ...
- Wed Oct 14, 2009 4:32 am
- Forum: Pro Audio Design
- Topic: Using the THAT1646 As A Transistor Pre-Driver/Headphone Amp
- Replies: 80
- Views: 354159
Re: Using the THAT1646 As A Transistor Pre-Driver/Headphone Amp
OK, glad that worked out. For RFI filtering you might consider a series R and capacitive shunt ahead of the pot at the RCA jack. With the inverting input of the op amp unaccessible its difficult (impossible?) to put it in the feedback loop.
- Tue Oct 13, 2009 1:58 pm
- Forum: Pro Audio Design
- Topic: VCA theory question
- Replies: 36
- Views: 54534
Re: VCA theory question
Why not use the 4.98V directly - why scale it down? Like John I'm not sure I understand the question either. But if you want to apply 4.98V directly to Ec+ or Ec- it will cause problems. Ec is limited to less than one Vbe or the junctions in the gain cell will become reversed biased. Take a look at...