Search found 3202 matches

by mediatechnology
Fri Nov 16, 2018 6:33 pm
Forum: Pro Audio Design
Topic: The Waveulator: Two VCA-based Clipper Saturators
Replies: 4
Views: 176

Re: The Waveulator: Two VCA-based Clipper Saturators

Now you have the answer to the question posed here: https://www.proaudiodesignforum.com/forum/php/viewtopic.php?f=6&t=111&start=20#p6574 Likely, I'm missing something, but - Isn't the behavior of the peak of the wave a whole lot more important than the zero-crossing behavior for level indicator appl...
by mediatechnology
Fri Nov 16, 2018 6:07 pm
Forum: Pro Audio Design
Topic: Mid Side M-S Matrix Uses No Precision Resistors
Replies: 244
Views: 305682

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

I changed the 10K resistors to 0.1%. No difference. I'm planning to completely switch the M/S board out of the circuit unless it is being used to alter the M or S gain. So in a way I guess the crosstalk is okay. I'd like to find a better way to do this though. What about putting attenuator between ...
by mediatechnology
Fri Nov 16, 2018 5:46 pm
Forum: Pro Audio Design
Topic: The Studer "90° Filter" Stereo to Mono Summer/Recorrelator
Replies: 0
Views: 6

The Studer "90° Filter" Stereo to Mono Summer/Recorrelator

The Studer 90° Degree Filter This active 90° filter is used to form a monophonic signal from the left and right channel of stereo signals. Simple mixing of the left and right channel will not produce a mono signal of satisfactory quality, but results in an emphasis of the center information. By sum...
by mediatechnology
Fri Nov 16, 2018 5:31 pm
Forum: Pro Audio Design
Topic: Simple Variable Attack/Release for THAT4301 Compressor
Replies: 4
Views: 24

Re: Simple Variable Attack/Release for THAT4301 Compressor

It's being used as a comparator so some positive feedback around U5A might help too. Notice that he characterizes it as "linear enough." :lol: The THAT version was a bear to stabilize: http://www.thatcorp.com/datashts/dn115.pdf https://proaudiodesignforum.com/images/jpg/THAT_DN-115_Schematic.JPG THA...
by mediatechnology
Fri Nov 16, 2018 3:22 pm
Forum: Pro Audio Design
Topic: Mid Side M-S Matrix Uses No Precision Resistors
Replies: 244
Views: 305682

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

Paul - I would hand-match the 10K and 20KΩ "1%" resistors since encode/decode reversal puts them in the M/S pathway. The absolute values aren't too critical: Just match the 10Ks to each other and the 20Ks to each other. e.g. if you have a 10K that measures 9982 try and find another one near 9982 Ω. ...
by mediatechnology
Fri Nov 16, 2018 3:15 pm
Forum: Pro Audio Design
Topic: Simple Variable Attack/Release for THAT4301 Compressor
Replies: 4
Views: 24

Re: Simple Variable Attack/Release for THAT4301 Compressor

I recall the original application for this was Electronic Music.
This particular one has been pretty widely-used in a kit IIRC.

The slopes in the dBx adjustable attack-release circuit were also linear being current sources/sinks charging/discharging a capacitor.
FWIW the 4301 is linear dB/V.
by mediatechnology
Fri Nov 16, 2018 12:32 pm
Forum: Pro Audio Design
Topic: Simple Variable Attack/Release for THAT4301 Compressor
Replies: 4
Views: 24

Simple Variable Attack/Release for THAT4301 Compressor

Note that U5A is connected as a comparator and that C3 is referenced to -15V so that it can remain polarized.

Image
Variable Slew Limiter Circuit from http://burnit.co.uk/sdiy/images/boxotri ... ressor.gif
by mediatechnology
Fri Nov 16, 2018 8:44 am
Forum: Document
Topic: Demrow: Evolution from Operational Amplifier to Data Amplifier, 1968
Replies: 1
Views: 18

Demrow: Evolution from Operational Amplifier to Data Amplifier, 1968

"Evolution from Operational Amplifier to Data Amplifier," Robert Demrow, Analog Devices, 1968. https://proaudiodesignforum.com/images/pdf/ADI_Demrow_Evolution_from_Op_Amp_to_Data_Amp.pdf https://proaudiodesignforum.com/images/jpg/Demrow_INA_1968.jpg Demrow: Evolution from Operational Amplifier to D...
by mediatechnology
Fri Nov 16, 2018 7:57 am
Forum: Test, Measurement and Repair
Topic: Are Linear Bench Supplies Really Quieter Than Switchers?
Replies: 7
Views: 148

Re: Are Linear Bench Supplies Really Quieter Than Switchers?

Does the silent switcher galvanically isolate USB DC 0V from its +/-15V and +5V DC 0V? There's a leakage current path from Line > USB DC 0V > Supply DC 0V > Planet Earth 0V even if there isn't a galvanic one. I just wonder how big it is. It would seem to vary greatly with the USB supply which would ...
by mediatechnology
Thu Nov 15, 2018 7:58 pm
Forum: Test, Measurement and Repair
Topic: Are Linear Bench Supplies Really Quieter Than Switchers?
Replies: 7
Views: 148

Re: Are Linear Bench Supplies Really Quieter Than Switchers?

I must admit to wussing out for sensitive circuits and have a couple of these https://linearaudio.nl/silentswitcher . Powered from a USB battery pack you get clean rails and no grounding issues. Total cop out, but works. I like it. We have cell phones to thank for those high-performance linear post...