Search found 5441 matches

by mediatechnology
Wed Feb 28, 2024 7:22 am
Forum: Pro Audio Design
Topic: A Quadrature Power-Summed Compressor Sidechain For "The Uno Compressor"
Replies: 35
Views: 10302

Re: A Quadrature Power-Summed Compressor Sidechain For "The Uno Compressor"

I needed to assemble some boards for a client and had to move this off the bench for a few days. I should be getting back to it soon. One of the issues I found in the original Pico, and some of the earlier 4301 app notes, is that the "Over Easy" pre-bias diode was pulled up by a large valu...
by mediatechnology
Fri Feb 23, 2024 6:45 pm
Forum: Pro Audio Design
Topic: A Quadrature Power-Summed Compressor Sidechain For "The Uno Compressor"
Replies: 35
Views: 10302

Re: A Quadrature Power-Summed Compressor Sidechain For "The Uno Compressor"

Updated Schematic. Gary Hebert of THAT suggested that I use a detector that is not "one Vbe up" at the timing capacitor node to reduce temperature drift between channels arising from the two channels being on different transistor arrays. The original dBx 303 detector and 2252 are one Vbe ...
by mediatechnology
Tue Feb 20, 2024 2:41 pm
Forum: Pro Audio Design
Topic: A Quadrature Power-Summed Compressor Sidechain For "The Uno Compressor"
Replies: 35
Views: 10302

Re: A Quadrature Power-Summed Compressor Sidechain For "The Uno Compressor"

I’ve noticed that most of the time I’ve been using short attack/short release, medium attack/medium release or long attack long release. That's the beauty of the variable timing capacitor approach - the attack/release relationships remain proportional to each other as the Ct is varied. It also rema...
by mediatechnology
Mon Feb 19, 2024 3:14 pm
Forum: Pro Audio Design
Topic: A Quadrature Power-Summed Compressor Sidechain For "The Uno Compressor"
Replies: 35
Views: 10302

Re: A Quadrature Power-Summed Compressor Sidechain For "The Uno Compressor"

https://proaudiodesignforum.com/images/jpg/Unocomp_Sidechain_Schematic_022424.jpg I just changed the above circuit to make the cap multiplier op amp (connected to the bottom of Ct) to a conventional inverting amp with a 10K Rfb. For 600 dB/s Rin = ∞ ; 480 dB/s = 40KΩ; 360 dB/s = 15KΩ; 240 dB/s = 4K...
by mediatechnology
Mon Feb 19, 2024 12:08 pm
Forum: Pro Audio Design
Topic: A Quadrature Power-Summed Compressor Sidechain For "The Uno Compressor"
Replies: 35
Views: 10302

Re: A Quadrature Power-Summed Compressor Sidechain For "The Uno Compressor"

It's in the original schematic at the end of the 2u2 film cap. When Av is 0 it's at AC ground and Ceffective is 2.2. When Av is -9 Ceffective is 2.2 uF + 19.8 uF.

Edited sign of Av. Ct is "anti-bootstrapped."
by mediatechnology
Mon Feb 19, 2024 8:53 am
Forum: Pro Audio Design
Topic: A Quadrature Power-Summed Compressor Sidechain For "The Uno Compressor"
Replies: 35
Views: 10302

Re: A Quadrature Power-Summed Compressor Sidechain For "The Uno Compressor"

One thing I'm going to change is the gain control of the capacitance multiplier. The pot is too cramped at slow rate settings and most people would want stepped controls anyway. Switching input resistors on the inverting stage to use a 6 position rotary switch with 600, 480, 360, 240, 120 and 60 dB/...
by mediatechnology
Sun Feb 18, 2024 6:43 am
Forum: Pro Audio Design
Topic: A Quadrature Power-Summed Compressor Sidechain For "The Uno Compressor"
Replies: 35
Views: 10302

Re: A Quadrature Power-Summed Compressor Sidechain For "The Uno Compressor"

I did some tests comparing the Attack and Release signatures of some of the compressors that we have that are favorites for voice. Here's the info on these tests: The test tone was generated by an Audio Precision System One, and recorded to Pro Tools at 96kHz through a 192 interface. 0 crossing for...
by mediatechnology
Sat Feb 17, 2024 5:37 am
Forum: Pro Audio Design
Topic: A Quadrature Power-Summed Compressor Sidechain For "The Uno Compressor"
Replies: 35
Views: 10302

Re: A Quadrature Power-Summed Compressor Sidechain For "The Uno Compressor"

I recall you posting that in this thread from bruno2000 (RIP) but the schematic disappeared: https://proaudiodesignforum.com/forum/php/viewtopic.php?p=3096 My toneburst tests were a "0-60" pedal to the floor test. I decided to use bruno's test tone to compare it to his findings and built o...
by mediatechnology
Thu Feb 15, 2024 4:19 pm
Forum: Pro Audio Design
Topic: A Quadrature Power-Summed Compressor Sidechain For "The Uno Compressor"
Replies: 35
Views: 10302

Re: A Quadrature Power-Summed Compressor Sidechain For "The Uno Compressor"

A comparison of conventional "True Power Summing" to "Quadrature Power Summing" with a variable timing capacitor. The test is 10 cycles of 50 Hz with about 10 dB of compression. The first sequence is conventional True Power Summing (TPS) with the decay rate swept from 60 dB/s to...
by mediatechnology
Tue Feb 13, 2024 4:31 pm
Forum: Pro Audio Design
Topic: A Quadrature Power-Summed Compressor Sidechain For "The Uno Compressor"
Replies: 35
Views: 10302

Re: A Quadrature Power-Summed Compressor Sidechain For "The Uno Compressor"

I remember that drawing. The cap multiplier I'm using is a single op amp inverting stage Av = 0 to -9 connected to the normally-grounded end of the timing cap. At a gain of 0 the timing cap's value is 2.2µF making the total range 10:1 to synthesize a 22 µF. I just finished listening to a walking bas...