Search found 5447 matches

by mediatechnology
Wed Mar 27, 2024 3:55 pm
Forum: Pro Audio Design
Topic: A Quadrature Power-Summed Compressor Sidechain For "The Uno Compressor"
Replies: 40
Views: 17017

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

bruno2000 aka Joe Neil published his Threshold, Ratio and Makeup mods here but I think I was asked to delete them.
by mediatechnology
Wed Mar 27, 2024 9:10 am
Forum: Pro Audio Design
Topic: A Quadrature Power-Summed Compressor Sidechain For "The Uno Compressor"
Replies: 40
Views: 17017

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

The original Pico Stereo compressor used a threshold and ratio circuit where the pot element becomes part of a voltage divider. https://proaudiodesignforum.com/images/jpg/PicoSE_Threshold_Ratio.JPG At higher compression ratios small changes in control attenuation make for big changes in slope. Witho...
by mediatechnology
Wed Mar 27, 2024 6:19 am
Forum: Build
Topic: Phono Transfer System Construction Information
Replies: 249
Views: 6532445

Re: Phono Transfer System Construction Information

These are working into a 14K3Ω load.
Wima now have some nice 5 mm lead spaced films in the MKS2 series that go up to 6.8µF so keeping them film is do-able.
by mediatechnology
Tue Mar 26, 2024 7:27 am
Forum: Pro Audio Design
Topic: A Quadrature Power-Summed Compressor Sidechain For "The Uno Compressor"
Replies: 40
Views: 17017

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

After clearing off the workbench to build some boards and spring yard cleanup I'm finally back to working on the Uno Compressor. During my break I thought a lot about the ratio control and wrote a spreadsheet to calculate trial values for a stepped switch and a means to linearize adjustment with a p...
by mediatechnology
Tue Mar 26, 2024 7:06 am
Forum: Build
Topic: Phono Transfer System Construction Information
Replies: 249
Views: 6532445

Re: Phono Transfer System Construction Information

On the latest run of RIAA boards I added more capacitor footprints for C33-C36. We found that when used as a cutting amp, with feedback, a 47uF should be used to reduce phase shift at C33-C36 so I added an electrolytic footprint. https://proaudiodesignforum.com/images/jpg/RIAAEQMONSW_Universal_Capac...
by mediatechnology
Tue Mar 12, 2024 5:21 am
Forum: Build
Topic: Phono Transfer System Construction Information
Replies: 249
Views: 6532445

Re: Phono Transfer System Construction Information

The rolloff at 20 Hz is intentionally introduced - to reduce warp - by the value of the film caps C33-C36.
You can make them much larger in value using electrolytics and it will follow the curve to 20 Hz.
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: 40
Views: 17017

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: 40
Views: 17017

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: 40
Views: 17017

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: 40
Views: 17017

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...