This stereo compressor any good

[radionortheast]

Just wondering, looks like it has the stereo encoder on one side and the compressor on the other, the trim pots for ajusting on the right, just make sure the left are the same as the right I suppose, I have stereo tool set up do still wonder.

[radionortheast]

theres also the digicolor from radiomaster, don't know if his stuff was hard to get hold of though

[Krakatoa]

The first one looks to be the PIRA coder and limiter in one board.
The second one from Radiomaster looks like a new development he made. It has a DSP chip on it, probably some ADAU... from Analog Devices doing the processing. Hard to tell from the video. We would need a direct audio sample and have a look at the modulation spectrum and waveform, and fm deviation statistics to tell if it's doing a good job.

[radionortheast]

I did see some stereo encoder compressor limiter things on ebay, considered getting one just mess about with, since it is a pain trying to build your own without getting clashing symbols, not just pre emp circuits, its the 15khz filters too, it becomes a nightmare.
Sounds like you need something from a garden center to get rid of the 15khz frequencies called a gyrator too.

[Albert H]

15kHz filters are simple enough. The "Gyrator" circuit emulates inductors, so it becomes easy to build a modern equivalent of the traditional passive coils and capacitors lowpas filter. The reason I went over to them was because the "Toko" brand filters we'd used for years were discontinued. The Toko modules were just a row of coils and capacitors in a neat little metal can and if it was driven and terminated with the right impedances, it gave a very good response shape.

The simple coil and capacitor filter emulated with Gyrators is cheap and easy to make. The only slightly tricky bit is that the capacitors should be 1% accuracy types, which tend to be a bit expensive. 1% accuracy resistors are cheap and easily found. I solved the capacitor problem by buying a large bag of 5% accuracy parts, and sorting them with a capacitance meter. It was time-consuming, but I got the parts I needed at low cost!

I think that I gave details of the Gyrator circuit in the norak section some time ago.