Which NRG PLL Pro 3?

[jvok]

There never were any Gerbers for these boards - they were designed using "EasyPC" made by Number One Systems. This was an ancient DOS PC design programme that Stephen used. I got a copy and did some of the design work myself - adding OLPD to the Pro III and a few other changes. I also used that same programme for the Pro III and Pro IV stereo coders and for the stereo limiter.

im find this one..

You got the sprint files for those rigmo? Would be good to get some boards made, hard to buy any NRG stuff nowadays

[yellowbeard]

Gerbers and sprint layout:

https://gareth.net.nz/nrgdocs/nrg/pll_pro_4/
Couldn't remember where I saw these, which was pretty geriatric of me...

[LeeCavanagh]

do you have the compressor limiter ?

You may struggle to find all the components, probably easier to build the sinus limiter which sounds very similar

[Albert H]

do you have the compressor limiter ?

There's little point - you won't be able to find the Toko lowpass filter - they haven't been made since the early 1990's. However, I designed a filter that will work as a replacement for that part. It uses two TL074 quad op-amps, and needs 1% resistors and (ideally) 1% capacitors in the tuned parts, unfortunately.

The limiter was a relatively simple single-band affair, and suffers from "breathing" problems, particularly when you have content with heavy bass. We did work on a split-band version, but Stephen's death intervened. I still have the circuit sketches somewhere, and a Veroboard prototype of the splitter and combiner.

The "Sinus" version of the limiter is very similar to the original single-band version, but lacks the filtering.....

[Albert H]

There's a further problem with getting matched FETs for the limiter too if you want stereo. NRG used to buy the FETs by the thousand, and then hand-select them into pairs, selected for both gm and pinch-off voltage.