Next SINUS project??

[Albert H]

The attack time is (mostly) determined by how quickly you can dump current into the timing capacitors. 270Ω into a 680n calculates at 734µs, so allowing for tolerances and thermal effects, just under 1 ms isn't unrealistic.

[Electronically]

15khz low pass filter, if I remember correctly ,I had this years ago lol ,was a steve moss design though .

[sinus trouble]

15khz low pass filter, if I remember correctly ,I had this years ago lol ,was a steve moss design though .

Electronically!

Lets get one thing straight here! I am a massive fan of Stephens work and have NO financial or status intentions!

My goal is to recreate the systems that Stephen implemented and inspired me over the years!

I can assure you that i will publish ALL schematics, PCBs etc... open source and free of charge to all that wish to experiment!

If you want to contribute to any design? feel free to do so!

[jvok]

One thing I'll add is that with time constants it makes a big difference how youre using the limiter. If you're purely using it as a protective limiter to catch the odd peak then you can get away with being much more aggressive, because you won't hear it working all that much anyway. I get the feeling this is what moss was going for in his design. But if you're trying to also use it as a compressor to pump your loudness up then you'll need to back off on the attack/release times because you're in some amount of limiting most of the time.

There are a few different ways of measuring attack/release times too which doesn't help. Two people could be talking about the exact same circuit but giving very different numbers, just because they're measuring it differently.

I usually just give the RC time constant, but another figure the BBC used to use (possibly still do) is called T12. This is the time it takes for a peak 12db over the limiting threshold to be reduced to just below the threshold (i.e. to fall 12db). I think this was used because its common to overdrive a limiter by around 12db to get a good level of compression.

[Electronically]

15khz low pass filter, if I remember correctly ,I had this years ago lol ,was a steve moss design though .

Electronically!

Lets get one thing straight here! I am a massive fan of Stephens work and have NO financial or status intentions!

My goal is to recreate the systems that Stephen implemented and inspired me over the years!

I can assure you that i will publish ALL schematics, PCBs etc... open source and free of charge to all that wish to experiment!

If you want to contribute to any design? feel free to do so!

I'm actually glad your trying on Stephen moss's work of art .he did once say he would like someone to carry on his designs .because components will become obsolete within time ,so its important that new components will be substituted ,and contribute to upgrading with project ideas ,if he was still here today ,he would have probably updated his limiter, and so on .so experiment is not a bad thing ,he would like that all upgraded I would imagine ,I have a schematic and components of the limiter ,I'll post up here for you .

[radium98]

Thanks Sinus , by the way a PM is sent very long time .

[Electronically]

15khz low pass filter, if I remember correctly ,I had this years ago lol ,was a steve moss design though .

Electronically!

Lets get one thing straight here! I am a massive fan of Stephens work and have NO financial or status intentions!

My goal is to recreate the systems that Stephen implemented and inspired me over the years!

I can assure you that i will publish ALL schematics, PCBs etc... open source and free of charge to all that wish to experiment!

If you want to contribute to any design? feel free to do so!

I'm actually glad your trying on Stephen moss's work of art .he did once say he would like someone to carry on his designs .because components will become obsolete within time ,so its important that new components will be substituted ,and contribute to upgrading with project ideas ,if he was still here today ,he would have probably updated his limiter, and so on .so experiment is not a bad thing ,he would like that all upgraded I would imagine ,I have a schematic and components of the limiter ,I'll post up here for you .

Screenshot_20230203_194117_Samsung Internet.jpg

Screenshot_20230203_194102_Samsung Internet.jpg

Screenshot_20230203_194041_Samsung Internet.jpg

Screenshot_20230203_194031_Samsung Internet.jpg

Screenshot_20230203_141441_Samsung Internet.jpg

[Electronically]

I've no schematic of it though .if I find I'll post here .

[Electronically]

When I had this years ago ,using a 1 watt pll ,I had to disable the pre emphasis when I used a stereo or limiter .

[Electronically]

I've just realised you have the schematic up already on this ,component list is there to match it .

[sinus trouble]

One thing I'll add is that with time constants it makes a big difference how youre using the limiter. If you're purely using it as a protective limiter to catch the odd peak then you can get away with being much more aggressive, because you won't hear it working all that much anyway. I get the feeling this is what moss was going for in his design. But if you're trying to also use it as a compressor to pump your loudness up then you'll need to back off on the attack/release times because you're in some amount of limiting most of the time.

There are a few different ways of measuring attack/release times too which doesn't help. Two people could be talking about the exact same circuit but giving very different numbers, just because they're measuring it differently.

I usually just give the RC time constant, but another figure the BBC used to use (possibly still do) is called T12. This is the time it takes for a peak 12db over the limiting threshold to be reduced to just below the threshold (i.e. to fall 12db). I think this was used because its common to overdrive a limiter by around 12db to get a good level of compression.

Very interesting Jvok!

I completely agree! Also as i have mentioned before, There is no "Golden Setting" for a limiter/compressor!

Settings can vary considerably from genre to genre!

Infact, a Limiter should be the last line of defence! A quality sounding station will pre-prepare its media for broadcast! Or in the case of live media will have a DJ who knows how to use a mixer correctly!

All Pirate stations i have been on had "Gaffa Tape" stuck all over the mixer gain knobs to deter amateur DJs!

[sinus trouble]

I'm actually glad your trying on Stephen moss's work of art .he did once say he would like someone to carry on his designs .because components will become obsolete within time ,so its important that new components will be substituted ,and contribute to upgrading with project ideas ,if he was still here today ,he would have probably updated his limiter, and so on .so experiment is not a bad thing ,he would like that all upgraded I would imagine ,I have a schematic and components of the limiter ,I'll post up here for you .

Exactly Electronically!

Not only was the performance of Stephens Products outstanding! They were also educational!

The VFOs were an excellent example of this! Allowing the user to grasp the importance of setup and alignment!

If Stephen was still was with us today? I would have bought every kit he released!

[sinus trouble]

PCBs are now in production!

I will release the Gerber files once initial testing has been carried out!

[Albert H]

Electronically

Unfortunately, the limiter you have posted about above was only mono capable. If you tried to use a pair of them for stereo, the image would wander around - especially if one side suddenly got very loud - since there was no coupling possible between channels.

However, I designed a way of interconnecting them, so that if you had matched FETs, you'd get a nice, coherent stereo image. My modifications led to the stereo limiter that NRG provided toward the end of Steve's life....

I'll put those circuit sketches up here later.

[Electronically]

I'm actually glad your trying on Stephen moss's work of art .he did once say he would like someone to carry on his designs .because components will become obsolete within time ,so its important that new components will be substituted ,and contribute to upgrading with project ideas ,if he was still here today ,he would have probably updated his limiter, and so on .so experiment is not a bad thing ,he would like that all upgraded I would imagine ,I have a schematic and components of the limiter ,I'll post up here for you .

Exactly Electronically!

Not only was the performance of Stephens Products outstanding! They were also educational!

The VFOs were an excellent example of this! Allowing the user to grasp the importance of setup and alignment!

If Stephen was still was with us today? I would have bought every kit he released!

His work was phenomenal, I had a 1 watt vfo and 5 watt vfo they both worked extremely well ,just slightly drifted off slightly ,but once he came out with pll, I was like oh my where did I put my bank card to purchase this online ,I ended up buying 2 incase one failed ,but pll was awesome .I mean if Stephen was with us all today ,he would be in here sharing his ideas etc .Good man he is .

[Electronically]

Electronically

Unfortunately, the limiter you have posted about above was only mono capable. If you tried to use a pair of them for stereo, the image would wander around - especially if one side suddenly got very loud - since there was no coupling possible between channels.

However, I designed a way of interconnecting them, so that if you had matched FETs, you'd get a nice, coherent stereo image. My modifications led to the stereo limiter that NRG provided toward the end of Steve's life....

I'll put those circuit sketches up here later.

Yea I did have the mono. Your absolutely spot on about the audio swings to the one side .does wander yup.there was no coupling agree .but Albert you and Steve did a great job leading those out for prdoction. without you guys, we would all be finding it hard to get radio stations on .it was you guys that got me into building kits to this day I still love it ,great hobby .

[Electronically]

Electronically

Unfortunately, the limiter you have posted about above was only mono capable. If you tried to use a pair of them for stereo, the image would wander around - especially if one side suddenly got very loud - since there was no coupling possible between channels.

However, I designed a way of interconnecting them, so that if you had matched FETs, you'd get a nice, coherent stereo image. My modifications led to the stereo limiter that NRG provided toward the end of Steve's life....

I'll put those circuit sketches up here later.

Yea I did have the mono. Your absolutely spot on about the audio swings to the one side .does wander yup.there was no coupling agree .but Albert you and Steve did a great job leading those out for production. without you guys, we would all be finding it hard to get radio stations on .it was you guys that got me into building kits to this day I still love it ,great hobby .

[yellowbeard]

I hope Gareth doesn't mind me doing this - he is the site admin so he can delete it if he's pissed...
http://www.gareth.net.nz/nrgdocs/Pro3_Limiter.pdf

[Albert H]

Here's the initial mods I did to the NRG Limiter to make it work properly in stereo. I added the left and right together to make the feed to the sidechain common, so there was only one sidechain needed. There were a couple of issues - the FETs had to be matched for pinch-off voltage, and it really needed an anti-overshoot clipper after it, with a further audio filter to shave off the upper harmonic clipping products.

We prototyped it, and it sounded great, but Stephen decided to go with two sidechains so that it could be separated (with minor modifications) for use as two separate mono limiters.

The circuit given below works well (with the above caveats), and I have a Veroboard layout that I did for the prototype and a PCB layout that I etched (by hand, as a one-off) - both worked well.

NRGlimmods+.png

You'll also notice that i used separate op-amps for each channel (NE5534) for the lowest noise and distortion. I also planned to replace the TL074 with an LM324, because it's a much cheaper part, and switches more slowly, making it much less likely to put switching noise into the audio as the LEDs light.

I also did a replacement op-amp based 15 kHz lowpass filter to replace the now unobtainable Toko Block Filter Modules.

[sinus trouble]

I hope Gareth doesn't mind me doing this - he is the site admin so he can delete it if he's pissed...
http://www.gareth.net.nz/nrgdocs/Pro3_Limiter.pdf

I have to confess! I browsed those files many times too!

Sorry G!! You are a ledge and i really appreciate the content!