THAT1646 Current Booster and Transformer Driver

Where we discuss new analog design ideas for Pro Audio and modern spins on vintage ones.
emrr
Posts: 524
Joined: Sun Mar 02, 2008 11:27 pm
Location: NC, USA
Contact:

Re: THAT1646 Current Booster and Transformer Driver

Post by emrr » Mon Aug 06, 2012 2:00 pm

Good to see some version back, if only in proto form.

Roger's gonna roll his eyes; I've said it privately enough times I'm sure: why does anyone need a 20 dB GR point on a meter? I'd always rather have great resolution near the threshold versus extended range. Once you're past 10 dB GR, the meter doesn't really matter any more. What goes on between 0 and -2 does matter a great deal to me, as it helps determine the best threshold. I am probably a minority.
Best,

Doug Williams
Electromagnetic Radiation Recorders

User avatar
mediatechnology
Posts: 4188
Joined: Sat Aug 11, 2007 2:34 pm
Location: Oak Cliff, Texas
Contact:

Re: THAT1646 Current Booster and Transformer Driver

Post by mediatechnology » Mon Aug 06, 2012 2:14 pm

why does anyone need a 20 dB GR point on a meter?
To prove it can go to "11?" :lol:

I do notice this GR has 2 dB steps which is cool.

Roger did you use a comparator string to get the 2 dB steps? Or just drop the intermediate steps on an LM3914 to make that jump from 10 to 20 dB?

I like the simple three-knob approach.
https://ka-electronics.com

"CDC Set Trap With Coronavirus Allowing a Month of Incubation" https://banned.video/watch?id=5e597d3934e11300790c4735
"Biggest Medical Scandal In History Breaking! UN Comes Clean, Admits Vaccine Death/Damage Coverup" https://banned.video/watch?id=5e1b9ed434b802001ed99b14
Mirror/Download: https://proaudiodesignforum.com/content ... overup.mp4
More: https://proaudiodesignforum.com/content ... People.mp4

User avatar
mediatechnology
Posts: 4188
Joined: Sat Aug 11, 2007 2:34 pm
Location: Oak Cliff, Texas
Contact:

Re: THAT1646 Current Booster and Transformer Driver

Post by mediatechnology » Wed Aug 08, 2012 10:47 am

I do like those square LEDs.

The red hex screws are a nice touch.
https://ka-electronics.com

"CDC Set Trap With Coronavirus Allowing a Month of Incubation" https://banned.video/watch?id=5e597d3934e11300790c4735
"Biggest Medical Scandal In History Breaking! UN Comes Clean, Admits Vaccine Death/Damage Coverup" https://banned.video/watch?id=5e1b9ed434b802001ed99b14
Mirror/Download: https://proaudiodesignforum.com/content ... overup.mp4
More: https://proaudiodesignforum.com/content ... People.mp4

User avatar
JR.
Posts: 3202
Joined: Sat May 24, 2008 7:21 pm
Contact:

Re: THAT1646 Current Booster and Transformer Driver

Post by JR. » Wed Aug 08, 2012 11:35 am

Back when I designed dynamics processors (a long time ago), I oriented VCA status meters to indicate gain reduction going down, and gain boost up. Of course this was in an odd-ball full range compressor that boosted low level stuff that was below threshold, and dropped high level stuff that was above threshold, not too mention added parallel downward expansion/noise gating... and more, perhaps too much.

Your display effectively communicates how much the signal is squashed, with higher is more, all good. The customers generally like all blinky lights.

====

Agreed the rectangular LEDs look better to me too...

The painted allen head screws are a nice detail but almost look like indicators. The rectangular LEDs reduce the potential for confusion.

JR
Don't only half-ass tune your drums. Visit https://circularscience.com to hear what properly "cleared" drums sound like.

emrr
Posts: 524
Joined: Sun Mar 02, 2008 11:27 pm
Location: NC, USA
Contact:

Re: THAT1646 Current Booster and Transformer Driver

Post by emrr » Wed Aug 08, 2012 1:45 pm

raf wrote: this meter implementation is one Doug suggested many moons ago. It uses a standard LM 3914 and skips the intermediate steps.
That's funny, I remember some angst over the options with a reduced number of LED's. Today I'd probably vote 1/2/3/4/6/8 or 10. Tomorrow?
Best,

Doug Williams
Electromagnetic Radiation Recorders

User avatar
JR.
Posts: 3202
Joined: Sat May 24, 2008 7:21 pm
Contact:

Re: THAT1646 Current Booster and Transformer Driver

Post by JR. » Wed Aug 08, 2012 9:15 pm

I have been kicking around the idea of making an universal meter chip based on a microprocessor... It is almost easier to make a big meter effectively than a small one. The rap against the 3.3V micro family I like is that they don't look like they can drive bare LEDs adequately, but i suspect modern high efficiency LEDs could probably work. For large scale meters, simple to drive a latch IC.

While it is hard being all meters to all people, i could pretty easily support an optional linear scale, or even a proportional log scale where the step size between LEDs is read in from a pin. Say you divide the PS by some fraction and feed that into an A/D input. The micro reads that voltage, determines the ratio of the 3.3V supply, and makes that the ratio between each LED down as far as it can.. Easy to make 1dB, 2 dB, whatever dB steps down to the resolution floor of the A/D.

This us not worth killing a lot of brain cells over but i have a sweet PK/VU technology I have in the can to use. I'f love to make a generic swiss army meter (in my spare time)

JR.
Don't only half-ass tune your drums. Visit https://circularscience.com to hear what properly "cleared" drums sound like.

Post Reply