Passive audio compressor..

[pucho812]

This was interesting...,

https://m.youtube.com/watch?feature=youtu.be&v=e6XiavBCPqY

 

[emrr]

Everyone should wire various lightbulbs in series with a guitar amp cabinet at least once. 

 

[user 37518]

This was interesting...,

https://m.youtube.com/watch?feature=youtu.be&v=e6XiavBCPqY

Nice!

 

[moamps]

Everyone should wire various lightbulbs in series with a guitar amp cabinet at least once.

Some of as replaced burned "passive audio compressors" on abused JBL CTRL 1.

 

[jensenmann]

That´s an old trick that has been used since the early days of PA systems to protect HF drivers. There´s even a 500 product out which uses a bulb: https://www.anamodaudio.com/tlcompressorbr.html

 

[JohnRoberts]

I had to watch the video before posting.  :-\

I am not sure that lamps are completely passive, but they have long been used for level control (inside sine wave oscillators like that classic old HP) but more widely as protection for loudspeakers (tweeters).

JR

 

[clintrubber]

That´s an old trick that has been used since the early days of PA systems to protect HF drivers.

I learned that SWR 4*10" bass cabs use this method for horn-protection as well,
when band members alerted me on 4 illuminated circles per cab behind me: the cone edges of the 10" speakers 

A simple auto-lightbulb, effective.

 

[user 37518]

I had to watch the video before posting.  :-\

I am not sure that lamps are completely passive, but they have long been used for level control (inside sine wave oscillators like that classic old HP) but more widely as protection for loudspeakers (tweeters).

JR

I wonder about the linearity of the bulbs when not compressing.

 

[JohnRoberts]

I wonder about the linearity of the bulbs when not compressing.

Not very linear...  Peavey designed an improved version where a PTC fuse shorted across the lamp when cold, so clean when not limiting. After it heats up and starts limiting distortion is relative....

JR

 

[user 37518]

Not very linear...  Peavey designed an improved version where a PTC fuse shorted across the lamp when cold, so clean when not limiting. After it heats up and starts limiting distortion is relative....

JR

Nice idea!

 

[JohnRoberts]

Nice idea!

Not my idea, one of the lads working in transducer engineering came up with it.

I used some PTC fuses in my 1980s boosted rail power amp (PMA70+) to limit the recharge rate for the boost capacitors.  60W rms when cold, falling back to 35W continuous when slammed. Playing typical music it didn't fold back. It put out more than 60W for transient peaks.

JR