Pro Audio Design Forum

ricardo: My friend and previous co-worker Rosalfonso Bortoni wrote "Audio Amplifiers Principles, Characteristics, and Applications." His graduate work was with power amplifier output stages and current-driven speakers. As far as I know it has not been translated from Portugese. I think I m...

Yeah, I think the Delta-Omega was a negative OP impedance.

ricardo - I think a THAT1240/1246 could be used to measure the floating shunt's current.

Hmm. Let me think about where I saw something like this recently. I want to say it was an EDN or Electronic Design article or IFD.

What actaully was the Crown Delta/Omega?
We had those where I worked once.

I decided to try out an "equal mono power" version to distribute the mono energy equally between the Mid, and "Side" outputs. Mono (L+R) drives the headphone transducers in common mode. Difference (L-R) drives the headphone transducers differentially. The Side outputs operate di...

Cool John. Would you have a resource for an old manual for that product showing it to be prior art? The Freescale patent has a lot of claims that include the filters and ground detection. But it looks like from the patent that they may have convinced the examiner sum/difference drive was unique. It ...

I have often wondered about constant-current drive for phones. We used it driving spring reverb transducers at MicMix. WRT Ro some common values are 32 and 63 Ohms. I've seen ranges from 10-200 Ohms. There may be one model at 300R. AKG re-designed the "most-highest" AKG-240 which was 500-6...

JR's the expert but my vote would be to back-ground.

This is something I've wanted to try for along time just to see if I could. I wasn't sure if it had ever been done. Drive the shield with mono, and tip and ring with difference. This de-matrixes the Mid Side/Sum Difference in the transducer wiring and can be used with conventional 1/4" or 3.5 ...

Better is always better,,, Driving magnetic systems like transformers IIRC benefit from lower source impedance, perhaps a transducer's magnetic system also benefits. My distortion overlay is not completely fair, as some distortions are more audible than others... I recall hearing modest amounts of ...

Not to be more contrarian than usual he is talking about distortion spurs down at -70dB.. for chuckles how about a distortion overlay for the transducer? Ah, there's the rub... He does admit that acoustic measurements may show more distortion... All measurements shown in this paper are taken at the...