DBX vinyl discussion (moved from "Who Are You" thread)

[SeeMoreDigital]

I used my Panasonic S-VHS deck far more for recording radio since it had much better sound quality. That's still in my rack but doesn't get used often now.

Lol... My JVC S-VHS deck is in my loft along with some blank S-VHS tapes... Most probably all rotting away now. Too much sentimental attachment to these things!

 

[Owen Smith]

Lol... My JVC S-VHS deck is in my loft along with some blank S-VHS tapes... Most probably all rotting away now. Too much sentimental attachment to these things!

I have half a dozen blank JVC S-VHS tapes still in the shrink wrap. Mostly 180 minutes with one 240 minutes. I also have one of each of TDK MA-XG C90 and TDK MA-R C90 cassettes still in the shrink wrap, together with one of each that I opened but never used. Colleagues at work in their 20s have never seen any.

 

[ar surround]

View attachment 114157

Here is a picture of one I grabbed from online model 224. There were a couple of later model variations but I understand this is the preferred model for decoding dbx encoded records.
At one time you could find them for around $20 online have not checked for years. I have a couple including some dbx encoded records including Who Are You.
Some of the classical records had astonishing dynamic ranges.

That's the dbx unit that I had, the 224. In addition to its excellent performance, I always loved the low-profile look of it.

 

[Sonik Wiz]

Indeed, dbx really was very good for the time. In the early 80's I would record dbx LP's onto cassette tape using a Technics dbx capable cassette deck. By the mid 80's I would record CD's onto cassette tape using a newer version of a Technics dbx capable cassette deck. As analogue audio goes, nothing could touch it.

In the early 90's I dabbled recording CD's onto cassette tape using a Sony Dolby-S deck, which also sounded very good... But by this time the writing was well and truely on the wall for playing analogue tapes!

Like you I have a Technics cassette unit. It even had an LP pre-amp built in for playing dbx records. I have about 1/2 dozen of those, stereo only. I think there has been previous discussion here about matrix encoded dbx records. Just think about it... in those olden times we had an analog disc with surround sound encoded with dbx and then ⁹by Sansui Vario-Matrix or Fosgate with Tate DES that subjectively rivaled digital discrete today.

I've always had an interest in audio line level signal processing. This might apply to LOG/RMS detection circuits and Voltage Controlled Amplifiers. Whether it's SQ Logic, Sansui Vario-Matrix , Tate DES the decoder functions rely on circuits like this. Back then designers used a trans-conductance circuit to modify an audio signal with a control voltage. Sansui used FET's. The famous 3 chip Motorola SQ decoder used basic bipolar trans-conductance amps for the job.

Enter dbx. They invented the Blackmer Gain Cell that over came so many of the previous problems. They never had any involvement with quad decoding but it would have been a blessing if they did.

Read all about it here.

I always thought dbx was much better than Dolby NR but also was concerned at the time they might offer even a lower quality audio. Based on my knowledge of earlier VCA designs.I was wrong. And in today's squashed to death loudness wars, I sure wish I had one of their 3bx Dynamic Range Expanders.