ABBA Gold is in DolbyA form (with some tweaks)

I kept trying to FA decode the ABBA Gold album and ended up with a mess (new FA, new DA).  I knew that the FA decoder was nearly perfect now, and the DA was also pretty close to correct.  Some aspects of DA accuracy aren't critical for FA decoding, so I might need a few tweaks for the threshold below.

The 'slimey' sound on the ABBA Gold reminded me of DolbyA, but never seriously tried it.   Did some tweaking, and found the formula:

On sox:  treble -3 9k 1.414q

Use the DA decoder section of the FA decoder, with a --tone=-18  (normal tapes are often --tone=-13, or -14.4 or somes -15 so, where -13 is near the bend of one of the DolbyA curves.)

Voila -- decoded ABBA Gold, not slimey sounding.   Still experimenting -- might need a few more tweaks for perfection.   I tried SuperTrouper (cut 6) and SOS (cut 10).  The vocal on SOS is a bit jarring, the intro is a bit dead sounding.  The weird electronic sound mostly on the right hand side is quite audible.   Since my DA decoder might have a minor threshold issue, there might need to be some minor tweaking of --tone.   --tone=-18 is 3dB away from -15, so that seems normal.  I'll be using it now to fine tune the DA decoder, hopefull before the release after the next one.

So, all you gotta do is do a -3dB at 9kHz, and you can hear what DolbyA sounds like.

John

1 hour ago, John Dyson said:

I kept trying to FA decode the ABBA Gold album and ended up with a mess (new FA, new DA).  I knew that the FA decoder was nearly perfect now, and the DA was also pretty close to correct.  Some aspects of DA accuracy aren't critical for FA decoding, so I might need a few tweaks for the threshold below.

 

The 'slimey' sound on the ABBA Gold reminded me of DolbyA, but never seriously tried it.   Did some tweaking, and found the formula:

 

On sox:  treble -3 9k 1.414q

Use the DA decoder section of the FA decoder, with a --tone=-18  (normal tapes are often --tone=-13, or -14.4 or somes -15 so, where -13 is near the bend of one of the DolbyA curves.)

 

Voila -- decoded ABBA Gold, not slimey sounding.   Still experimenting -- might need a few more tweaks for perfection.   I tried SuperTrouper (cut 6) and SOS (cut 10).  The vocal on SOS is a bit jarring, the intro is a bit dead sounding.  The weird electronic sound mostly on the right hand side is quite audible.   Since my DA decoder might have a minor threshold issue, there might need to be some minor tweaking of --tone.   --tone=-18 is 3dB away from -15, so that seems normal.  I'll be using it now to fine tune the DA decoder, hopefull before the release after the next one.

 

So, all you gotta do is do a -3dB at 9kHz, and you can hear what DolbyA sounds like.

 

John

 

PS -- my EQ numbers were wrong.  It is still DolbyA, but the EQ should be a little more downward.  My hearing is not very reliable WRT HF.   If anyone wants the actual EQ numbers, let me know.   I screw up EQ ALL of the time...  Sorry about this.  I don't want to pollute this forum unnecessarily.