Better hope the tones stay with the copy, otherwise it will never decode correctly.
I was taught strictly the opposite by the late Dave Smith, who probably would know. Phase errors accumulate, tape compression effects accumulate (which is part of why some played games with the encode/decode to get a brighter playback after having unintentionally de-essed the encoded recording with the tape then wonder why it comes back dull and pumpy), head bumps, yikes.
As for 5 generations - If you want hiss pumping from the noise added by all copies then definitely add 4 generations of hiss then apply the fixed expanding algorithm on all of it. It will audibly bounce, and thatís mega-distracting.
> On Feb 9, 2016, at 11:19 AM, Rob Poretti - Cube-Tec <[log in to unmask]> wrote:
> As a mastering engineer in the early-mid 80's the practice was definitely
> not to decode Dolby for copy's. That was standard practice for all the
> label work we did - which at the time included Capitol, A&M, RCA, WEA and
> many others...
> Rob Poretti - Sales Engineer - Archiving
> Cube-Tec North America LLC
> Vox.905.827.0741 Fax.905.901.9996 Cel.905.510.6785
> -----Original Message-----
> From: Association for Recorded Sound Discussion List
> [mailto:[log in to unmask]] On Behalf Of Dave Burnham
> Sent: February 9, 2016 3:43 AM
> To: [log in to unmask]
> Subject: Re: [ARSCLIST] Playing reels backwards - separating myth from fact
> Actually back in the Dolby A days I copied many encoded tapes without
> decoding them. On decoding, the Dolby will address ALL of the hiss
> regardless of how many generations there are. There will be losses such as
> cumulative frequency response errors and compounded distortion but those
> would happen anyway, even if you decoded and encoded for every dub. If you
> don't decode/encode when you copy, you'll avoid all of the errors introduced
> by the Dolbys themselves.
> Sent from my iPhone
>> On Feb 9, 2016, at 1:09 AM, Corey Bailey <[log in to unmask]> wrote:
>> I need to remind everyone that I never made a backwards copy of an encoded
> (stretched) tape, regardless of the noise reduction employed. I was there
> when the "to decode or not decode" controversy was at it's height. My
> position was (and still is) to decode the original and re-encode the copy.
> Reason: If you make a copy of an encoded tape without decoding it, the copy
> will have baked in tape hiss that will ultimately not be affected by the
> noise reduction when applied for final playback. Thus, the copy will be
> nosier than if you decoded and re-encoded the copy.
>> Corey Bailey Audio Engineering
>>> On 2/8/2016 9:19 PM, Jeff Willens wrote:
>>> Actually, that was the one thing I always heard you could NEVER do
>>> with Dolby encoded tapes -- dub them without decoding them.
>>> I'm going back 15 years or so to remember this, but it is possible I
>>> did not decode the Dolby on some of the analog copies I made,
>>> probably for test purposes. As I said, decoding backwards was not my
>>> preferred method, but no one seemed bothered by my concerns. I did
>>> the dubs per the request of the reissue producer. If there were
>>> residual decoding artifacts, I never heard them or heard about them from
> the others involved.
>>> On Mon, 8 Feb 2016 21:23:34 -0000, Ted Kendall
>>> <[log in to unmask]> wrote:
>>>> This runs counter to my own experience. Firstly, one great benefit
>>>> of Dolby A was that straight copies of encoded tapes could be made
>>>> without decoding, provided that the reference tones were retained on
>>>> the copy, so there was no need to decode as part of the dubbing
>>>> process. Secondly, to decode a Dolby A tape on reverse play is just
>>>> plain wrong - the attack and decay chracteristics of the system are
>>>> asymmetrical, so the decoding will be wrong, no matter how much you have
> finessed the other parameters.
>>>> ----- Original Message -----
>>>> From: "Jeff Willens"<[log in to unmask]>
>>>> To:<[log in to unmask]>
>>>> Sent: Monday, February 08, 2016 1:22 PM
>>>> Subject: Re: [ARSCLIST] Playing reels backwards - separating myth
>>>> from fact
>>>> I should think the net gain depends on the type of music involved.
>>>> Back at Universal, I was asked by a producer to make 1:1 analog
>>>> copies of album masters played in reverse to be sent out for
>>>> mastering. The thinking was exactly as you describe: sharper
>>>> transients, better bass response and definition,etc. Since these
>>>> were all reggae albums from the 70s and 80s, they felt it was worth the
>>>> In my own crude testing, I found that, aside from making sure the
>>>> channels were consistent (something one can easily overlook), I also
>>>> found azimuh to be the crucial factor in achieving any success, Many
>>>> masters were Dolby encoded, which gave me much pause, but no one
>>>> else was concerned about it (I figured decoding between the two tape
> machines was the least of all evils).
>>>> Was there a difference? Hard to say. I believe there was a slightly
>>>> better result from reverse transfer, but nothing drastic. And
>>>> definitely nothing that couldn't be got with skillful use of modern
> compression and EQ.