Thanks for the detail on U-he.  
Melissa. 

> On Jun 4, 2018, at 11:35 AM, Melissa Widzinski <[log in to unmask]> wrote:
> 
> There's a u-he forum that had this helpful info about the five types of NR.
> This info comes from the Satin manual. No Dolby C, unfortunately.
> ---
> No tape machine plugin should be without a noise reduction encoder/decoder!
> You can use these purely as coloration effects, or for decoding old
> cassettes (for instance) that have been recorded with noise reduction
> switched on. Satin includes five different types - all models of well-known
> hardware (or parts thereof), despite the "obscured" names...
> 
> A-Type
> First implemented in early professional video recorders, this type also
> became the noise reduction standard for multitrack tape and, to a lesser
> extent, optical movie soundtracks. A-Type processes four different
> frequency bands, with the two higher bands overlapping so that typical tape
> hiss frequencies are companded more strongly. The A-Type typically provides
> about 12 dB of noise reduction (A-weighted).
> 
> A-Type Mod
> This type mimics the 'Cat-22' modification that was popular among users of
> the original A-type hardware from the early 70s. All four bands were
> realized on a single card, and the signal that was added to (or subtracted
> from) the main path was mixed via four resistors. By simply cutting or
> desoldering the resistors of bands 1 and 2, only the treble bands remained
> active, resulting in the very 'airy' sound heard on numerous hit records.
> A-Type Mod works especially well with vocals, acoustic guitars or anything
> that would benefit from a very 'up-font' and bright top end without
> sounding harsh or shrill.
> 
> B-Type
> This was added to countless consumer products, for instance pre-recorded
> compact cassette tapes. B-Type is a single-band system that only processes
> high frequencies. With its relatively mild compansion, B-Type typically
> provides about 9 dB of noise reduction (A-weighted).
> 
> uhx Type I
> This 2:1 broadband compander was meant for professional systems using tape
> with a signal-tonoise ratio of at least 60 dB, and a relatively flat (+/-3
> dB) frequency response within a range of at least 30 Hz to 15 kHz.
> 
> uhx Type II
> This related method was destined for the cheaper, more noisy consumer media
> with a much more restricted frequency response. Type II rolls off high and
> low frequencies in the control signal path (the sound isn't affected) to
> desensitize the system to frequency response errors.
> ---
> 
>> On Mon, Jun 4, 2018 at 1:18 PM, Gary A. Galo <[log in to unmask]> wrote:
>> 
>> Hi Richard & John,
>> 
>> The U-He Satin web site now says they're doing "5 popular" NR systems, so
>> I wonder if they've added Dolby C. What do they call the various systems,
>> if they're not using the trademarked names?
>> 
>> The dbx I and II units are all built around single-ended, discrete
>> transistor circuits, which will certainly add low-order THD compared to
>> full-complementary topologies. So, I think you're right regarding where the
>> "warmth" is coming from.
>> 
>> I hope my Dolby A (360) units continue to work for a long time to come!
>> 
>> Best,
>> Gary
>> 
>> ____________________________
>> 
>> Gary Galo
>> Audio Engineer Emeritus
>> The Crane School of Music
>> SUNY at Potsdam, NY 13676
>> 
>> "Great art presupposes the alert mind of the educated listener."
>> Arnold Schoenberg
>> 
>> "A true artist doesn't want to be admired, he wants to be believed."
>> Igor Markevitch
>> 
>> -----Original Message-----
>> From: Association for Recorded Sound Discussion List [mailto:
>> [log in to unmask]] On Behalf Of Richard L. Hess
>> Sent: Monday, June 04, 2018 12:46 PM
>> To: [log in to unmask]
>> Subject: Re: [ARSCLIST] Noise Reduction Companders (was: question about
>> baking cassette tapes)
>> 
>> Hi, John and Gary (and Listmembers),
>> 
>> Yes, U-He Satin does four flavours of noise reduction. None of them are
>> called what they are because of copyright/trademark restrictions
>> outliving patent restrictions.
>> 
>> These are equivalent to:
>> 
>> DBX I, DBX II, DOLBY A, and DOLBY B.
>> 
>> I have not evaluated DBX II or DOLBY B to any significant extent.
>> 
>> U-He's DBX I is very close to a hardware decode, but the client thought
>> that the hardware decode was "warmer." My take on it now is that the
>> warmth in the hardware decoder is potentially additional distortions.
>> 
>> The U-He DOLBY A decode, while initially exciting is not good. It showed
>> the way towards eliminating some of the darkness (loss of
>> brightness/highs) that the Dolby hardware decoders seem to add to
>> certain dynamic regions. It is possible to come much closer in software
>> than U-He.
>> 
>> --------------
>> 
>> I do not use the DOLBY B U-He plug in because I have multiple Dolby 422
>> units (currently only one wired in the rack). What I have found is that
>> I can better adjust Dolby B by having one hand on the output knob of the
>> Dragon and one hand on the studio monitor level control...keeping the
>> levels constant and listening for minimum pumping on the Dolby B
>> decode...in real time with a hardware decode. I then record two stereo
>> files: Raw and decoded.
>> 
>> --------------
>> 
>> I have never seriously used dbx for recording. I bought an early model
>> 124 and tried it out at my sideline gig of recording the St. Thomas
>> Church (Fifth Avenue, NY City) choir of men and boys (and organ) for one
>> concert (alongside a Dolby B recording). I still have the unit, but it
>> only got used for one or two spoken word things down the road.
>> 
>> The sharp attack of the boys' singing on certain pieces caused the dbx
>> II to behave horribly. I ultimately bought a pair of 361s from George
>> Schowerer (which I also still have).
>> 
>> -------------
>> 
>> Long term, I believe software decoders are more sustainable than
>> hardware decoders, especially considering the proprietary nature of the
>> "select on test" resistors and such.
>> 
>> I hope there will be a better Dolby A SW decoder available. One of the
>> challenges is how far to go to eliminate the artifacts of the gain
>> riding within the decoder.
>> 
>> Since I changed the subject, I left the thread intact below.
>> 
>> Cheers,
>> 
>> Richard
>> 
>> 
>>> On 2018-06-03 4:59 PM, John Haley wrote:
>>> Gary, yes U-He Satin will decode dbx--but I am not sure about dbx-II.
>>> Satin has to call it something else, and I will have to look at the
>> program
>>> to see what they are calling it, but it is just dbx.
>>> 
>>> If Richard Hess sees this--what about dbx II, Richard?  Does U-He Stain
>>> decode that?  I have not seen that.
>>> 
>>> As you know, live music recorded on cassettes is very often problematic!
>>>  I have a good many important live concerts recorded on them with no
>> other
>>> source.  From a restoration viewpoint, cassettes can be real disasters,
>> but
>>> the Nak Dragon helps that.
>>> 
>>> I used dbx years ago but never for cassettes.  And you will recall that
>>> there were LPs that were encoded with dbx.  You needed a decoder and they
>>> never caught on much.
>>> 
>>> The problem with making recordings with dbx was always that there could
>> be
>>> a bit of audible pumping.  Usually it wasn't a big deal, but it could be,
>>> depending on what was being recorded-- whether the noise was being masked
>>> by the content.  Dolby B and C were better in this regard (noise
>> pumping),
>>> when they were working right.  Dolby NR was not nearly compatible enough
>>> from one machine to the next.  dbx was thought to be better with respect
>> to
>>> compatibility.  At least that was the common belief at the time.
>>> 
>>> You may recall that when VHS machines with the matrixed Hi-Fi sound (as
>>> opposed to the mono edgetrack) first became available, they were very
>> good
>>> to use as just tape recorders for music, although you needed a machine
>> with
>>> defeatable automatic level control (ALC).  You could copy CD's, which
>> were
>>> still fairly new then, and the results were fairly close to the sound of
>>> the CD, with great frequency response and dynamic range.  I was always
>> told
>>> that the noise reduction used to get that good result was nothing but
>> dbx,
>>> although they called it something different.  It worked very well for VHS
>>> tapes, at all three speeds.  As I recall the sound was FM modulated.
>>> 
>>> The advent of digital recordings caused all of these various noise
>>> reduction complications to vanish.  That is all fine with me--they are
>> not
>>> missed.
>>> 
>>> Best,
>>> John
>>> 
>>> 
>>> Best,
>>> John Haley
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
>>>> On Sun, Jun 3, 2018 at 3:20 PM, Gary A. Galo <[log in to unmask]> wrote:
>>>> 
>>>> Hi John,
>>>> 
>>>> Sounds like you're making the best of a BAAAD situation (which cassettes
>>>> invariably are). Have you dubbed any cassettes with dbx II  noise
>>>> reduction? In my view, dbx II was a huge mistake for cassettes. dbx was
>>>> very sensitive to errors in playback frequency response. Cassettes made
>>>> with dbx II would often sound fine played back on the same machine they
>>>> were recorded on. But, when you moved them to another playback machine,
>>>> they would pump and breathe and otherwise sound lousy. Does U-He Satin
>> do
>>>> dbx NR? If so, how well does it work?
>>>> 
>>>> dbx I was made for fast speed reel-to-reel recording - usually 15-ips.
>> It
>>>> extended the high-frequency boosts in record up to the top end of the
>>>> audible spectrum, so accurate machine alignment was necessary for proper
>>>> high-frequency tracking in playback. I used it successfully at 7.5-ips,
>> but
>>>> you had to really make sure your machine was properly aligned.
>>>> 
>>>> dbx II was intended for slower-speed reel-to-reel recording, usually
>>>> 7.5-ips, and it would work OK at 3.75. The HF boost in record was
>> limited
>>>> to, as I recall, around 10 kHz, so it wasn't as sensitive to
>> high-frequency
>>>> alignment in playback; it more forgiving of frequency response errors in
>>>> the top octave. But, it was never intended for cassettes, and should
>> never
>>>> have been used on them.
>>>> 
>>>> Best,
>>>> Gary
>>>> 
>>>> ____________________________
>>>> 
>>>> Gary Galo
>>>> Audio Engineer Emeritus
>>>> The Crane School of Music
>>>> SUNY at Potsdam, NY 13676
>>>> 
>>>> "Great art presupposes the alert mind of the educated listener."
>>>> Arnold Schoenberg
>>>> 
>>>> "A true artist doesn't want to be admired, he wants to be believed."
>>>> Igor Markevitch
>>>> 
>>>> 
>>>> -----Original Message-----
>>>> From: Association for Recorded Sound Discussion List [mailto:
>>>> [log in to unmask]] On Behalf Of John Haley
>>>> Sent: Sunday, June 03, 2018 3:05 PM
>>>> To: [log in to unmask]
>>>> Subject: Re: [ARSCLIST] question about baking cassette tapes
>>>> 
>>>> I second the suggestion of getting a NAK Dragon for serious dubbing of
>>>> cassettes.  I bought one a few months ago, and it has completely changed
>>>> what I can get out of a lousy old cassette (which refers to most of
>> them).
>>>> And I used a nice TASCAM deck before that.  I could adjust the azimuth
>> on
>>>> the TASCAM and always did that, but it's not much fun.  Adjusting the
>>>> azimuth is essential for music cassettes.
>>>> 
>>>> I really love using the NAK Dragon.  It will play cassettes that won't
>> play
>>>> on other machines--the double capstan system is great.  In many older
>>>> cassettes, the foam pressure pad that is supposed to press the tape
>> against
>>>> the head has fallen off--that's no problem in the Dragon.
>>>> 
>>>> The Dragon has one drawback--no speed control.  If a cassette is off
>> pitch
>>>> (and plenty of them are--the old machines, even expensive ones, were
>>>> notoriously inexact on the speed, which matters a lot for a tape that is
>>>> moving at only 1 7/8 IPS), and if that cassette is also Dolbyized, you
>> need
>>>> to dub it with Dolby off, correct the pitch on the computer in the
>> digital
>>>> domain, and then apply Dolby NR with software.  U-He Satin is a good
>>>> program choice for doing that.
>>>> 
>>>> Best,
>>>> John Haley
>>>> 
>>>> 
>>>> 
>>>> On Sun, Jun 3, 2018 at 12:14 PM, Dan Gediman <[log in to unmask]>
>> wrote:
>>>> 
>>>>> Folks,
>>>>> 
>>>>> I can’t thank you all enough for your thorough and very helpful
>>>>> suggestions about dealing with cassette tapes. I am reassured that old
>>>>> cassettes generally have fewer problems than RTR tapes of the same
>>>> vintage.
>>>>> It seems like having a playback deck with an azimuth adjustment and
>> some
>>>>> empty shells available to rehouse troublesome tapes are the most
>>>> important.
>>>>> My primary deck is a portable Sony D5M which I used for years as my
>> main
>>>>> deck for field recording, and have generally used it to play back
>> tapes I
>>>>> have recorded. I also have another Sony deck in my studio. But I am
>>>>> entirely open to investing in one of the Nakamichi decks that have been
>>>>> suggested for both the dual capstan and azimuth adjustment.
>>>>> 
>>>>> Thanks again for all your good counsel!
>>>>> 
>>>>> Best,
>>>>> Dan
>>>>> 
>>>>> Dan Gediman
>>>>> [log in to unmask]
>>>>> 502.299.2565
>>>>> 
>>>>>> On Jun 3, 2018, at 12:00 AM, ARSCLIST automatic digest system <
>>>>> [log in to unmask]> wrote:
>>>>>> 
>>>>>> There is 1 message totaling 19 lines in this issue.
>>>>>> 
>>>>>> Topics of the day:
>>>>>> 
>>>>>>  1. Question about baking cassette audio tapes
>>>>>> 
>>>>>> ------------------------------------------------------------
>> ----------
>>>>>> 
>>>>>> Date:    Sat, 2 Jun 2018 00:28:11 -0400
>>>>>> From:    Jeff Willens <[log in to unmask]>
>>>>>> Subject: Re: Question about baking cassette audio tapes
>>>>>> 
>>>>>> What Peter said.
>>>>>> 
>>>>>> There are a very few brands of cassettes that do indeed shed, and can
>>>>> benefit from a limited amount of baking time. I’m dealing with several
>>>>> boxes of them right now. But before doing that, I would check to see if
>>>>> rehousing them in new shells would help first. These tapes did not
>>>> squeal.
>>>>> They just flat out didn’t move. Some needed a better tape path. Some
>>>> needed
>>>>> baking. But itis generally less common than for RTR tapes.
>>>>>> 
>>>>>> ------------------------------
>>>>>> 
>>>>>> End of ARSCLIST Digest - 1 Jun 2018 to 2 Jun 2018 (#2018-116)
>>>>>> *************************************************************
>>>>> 
>>>> 
>>> 
>> --
>> Richard L. Hess                   email: [log in to unmask]
>> Aurora, Ontario, Canada                             647 479 2800
>> http://www.richardhess.com/tape/contact.htm
>> Quality tape transfers -- even from hard-to-play tapes.
>> 
> 
> 
> 
> -- 
> Melissa Widzinski
> Audio Preservation Engineer
> Media Digitization and Preservation Initiative <https://mdpi.iu.edu/>
> Indiana University