Hello, Richard,

This is off list.  I read your post with great interest, and I hope you
will do the paper about azimuth, which I believe will prove to be a very
valuable resource.

I bought Izotope RX3 Advanced a few months ago, based on your
recommendation and that of others, and it never stops amazing me, as I get
more skilled with it.  It is really fantastic in many respects, and I can
get results with it, on removing noise (in various ways), that I could
never achieve before.  So thanks very much for your good recommendation on

Your email to the list mentioned an azimuth compensation feature in Izotope
RX3, but I haven't found that yet!  Could you tell me where it is?

John Haley

On Wed, Sep 10, 2014 at 10:25 AM, Richard L. Hess <[log in to unmask]>

> Hi, Andrew and Tom,
> I am (very) slowly working towards a paper on azimuth.
> The full-track mono tape is, of course, the hardest to play from an
> azimuth perspective (of the common formats)--I hate to think about the
> 1-inch two-track!
> Transport guidance is a huge issue and I have found that the Studer A80 is
> magical in that regard--and the Studer A810, not so much. The Sony APR-5000
> is between the two.
> For those of us who have taught ourselves how to adjust azimuth by ear
> (sort of the same thing as focusing a camera lens in many ways), we do not
> need crutches, but I have come to realize that using a two-track head for
> "factory workers" might be beneficial.
> For one project I proposed (but we chose not to implement) a wide/narrow
> head for full track mono. We batted around a few different
> configurations--including a long discussion with Greg Orton. I was thinking
> of something like 0.120 and 0.04. The nice thing is even if things go
> south, you still have a good percentage of the highs on the 0.04 track,
> albeit noisy.
> With that said, for oral history cassettes, I use, in addition to manual
> azimuth adjustment, the azimuth compensation feature of
> This allows excellent channel summing for improved noise, assuming both
> channels were recorded.
> There is a similar feature in iZotope RX Advanced.
> Cheers,
> Richard
> On 2014-09-10 7:51 AM, Tom Fine wrote:
>> Hi Andrew:
>> It's interestng you bring up this topic. I was just reading the book
>> that comes with the new Beatles In Mono LP box and they talk
>> specifically about azimuth on the full-track tapes. Despite the fact
>> that these mono masters were made in-house at Abbey Road, most of them
>> on the same machines, the mastering engineer said he had to adjust
>> azimuth on the fly as records were being cut, especially with the later
>> albums where mono mixes were done days or months apart. His point was,
>> azimuth was specific to each track on some albums. He had made notes and
>> used a gauge-based azimuth adjustment on his Studer A80 playback deck,
>> so he was able to make precise tweaks as the tape rolled between cuts,
>> according to the book text.
>> I was taught, with full-track azimuth, that you really have to adjust to
>> ear, how the top end sounds best. Keep in mind that time-damaged tapes
>> and poorly slit tapes will likely "country lane" through the transport
>> and wreak havoc with azimuth. Adjusting tones at the head of the
>> full-track tape (when they exist) is somewhat helpful, but ears need to
>> be the final judge.
>> Azimuth is a tricky thing and I'm still learning about it after 40 years
>> of playing tapes. What I have learned is that it's really critical to
>> solve the azimuth puzzle in the analog domain because problems can't be
>> satisfactorily fixed in the digital domain.
>> For old full-track tapes, I am curious about using the center two tracks
>> of a 4-track quarter-inch machine. I haven't done much with this, but
>> when there are tones on the tape, you can get a scientific azimuth
>> adjust with a scope. Many old tapes are edge-damaged and I wonder if
>> it's better not to play the outer edges of the tape. However, the
>> effects of country-laning may be even worse if you're grabbing two
>> narrow bands of signal and either combining them or not.
>> If you want to hear a prime example of azimuth issues, get a copy of the
>> "Sun Records Greatest Hits" LP that was sold on Record Store Day this
>> year. The tapes were clearly and audibly played back with a 2-track head
>> and either were in such poor shape that they couldn't go through the
>> transport correctly or the playback engineer was inept. In any case,
>> with many of the songs, if you combine them to mono, they flange, "phase
>> effect" and go in and out of treble cancellation, telltale signs of
>> being played out of azimuth. If you listen on a stereo cartridge and
>> don't combine to mono, it's not as bad, it just sounds like bad
>> edge-warp. I think it was inept playback all around, but I've never
>> handled the tapes. I do bet that they'd sound better if played back
>> either through a narrow-width single head capturing the middle 1/2 of
>> the tape height or with the middle two tracks of a 4-track quarter-inch
>> head with azimuth constantly monitored on a scope and tuned to ear.
>> By the way, even with the less than ideal playback and remastering, the
>> tunes on that Sun LP jump right out the speakers, still hot and rockin'
>> to this day.
>> -- Tom Fine
>> ----- Original Message ----- From: "Andrew Dapuzzo" <[log in to unmask]
>> >
>> To: <[log in to unmask]>
>> Sent: Wednesday, September 10, 2014 7:34 AM
>> Subject: Re: [ARSCLIST] recording "cleanup" plugins and 192/24
>>  While I understand the importance of capturing output "above 20kHz" with
>>> the aforementioned tools, are there any tools available to help with
>>> azimuth adjustments?  Older recordings, especially those made in the
>>> field
>>> with machines that have been "banged up", may be recorded with azimuth
>>> that
>>> is slightly off.  Therefore, the higher frequencies may be lost or
>>> diminished if playback is not adjusted to the exact azimuth of the
>>> original
>>> recording.  Is the only tool available our ears listening as we manually
>>> adjust the azimuth?
>>> On Fri, Aug 29, 2014 at 6:18 PM, John K. Chester <[log in to unmask]>
>>> wrote:
>>>  At 04:49 PM 8/29/2014, Tom Fine wrote:
>>>>  John, is there a modification for to remove those noises? Do 3rd party
>>>>> electronics also carry those noises or are they something with the
>>>>> power
>>>>> rails under the transport? Sorry if these are ignorant questions,
>>>>> I'm not
>>>>> that familiar with the innards of ATR's.
>>>> I suspect this is neither the list nor the proper subject heading for
>>>> discussing such a highly technical issue, but here's a brief answer:
>>>> I have never tried to clean up an ATR with stock electronics, although I
>>>> have a good idea of where to start.  I have no data on 3rd party
>>>> electronics other than Plangent's.  When I got the Plangent
>>>> electronics to
>>>> be clean enough for our purposes, I stopped worrying about the problem.
>>>> Plangent does use a preamp in the headblock with a cable running
>>>> directly
>>>> to our box, which helps keep things clean.
>>>> I do find it a bit odd that folks doing 192k transfers often don't
>>>> seem to
>>>> worry about how much signal gets from the tape to the tape machine
>>>> output
>>>> above 20 kHz, and how much noise in that region comes from the machine
>>>> rather than the tape.  There are useful signals up there, and we know
>>>> that
>>>> if the transfer captures them they can later be used to improve the
>>>> quality
>>>> of the audio below 20 kHz that we can actually hear.
>>>> -- John Chester
>>>>  ----- Original Message ----- From: "John K. Chester" <[log in to unmask]>
>>>>> To: <[log in to unmask]>
>>>>> Sent: Friday, August 29, 2014 4:33 PM
>>>>> Subject: Re: [ARSCLIST] recording "cleanup" plugins and 192/24
>>>>>  At 05:06 PM 8/29/2014, Shai Drori wrote:
>>>>>>  So if I turn the display off the 28.8 kHz goes away?
>>>>>> No, that noise on an ATR is actually coming from the reel motor
>>>>>> drivers.  The display generates other noise which starts somewhere
>>>>>> in the
>>>>>> mid-50's of kHz and has lots of harmonics.
>>>>>> Turning off the display removes a lot of the noise spikes in the audio
>>>>>> output but not all of them.
>>>>>> -- John Chester
>>  --
> Richard L. Hess                   email: [log in to unmask]
> Aurora, Ontario, Canada                             647 479 2800
> Quality tape transfers -- even from hard-to-play tapes.