Below is a link to an F1 manual that illustrates the differences between the
14-bit and 16-bit formats:
As you can see, the 16-bit format has one error correction word: "P" - while
the 14-bit has tow "P" & "Q"
Earlier in the manual, they talk about the fact that a 16 horizontal line
burst-error can be accommodated in 16-bit - and 32 H lines in 14-bit.
In terms of correcting channel delay - IMHO: yes!
(Ask any mastering engineer.)
Rob Poretti - Sales Engineer - Archiving
Cube-Tec North America LLC
Vox.905.827.0741 Fax.905.901.9996 Cel.905.510.6785
From: Association for Recorded Sound Discussion List
[mailto:[log in to unmask]] On Behalf Of Matthew Sohn
Sent: December 12, 2014 12:19 AM
To: [log in to unmask]
Subject: Re: [ARSCLIST] Sony 601-esd pcm audiio processor decoder
John, thank you for your detailed answer. My few experiences with F-1 tapes
have been nightmarish. Everything is fine, until you hit that one spot where
it just won't track..I applied the skew method. twist the knob left or right
until the lights look good, remember where you started, and do it again for
real. When it works, it sounds great, when it doesn't... Ugh..
On Thursday, December 11, 2014 10:10 PM, John Gledhill <[log in to unmask]>
o The tape are recorded in the 14 bit mode with TOSHIBA DX-900. They
actually have FM tracks of the same material
o I am capturing both the FM and PCM
To David Glasser
o I understand re the sample rate.
o live performance recordings - 6 hours per tape
I have the 14 bit recovery working well with the EP tapes and have a solid
right green on (or flashing) MOST of the time.
I just wanted to know the significance of the LEDs
I actually record a new tape through the coax in from a CD player to the
601-esd (16 bit) , and then played the tape back and captured through spdif
to compare the waveforms. I think the the 601 saturates slightly before
0x7ffff (around 0x7fef) but the lower values were a bit for bit match.
To Rob Poretti
o I agree re the 14 bit versus the 16 bit - if the 601-esd does not like
the VCR then more error correction will win.
o However, from watching the screen it is no 1 party bit versus two parity
I think all of the stuff on the right hand side of the screen is error
correction data. Each line has 3 word pairs and a huge pile of ECC .
Roughly 3 * 15.75 minus the time lost during the vertical will give you the
44.056 This is also confirmed by the fact I can pop up the on-screen diiplay
from the VCR and mot hear any errors,. Like a CD the ECC is spread over tape
space = time to work around dropouts
Is it important to correct for a 1/2 sample offset. Is this not the same as
moving one speaker in a stereo pair 3mm further back.
Slightly interesting aside.
While doing my experimenting for this I tried feeding the video from a vcr
through a time base corrector to clean it up before going to the 601-esd.
Video looked much more stable on the screen but the 601-esd did not like
this arrangement and the tracking bar stayed on the left.
Perhaps it was the digital re-sampling in the TBC that cause this result.
Anyways - I am getting very clean audio back from the ep tapes and wanted to
know about the lights.
I might guess that the guy who designed the LSI to do the decoding put the
logic outputs there for his own diagnostic purposes and a bright marketing
guy said "we have left oer LEDs - lets use em" with no one really writing
down what they meant.
On 12/11/2014 7:44 PM, Tom Fine wrote:
> Hi John:
> My experience is that NO F1 decoder works well with 16-bit recordings
> made at EP speed. I also think that later VHS machines with
> auto-tracking may not align best for F1 recovery because they were
> designed to also take into account VHS-HIFI signal. A
> professional-quality VHS deck, even a late-era VHS-HIFI deck, will
> have a tracking control, but the consumer models lost the tracking
> control shortly after VHS-HIFI was developed.
> I'm curious, what sort of material are you working with and how many
> -- Tom Fine
> ----- Original Message ----- From: "John Gledhill" <[log in to unmask]>
> To: <[log in to unmask]>
> Sent: Thursday, December 11, 2014 4:45 PM
> Subject: [ARSCLIST] Sony 601-esd pcm audiio processor decoder
>> I am recovering sony F1 type audio (PCM and ECC in the video image)
>> from some VHS tapes (ep speed 6 hr per tape) - it was actually
>> recorded with a Toshiba version.
>> I have the manual for the Sony 601-esd and I think is says the boobie
>> lights (Red, FlashRed, FlashGreen, FlashGreen, SteadyGreen) is a
>> logical procession from poor signal to good signal.
>> Additionally there is a tracking indicator (bar graph moving to the
>> I can see from the schematic the LED's are driven from the decoding
>> logic (didn't really need a schematic for that one).
>> However, I an not find out at which point errors are still being
>> corrected (apparently a few red flashes are fine) and at what point I
>> can not count on the data.
>> I am recovering through the spdif -> PC.
>> I am hoping there there is a audio archivists list with somebody who
>> used these 30 years ago and thought to ask Sony exactly what was
>> being measured with the lights.
>> P.S. I found the Sony 601-esd encoder/decoder is not a good match
>> with most later model VCR's and ep tapes. (the data on the back of a
>> VCR switch disappeared years ago).
>> John Gledhill
>> BIT WORKS Inc.
>> 905 881 2733
>> [log in to unmask]
BIT WORKS Inc.
905 881 2733
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