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
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
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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