High speed cassette transport

[Amy Linari]

I'm trying to put together a solution to replace a poor performing and
rather expensive solution (~$9000 for 2 duplicators and 1 card) that
uses a Sony CCP-1300 and the Telex EDAT Zing A/D card. The card is
sampling at 352.8khz and with the playback at 30ips (16x) it provides
a frequency response to about 11khz, which is more than is really
usable out of the duplicator anyway. The card has a suprisingly low
noise floor of approx -54db, which of course means marginal SNR for
cassettes.

The content to be digitized is always speech, but the quality of the
tapes is quite variable. No more than a very slight loss in
intelligibility and noise floor can be tolerated in the process, as
tapes often need heavy compression and eq to be usable.

I'm considering switching to 15ips playback and using a 192khz/24bit
audio interface. The biggest stumbling block is a lack of appropriate
cassette tape transports for that speed and frequency range. Since
this is a high volume operation with multiple tapes will be running at
the same time to meet volume requirements) I'm trying to come up with
a solution that is more cost effective than duplicators and zing card
and who's control signals can be interfaced with the PC.

Does anyone out there have any guidance on how to get the performance
I'm looking for? Should I start with an 8X duplicator? Some of the 1:1
models are pretty inexpensive (~$500) but I need a better SNR and I
would need to hack the controls in, which is definatly an option. Can
I do a head and amplifier replacement to bring it up to spec for a
reasonable price? I'm looking to extract as much SNR as the tape
provides, or very close to it, I'm thinking within 3db at worst. The
duplicators that deliver that are all in the same price range as I'm
using now, and $2500-3000 seems really excessive for a machine that
only gets used for playback.

Thanks,
- Amy Linari

[Scott Dorsey]

Amy Linari > wrote:
>
>I'm considering switching to 15ips playback and using a 192khz/24bit
>audio interface. The biggest stumbling block is a lack of appropriate
>cassette tape transports for that speed and frequency range. Since
>this is a high volume operation with multiple tapes will be running at
>the same time to meet volume requirements) I'm trying to come up with
>a solution that is more cost effective than duplicators and zing card
>and who's control signals can be interfaced with the PC.

It should not be too hard to hack the existing Sony transports to run
at 15 ips. I am assuming that the existing transports are intended
for duplicator service and therefore have no de-emphasis networks in
them that need to be tampered with, so it would just be a matter of
fiddling with the motor control PLL to run at half speed.

You might also look into the Tascam duplicator transports.

The horribly overpriced KABA transports are rebadged from a large
Japanese manufacturer but are now showing up used for reasonable prices.
Watch out, though, since some of them have outrageous amounts of wear
on them.

>Does anyone out there have any guidance on how to get the performance
>I'm looking for? Should I start with an 8X duplicator? Some of the 1:1
>models are pretty inexpensive (~$500) but I need a better SNR and I
>would need to hack the controls in, which is definatly an option. Can
>I do a head and amplifier replacement to bring it up to spec for a
>reasonable price? I'm looking to extract as much SNR as the tape
>provides, or very close to it, I'm thinking within 3db at worst. The
>duplicators that deliver that are all in the same price range as I'm
>using now, and $2500-3000 seems really excessive for a machine that
>only gets used for playback.

I'd try running the existing ones at half speed, and also checking the
head condition very carefully. Those heads wear out very quickly and
the end result is poor high end response.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Scott Dorsey]

Amy Linari > wrote:
>
>I'm considering switching to 15ips playback and using a 192khz/24bit
>audio interface. The biggest stumbling block is a lack of appropriate
>cassette tape transports for that speed and frequency range. Since
>this is a high volume operation with multiple tapes will be running at
>the same time to meet volume requirements) I'm trying to come up with
>a solution that is more cost effective than duplicators and zing card
>and who's control signals can be interfaced with the PC.

It should not be too hard to hack the existing Sony transports to run
at 15 ips. I am assuming that the existing transports are intended
for duplicator service and therefore have no de-emphasis networks in
them that need to be tampered with, so it would just be a matter of
fiddling with the motor control PLL to run at half speed.

You might also look into the Tascam duplicator transports.

The horribly overpriced KABA transports are rebadged from a large
Japanese manufacturer but are now showing up used for reasonable prices.
Watch out, though, since some of them have outrageous amounts of wear
on them.

>Does anyone out there have any guidance on how to get the performance
>I'm looking for? Should I start with an 8X duplicator? Some of the 1:1
>models are pretty inexpensive (~$500) but I need a better SNR and I
>would need to hack the controls in, which is definatly an option. Can
>I do a head and amplifier replacement to bring it up to spec for a
>reasonable price? I'm looking to extract as much SNR as the tape
>provides, or very close to it, I'm thinking within 3db at worst. The
>duplicators that deliver that are all in the same price range as I'm
>using now, and $2500-3000 seems really excessive for a machine that
>only gets used for playback.

I'd try running the existing ones at half speed, and also checking the
head condition very carefully. Those heads wear out very quickly and
the end result is poor high end response.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."