Reply
 
Thread Tools Display Modes
  #1   Report Post  
Steve Puntolillo
 
Posts: n/a
Default Fostex analog multitracks @ 30 ips?

Hi --

I'm hoping someone can help me with some questions about Fostex analog
multitrack machines running at 30 ips. Some background first:

Our business is high-quality multitrack analog to digital transfers. For a
quick technical overview, please see:

http://www.sonicraft.com/a2dx/a2dx_tech.html

When we set the lab up initially, we were planning to focus exclusively on
formats where track density did not exceed 4 tracks for every 1/4" of tape
width.

Now that business is in full swing, we're learning that some very nice
projects have also been done on formats like 1/2" 16-track and 1" 24-track.
Furthermore, many of the same folks who send us work on formats like 2"
24-track also want to send us projects that used these smaller, denser
formats. So, we've started to gear up and can now transfer most of these
tapes.

Recently, we got a tape in that was done in the 1/2" 16-track format but at
30 ips. After a bit of research, I learned that the E16 Fostex machine had a
jumper on the capstan motor that would kick it up to 30 ips and that perhaps
Fostex had even issued 30 ips E16 machines.

By putting a jumper on the capstan where someone could crack the machine
open and change only the capstan speed, Fostex has created an interesting
problem for me. If a job comes in on 1/2" 16-track tape at 30 ips, I now
have to figure out whether the tape was made on:

(1) a properly modified or factory built 30 ips machine,

(2) a hot-rodded 15 ips machine (where the only change was to bump up the
capstan speed) and some attempt was made (through bias, record, and playback
re-alignment) to get a stock 15 ips IEC EQ machine to "work" at 30 ips

or

(3) a hot-rodded 15 ips machine where all that was changed was the capstan
speed jumper to make a 15 ips machine move tape at 30 ips.

I think the E16 (G16?) machines were built using either Dolby C or Dolby S
NR. So, figuring out how the tape was made gets even more critical if the 30
ips tapes were made using the machine's built-in noise reduction system.
(Yes, some people actually run 30 ips *with* noise reduction.) Stated in a
simplified way, if the playback EQ we use isn't reciprocal to the original
record EQ, the noise reduction decoding will suffer.

I'm also wondering whether or not the 1" 24-track Fostex has a similar
jumper and/or was capable of 30 ips operation from the factory.

Also, while we're here, what are the differences between the E series and G
series Fostex machines in sound quality and build quality? Which models
supported which noise reduction systems?

Are there any Fostex mavens out there who can help me out with some answers?

Thanks!

-- Steve

=================================================
Sonicraft A2DX Lab
Ultimate Multitrack Analog-to-Digital Transfers
http://www.sonicraft.com/a2dx
=================================================


  #2   Report Post  
James Perrett
 
Posts: n/a
Default

On Sun, 26 Jun 2005 18:26:08 -0400, Steve Puntolillo
wrote:


By putting a jumper on the capstan where someone could crack the machine
open and change only the capstan speed, Fostex has created an interesting
problem for me. If a job comes in on 1/2" 16-track tape at 30 ips, I now
have to figure out whether the tape was made on:

(1) a properly modified or factory built 30 ips machine,

(2) a hot-rodded 15 ips machine (where the only change was to bump up the
capstan speed) and some attempt was made (through bias, record, and
playback
re-alignment) to get a stock 15 ips IEC EQ machine to "work" at 30 ips

or

(3) a hot-rodded 15 ips machine where all that was changed was the
capstan
speed jumper to make a 15 ips machine move tape at 30 ips.

I think the E16 (G16?) machines were built using either Dolby C or Dolby
S
NR. So, figuring out how the tape was made gets even more critical if
the 30
ips tapes were made using the machine's built-in noise reduction system.
(Yes, some people actually run 30 ips *with* noise reduction.) Stated in
a
simplified way, if the playback EQ we use isn't reciprocal to the
original
record EQ, the noise reduction decoding will suffer.


It looks like you probably know as much as I do about adjusting the E
series Fostex's to work at different speeds. Do you have a service manual?
I don't remember any mention in the service manual of any component
changes for 30ips so I suspect that any changes in eq that were necessary
can be made using the standard preset pots.

E16's were Dolby C only and it would be rare to find that it wasn't used -
even at 30ips the noise would have been fairly apparent.

I'm going away for a couple of weeks at the end of this week but if you
need any info from the service manual then send me an email and I'll see
what I can do.

Cheers.

James.

Reply
Thread Tools
Display Modes

Posting Rules

Smilies are On
[IMG] code is On
HTML code is Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
on topic: we need a rec.audio.pro.ot newsgroup! Peter Larsen Pro Audio 125 July 9th 08 06:16 PM
fostex D2424LV simultaneous digital and analog recording ispossible michael cleary Pro Audio 1 October 15th 03 02:50 AM


All times are GMT +1. The time now is 04:20 PM.

Powered by: vBulletin
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 AudioBanter.com.
The comments are property of their posters.
 

About Us

"It's about Audio and hi-fi"