Topic: Sony D8 recording in long play

[datman229]

I hope someone can help me.  I've always used standard play 44.1 khz when recording concerts.  I use 90 min or 120 tapes.  I'm always worried I am going to run out of tape and just dont want to go through the unload and loading process.  Would I notice much difference in quality recording in long play in a concert environment?  I use Sony ECM 101 and ECM-MS907 mics.  Any advise would be appreciated.


Cheers

datman229

[ianstone]

I hope someone can help me.  I've always used standard play 44.1 khz when recording concerts.  I use 90 min or 120 tapes.  I'm always worried I am going to run out of tape and just dont want to go through the unload and loading process.  Would I notice much difference in quality recording in long play in a concert environment?  I use Sony ECM 101 and ECM-MS907 mics.  Any advise would be appreciated.


Cheers

datman229

Yes, you would definitely notice a difference. the LP or "long play" mode on the d8 essentially switches the sampling rate to 32khz... thus, lowering the quality of the recording.

Furthermore, if you transfer the tape to the computer (digitally) and then want to burn to disc - you won't be able to unless you "upsample" to a 44.1khz file... basically when you do that, the computer program is "filling in the gaps" between 32khz and 44.1 khz, basically making that data up based on what data is already there - almost like "connecting the dots"

I wouldn't reccomend it unless in a dire situation for more tape time.

if you get the Sony or Maxell "Data DDS Dat Tapes" you can get a 90 meter tape - which is equivalent to a 180min audio dat tape... i have never been able to tell the difference between dats recorded on the data tapes vs. the 'audio' grade tapes... i believe the actual tape itself is the same.


hope this helps!
-ian

[DSatz]

Datman, the LP mode slows down the linear travel of the tape, and makes dropouts in playback quite a bit more likely to reach audible proportions. The one time I made a recording of music in the LP mode of my TCD-D7, it did have an uncorrectable drop-out at one point, with about 1/2 second of material being lost in the process.

Chances are, the same defect in the tape would have caused massive error correction or even error concealment if I'd recorded at the full tape speed, but the music probably wouldn't have been interrupted.

In terms of audio quality, I'd have no objection to a clean cutoff at 16 kHz, except in a professional situation where the recording might be issued as a commercial CD (those still exist, don't they?). But I don't remember for sure whether the LP mode of these recorders used 16-bit linear PCM at 32 kHz (which would be fine for most purposes), or a range-scaling system with fewer bits (which I'd want to test more carefully). You might check the manual to see about that.

--best regards

[ianstone]

Datman, the LP mode slows down the linear travel of the tape, and makes dropouts in playback quite a bit more likely to reach audible proportions. The one time I made a recording of music in the LP mode of my TCD-D7, it did have an uncorrectable drop-out at one point, with about 1/2 second of material being lost in the process.

Chances are, the same defect in the tape would have caused massive error correction or even error concealment if I'd recorded at the full tape speed, but the music probably wouldn't have been interrupted.

In terms of audio quality, I'd have no objection to a clean cutoff at 16 kHz, except in a professional situation where the recording might be issued as a commercial CD (those still exist, don't they?). But I don't remember for sure whether the LP mode of these recorders used 16-bit linear PCM at 32 kHz (which would be fine for most purposes), or a range-scaling system with fewer bits (which I'd want to test more carefully). You might check the manual to see about that.

--best regards

i can confirm that the LP mode used 16 bit linear PCM @ 32khz

one time i made a recording in this mode (on accident, unknowingly) and when i played the tape in my home dat deck (da20mkII) the sample rate registered as 32khz
Mine was with a d8, so it may have been different than your experience w/ the d-7, dsatz.

[DSatz]

ianstone, I also have a D8 here; I don't think that there's any difference in the LP mode of the one versus the other. It's just that the recording I made which had the audible dropout (and I never have had a similar problem with the D7 or D8 at the regular tape speed, in several hundreds of hours of recording) was made on the D7.

What I was half-remembering about slow speed recording must have been from the old Video 8mm video format, which I vaguely recall went into a scaled low-bit mode at the slower tape speed. The DAT cassette format is derived from the Video 8mm design, as is the auto-tracking system.

The half-diameter drum and the single-head design of these little portables makes dropouts rather more likely than they would be on a full-size drum with two opposing heads.

--best regards

[chrise]

i can confirm that the LP mode used 16 bit linear PCM @ 32khz

Strange - I always thought it was 12 bit @ 32khz. 

(which works out at half the data-rate of 16 bit 48khz)

[udovdh]

i can confirm that the LP mode used 16 bit linear PCM @ 32khz

Strange - I always thought it was 12 bit @ 32khz. 

(which works out at half the data-rate of 16 bit 48khz)

Indeed.
On playback it is recoded back to 16 bits.
So there's only 12 bits of actual resolution.

This does not mean that things will sound awfull but there is a degradation when coming from 16/48.

[johnmuge]

I used it once by accident on my D7 amd the recording came out bad.  I would advise against it.  You won't be happy with the results.