Dolby SR

[topoxforddoc]

One of my friends, Stewart Emmings, suggested a little while back that I buy a Dolby 363 machine with SR. I bought a pair in the UK at GBP400 for the pair. I have just lined up one of my (new to me) Dolby 363 SR/A units to my Sony APR5003 and duplicated a 15 IPS tape of Doors Morrison Hotel onto another reel of LPR35. The Dolby SR is just stunningly good - just makes this R2R experience even better. No tape hiss or noise - great dynamic range and no "muffling" like Dolby B on cassette. It makes the tape sound like a clean digital source, but with all the nice btw of analogue tape still there.

[rbbert]

There are a few albums where the master tapes were recorded using Dolby SR (although since that was well after the introduction of the CD, further mastering has almost always been done in the digital domain)

[topoxforddoc]

The original 15ips has no NR. I always duplicate the tapes I buy - this time on SR. The SR dupe is stunning - way better than the original units SQ!

[Bruce B]

I bought a Dolby SR/A unit years ago. I've probably used it a half dozen times doing tape transfers. A Pain in the A$$ to calibrate. Has yours been calibrated?

[topoxforddoc]

I bought a Dolby SR/A unit years ago. I've probably used it a half dozen times doing tape transfers. A Pain in the A$$ to calibrate. Has yours been calibrated?

Hi Bruce,

I calibrated it myself to my Sony APR5003. I bought two units, so that I can have one for both my Sony APR 5000 series machines. The set up wasn't too difficult - took about 15 minutes, once I had read the instruction manual (available on line here http://www.broadcaststore.com/pdf/mo...3_8.Manual.pdf ). I used calibrated test tones at 0 level fed out of my Macbook Air with an Alice Matchpak (unbalanced to XLR converter). The levels were monitored with my PPM meters, so that the meters read 0 level (0dBU, -4dBVU, PPM4) when calibrating the unit on record and playback. Once done, it seems to be a breeze to use.

I have about 50 x 15IPS master tapes of varying provenance (some excellent, some less so). All my "masters" have already been transferred to fresh tape stock. But I am now going back to re-do them with the Dolby SR, as the difference is astonishing. The Dolby SR duplicates actually sound better than the originals with no NR.

Best wishes,

Charlie

[rbbert]

...
The Dolby SR duplicates actually sound better than the originals with no NR.

Best wishes,

Charlie

Not really a positive attribute, and I suspect Bruce will have a pertinent comment

[topoxforddoc]

I know that my comment was a bit odd. But losing the low level tape hiss and increased dynamic range has made the listening more enjoyable. The dupes don't seem to have lost any of the subtlety and detail of the original (I had to adjust some of the replay levels slightly when reviewing the test tones on the originals).

[rbbert]

If the hiss is lower than the original, there is some (unwanted) filtering going on somewhere

[topoxforddoc]

You are probably correct, but it does sound better (at least to my ears). I listen to a lot of live music. My wife gave up her medical career and is a musician. I spend a fair bit of time photographing rock and jazz bands. 15 IPS tape w/o NR is great, but Dolby SR copies are astonishing (that word does not mean of course that what I'm hearing is better, just that I am taken aback).

[JCOConnell]

If youre dubbing tapes, the best the dubs can sound is identical to the source tapes, not better.

[topoxforddoc]

If youre dubbing tapes, the best the dubs can sound is identical to the source tapes, not better.

That's exactly what I thought, until I tried Dolby SR. My friend, who suggested this, worked at the BBC and is now one of the senior engineers at the British Film Institute, responsible for maintaining the machines (audio and video) as well as doing the digital archiving of old TV shows etc.

Both machines are lined up every time I use them. If the originals aren't quite right (levels slightly unbalanced etc), I try and correct these at the beginning by lining up the replay of my playback machine to the test tones with a set of PPM meters. But the lack of background noise and tape hiss on the Dolby SR copies is very noticeable.

I'm not an audio engineer (just a straight forward cancer surgeon), who started selling hi-fi 35 years ago. Maybe someone can explain what I'm experiencing

[JCOConnell]

a perfect recorder does not change the original signal, if dolby SR is removing tape hiss heard in the original tapes, something is wrong.

[Bruce B]

Think of it this way. A lot of people archive their vinyl collections. Most folks use some sort of declick / denoise software, but to them, it sounds better. I've never found a software that doesn't take out some of the recording, as little as it may be.
Of course it sounds different, but it can never be better than the original!!

[MylesBAstor]

a perfect recorder does not change the original signal, if dolby SR is removing tape hiss heard in the original tapes, something is wrong.

Huh? That is exactly what Dolby was built to do.

The Dolby SR (Spectral Recording) system, introduced in 1986, was the company's second professional noise reduction system. It is a much more aggressive noise reduction approach than Dolby A. It attempts to maximise the recorded signal at all times using a complex series of filters that change according to the input signal. As a result, Dolby SR is much more expensive to implement than Dolby B or C, but Dolby SR is capable of providing up to 25 dB noise reduction in the high frequency range. It is only found on professional recording equipment.^[7][8]

https://en.m.wikipedia.org/wiki/Dolby_noise-reduction_system

[astrotoy]

Think of it this way. A lot of people archive their vinyl collections. Most folks use some sort of declick / denoise software, but to them, it sounds better. I've never found a software that doesn't take out some of the recording, as little as it may be.
Of course it sounds different, but it can never be better than the original!!

Here I will disagree with Bruce. Two examples:
I bought a copy of EMI ASD255, one of the rarest and most expensive classical records - normally about 500GBP, for 4GBP. Why? It was really beat up - scratches and surface noise, even some skips. After processing through Izotope RX3 Advanced and doing some manual work for a few of the skips, the 192/24 file sounds much more than acceptable. No comparison to the original.

Second, I have recently been listening to a tape which was remastered by Bruce. He included the original unmastered versions of four of the songs for comparison. Bruce's work made subtle, but noticable improvements in the sound quality. Better than the original tape.

The great remastering engineers do this every day to both rescue tapes that have problems and improve the sound of tapes that were not that good to begin with.

Larry