PR99 Levels

[Linnovice]

Hi all, I have a Revox PR99 MkII which in recent months which has been giving me some odd problems with dropped channels and an inability to record. Last week I decided to bite the bullet and completely re cap it. It now works and sounds absolutely beautiful. It's clear, sharp, responsive and sounds great. But (and there's always a but) I've found that when playing tapes recorded on my Studer the output levels are quite high. The VU needles bounce off the end of the scale (+3dB or more) and the peak level lights are on virtually all the time.
Now, it records and plays its own material perfectly. ie. If I record from CD, Vinyl, tuner all is well. What goes in matches what comes out perfectly. I defy anyone to tell the difference in level or quality and the recordings that I have made with the Studer play equally as good but just appear about 5dB +/- hotter but without any distortion. The Studer has recently been set up by an experienced sound engineer so I know there is not a problem with it. So, my question is. What would cause this kind of variation and is it something I should just live with and not worry about?
The Studer is fed by a Tascam M30 mixer (which has been set up perfectly to spec) from Tuner and/or sources from the Internet. The PR99 is part of my 'listening' system (along with a Tascam 42b/34b) which are fed by a Linn Kairn/Karik/Kudos combination.
Any suggestions (preferably polite &#128540?
Mike

[Michael Maurice]

See if you can borrow an alignment tape from someone, and set up the playback levels and VU meters using that.

[TIMTAPE]

Unlike digital recording, with analog tape there is no clearly defined point at which the signal goes from undistorted to distorted (clipping). It goes from less distorted to more distorted! The distortion also varies depending on the tape type and the record bias level. So tape machines can be set up for different levels of record "magnetisation" of the tape. It depends on the tape type, and the recording trade offs you want such as noise versus distortion.

In a professional situation normally 0 db on the VU meter refers to a voltage matched to the other equipment connnected to it so that levels are compatible throughout the system. But machines can still be set up for different levels on the actual tape even though the level at the machine's output and on the VU meter remain the same.

Sounds like the tech set your Studer up for a higher level than your Revox, probably consistent with modern tapes which can output that higher level. These things are not necessarily fixed in stone. In your case it would probably be best to have the two machines calibrated to the same tape level reference, but it's more critical for recording. For just playing back, the recording is "what it is" and what a VU meter is doing is irrelevent so long as there is no distortion/overload in the machine's replay chain.

Tim

[Linnovice]

Hi, thanks for the responses and advice. When I set up,the PR99 I followed the manual and set the input levels as prescribed 1kHz 0.775V 0dB the repro levels from a reference tape calibrated to 250nWb 0dB and set the recording level to match, ie. Switching from input to tape with no change in signal whatsoever. All with perfect results as a stand alone deck.
I spoke to the Technician and he couldn't remember the flux level he used but recommended dropping the repro on the PR99 by -4dB. I tried that and it works with the Studer tapes but throws everything else out when recording from my Linn system.
At the end of the day I think it's something I will have to live with. The sound reproduced is very good either by the PR99 or the Studer. Just slightly disconcerting seeing the VU meters bouncing right over. M.

[Linnovice]

Hi all. I've decided to bite the bullet and attempt to realign my Studer. I'm lucky in that there is two setups available for different tape specs so I can leave one as is without completely mucking up the settings.
I notice that there doesn't appear to be any method is setting the line in level. I think I'm right in saying that I set the repro level from the reference tape and then adjust everything from that. Someone please tell me if that's wrong. I'm struggling to make sense of the manual as it assumes that a technician will be doing the work. Not dumbo here. I found that if I set my generator at the specified 1kHz 0.775V 0dB (that's also what I get from the reference tape so I know the repro level from tape is good) and feed the inputs with it the millivolt meter was overloaded (on the 1V scale the needle is stuck of the scale) I've tried attenuating the signal by 20dB but it's still a bit much. Can anyone guide me where/what the signal strength should be please? M.

[mitajohn]

What's the model of the Studer machine?

[Linnovice]

Hi John, the model is an A807. I realised a while after making the post that the reason my levels were so high. I'd moved the jumpers on the audio boards to reduce the output levels on tape. If I now reduce the signal generator by 14dB all falls into spec.

[Restoration73]

Surely the useful indicator is the peak LED, rather than the VU meter. Often it is
acceptable to drive the VU to +6 with a good tape, there is no need for Dolby
and a high saturation is required, even more so at 15 ips.
If you install a PPM in your system this is a better indicator.
When hi-fi states the 0.1% distortion is ideal for an amplifier, it is normal to accept 1%
for a tape recording !

[Linnovice]

I get your point but I think there is a little confusion. My Studer is an ex BBC Bush House machine with Bauch audio cards but no meters or peak level lights. I use a standard tone generator and an ac Millivolt meter to set the levels. I have to say that actually getting my head around the aligning and calibrating of the machine has improved things no end. The machine has the facility of two tape calibration circuits. I have one set permanently on Maxell XL1 (which I have a good stock of) and the other I adjust according to whatever tape I have to hand. As all the setting is from the counter keyboard it's an absolute breeze just to calibrate. I'm getting some unbelievably good recordings. So it's back to the small (?) Scotch and happy ears.�� The only down side is if I listen to recordings I've made previously I sit there thinking '******' I'll have to rerecord that ��. M.