Help with RMGI 911 Recording Levels

[Max26]

This is a beginner question about proper recording level.

I have a Technics 1500 that has been calibrated and biased for 456 tape and I am trying to record from vinyl to RMGI 911 tape at the correct level on my VU meters.

I understand that the 911 tape (and 456 for that matter) is +6 tape. Does this mean that with my machine biased as it is for 456 tape that my VU meters should be peaking at 0 on my 1500 meters or should I be able to go up to +6 on my VU meters?

If I want to record using Ampex 499 tape which is +9 and the machine stays biased for 456, where is the best level? At 0 or at +9?

Thanks very much for the help and if there is a thread somewhere about this I'd appreciate being pointed in that direction as well so I can learn more.

 

[Beck]

Short answer:

Keep the levels around 0 VU for either 456 or 911 if the machine is calibrated for 456.

Long answer:

It depends. The RS1500 is quite user configurable form the front panel…. Almost too much so. When you say biased I assume you mean calibrated. Bias, equalization curve, and flux level are all different things you can fiddle with. If the machine is calibrated to factory standards this is how it should be set for SM911 or 456:

Level switch set to +6
Bias switch set to 2
Equalization switch at 2

SM911 is bias and level compatible with 456. It was originally introduced by BASF to be compatible in reference to 456, so generally speaking you treat it just like 456. However, you can fine tune bias for any tape if you want. IMO there is too little difference in bias requirements between SM911 and 456 so I wouldn’t bother. There is really a window rather than a precise point for bias.

I’m not sure about using a +9 tape like Ampex 499 or RMGI SM900 on that machine. It depends whether the bias oscillator can be ramped up high enough to properly bias the tape. If it can then you could use it. You could burry the meters in the red with that tape and never overdue it with the machine set as is.

Personally I would use 456 and/or SM911 and forget about it.