Reference Fluxivity

[xcortes]

What's the reference fluxivity of the TP tapes? Th only reference I've found in the archives is that  on the alignment tape "the tones are going onto the tape at 250 nanoWebers/meter calibrated to 0dB on the VU meter". Can I assume that 250nW/m then?

I ask because I'm ordering some tapes and I have the option of 320nW/m or 514nW/m: "the RS1500 was originally aligned to a reference flux level of 180 nWb/m only. This level may have been upgraded to a higher level in course of a restoration/realignment. Our tapes are be made to a reference level of 320 nWb/m. They may be made to the german broadcast standard of 514 nWb/m as well which will yield an output about 3 dB higher. In the latter case the amplifier electronics should be able to sustain voltages higher than 3 Volts without noticeable distortion"

Should I want all my tapes to be similar in eq, bias and output or should I go for higher a figure for less nosie? Playback will be through an RS-1500 with flux magnetics head and Bottlehead Seduction amp, I think I have headroom for more output?

Thanks!

[Ben]

Here is the tape used PDF.
http://www.rmgi.eu/pdf/RMGI_SM_468.pdf

[xcortes]

Thanks, Ben

Yep. I'd seen that one. However, that the spec sheet for the tape specifies 320nW/m doesn't necessarily mean that's the level actually used for our TP tapes, right?

In any case if we assume it is 320nW/m my second question still remains: should I go for 514nW/m for reduced noise?

I'm pretty sure my Seduction/Foreplay combination can handle it very well. Moreover since seduction tends to err on the lowish gain side and also because the Flux Magnetics head has less sensitivity that stock but I'd like confirmation from the experts.

That leads me to a third question. If there's already that can handle 514nW/m that yields to lower noise why does TP uses lower levels? I'm sure there's an explanation here as simple as "because we like better the sound on 468 than, say, 900".

[Ben]

Off hand I would assume 320nW/m since that is what my OTARI MX-5050 is
set for for ICE 7 1/2 IPS.

[reelnut]

Hi Xavier-

Reference fluxivity is a signal of known and standardized magnetic magnitude which is used to calibrate the gain of the reproducer so that program level meters (VU or PPM) read some standard level, usually 0db. The recorder will be calibrated to record this same fluxivity. Thus, reference fluxivity is used indirectly to set the levels recorded on tape.

So knowing what reference flux the recording engineers at TP use has no bearing on how the tape plays back on our machines, and isn't a value that we need to consider. You and I can rest assured that the brains at TP are recording at the level which is perfect for the source (i.e. say, classical or jazz) and the type of tape used.

As for the question of why use SM468 when there are other tapes with higher output available, the type of tape needed depends on many, many, MANY factors besides output, and I certainly don't have enough knowledge to intelligently comment on that, except to note that it is a "high output" tape and according to USrecordingmedia is the most sought-after tape on the market today.

Does this help out?

[xcortes]

Thanks John

I'm ordering the Quinton Tapes and their recording engineer sent me an email asking if I want them at 320 or 514nW/m and I don't know what to do!

[ironbut]

Hey Xavier, if you were recording live music with a wide range of dynamics from the quietest passage to the loudest (classical), you'd want all the headroom that you could get. That way, the tape hiss would be less audible during those quiet passages. But since we're talking about playback only, the compression of these dynamics from processing (duplication to a running master and to your copy at least) should negate the extra 3dB that these higher output tapes have . One of the ways that these tapes increase output is by having more oxide applied to the backing. I've heard it said that this increases the abrasive nature of the tape by increasing friction. It also makes the tape less flexible which could require an increase in tape tension to maintain correct head wrap for optimum playback performance. I have no issues with 468 since it sounds like most of the tape hiss I can hear are from the master tapes. Paul has been a fan of this formula for many years and first hand experience and endorsement from such a lofty source is good enough for me. In other words, I'd stick with the normal high output for playback purposes.

[xcortes]

So 320 it is.

Thanks guys!

[reelnut]

Hi Xavier-

The magnetic flux level is also indirectly related to your operating level (how loud the signal is at the tape outputs) because you also set the VU meters to zero for the operating level you use. If reference level is left constant and you increase your operating level by say, +4db you will get a volume increase of +4db at the tape output. If operating level is left constant and you raise the reference flux level from 320nWb/m to 510nWb/m the difference also happens to be exactly +4db! So it's two ways of saying the same thing: "How loud do you want the signal at your tape outputs to be?" 514nWb/m is not commonly used in the USA, so your decision to get the 320nWb/m tape would appear to be the correct one. Although either one would work, you'd simply turn down the output control on your deck by 4db if you played the 514nWb/m tape.