11
Nagra –
JAZZ
Tube ageing
The JAZZ tubes are selected by Nagra according to exacting criteria. Their
theoretical minimum useful life is 5000 hours. Actually, some tubes operate
consistently for more than 10 000 hours.
Thus, the useful life of the tubes is somewhat unpredictable. Rather than
replacing the tubes arbitrarily after 5000 hours, we suggest that you identify the
signs of ageing:
The distortion gently increases to an audible level;
Presence of clicks (dry and short noise, like breaking dead wood);
Presence of pops, short noise in the low frequencies;
Presence of hiss, higher background noise.
As soon as one of these signs appears, please contact your Nagra dealer to order
a JAZZ replacement tube kit, reference 7055764000.
Case cleaning
Clean the JAZZ casing using a soft, non-fluffy, slightly damp cloth. Do not use
any cleaning products which could have a corrosive effect.
Technical specifications
Input impedance
> 75 K Ohms
Output impedance
50 Ohms
Frequency response
10 Hz - 50 kHz
(+0 /-0.5 dB)
Signal to noise ratio
Typically 105 dB (ASA A)
Ref 1 V
Dynamic range
> 112 dB
Gain at +12 dB
Minimum input level to
reach 0 dB (meter)
0.25 V rms
Gain at + 12 dB
Maximum input level to
reach 0 dB (meter)
> 25 V rms
Gain at 0 dB
Total harmonic distortion
(THD)
<0.02 %
@ 1 kHz, 1 V out, no load
Crosstalk
> 78 dB
Vacuum tubes
2x 12AX7 / ECC83
1x 12AT7 / ECC81
Selected by Nagra
Laboratory
JAZZ consumption
12 V 900 mA
Standby <10 mW
Power supply
115 V or 230 V AC input
ACPS II power supply
Dimensions
310 x 254 x 76 mm
12.2 x 10 x 3 inches
Weight
3.3 Kg – 7.27 pounds
JAZZ unit alone
