14
Phonitor 2
120 Volt operating voltage and its effects
These diagrams clearly show how our 120-volt technology compares
to other circuits with a lower operating voltage. The direct relation bet-
ween operating level and maximum level is fundamental for the classi-
fication: the higher the operating level, the higher the maximum level
a circuit can handle. And since virtually all essen-
tial acoustic and musical parameters depend on
this relation, a higher operating voltage also has
a positive impact on the dynamic range, distortion
limit and signal-to-noise ratio.
Do bear in mind that dB scales do not represent
linear but rather exponential increases. A 3dB
increase corresponds to doubling the acoustic
power, +6dB correspond to twice the sound pres-
sure level, and +10dB correspond to twice the per-
ceived loudness.
When it comes to volume, the 120-volt technolo-
gy exhibits a performance, in regard to maximum
level and dynamic range, that is twice that of com-
mon components and circuits given that its values
are approximately 10dB higher.
THD measurements of the SPL op-amp show a dif-
ference of more than 3dB compared to the OPA134
at 36V — in terms of sound pressure level, that cor-
responds to an improvement of more than 50%.
The operating level most commonly used for audio
equipment is 30 volts.
Diagrams
Tech Talk
120
125
130
135
140
145
dBu
Comparison Dynamic Range
OPA
134@30
V OPA
134@36
V SPL-OP@
120
V
124,2
129,1
141,4
0
5
10
15
20
25
30
35
dBu
OPA
134@30
V OPA
134@36
V SPL-OP@
120
V
21,5
22,5
33,2
Comparison Maximum Levels
0
20
40
60
80
100
120
Volt
+/- 15 Volt
+/- 18 Volt
+/- 60 Volt
30 V
36 V
120 V
Comparison Operational Voltages
-115
-113
-111
-109
-107
-105
dBu
TL
071@30
V OPA
134@36
V SPL-OP@
120
V
106
111,7
114,2
Comparison THD&N
