On the Bench
At 5 volts, 20 volts, and 32 volts into 8 ohms
(32 volts is 128 watts continuous), both channels driven, THD+N stayed below
0.05%. I measured clipping (1% THD+N) at 140 watts output, both channels
driven, continuous, using a single 1 kHz sine wave test. Some AC ripple (60
Hz and its harmonics) is getting through, but that is not unusual.
IMD remained low at 5 volts and 20 volts
output to 8 ohms, and clipped at 28.3 volts, which is 100 watts. This is at
a lower wattage output than with the 1 kHz test and tells us that as the
signal becomes more complex, the maximum output before clipping becomes
lower.
Maximum output at clipping was 140 watts into
8 ohms, and 220 watts at 4 ohms.
With both 8 ohm and 4 ohm loads, THD+N vs.
frequency stayed below 0.5% throughout the measured range of 10 Hz to 50
kHz. This is really very good for such an inexpensive receiver.
Frequency response under all conditions
measured was 10 Hz - 70 kHz ± 1 dB. It's
down 3 dB at 140 kHz, which is an improvement over the spec of the original
unmodified unit.
Conclusions
All I can say is, "Wow!" I did not have the
luxury of being able to compare the modified 3480 with an original one, but
the modified unit sounds and measures like no other $550 receiver I have
ever seen. The current model is the 3485, and the mods are $350, bringing
the total price of that unit to $650 plus shipping.
This is a no brainer for anyone who wants a
two-channel receiver that looks like something they might have purchased at
CostCo, but sounds like it came from an audiophile salon.
- John E. Johnson, Jr. -