This is a review and detailed measurements of the Prima Luna Dialogue Three tube preamplifier. It is on kind loan and cost US $2,599 when available in early 2000s.
The amp fit and finish seems excellent even after so many years. There seems to be microprocessor control for power on delay and input selection through rotary controller. Back panel impresses yet again with very high quality connectors:
Product is designed in Europe but manufactured in China as you can see from the torn sticker.
The amplifier is extremely heavy. At 52 pounds, that is one heck of lot of iron for a preamp!
Edit: specs are for different model. Will update tomorrow.
PrimaLuna Dialogue Three Measurements
I set the input to 2 volts and adjusted the volume control to get to same 2 volt output (about 3:00pm on the dial):
Good to see that the distortion level is within spec. Not so good is copious amount of it in the form of second and third harmonic. Performance can be substantially improved if you keep the input level much lower (but then again, you may not be able to get max power):
Noise performance is surprisingly good for a tube preamp:
Frequency response was excellent with small deviation between channels:
Crosstalk was poor for a "dual mono" configuration:
Distortion is mostly frequency independent until you get to very low frequencies:
Finally, channel balance was impressively good:
Conclusions
Rating it by modern solid state preamps, performance of the Three is abysmal. By tube standards though, it seems OK. I let you all opine what you think.
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As always, questions, comments, recommendations, etc. are welcome. Click here if you have some audio gear you want me to test.
Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
The amp fit and finish seems excellent even after so many years. There seems to be microprocessor control for power on delay and input selection through rotary controller. Back panel impresses yet again with very high quality connectors:
Product is designed in Europe but manufactured in China as you can see from the torn sticker.
The amplifier is extremely heavy. At 52 pounds, that is one heck of lot of iron for a preamp!
Edit: specs are for different model. Will update tomorrow.
Inputs | 5 Pair RCA + 1 Pair HT bypass |
Outputs | 2 Pair RCA Preamp Outs 1 Pair RCA Fixed Tape Out |
Gain | 12 dB |
Freq. Response (+/- 3dB) | 10Hz - 130kHz |
THD | Less than 0.15% at 2 Volts |
S/N Ratio | >100 dB A-weighted @ 2 Volts |
Input Sensitivity | 220mV |
Input Impedance | 200k Ohms |
Output Impedance | 2.5k Ohms |
Power Consumption | 50 watts |
Standard Tube Complement | 4 - 12AU7 2 - 5AR4 |
Dimensions (WxHxD) | 15.9" x 8.3" x 15.2" |
Weight | 52.9 lbs |
PrimaLuna Dialogue Three Measurements
I set the input to 2 volts and adjusted the volume control to get to same 2 volt output (about 3:00pm on the dial):
Good to see that the distortion level is within spec. Not so good is copious amount of it in the form of second and third harmonic. Performance can be substantially improved if you keep the input level much lower (but then again, you may not be able to get max power):
Noise performance is surprisingly good for a tube preamp:
Frequency response was excellent with small deviation between channels:
Crosstalk was poor for a "dual mono" configuration:
Distortion is mostly frequency independent until you get to very low frequencies:
Finally, channel balance was impressively good:
Conclusions
Rating it by modern solid state preamps, performance of the Three is abysmal. By tube standards though, it seems OK. I let you all opine what you think.
----------
As always, questions, comments, recommendations, etc. are welcome. Click here if you have some audio gear you want me to test.
Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
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