Cube Audio Nenuphar Single Driver Speaker (10 inch) TQWT Enclosure
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Parameters (from Cube Audio):
Power: 40 W
Efficiency: 92 dB
Frequency response: 30Hz - 18kHz ( 6db)*
Dimensions: 30 x 50 x 105 cm
Weight: 40 Kg
The F1 and F2 amps really have output impedances that high? This seems impractical for use with most any speaker. 80. and 15. ohms? Is there a missing decimal point? Particularly elevated for a transistor amplifier. What would be Nelson Pass' rationale for those levels? The S.I.T.-1 and 2 at 4 ohm I can understand. Charles |
Yes, it is high. Here is a link from FirstWatt on the F1: www.firstwatt.com/f1.html "It has both balanced and single-ended inputs. The input impedance is nominally 80 Kohm, and the output impedance is 80 ohms." And from the F1 manual: www.firstwatt.com/pdf/prod_f1_man.pdf "Input Impedance, unbalanced 50 Kohms, 8 ohm load Output impedance 80 ohms" In his 2004 review of the F-1, Dick Olsher wrote: "Current drive offers a major alternative to the speaker-amplifier interface. A transconductance amplifier is operated as a current source with a high source impedance relative to that of the speaker. The output impedance must also be linear and frequency independent. An ideal current source would possess an output impedance so large as to be considered infinite relative to that of the speaker. The F1's 80-ohm impedance is certainly adequate in this regard." |
Just to complicate things, I was reading back through the thread and came across toetapaudio's comment from a year ago (6/20/19): "We are getting great results driving the Cubes with Mola Mola Makua/Kaluga’s and look forward to trying Bakoon amplification soon with the Cubes." The Kaluga's output impedance is listed as <0.003 ohm with a damping factor >4000. www.mola-mola.nl/kaluga.php Go figure. |
Bakoon 13R is my preference with the Cubes. I’m using it with the Bakoon DAC21 which is out of production but I’m looking forward to a new dac from Bakoon in the imminent future. Physically the new dac will match the 13R. I’m expecting it not to cost more than the amp. I’m over joyed with the sound I’m getting with the Cube/Bakoon pairing and I have had great comments from customers. The Bakoon very small, which proves bigger is not always better. I’m finding increasingly people want a simple and uncluttered system. |
