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Pass X5

Owner's Manual

Summary of Contents for Pass X5

Page 1: ...Page 1 Pass X5 Owner s Manual ...

Page 2: ...y distorted signal Supersymmetry seeks merely to create perfect matching Matched balanced power circuitry typically sees a distortion and noise reduction of about 90 20 dB through a balanced connection without any additional effort TheSupersymmetric circuit delivers another 90 reduction so that the X series has about 1 100 of the distortion of a conventionally simple amplifier Actually this ordina...

Page 3: ... the switch on up The lights in your house will blink when the power supply charges the capacitors On the front panel the Standby LED indicator should be glowing blue indicating that the power is on The Power LED should not be on If the Power LED is on don t get excited just use the front panel stand by button to go to stand by mode with the Standby LED on and the Power LED off OK so the amplifier...

Page 4: ...onnection open So much for essential information Speaker Interface The X5 is optimized for loads nominally rated at 4 ohms and above You can run the amplifiers into a lower nominal impedance without difficulty and we are not aware of a speaker on the market that presents unusual difficulty with these amplifiers The X amplifiers do not care particularly about the reactivity of the load Reactive loa...

Page 5: ...in the amplifier the transformer will deliver about 1800 watts for short duration To avoid huge inrush of current during charge up each of the transformer primary coils has its own inrush suppressor which keeps the inrush down to 100 amps or so The X5 has 4 computer grade the old large style computer capacitor cans not the new dinky ones capacitor cans at 31 000 uF and 50 volts each These are used...

Page 6: ...mplifiers operating in the field in excess of 20 years with no particular mortality except capacitors The answer is I don t have good information beyond that More to the point I would suggest that you not worry about it This is a conservatively built industrial design not a tweaky tube circuit run on the brink If it breaks we will simply get it fixed so sleep well Warranty Information This product...

Page 7: ...t with the result that the amplifier did not sound very good in spite of good distortion measurements Push pull circuits while allowing high efficiency and cheap manufacture did not improve the character of the sound at lower levels where we do most of our listening a deficiency which designers often use feedback to cover up It appears that the human sense of hearing is more subtle in some ways th...

Page 8: ... with fast amplification high slew rate In retrospect the idea was at least half right but I believe not completely for the following reasons First it presumed that there was really fast signal in music Research conducted independently by Peter Walker and myself showed conclusively that real music contained very little signal with appreciable slew rate therefore slew rate limiting on the order pro...

Page 9: ...e input look like the output in the conventional sense Instead it works to make two halves of an already symmetric balanced circuit behave identically with respect to distortion and noise dramatically lowering the differential distortion and noise but not the distortion and noise of each half of the circuit considered by itself If you build such a symmetric balanced circuit you get much of this ef...

Page 10: ...terestingly the single ended nature of each half of the balanced circuit doesn t give rise to much in the way of odd order distortion and when the even order components and noise are cancelled there isn t much distortion and noise left In any case Balanced single ended is a phrase that accurately describes the circuit For the amplifier s front end a balanced single ended gain stage was developed w...

Page 11: ...signal symmetry with respect to both the voltage and current axis and anti symmetry for distortion and noise This means that the distortion and noise of each half appears identically and cancels The diagram on the patent cover sheet shows an example of this topology Each of the two input devices 20 and 21 are driven by an input signal and their outputs run through a folded cascode formed by device...

Page 12: ...unwanted components As long as the two halves are matched this performance tends to be frequency independent and does not deteriorate over the audio band With mid level distortion figures on the order of 002 this is very high performance for a single balanced gain stage The following pages include a typical distortion curve of the amplifier a list of specifications for the amplifier and where to r...

Page 13: ...inus 10 amps Input Impedance 22 kohm balanced Damping factor 200 ref 8 ohms nominal Slew rate plus minus 50 V uS Output Noise 300 uV unweighted 20 20 kHz Random noise floor approximately 2 uV Dynamic range 140 dB random noise floor to peak output Balanced CMRR 85 dB 1 kHz input common mode rejection ratio DC offset 100 mv Power Consumption 200 watts idle 600 watts maximum Temperature 20 degrees C ...

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