Amplifier 擴音機 / MANLEY / Snapper
Snapper

Another brilliant design from Mitch Margolis features a quartet of EL34 or 6CA7's in a fully differential circuit topology, including the input and driver stages. This Snapper can be driven fully balanced all the way through via the XLR inputs. If you hav

Specification

Manley Snapper®

100 Watt partial triode (UltraLinear) EL-34 output stage is tolerant of a wider variety of output load conditions than pure pentode.
Precise and balanced signal path from input to output. Circuit self-balances with either single-ended or balanced inputs. [Don't let either speaker terminal contact chassis, earth or any other ground. Otherwise there could be fire ;^}
Switch-selectable RCA unbalanced inputs, or XLR balanced inputs. RCA jack input impedance about 330 kOhms, XLR 15 kOhms. If one input is not occupied, the input selector switch may then be used as a poor-man's MUTE switch. Handy for checking the bias, swapping input cables, etc..
Input Sensitivity RCA jack: 750 mV RMS for full output into 5 Ohms
Input Sensitivity RCA jack: 71 mV RMS for 1 watt output into 8 Ohms
Input Sensitivity XLR jack: 1.5 V RMS for full output into 5 Ohms
Overall voltage gain RCA jack to Output: 31 dBu, or about 32 volts per volt.
Signal to A-weighted noise ratio on Humberto's bench is about 110 dB.
Damping Factor: 4.7
All-balanced amp topology keeps B+ voltage variations from degrading the performance of the input and driver stages. This technique can help make a push-pull amplifier very revealing of signal detail, in part by canceling power-supply-related perturbations and increasing signal-to-noise ratios.
Portly 180 Joule energy storage reservoir in the main B+ supply channel for explosive transient response and athletic musical stamina. Also reduces B+ fluctuations due to varying current demands of output stage [duh].
Wideband transformerless balanced input with switchable bridged 15 kOhm or terminated 600 Ohm input impedance. Balanced input sensitivity may be selected by changing one resistor to suit whatever operating level may be required. 0 dBu, +4, +8, etc... If desired, the user may safely ground either pin 2 or 3 for single-ended drive of the balanced XLR input... [Be careful NOT to drive pins 2 and 3 of the XLR with a large common-mode signal, or the internal B+ fuse could blow.]
Quiet DC supply for the input and driver tube filaments.
Excellent square-wave response, and very low excess phase-shift with frequency.
Amp actually puts out 110W @ 5 Ohm load @ 2 kHz @ onset of clipping, 117 VAC mains voltage, 3.5 amps mains current.
100 W spec: 15 Hz - 40 kHz into 5 Ohms
Puts out 100W into an 8 Ohm load.
Snapper unit weight: 38 lbs.