Born from the ashes of the Retro SE/PP 300B amplifiers we took in trade from customers who had upgraded to the newer Neo-Classic SEPP 300B model, we created this KT90-based 100 watt model from those traded-in units.
You can consider them as B-stock models as a way to score some neat tube amps on-the-cheap. We will consider them as new and stand behind them just like new amplifiers with our standard 5 year warranty. No problem. You know how good the Manley Service Department is! We treat you right here at Manley Labs.
These Retro 100 amplifiers feature two beefy KT90 output tubes, running in push-pull. They yield just about 100 watts in Tetrode mode, or switch to about 50 watts of sweet Triode mode.
The Russian 6SN7 and 6SL7 tubes take care of the input and driver stage duties. For this re-work, the vacuum tube rectifiers have been removed and replaced with faster and more reliable solid state traditional rectification, better capable of driving the large B+ caps (4 x 1300uF per unit) for even more bass punch.
Our Retro 100 model gives you the choice in precision switched 1 dB steps to go from ZERO dB's to 10 dB's of negative feedback for a variety of sound colors and gain optimization. For more information about variable feedback read "Notes on Negative Feedback". One interesting aspect of negative feedback is it gives a higher damping factor. Conventional wisdom would have us think that the higher the damping factor, the better. Our experience is that the optimum damping factor is not infinity and that it depends on the speaker, the room. and the taste of the listener. In other words, the optimum is variability, and this we provide.
There is no Owner's Manual right now. Follow general bias setting instructions such as found in the Manley SNAPPER manual. Set bias for 275mV.
- Vacuum Tubes: 2 x KT90 (Output), 1 x 6SN7 (Driver), 1 x 6SL7 (Input)
- Input Impedance: 75 kOhm
- Output load taps: optimized for 5 Ohms
Triode Measurements (with 5dB of Negative Feedback applied):
- Output Power into 5 Ohmns: 46 Watts @ 1 kHz 2.5% THD
- Output Power into 16 Ohmns: 44 Watts @ 1 kHz 3% THD
- Frequency Response at Full Power into 5 Ohms: 20 Hz - 18 kHz FLAT
- Frequency Response at 5W output into 5 Ohms: 10 Hz @ 0.2% THD, 1Khz @ 0.09% THD, 20 kHz @ 1.7% THD
- Input Sensitivity: 700 mV produces 46W
- Gain: 27 dB
- THD + Noise @ 1 W: 0.05%
- Noise floor: -68 dB
- Power consumption Idle: 85 Watts (900mA @ 120V)
- Power consumption Full Power: 170 Watts (1.8A @ 120V)
Tetrode Measurements (with 5dB of Negative Feedback applied):
- Output Power into 5 Ohmns: 90 Watts @ 1kHz 1.6% THD
- Output Power into 16 Ohmns: 89 Watts @ 1kHz 2% THD
- Frequency Response at Full Power into 5 Ohms: 20 Hz - 28 kHz FLAT
- Frequency Response at 5W output into 5 Ohms: 10 Hz @ 0.3% THD, 1Khz @ 0.4% THD, 20 kHz @ 1.9% THD
- Input Sensitivity: 800 mV produces 90W
- Gain: 29 dB
- THD + Noise @ 1 W: 0.10%
- Noise floor: -68 dB
- Power consumption Idle: 88 Watts (930mA @ 120V)
- Power consumption Full Power: 263 Watts (2.8A @ 120V)
- Factory set for 100V, 120V or 220-240VAC operation for original destination country's mains voltage.
- Operating Mains Voltage changeable with power transformer re-wiring and fuse value change.
- Mains Voltage Frequency: 50 ~ 60Hz
- Dimensions: W=8". D=21". H=7"
- Shipping Weight: 30 lbs. each
Specifications subject to change because they just might.
There is no Owner's Manual for these amps. Follow general bias setting instructions such as found in the Manley SNAPPER manual. Set bias for 275mV.