Some of the coolest looking tube monoblocks we've ever had the pleasure of enjoying. They're made in California. They wind their own transformers. And they've got an attitude that we fell in love with instantly. Oh yeah, and in Tetrode, they put out almost 100wpc. Bring on those hungry speakers.
Condition
9/10
Serial No.
87U191097
Restoration
- Full service check
- Cleaned controls and switches
- Tubes tested strong
- Detailed
Factory Specs
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
Power Requirements Factory set for 100V, 120V or 220-240VAC operation for original destination country's mains voltage. (Operating mains voltage changeablewith 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
Measurements in Triode Mode
Output Power 46 Watts @ 1 kHz 2.5% THD into 5 Ohms; 44 Watts @ 1 kHz 3% THD into 16 Ohms
Frequency ResponseAt 5W output into 5 Ohms: 10 Hz @ 0.2% THD, 1Khz @ 0.09% THD, 20 kHz @ 1.7% THD; At Full Power into 5 Ohms: 20 Hz - 18 kHz FLAT
Input Sensitivity 700 mV produces 46W
Gain 27 dB
THD + Noise 0.05% @ 1 W
Noise floor -68 dB
Power consumption Idle 85 Watts (900mA @ 120V)
Power consumption Full Power 170 Watts (1.8A @ 120V)
Measurements in Tetrode Mode
Output Power 90 Watts @ 1kHz 1.6% THD into 5 Ohms; 89 Watts @ 1kHz 2% THD into 16 Ohms
Frequency Response At 5W output into 5 Ohms: 10 Hz @ 0.3% THD, 1Khz @ 0.4% THD, 20 kHz @ 1.9% THD; At Full Power into 5 Ohms: 20 Hz - 28 kHz FLAT
Input Sensitivity 800 mV produces 90W
Gain 29 dB
THD + Noise 0.10% @ 1 W
Noise floor -68 dB
Power consumption Idle 88 Watts (930mA @ 120V)
Power consumption Full Power 263 Watts (2.8A @ 120V)
Liner Notes
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" Below. 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.What's so cool about Variable Feedback?Global negative feedback takes a small portion of the output signal and re-injects it back into the input stage which greatly improves linearity and distortion performance of an amplifier. A tasteful amount of negative feedback is the key: too much and you're into poor transient response and phase shift problems. We generally use somewhere between 4 to 14 dB's of feedback in our line preamplifiers and within that window is a definite point of maximized stability with optimum sonic performance. So we give you the choice of where you want to be in several of our products. Changing the amount of feedback alters the overall gain of the amplifier as well as the slew rate (speed).In the context of a hifi amplifier or preamplifier with the Variable Feedback feature, such as our 50 Watt Monoblock or Neo-Classic SE/PP 300B amplifiers, EveAnna uses variable feedback to suit different CD's and recording styles when she's listening to music at home. "For the most part I keep the variable feedback controls around the middle but sometimes when I'm playing a CD which is kind of harsh and aggressive sounding or I just want to mellow out, I just turn those control down and apply more feedback to get a smoother, richer texture. But when I'm the one in the aggressive mood, I crank 'em up for a faster, punchier sound. The bass gets tighter and the top end sizzles. Vocal placement; is more forward. And, oh yeah, it gets louder too!"The "GAIN" switch in the Micpre section of the Voxbox is actually a variable feedback switch offering a range of 20dBs of global negative feedback in five settings of five dB steps to alter how much variable feedback is applied around the tube circuit. This GAIN switch can be used in the higher 55 and 60dB settings (in conjunction with turning up the Input Attenuator) to achieve maximum amplification for quiet singers or lower output ribbon mics. With most "normal" condenser mics and applications, the GAIN switch setting can be chosen at will for sonic variety for a "more tube-y" sound in the lower 40 or 45 dB settings, "straight forward" sounding middle positions, or "more aggressive" "punchy" sounds in the higher gain positions. There is no right or wrong with this switch. Have fun playing around with it and we hope it brings you some interesting results.
Stock No.
6750091837608
