YAMAHA 101M

Commentary

Yamaha's top-of-the-line stereo power amplifier with the enormous power and toughness of a studio amplifier without sacrificing the precision and high quality of an audio amplifier.

The 101M consists of two monaural amplifiers in one unit, and is a fully twin monaural configuration with the left and right sides separated from the AC power cord. This allows one channel to be used and the other channel to be turned off, eliminating harmful interference such as mutual interference.
In addition, the entire layout and wiring patterns are designed to be perfectly symmetrical on the left and right. The micro power section is arranged on the upper side and the large power section is arranged on the lower side. The signal flow is also designed to flow from the front panel toward the rear panel where the power transistors in the final stage are arranged.

The power stage is based on a new concept including the power supply circuit so that it can supply as much power as possible with low distortion. Yamaha ZDR (0 distortion circuit) is installed to realize high output and low distortion factor.
The power transistor consists of a Pc200W metal can case with a total of 10 para (20 pieces) of each channel and a flexible configuration in which 4 para of ± 120 v are added as required based on 5 para of ± 70 v operation. Therefore, while the power stage as a whole has a high voltage operation capability of ± 120 v, as individual power Tr, 5 para of ± 70 v side does not become saturated, and 4 para of ± 120 v side does not need to be always operated. Thus, a high margin is realized in the power stage as a whole.

It is equipped with ZDR (0 distortion rule) which reduces the generation of any distortion to 0 in the power stage, and realizes low distortion by canceling the general crossover distortion in the power stage, thermal distortion peculiar to music signal amplification and distortion caused by speaker back electromotive force, etc..

In order to improve reliability at the time of large current and large voltage amplitude, the main power supply for the power stage is separated from the sub power supply for other power stages.
In addition, the main power supply is provided with ± 70 v and ± 120 v according to the configuration of the power stage, and the real-time power supply control circuit adds voltage as necessary, thus achieving excellent power supply capability.
The power transformer uses an oriented core with excellent magnetic properties, and the winding uses a large transformer of approximately 10 kg, using a thick oxygen-free copper wire with a wire diameter of 2 mm. The primary side DC resistance is as small as 0.35 Ω, making it possible to supply large power.
The Chemi-Con of the power supply unit uses 2 para (4 units) of 100V18,000 μ F and 1 para (2 units) of 63V39,000 μ F. The total Chemi-Con capacity of the power stage used in one 101M unit has reached 300000 μ F.

It is equipped with a protective circuit to prevent the speaker from an accident.
The DC detection protection detects the DC output and turns OFF the speaker relay when there is a DC input outside the DC servo area. The high frequency detection protection turns OFF the speaker relay when there is a high frequency and large amplitude exceeding 100 kHz full power width.
In addition, it is equipped with a muting circuit that turns off the speaker relay for 5 seconds with power ON, and at the same time activates the 70 Apeak inrush prevention circuit.
When these three protection circuits are activated, the protection LED lights up and warns.

A Pc limiter is mounted. When the load is short-circuited, continuous load short-circuit is detected according to the output current and voltage conditions, and the operation curve of the Pc limiter is changed to protect the transistor.

It can also be used as a BTL connected monaural amplifier by using the operation mode switch on the rear panel.

The input terminal is equipped with pin terminal and male / female canon terminal.
Use the rear panel input mode switch to select between balanced and unbalanced inputs.

Equipped with an input level attenuator, it can be continuously variable from 0 to ∞.

Equipped with a subsonic filter.

Equipped with a full-scale 1000W/8 Ω peak meter with 500W as 0 db.
This meter also has a W display for BTL and a clip indicator.

Rack mounting is possible with high rigidity structure using aluminum frame structure.

Model Rating

Type	Stereo / monaural power amplifier
Rated Output (20 Hz ~ 20 kHz)	750W + 750W (4 Ω, Strain 0.01%) 500W + 500W (8 Ω, 0.003% strain) 1.5 kw (BTL Connection, 8 Ω, Distortion 0.01%)
Power bandwidth	10 Hz to 100 kHz (8 Ω, 250W, 0.1% strain)
Input sensitivity	1.73 V (8 Ω, 500W)
Impedance	25k Ω
Frequency characteristic	10 Hz ~ 100 kHz + 0 -3dB (1W, 8 Ω)
Signal-to-noise ratio (IHF-A)	122 dB (8 Ω)
Total harmonic distortion factor	0.003% or Less (8 Ω, 20 Hz to 20 kHz, 250W)
Cross modulation distortion factor	0.002% or Less (8 Ω, 50 Hz : 7 kHz, 250W)
Damping factor	500 (8 Ω, 1 kHz)
Subsonic filter	7 Hz, 12dB/oct.
Power consumption	580W/ch(100V)
External dimensions	Width 482x Height 264x Depth 441 mm
Weight	61kg