JBL SA640

Commentary

This is a stereo power amplifier that uses JBL's original T-circuit technology.

It adopts T-type circuit which is JBL's original circuit technology.
This method was developed by JBL in the early days of transistor amplifiers. It is essentially a symmetrical circuit with a pure complimentary service configuration with excellent linearity and basic performances. The SA640 adopts this method while using the latest devices to further improve sound quality.

A 3-stage Darlington pure complimentary service push-pull T-type circuit is used.
In addition, by composing the summing point of the NF circuit with passive elements, stable operation with good linearity is realized even for large input.
In addition, the sound quality and characteristics have been improved by using the latest high-quality parts for all parts including the high-speed device adopted in the first stage.

The power supply section uses a large EI transformer with excellent regulation and a 40,000 μ F large-capacity capacitor to provide stable sound even when ultra-low-frequency transient signals are input.
In addition, this condenser uses a high-precision condenser developed for computers to improve sound quality and characteristics that do not appear in specifications.

Large heat sinks on both sides effectively dissipate heat generated by the power transistor.
In addition, we have adopted a temperature protection circuit that also serves as a delay circuit to prevent shock noise from the preamplifier when the power is ON. Thus, no additional circuit is added to the output to improve sound quality and characteristics.

From precision metal-coated resistors and high-precision power capacitors to printed circuit boards, we have carefully selected products with an emphasis on sound quality.

Model Rating

Type	Stereo power amplifier
Effective output (continuous sine wave input, 0.06% THD)	100W + 100W (8 Ω)
Total harmonic distortion factor (at effective output)	0.06% (8 Ω)
Output bandwidth	0.16 Hz ~ 200 kHz (Dynamic Output) 0.16 Hz ~ 190 kHz (Electrostatic Output)
Input Sensitivity (1 kHz) / Input Impedance	1.05Vrms/8k Ω or More
SN ratio (20 Hz to 20 kHz, short circuit)	100dB
Channel Separation (10 kHz)	70dB
Pwer	100 VAC, 50Hz/60Hz
Rated power consumption	200W
External dimensions	Width 432x Height 140x Depth 342 mm
Weight	19kg