VAL JD-L1 Preamplifier and JD-845SE Monoblock Power Amplifier (sold)

by peterclting Thu May 02, 2024 5:08 pm

VAL JD-L1 Preamplifier and JD-845SE Monoblock Power Amplifier
In good condition 8/10

Like a Star @ heaven

Selling for ~~RM13800~~ (SOLD) as a set only
Previously retailed for RM40k

Like a Star @ heaven

VAL JD-L1 Preamplifier
uses 4x 6SN7 tubes
Runs on 2 individual tube rectified external PSU (1 for each channel)

Like a Star @ heaven

VAL JD-845SE Monoblock Power Amplifier
Uses 1x 845, 1x 300B and 2x 6SL7 per mono block
Outputs 28 watts per channel

Everything here is milled from solid solid material.

The preamplifier including power supply is also implemented in a complete double-mono design. The stabilization of the anode voltage and the operating voltage is designed using tube technology.
Grid potentiometers with closely selected fixed resistors ensure perfect control and channel equality.
The preamplifier offers 4 high level inputs and 2 pairs of outputs (1 x low for horn systems, and 1 x high for normal speakers).

The circuitry of the power amplifiers relies on a moderate overall negative feedback to achieve an adequate damping factor.
Additional circuit tricks enable a very low level of overall distortion.

Technical data and most important features:
• Continuous power 2 x 28 watts at K-2+3= < 1%
• Peak power 2 x 32 watts
• Input impedance 100k Ohm
• Input sensitivity 400 mV rms for 4 watts
• Input circuit 2 x SRPP (extremely low distortion)
• Driver stage 300 B and 845 have DC heating
• Output transformers with 4, 8 and 16 ohms
• Internal resistance approx. 1 ohm at 8 ohm output
• Fixed grid voltage supply for 845
• Extremely low-resistance (hard) power supply
• High voltage and mains transformer separated
• Dossel screening, operating voltage for the tubes 845 approx. 900 V and for the 300B at approx. 400 V
• Special 50 Hz transformers
• Vibration protection against high frequency interference
• Only one film capacitor in the entire signal path
• Cerafine electrolytic capacitors in the power supply
• Sound-defining driver and power amplifier circuit based on a model from the 1940s
• Pulse-stable dimensioning thanks to small internal resistances of the individual amplifier stages

VAL JD-L1 Preamplifier and JD-845SE Monoblock Power Amplifier (sold) Img_8932

VAL JD-L1 Preamplifier and JD-845SE Monoblock Power Amplifier (sold) Img_9111

VAL JD-L1 Preamplifier and JD-845SE Monoblock Power Amplifier (sold) Img_9110

VAL JD-L1 Preamplifier and JD-845SE Monoblock Power Amplifier (sold) Img_9112