Bought myself two pcb-s of JHL 1969 some years ago. This summer I want to finish the amp, and I will use a Switch Mode PS with 27volts. When I am adjusting the pot.meters, R1 and R7, how do I do that? I have lost all the documentation I got from the seller, but I think that R1 (100K) shall be adjust till I get half the voltage, 13,5volts, between one end of C4 and input ground?, is that right?
R7, 1K, I do not have the clue what to do with? The pcb have the text "www.diyhifishop.com"
R7, 1K, I do not have the clue what to do with? The pcb have the text "www.diyhifishop.com"
Attachments
You can design the circuit by part numbers and connections PCB.
To build, you need a big heatsink (alu radiator) for BJT & insulating thermal pads.
Усилитель А класса JLH1969, сборка модулей в рабочий проект
To build, you need a big heatsink (alu radiator) for BJT & insulating thermal pads.
Усилитель А класса JLH1969, сборка модулей в рабочий проект
I have already build the enclosure with a large alu-heatsink, and a thick copper angle screwed to the heatsink. The pcb-s are mounted on the copper angle. My question is how do I adjust the pot. marked R7 on the pcb? There must be someone out there who has builtthis amp, with the same pcb-s that I have?
It’s JLH not JHL, which the PCB got wrong on the silk screen. The typo will make this amp seem different from the numerous other pre-existing JLH threads.
Trimmer 1 sets 1/2 V of the output voltage in front of the output capacitor.
Trimmer 7 sets the consumption current to 1.2 a 27 V (with a load resistance of 8 ohms) after 30 minutes of heating.
It is precisely set to minimize consumption (0.9 a) or minimize distortion (up to 2 a).
Trimmer 1 is precisely set by the symmetrical limitation of the output signal.
Trimmer 7 sets the consumption current to 1.2 a 27 V (with a load resistance of 8 ohms) after 30 minutes of heating.
It is precisely set to minimize consumption (0.9 a) or minimize distortion (up to 2 a).
Trimmer 1 is precisely set by the symmetrical limitation of the output signal.