please diagram amplifier vacuum tube for model lafayette stereo 224
6GW8 version of the Lafayette Stereo 224 push-pull integrated tube amplifier schematic sent to thread starter.
This is a fantastic little amp with potted OPT's and a great sound. Rebuilding mine as we speak.
There were two LA224's...
One with ECL86 as power tubes and an other with EL84 power tubes.
here is schematic for the second one.
For the ECL86 model the schematic is not free available.
the differences between the two version should be in the power stage,(different tubes and cathode resistor, one ECC83 less, since triode sections of ECL86 provide for phase splitting) power supply (same rectifier but different resistors values in RC cells) and output transformers.
Thanks for sending the la224 manual but does not match the circuit of my stereo amplifier lafayette 224, and it brings: 4) 6gw8 - 3) 12AX7 - 1) 5ar4
Yes, infact I told in my previous reply that the ECL86 version of LA224 (ECL86=6GW8)presents some differences.
For the 6GW8 version of LA224, as far as I know, there is no FREE schematic available in the net.
But there shouldn't be other differences more than those I indicated in my previous reply.
I had a LA224 with 6BQ5s, brings back memories, my first amp. Wish I still had it.
for me this is my first tube amp and I want to recover, since the valve outlets 6gw8 overheats the plate is hot and the second valve tester tells me I q q biem and are not able to give and with the fails.
If it's one valve that's overheating check the grid resistor of that valve for open circuit and/or the coupling capacitor for leakage.
If both valves of one channel are overheating check for leaking cathode bias bypass caps.
At idle, there should be about 35 mA anode current and 5.5 mA screen current. Combined about 80 mA through the cathode resistor which is 90-145 ohms depending on the plate voltage. Calculate the voltage and compare with the measurements.
Hope that helps.
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