in this comparison I find the Pass amp to be a little more open and detailed with improved spatial qualities, both amps are very smooth relaxed and effortless. I have owned a number of Quad amplifiers and done many modifications to them. The protection circuitry used in the 405 severly limits its sonic capability and is best removed for best sound reproduction. If you get the chance listen to the Quad 303 which proceeds the 405 yet even a stock one today at such an old age will still sound wonderful and when fresh capacitors are installed it is a superb amplifier. Today I run the Benchmark AHB2 amplifier which is essentially a better balanced much better built version of the Quad 405 though with vastly superior power supplies. The AHB2 is the lowest noise amplifier available in the world today. Listen to one if you can and I think that if you do you will have found the amplifier of your dreams. thank you for posting I enjoy your videos.
As you said, the PASS amp is more open and detailed! Thank you for the information on the 405 protection circuit. That's right, I'll listen to Quad 303 when I get a chance. This was my first time seeing AHB2, so I'll check it out. Thank you 🍀
