No, but I heard my single Quads with some DIY OTL's. Nifty design, lots of special circuitry. Sounded very, very nice, and lightning fast. But too little power. You had to be easy on the volume knob. No reason such a design couldn't be upsized to handle the needs of the Quads. My friend who built it was using K-horns at the time so it was a monster powerhouse for him. Impressive was it being dead quiet idling with those K-horns.
