I use Quad 909 in both by systems, stereo in the smaller system, monoblocks in the larger one.

Have acquired a passive pre-amp and now have a fully balanced system - except the 909 monoblocks are unbalanced inputs only. I have put in a balanced amplifier and it is beneficial. I am therefore probably looking to move to balanced QMPs.

Quad 909 monoblocks are extremely rare. They were not sold in Europe due to some bizarre regulation related to their high power output, but were sold elsewhere. They are 300w Class A power dumpers. These came from a German Quad main dealer.

One has a small scuff on the top, possibly from stacking, could perhaps be polished out. Otherwise excellent. One was recently serviced by Quad. They don't run very hot and don't need warming up.

I have never seen them advertised before. I understand they are a bit of a collector's item.

Enquiries invited