Radford STA15 with Big Tannoys
I thought I would share my experience in finding the ideal amp to drive my Tannoys.
I have been trying for a couple of years to find the perfect amp for Tannoy 15” Monitor Reds. I used to own AN/Es paired with my Shindo D’yquems and the sound lived up to both the reputation of Shindo and the liquid musicality you would expect from a 300B SET design.
I then came across a pair of original condition Tannoy GRF Corner Horns. They were fitted with 15” MGs and whist they sounded ok with the D’yquems something was missing in terms of dynamics and speed. I had the drivers re-coned and then external cross-overs built by Paul Coupe at RFC which improved the sound a lot but still something was missing, so I bit the bullet and bought a pair of Monitor Reds, which being 15 ohm would be an easier load for the amps. Again, even with new external cross-overs from RFC the sound was not quite there, so reluctantly I decided that no matter how much I loved the Shindos, I had to find a replacement better suited to the big Tannoys.
I have tried more powerful SE designs with KT88s and the PP EAR861 but still felt I was not getting the combination of musicality and dynamics that I was looking for.
Paul at RFC, who probably knows more about Tannoys than anybody recommended I try a Radford amp. I also followed Tom (Montesquieu)’s posts on here about his use of Radford with his Tannoys.
So when an unmolested STA15 in good condition became available I took the plunge. I had never heard a Radford before and had my doubts about 15w being adequate.
It was obvious as soon as it was turned on that I was on to something. There was a clarity and foot tapping pace to the music that had been missing, together with a musical mid range, sweet highs and plenty of controlled bass. There were some obvious issues due to the amp being in original condition but already new rectifier and input valves have resolved most of them. A quad of NOS Mullard EL34 resolved the rest and sound-wise there is nothing else required.
I know it will need to go off for a full service and probable replacement of some internal components but I have heard enough to know that the STA15 is a great match for the Monitor Reds and has more than enough power for the job. That such a small amplifier can sound so good after over 50 years is a testament to the design and manufacturing skills of its maker.
