I pulled a car load of these out of a skip in the early 1980s when they were worth little.
I did not have the heart to pull them to bits at the time as they are built on a lovely cast chassis with cast case.
I hung onto them for 30 years and it was worth it
The line up is EF37A, ECC33, EL37, EL37 and GZ32.
Spare valves are not the cheapest things to get hold of.
So I started the electrics with a capacitor reform that took three days and while that was going on there was that valve that had gone to air to sort out.
I was very lucky on this score as I had also saved several NOS spares all be it in water damaged boxes so all markings washed off
I had to look for them.
So what the hell sent it to air then?
Well the distortion told me there was big trouble and it was not the coupling capacitors in the phase splitter for sure as they were checked on the cap reformer.
Half of the primary was half the DC resistance it should have been and the offers to rewind the transformer came rolling in. While investigating it I discovered the problem and very quickly fixed it.
The wire had come adrift from the location on the outside of the coil while the resin was still soft and the operative had just stuffed the wire back in in the wrong place. It was in the space by the link where the end of the first half of the primary looped over the secondary and just fell out when I checked out the dodgy look it had about it.
Now that is ready for cleaning and service.
A capacitor had to be sorted out and that is not an easy job and also must be dealt with carefully as there is a quality tag strip at risk if it goes wrong.
Now to select the one to be pared up with it for stereo service.
The capacitor reformer is back on but this time with music playing. This is now running from the from the optional external preamp supply with the pared up set only requiring some wiring sorting out.
The scrappy got the mechanical bits form on top so I get the fun with the amplifiers only.
I did not have the heart to pull them to bits at the time as they are built on a lovely cast chassis with cast case.
I hung onto them for 30 years and it was worth it
The line up is EF37A, ECC33, EL37, EL37 and GZ32.
Spare valves are not the cheapest things to get hold of.
So I started the electrics with a capacitor reform that took three days and while that was going on there was that valve that had gone to air to sort out.
I was very lucky on this score as I had also saved several NOS spares all be it in water damaged boxes so all markings washed off
I had to look for them.
So what the hell sent it to air then?
Well the distortion told me there was big trouble and it was not the coupling capacitors in the phase splitter for sure as they were checked on the cap reformer.
Half of the primary was half the DC resistance it should have been and the offers to rewind the transformer came rolling in. While investigating it I discovered the problem and very quickly fixed it.
The wire had come adrift from the location on the outside of the coil while the resin was still soft and the operative had just stuffed the wire back in in the wrong place. It was in the space by the link where the end of the first half of the primary looped over the secondary and just fell out when I checked out the dodgy look it had about it.
Now that is ready for cleaning and service.
A capacitor had to be sorted out and that is not an easy job and also must be dealt with carefully as there is a quality tag strip at risk if it goes wrong.
Now to select the one to be pared up with it for stereo service.
The capacitor reformer is back on but this time with music playing. This is now running from the from the optional external preamp supply with the pared up set only requiring some wiring sorting out.
The scrappy got the mechanical bits form on top so I get the fun with the amplifiers only.
