Hot Quads
Quad IIs always run rather hot, but they shouldn't be melting their pitch! There is no hazard at all in setting them to the 240V tapping rather than 220V - quite the reverse. And yes, it should make them run cooler.
Once done, check the HT voltage to the output stage against the specified voltage, and check that the 180R cathode resistor isn't on the verge of dying.
Quad IIs always run rather hot, but they shouldn't be melting their pitch! There is no hazard at all in setting them to the 240V tapping rather than 220V - quite the reverse. And yes, it should make them run cooler.
Once done, check the HT voltage to the output stage against the specified voltage, and check that the 180R cathode resistor isn't on the verge of dying.
Voltages
Hello!
Thanx for the reply.
I just switched them on (some other people assured me it's OK to change taps) and here's what I've got:
323V before the choke
316V after the choke
24V on the 180R
All other voltages as before.
Do you see anything potentially damaging here? Or (even worse) sonically deteriorating?
Btw, I had 360V at the choke before...
Cheers,
Tom
Hello!
Thanx for the reply.
I just switched them on (some other people assured me it's OK to change taps) and here's what I've got:
323V before the choke
316V after the choke
24V on the 180R
All other voltages as before.
Do you see anything potentially damaging here? Or (even worse) sonically deteriorating?
Btw, I had 360V at the choke before...
Cheers,
Tom
Your voltages are all 5% down on the Quad specified values, but that's unlikely to cause an audible problem, and your mains voltage variation might be as much as that anyway.
If it hasn't been done already, it's a good idea to replace the 180R 3W resistor with a 5W type, and also replace its parallel capacitor (the heat shortens its life).
Keep an eye on transformer temperature, although replacements can be had, they are expensive. I assume that you have left plenty of room around the amplifiers for cooling...
If it hasn't been done already, it's a good idea to replace the 180R 3W resistor with a 5W type, and also replace its parallel capacitor (the heat shortens its life).
Keep an eye on transformer temperature, although replacements can be had, they are expensive. I assume that you have left plenty of room around the amplifiers for cooling...
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