Turn on PRE. before POWER, but why?

[gints]

Check valves. I had this pop sound as well during warmup once, in one channel. Switched left, right channel valves, pop followed. Otherwise amp played fine.

 

[cjyosemite]

My Quad separates only have one switch too by the way (even for the tuners and the CD players).

This is only partially true as it depends on whether you use the QuadLink connection cables or phono cables.
However with the Quad 99 tuner you have to use the QuadLink as it has no seperate power supply & gets it from the pre-amp or CD player. My 99 CD player has its own power input & phono cable outputs (as well as QuadLink) so can be used with any make of amplifier.
The biggest problem with Quad power amplifiers is that the on/off switch is at the back & difficult to reach. Mine are permanenty switched on but I turn the power on/off at the mains - however this results in the power amps being the first to be switched on.

My Arcam system is linked by cables between the Pre & Power amps so they come on together - I do not know whether there is any built-in delay between the Pre & Power amps but they have to be switched off independently. I do the Powers first as there is humming if I switch the Pre off first.

With my Rega Elicit-R, I assume there is a built-in delay within the amp.

NB: I think the basic Quad 99 CD player may also have only the QuadLink sytem - like the Tuner.

 

[Arkless Electronics]

Never realised the difference and importance between types of mains fuse. I now realise that my fast blow (F 2A) fuses were blowing but the T 1.7A ones were not. Having been told that valve amps are invariably fitted with slow-blow on account of the switch-on surge, I checked, and I think that's one problem solved and a lesson learnt.

Actually, looking at the scribbled (by the late T de P some 30+ years ago?) circuit diagram, I just spotted '3A slow-blow' in tiny writing in the margin. Presumably, EAR fitted 2A slow-blows on one of the services; not sure why. Haven't fully tested the consequences of this theory yet but am quietly confident. 55 years of thinking a fuse is a fuse for practical purposes as long as the value is correct (well, maybe not quite but my memory fades !!)

Only fly in the ointment is that 'pop' as the valves warm up (on a 1.7 slow blow); not sure about that as I've never had switch-on noises from these amps.

Aha! That would do it....

BTW there is no such thing as a 1.7A fuse!

 

[Mike Reed]

Aha! That would do it....

BTW there is no such thing as a 1.7A fuse!

And indeed, it has, Jez ! Must've been a typo as it's a T1.6A. Stuck a T 2A in this morning and not even a pop. Still going strongly, so I'll reconnect to the ESLs tomorrow. Could have had this sorted in mid December but what with my pre phono section going down in November I thought it might have been a hifi witch-hunt and I gave up until Christmas/New Year had passed (from a courier p.o.v.)

My electronics orientated friend came up with this possibility and I found that I had a small collection of old slow-blow fuses. Pre-amp goes back to EAR Monday.