Some pics of what I'm using and not using right now.

I think the cheap Little Bear passive would probably sound fine with the Philips amp. It sounds great with every power amp I've used with it (as has the equally cheap FX Audio mini valve pre by the way). Sometimes results belie prices.

Yeah I'm starting to get that I think. Need to have a longer listen though. I've only tried a bit of Curtis Mayfield and Primal Scream so far. It sounds better than the Krell 50S did with this XTZ pre, quite a  bit better.  In fact nothing has ever sounded good with the XTZ pre up till now. I only ever used to use the power amp stage of it. 

No, not tried that and I guess in light of the other pre being fine with it then it must be an earthing issue so would probably work.

Will have to be next weekend now though. 

Yes I have had my mucky mitts inside one.

18th?

B'Jesus!!!

Didn't expect that at all!!

Especially as you didn't consider the XTZ to be much cop.

I think the Philips is just a very good power amp.

I suspected you'd get a surprise if you put it up against the Krells.  It doesn't have the sheer scale, but it has excellent transparency and speed.

Get the system earthing sorted and find out what the Philips amp can do with the DCB1 pre.
You're not comparing like with like otherwise.

Would that not then give me a hum if I use the Krell? I don't really understand ground loops. Clearly this is something to do with the DCB1 though.

My EE did give it a check over and he couldn't find anything wrong. He said he cleaned up some of the soldering and re-flowed a couple of joints and that's it. But it was already working fine (with the Krell).

I've noticed people using DACs as pre-amps sometimes have this issue with certain power amps whereas others with the same DAC but different power amp have no problem. I need to try the earthing thing like Jerry suggested.

That's why I initially dismissed the idea that it was a ground loop . But it seems that it must be, regardless that it is only on one channel.

In the DCB1? No idea. Ollies should know. 

Was having a bit of a more critical listen yesterday, bit splashy in the top end and one channel slightly louder than the other. Also a little 'thin' sounding. Stripped the speaker cables back to clean copper and cut them down from about 25 feet long to about 6 feet, reconnected everything more firmly, seems to have worked. Splashiness gone, channel imbalance gone. Might be a bit more body to the sound too but hard to be sure about that.

Listening to some Pat Metheney at the moment, sounds exquisite.

A couple of weeks in now with this Black Tulip amplifier, seems to be a solid performer. I came across some speaker cables in a kitchen cupboard, same Maplins cable with the transparent sheath but this (from memory) is 125 strand as opposed to the 55 strand one I lashed up with. I stripped all the ends back to fresh wire and got good connections I think. It just about fit into the sockets on the amp.

So now, I think I hear a bit more 'body' to the sound than with the thinner cable, but at the same time I think I lost some of that 'midrange delicacy' that impressed we about this amp to begin with. A slight 'thickening' of the sound. It's such a slight thing that I'm by no means certain it is 'real'. I will have to swap back again to the thin wire I think, and see what I reckon then.

But I got to thinking, if it is true that most amp designers will 'voice' an amplifier at least to a small extent, and back in the day this amp was designed (late 70s) they were using pretty thin gauge wire during that process, would that no affect the voicing of the amp i.e it is voiced to sound at its best with thinner cable? Any opinions?

Which means modding it and I'm loathe to do it.

Anyway do you not see my reasoning in the idea of using thinner cable deliberately with this amp? I wonder what speaker cable they had in the lab at Eindhoven back then?

I do have the adaptors that came with it....but I'm worried about them slipping out and shorting. The sockets point downwards for some reason I can only wonder at. I did use the adaptors at first with some nondescript 79 strand but at that point I was distracted by the hum problem.

Anyways they still won't work with the Spotfire cables as they have spades at the amp end. Which I specced specifically for fitting to the industrial type binding posts on the Krell KSA50S. Which is still tits up although I am in talks. And so the dance continues.