An observation

[Neonknight]

SNIP I always thought you switched off valves to save the life in them. I know Audio Research and VTL amps should be switched off, are cdp's different. My Project is left on 24/7. My brothers cdp is put on standby.

I am told that the main strain on a valve is switching it on. The advice I had from MF was, confusingly, to leave the player on and to switch the amplifier off. I leave the CD player on most all the time and switch off the amp when I'm away for a week or more. Seems like a sensible compromise and is consistent with advice from John Sampson who upgraded both.

Bottom line - you pays your money and stocks up on spare valves (yes I have spares - valve rolling is fun as well) - it's worth it for the sound quality. My Nu Vistors must be about 20 years old and have been switched on and off no more than 20 times I'd guess.

This has been a question I have wondered about with this Nu Vista integrated. With my SS gear I would leave it on 24/7, and with my tube gear I would turn it off after a listening session. The Nu Vista does not fit either scenerio. So what I have taken to doing is turn it on for my morning coffee and vinyl listening session, and leave it on all day. Turn it off after my evening listen and go to bed. Not sure if this is the best solution, but it was one that made intuitive sense to me. I have not opened this unit up, can an owner change the Nu-Vistor tubes, and where does a fellow find a good matched set?

[TheMadMick]

This has been a question I have wondered about with this Nu Vista integrated. With my SS gear I would leave it on 24/7, and with my tube gear I would turn it off after a listening session. The Nu Vista does not fit either scenerio. So what I have taken to doing is turn it on for my morning coffee and vinyl listening session, and leave it on all day. Turn it off after my evening listen and go to bed. Not sure if this is the best solution, but it was one that made intuitive sense to me. I have not opened this unit up, can an owner change the Nu-Vistor tubes, and where does a fellow find a good matched set?

1. Solid state is more tolerant being switched on and off but is also better left on as it still takes time to warm up. It minimises thermal stresses in the silicon. I'd leave it ON like I do for my kW550 - there are a lot of similarities.

2. Matched sets of 4 Nu Vistors are like hens teeth. I've got 2 matched pairs as spares but I'm hoping not to need them. Search the web. Tubes in USA are much easier to get for some reason and they tend to be relatively cheaper (the same number of $ as we pay in £ if not better).

Good luck. Enjoy.

[Geoff.R.G]

I always thought you switched off valves to save the life in them. I know Audio Research and VTL amps should be switched off, are cdp's different. My Project is left on 24/7. My brothers cdp is put on standby.

The bit of a valve (tube for US readers) that fails is the heater which is little different from the filament in a lamp. The most likely time for a filament to fail is when it is switched on. The designers of the original, valve, computers determined that the valves lasted longer when left powered at all times.

[TheMadMick]

SNIP Consider that the HT of many valve amps is often around 480VDC. My last valve amp had an HT of 565VDC and higher values are easily possible. Are you willing to go out and leave your valve amp switched on and unattended? Of course, in the winter no central heating will be required because the house will be permanently toasty and your electricity bill will be through the roof. Apart from that, leaving them on is a great idea!

Not all valves are in the power section and require such voltages. The equipment being discussed use valves in the signal stages and voltages are comparatively low. Leave them on or buy spares is my advice.

[Lurcher300b]

There are also problem with possible cathode poisoning if you just keep the heaters on and no voltage on the anode. In reality there is not much to wear out in a valve when its on, especially is its not being driven near in max anode dissipation. And conversely, if the heater supply is built to have a soft start, the turn on stress is minimal as well. But most heater supplies are not built like that. There are hidden problems as well. Heating a DHT up first and then applying anode voltage with a bang will cause a twisting moment in the filament as its suspended in the electrostatic field. Its almost always more complex than it seems at first.

[_D_S_J_R_]

I was also going to say that the heater in a valve isn't always the thing that fails, especially in output valves if they're pushed too hard as some unscrupulous amp makers used to in my experience (The TVA1's that caught fire is the tip of the iceberg - and you lot had a go at me because I despise MF and their practises!).

Solid state amps designed well don't always need to be left on to stabilise. I mean, I have enough NVA amps under my belt now to know that they sound great right from first switch-on with a pair of speakers connected to them. My existing now well used NVA amps don't sound any 'better' than a freshly assembled A20 in the first five minutes of it's life - a bit more powerful perhaps, but that's it really... The only amps that started all this warm-up nonsense were CB Naims, which I now realise were mostly cack to start with, suffered severe circuit drift over time and in all honesty, Nait 1 and 135's aside, were pretty damned harsh even when re set-up after years of drifting off and knackered cap replacement ('cos they were reversed biased apparently on the main board and the supply caps were throttled to their limit continuously by the sheep following the Naim-shepherd's tune regarding 24/7 use.

[TheMadMick]

I was also going to say that the heater in a valve isn't always the thing that fails, especially in output valves if they're pushed too hard as some unscrupulous amp makers used to in my experience (The TVA1's that caught fire is the tip of the iceberg - and you lot had a go at me because I despise MF and their practises!).

SNIP.

I'm really sorry you think I was having a go at you. It was not intentional. I believe you are entitled to your opinion whether or not it agrees with mine. What I do reserve is the right to reply.

I'm not surprised you have no love for MF but their poor business practices does not necessarily mean poor equipment. It also seem your brain and mine are wired differently in the aural sense - so there we go.

Enjoy the music.

[_D_S_J_R_]

I was also going to say that the heater in a valve isn't always the thing that fails, especially in output valves if they're pushed too hard as some unscrupulous amp makers used to in my experience (The TVA1's that caught fire is the tip of the iceberg - and you lot had a go at me because I despise MF and their practises!).

SNIP.

I'm not surprised you have no love for MF but their poor business practices does not necessarily mean poor equipment. It also seem your brain and mine are wired differently in the aural sense - so there we go.

Enjoy the music.

I'm a big boy now, so no angst at all How are our brains aurally wired differently? Don't you like NVA amps then?

Irrespective of opinions, all I can ask anyone is to catch a few small jazz groups at local pubs Forget whether you actually *like* jazz for a minute, but the rawness of the instruments and dynamics of the sound should help put a lot of 'HiFi spiel' and general audio nonsense into perspective. It's because of this suggestion as applied to me that I'm getting truly pissed off with many loosely ported speakers of all sizes, where 'boom' passes as bass.

[TheMadMick]

I don't have any NVA amps to like or dislike. I have what I have and I'm happy with that.

Saturday night I was out listening to Fairport Convention. You are right, the sound in the theatre sound is different to that in my system. The question is "which do I enjoy more" and my response is that I enjoy both differently. The live experience is about the group interacting with each other both physically and musically. The recorded experience is about the sound only. I don't believe you can compare them.

I could wax lyrical about sound systems and why we choose what we choose but it has nothing to do with reality. Recreating reality in your home is well nigh impossible for all but the smallest group and for studio produced albums there is no reality. In my view it's about what pleases you and the HIFi myth is just that. It is not high fidelity but it is fun!!!

[TheMadMick]

Just to add confusion - I came home yesterday after a lunch and a few beers with my mates. After tea I put in Sade (well recorded and sounds good even when the system is cold). I was gob smacked! Wonderful. Lots of detail, beautiful tonal balance and a stereo image to die for. So, I think, why not a bigger challenge. I put on River City People (remember them?). Same thing. It's just the beer talking I thought, I'll try again tomorrow (today).

I put on another Sade CD tonight. Same thing. Great sound, great definition and great image. I know, I'll put on Alicia Keys (you can tell I like female vocals) "Songs in the Key of Am". This is a really dense mix with stacks of different rhythms, harmonies and counter harmonies all going on at the same time. Guess what - it was brilliant.

There are only 2 explanations I can think of:

a) the whole system has finally come to its peak performance - however, experience says when you think you've got there, then you find another improvement. Such is this hobby.
b) this coincides with the recent ambient temperature increase. We don't keep the house like a sauna but we do like to keep warm in our old age. I'm pushed to see that it's down to this but I can't be sure. Given the original post on this thread, it is credible.

Any thoughts?