HiFi Subjectivist ¦ Audio Forum ¦ NVA User Group

It might be worth remembering that valves are still very much in current usage.

Valve amplifiers never really went away it is simply that speakers became less efficient and couldn’t be driven adequately by relatively inexpensive valve amps. Transistors could deliver more power at a much lower cost. Best way to find out whether there is anything in it is to try one.

It appears most of the things written about valves is bullshit.

A good valve amp is not just about the valves used .

Daniel Quinn wrote: ↑Mon Apr 19, 2021 8:41 am It appears most of the things written about valves is bullshit.

Most of the stuff written about 300Bs is complete crap. They are an absolute bastard to drive, which means that getting a good power bandwidth out of them requires large voltage swings and plenty of quiescent current in said driver.

The 6SN7 cascaded setup that a lot of manufacturers use to drive 300Bs only does half the job. Yes, it provides plenty voltage swing but current drive is inadequate. The resulting amp works, but sounds warm, and cuddly with crap bass. Some people want that and think it is the sound of valves because that is what they’ve been led to believe a valve amp sounds like. It’s not what a good valve amp sounds like, it’s what a mediocre valve amp sounds like.

To be quite honest, I’ve never liked 300B amps, even when they are done right with adequate drivers, but that’s only my opinion. Others love them. The valves themselves are very expensive and the amps are not worth the prices being charged. A cheap one is worse than useless (crappy output transformer) and will not give the listener a proper tase of what a decent valve amp is capable of. TBH direct heated, single ended triode 300Bs are a bloody minefield.

If you are used to solid state amplifiers, I would start with manufacturers such as Primaluna or Icon Audio and have a look at their ranges. EL34s and KT88 in push-pull ultra-linear operation sound great and give decent power outputs into real world speakers.

Single ended valve amps require high efficiency speakers such as the Klipsch speakers Paul uses otherwise you are on a hiding to nothing.

Daniel Quinn wrote: ↑Mon Apr 19, 2021 8:41 am It appears most of the things written about valves is bullshit.

A good valve amp is not just about the valves used .

To your first point, that may be because those who really know about valves don't/didn't write much, discussion forums weren't around in the 1960s. Many people who had done well with valves, Harold Leak, Peter Walker and the like were happily embracing transistors.

To your second point, spot on!
To say that an amp is defined by the valves used is rather like saying that good music is defined by the instruments. By that measure, give me a Stradivarius and I should be able to play beautifully, which is patently rubbish because I can't play the violin, irrespective of the maker. A good valve amp is about how the valves are used rather than which ones.

Yes, but.

There are certain valves that are more likely to give you an excellent amplifier, but they still need proper implementation and good quality hardware.

The Audio Talk Owston event is a good place to go to hear a varied selection of amplification and complete systems. I'm certainly looking forward to when the next one might be.

Another thing, It's not uncommon for valve amps to use solid state components to heat directly heated valves and to drive the power valve.

My own 833a (GU-48) monster will have a solid state "power drive" stage to drive the 833a into A2.

So, does that make them "hybrid" amps ?

'Lots of iron' is one thing I'm told a lot about valve amps.

The SET I have here weighs around 45kg!

nilsatisnisioptimum wrote: ↑Mon Apr 19, 2021 7:01 am

CN211276 wrote: ↑Sun Apr 18, 2021 8:50 pm The Doc's view was that valves cannot compete with solid state and the only reason why they had a revival is because Naim amps sound so bad.

That's a deliberately provocative view and not one I believe RD was truly signed up too, I guess he was just having a bit of fun at Naim's expense
I will one day give them a go simply to satisfy my curiosity

What the Doc said is in his opening post in the hifi industry hobby thread. I got it slightly wrong. He basicaly said because Naim amps are so bad enthusiasts went retro and turned to valves because the flat earth said valves could not compete with transistors.

I owned tube amplification from my early 20s to just a few years ago. If you have the right speakers a SET amplifier can be heavenly. I have heard many a push pull sound nice also, but in the end there is some coloration to tube amps. It also drives me crazy that you can change tubes and alter the sound significantly, so how do you know what sound is "right" or if the amp is operating optimally?

One type of amp I have never heard but am intrigued by is OTL. Transformers seem to have a significant impact on sound and really are a bottleneck in some ways. So if you remove them and directly couple to the tube, what will the end result be?

Maybe one day I can find some Atmasphere and will give it a shot.

Does it really matter if you are listening to the 'right' sound NK, as long as you enjoy it. When listening to different brands of SS amps, they sound different, which of them are 'right'.