valve amplification

How big is your room? Which neat speakers do you have?

Be careful!

Just like ss amps, there're good and bad tube amplifiers. In fact, not all valve projects are good. Some of them sound overcooked on top end (rolled-off sound) and lacks control on the botton (boomy bass).

As regards power, a 15wpc tube amplifier is likely to produce a SPL like a 25-30wpc ss model. Maybe a 8 ohm impedance / 90dB sensitivity loudspeaker model shall be enough for a small to medium room as long as you don't desire to shake your living room floor.

 

Have you considered going for a pre / power set-up? A valve pre-amp with a solid state power amp? This is the set-up I have an I’m delighted with the results. I have a Croft 25 (line only version) which is £600 partnered with a Quad 909 which I got end of line also for £600, personally I think it punches well above it’s price tag, I can’t wait to get some better speakers to do them justice.

 

I realise that is a fair bit above the price area you’re talking but it’s not a crazy price either considering I bought one at a time. That said as mentioned in another post you get good valve equipment and very poor valve equipment too, I’m really not sure I’d go near most of the budget valve stuff. I haven’t really heard much of the cheaply made Chinese stuff, you never know they might have some gems at very good prices.

 

When I was looking for a valve pre on a budget one suggestion was made to me which I was intrigued with but ultimately didn’t need to explore as I find the Croft ideal for me. But that was to use a valve headphone amp as a pre-amp into a power amp, there are some very good headphone amps in the £150-£250 (new) region, pick you self up a hefty used Rotel SS power amp or similar and you’re away for well under £500.

 

All that loveliness that tubes bring, plenty of SS power and flexibility in the future. Just another option for you….

Don't get tempted by Watts with Valves. I have seen a 2x30 Watt self made valve amp beat a 100 Watt krell in drive and headroom. When the valve amp is designed good and has quality output transformers, it will drive just any speakers.

I like the Pure Sound amps, both the A30 and the budget A10:
http://www.techradar.com/reviews/audio-visual/hi-fi-and-audio/amplifiers...

To get the most out of the A10, you will need sensitive speakers from the likes of Audio Note.

In a practical sense I'd stick with ss. valve or tube amps do overheat a lot quicker, and as someone else pointed out and, generally speaking, they are fairly low powered.

Hey gbhsi1, I think I can relate to you with regards to valves. I too have thought that I was missing out on something before owning one. It's an experience not for everyone, certainly if you listen to a lot of dance music it won't be the best thing, solid state is more suited to those. However, if your listening taste is varied enough and you listen to the ocassional dace track these are amazing. Don't think 15 watts are too bad tbh. My amp is rated at 45 watts/channel in triode and 20 in ultra linear. I usually listen to 20 watt mode, even at 11 o clock it is loud enough for my relatively efficient (89db) floorstanders. I think power ratings on valves in general are more conservative than solid states....I previously had a 40 watt ss amp and it sounds much less powerful than the 20watt amp. If you are looking for good budget valve amps, try unison research, dark voice and cayin. If you look around for Cayin on fleabay, you might get a bargain...the build quality and performace for the price is astonishing. However, make sure your existing speakers will work well with them. Valve amps are warm in general, I don't like them when they are partnered with warm speakers....it just sounds too woolly. 

Hope this helps,

Shafin

 

I can see lots of disadvantages to valve amps, low power output and high distortion to name two, but what are the advantages?  Why are they still made and bought?

valve amps are still bought today simply because it sounds more real and intimate. It might be inferior to a ss amp in terms of specs but anyone who knows anything about hifi know that specs are not the be all and end of all. I could go on and on about how they sound but it has to be heard to be appreciated. 

 

Why would a valve amp sound more real and intimate than a SS amp?  Is the distortion they add somehow adding to the music making it sound in some way more real?  Is it something they add, e.g., nice sounding distortion, or something they don't do, e.g., they don't distort the way SS amps do but can't yet bet measured)?

Thanks.

 

 

Yes they essentially have a different sort of distortion compared to ss amps which is more pleasing to the ear. Don't ask me whether its 1st order, 2nd order or whatever order of distortion that is though, I will leave that for a more qualified forum member to answer. Its kinda like if you have a digital distortion pedal for a guitar vs a tube distortion pedal, the tube one sounds crunchier and has a more palpable feel. The digital one sounds clean but feels fake. 

Advantages of valve amps include lower distortion at lower power levels, typically in the nano watt to milliwatt range. Subjectively this makes valve amps better at low level details, as well as sounding more natural and less synthetic than solid state amps in the midrange.

 

Take a good valve amp and use it on medium efficiency speakers for the midrange and you'll understand why they are still made. Take a good valve amp and use it with a good pair of high efficiency speakers and you'll understand why valve amps are still bought.

Unless, of course, if your speakers have a pair of Audio Research Reference 750s up their bottom .

My 845s dont fair too badly either  . 

 

It is fair to say that, in general, valve amplifiers have a higher output impedance than solid state amplifiers, and therefore a lower damping factor which results subjectively in a less tight bass. However the effect of this is less than the difference in bass tightness between different speakers so that an easy to drive speaker with tight bass with a valve amplifier will have tighter bass overall than a speaker with bloomy bass with solid state amplification.

 

At higher volumes, output transformer quality is important for valve amps which have output transformers - which is most of them with exceptions such as the Graaf ones. Output transformers can get saturated, resulting in higher levels of bass distortion.

 

Optimum choice of amplifer: solid state or valve push pull or valve SET will depend upon the amplification task, the quality of execution of the amplifier design, the compromises that the listener is happiest with.

I tend to agree with the audio critic:

 

 The Vacuum-Tube Lie
This lie is also, in a sense, about a peripheral matter, since vacuum tubes are hardly mainstream in the age of silicon. It's an all-pervasive lie, however, in the high-end audio market; just count the tube-equipment ads as a percentage of total ad pages in the typical high-end magazine. Unbelievable! And so is, of course, the claim that vacuum tubes are inherently superior to transistors in audio applications--don't you believe it.

Tubes are great for high-powered RF transmitters and microwave ovens but not, at the turn of the century, for amplifiers, preamps, or (good grief!) digital components like CD and DVD players. What's wrong with tubes? Nothing, really. There's nothing wrong with gold teeth, either, even for upper incisors (that Mideastern grin); it's just that modern dentistry offers more attractive options. Whatever vacuum tubes can do in a piece of audio equipment, solid-state devices can do better, at lower cost, with greater reliability. Even the world's best-designed tube amplifier will have higher distortion than an equally well-designed transistor amplifier and will almost certainly need more servicing (tube replacements, rebiasing, etc.) during its lifetime. (Idiotic designs such as 8-watt single-ended triode amplifiers are of course exempt, by default, from such comparisons since they have no solid-state counterpart.)

As for the "tube sound," there are two possibilities: (1) It's a figment of the deluded audiophile's imagination, or (2) it's a deliberate coloration introduced by the manufacturer to appeal to corrupted tastes, in which case a solid-state design could easily mimic the sound if the designer were perverse enough to want it that way.

Yes, there exist very special situations where a sophisticated designer of hi-fi electronics might consider using a tube (e.g., the RF stage of an FM tuner), but those rare and narrowly qualified exceptions cannot redeem the common, garden-variety lies of the tube marketers, who want you to buy into an obsolete technology.