Advice please !

[ukfatboy]

Hi all,

Wondering if I can get a bit of advice from anybody in the know.

I've long lusted after a valve amp but know nothing about them except don't expect alot of bass.

I now think the time is right to start experimenting. What I plan to do it bi amp a top end centre speaker with my exisitng tag power amp and with a valve amp.

Starting to do a bit of digging but the valve seems to be dominated by integrated amps and not power amps.

So can I use an integrated in any way to partner my tag ?

Any advice , experiences or recommendations gratefuly received !

cheers

[buns]

what money are you looking to spend? I know of at least one nice valve power amp, though not cheap

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[ukfatboy]

Well I'd be guided by people in the know ! I will spend what it takes but alot of my kit is 2nd hand so sometimes I have to wait for an opportunity. Please tell me more

[buns]

The manufacturer of my amps, korato, is big on valves in more than just pre amps. There are a number of models (i have only heard one of them though) which you can find at http://www.korato.com/series.php?id=22 and they have distributor 'A' audiosolutions (incidentally who I dont like).

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[gover_1]

if you are looking for buying second hand you could consider a quad II mono block , these are a bit old but supposed to bevery good and often change hands second hand, i think you can pick one up for around £200 , mark

[alexs2]

The current price od Quad II monoblocs is running at about £600 per pair,for a good set,and less for ratty versions....beware of modified ones,and those running chinese or russian KT66 valves,which often have higher heater current requirements than the II's mains transformer was designed for.

Getting back to the original question,I've owned a number of valve power amps including the aformentioned Quads,plus Tube Technology 100 watt monoblocs,and a Lumley.

Some valve power amps are admittedly a bit gutless in the bass,and especially some of the lower powered,and zero feedback single ended triode jobs....the midrange and treble on some of these,especially the Audionotes has to be heard to be believed....absolutely exquisite.

Leaving lower powered amps aside(unless you plan to use very efficient speakers such as horns)you will need at least 50W or more,and there are loads of valve power amps,both new and used,to suit your needs here.

As well as the Korato's that buns has mentioned,have a look at the following

Audio Research
Manley Labs
Tube Technology
BAT

There are loads of others,but these are mainstream audio manufacturers with a very good track record for service and reliability.

There are plenty of valve amps with very good levels of bass power and control,but the latter usually comes from a combination of good transformer design,and lowish output impedance from careful valve choice,and parallel valve output stages to reduce impedance.....an exception here is in the use of transmitting triodes such as the 845 and 211 in SET amps...expensive,but plenty of grunt,and lovely sound.

A long post,but I hope it helps....I've run a triamped Linn/Krell system,with tubed top end before,so if you have any questions,drop me a PM and I'd be happy to answer anything I can help you with.

[karkus30]

FWIW Valve Power Amps Valve pre Total valve solution

Why ? Well transistors have come on a long way in the last 20 years, they produce very low distortion and huge power and switch extremely fast and do this very reliably. This makes them very suitable in power amps. Valves can be made to perform a similar task, but to do this they become very expensive.

Pre amps, different story. They handle far smaller signals, so valves are fine and for a lot of people its a preference. The old adage of warm sounding amps with poor bass is only applied to older equipment, the new stuff can swing with the best that transistor amps offer, but tend to offer a different sonic flavour.

Total valve solution ? again, this works because you can aim towards a paticular sonic flavour. Take something like a big audio research amp, stunning sound stage, big hearted bass and very warm. With the right speakers.........superb.

But where valves fall down is general reliability, in short they wear out and are very expensive to have replaced, unless you have automatic bias capability. They dont like being bumped and knocked. They can have feedback and microphony problems.

Valve for H/C........I wouldnt

[alexs2]

Valves needn't be either unreliable or expensive to replace,if they are run within their plate limits,and if readily replaceable valve types are used.
There is of course,no doubt about them requiring replacement at some stage,but a useful life of several thousand hours is quite easily achievable,even for power tubes.

If you choose NOS(new old stock) tubes,then the cost can run very high indeed,with EL34s fetching over £50 each,and KT66s fetching up to £80 each,these being 2 of the most common types along with KT88s.

Feedback and microphony are usually more of a problem with certain small signal valves(some of the ECC86s and EF86s can be problematic)but a good set of tube dampers will ease this.

I don't deny that I would think twice before using valve amps as the power stages for HC use,but there are a few such designs beginning to appear for the high-end where I think they will always remain...no-one in the lower end of the market is going to want to invest time and ongoing costs in their upkeep...cheap power also becomes an issue there,and good tube based power isn't cheap.

karkus's point about big AR amps is quite right...lots of power and control,as you will also find with Manleys,but neither of these are cheap,and power outputs with some models will rival all but the most powerful solid state amps(750W or more).

If you do choose to go down the tube route,be very careful and listen to as many as possible...the sonic variations are enormous,and they don't all sound warm and cuddly....rated power outputs can often be ignored somewhat due to the softer clipping characterstics of valve amps,and there are some which are virtually unbreakable,and others which die way too easily.

A solid state solution can often be found in MOSFET output stages,which often have a valve-like sound,as can some Class A designs,and one which has both(superseded now but worth hunting down)is the Pass Labs Aleph series of amps...single ended Class A designs with ferocious heat output but wonderful smooth sound and control.

[lowrider]

Also take a look at the new "digital" amps, I have Bel Canto, people say they mix the strengths of valves and SS, I cannot confirm as I am not familiar with valve sound, but I can confirm they have very solid bass, detailed mids and the sweetest treble, fully extended, that I have heard fron SS...

[Ed Selley]

I too would be a bit wary of using Valve amps in an AV context. If I had the resources, I would look toward to the Exposure 3010p or XXVIII which is class B but amazingly "Valve like" in sound and effect (although the bass is better). Unlike (most) valve amps though, they are 100w+ into 8ohms which means they don't struggle with much.

Would agree with Alexs2 that Audio Note amps are capable of exquisite things in the treble and mid (although the bass is nothing to write home about and they're generally underpowered). We've been using an Oto SE for years to assist in voicing our product.

[mjn]

i like these http://www.ukd.co.uk/pathos.htm but they're not cheap!