single ended low power valve amp?

indus

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:)Hi guys,

still trying to put together a shortlist of amps for my new MA PL300 speakers.

I read a review of these speakers in Hi Fi World, and the reviewer said that big efficient speakers like this need really small amounts of power. Indeed, he measured a usage of max 10 watts.

He said its in these low power usage situations that solid state amps perform badly, and suggested a 'single ended low power valve amp' would suit better.

I think this is something that IBstyling tried to explain to me in another thread.

1) What does 'single ended' mean?

2) Are all non valve amps termed solid state?

3) Can anybody recommend me some single ended low power valve amps to look into?

Thanks:)
 
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Single ended means no feedback, I have a SET (single ended Triode) 211 valve amp, Superb but not for home cinema, unless you choose full range horn speakers, you will need a very big room and an even bigger pocket !

All non valve amps I consider sold state.

I can recommend lots but good ones are very expensive TRON, KONDO, BORDER PATROL
 
I'm not sure you're quite into the single ended amplifier teritory with these speakers... nearly.... you will get a lovely mid and treble, but you need to go to a GENUINE 95db/1w speaker to use the awesome bass potential of this speaker. (I heard a pair in Harrods on Monday- what are the chances!!)
Please demo away for a good matching amp - but i would be looking at a pair of jungson ja-50 monoblocks myself- or the ref 100's
(That's a bit of a audio gem right there- only for those in the know :smashin:)
Snken transistors, no negative feedback, all class A- sounds like a valve amp, but with guts-and a ridiculous price for what you're getting- it would cost me double to build it!!

just do me one favour- invite me over to hear it if you buy one!!
 
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sorry, I'm a bit confused. Are we saying that single ended valve amps may not be suitable because

1) Very expensive

2) Not suitable for home cinema (why?)

3) Can't control/produce/control the bass on these speakers (why?)

Thanks:)
 
sorry, I'm a bit confused. Are we saying that single ended valve amps may not be suitable because

1) Very expensive

2) Not suitable for home cinema (why?)

3) Can't control/produce/control the bass on these speakers (why?)

Thanks:)

I'd say 3),as they're not quite efficient enough for a 10 watter to fully get hold of the bass end of the drivers, like 'lbstyling' says, you really ought to have much higher sensitivity than 90db for use with a low power SET amp
 
SETs are generally considered the gold standard in rarified circles. They have the most transparency but the least power - typically only a few watts. They're usually used with really high efficiency speakers - horns, and Zu Druids, and things like that.

I think there's a lot to be said for no feedback and no cross-over distortion (or jitter!). You get it right first time, rather than correcting it after it goes wrong. The figures look worse, but the sound is better. Often the way, to my mind.

Nick

BTW, SETs use triodes rather then tetrodes or pentodes, which are more commonly used on valve power amps.
 
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This is confusing a simpleton like me.

I started off looking for very powerful amps because that's what I thought the new speakers needed.

Then people here start to explain its not all about the power, and the HiFi world reviewer said he couldn't find a singlr solid state amp that really worked with the pl300s.
As a result he recommended the low power valve that he said was very good with the bass.

Now here the impression seems to be that valves won't control the bass.

Organising a home demo is time consuming, so I'm trying to focus on a handful, but seem to be going around in circles
 
I'll keep it simple.

10w, regardless of what is producing it and how well it is producing it, simply isn't enough to drive, or control the PL300s at even moderate levels. They do some wacky things in HfW and I'm pretty sure that when the reviewer made that recommendation he qualified it by suggesting the combination wasn't going to suit large rooms, party volumes or Dolby Reference levels in a Home Cinema. If he didn't he probably considered it implicit in the use of SET valve amps.

Here's the simple bit; If you want an obvious suggestion, then what about the amplifier that you liked the sound of the PL300s partnered with enough to buy them? That sound was so good it got your cheque book out.

Russell
 
This is confusing a simpleton like me.

I started off looking for very powerful amps because that's what I thought the new speakers needed.

Then people here start to explain its not all about the power, and the HiFi world reviewer said he couldn't find a singlr solid state amp that really worked with the pl300s.
As a result he recommended the low power valve that he said was very good with the bass.

Now here the impression seems to be that valves won't control the bass.

Organising a home demo is time consuming, so I'm trying to focus on a handful, but seem to be going around in circles

i feel for you indus, i realy do. been here- round and round!

ill do my best to help you see my opinion at least....

1) above all else, and before anything else- you need a system that will energize a room fully, this means that you need to select a speaker that has a reasonable cone area compaired to your room.
-its much harder to have a cone area too big for a room than too small- too big a speaker is a unlikely and un-common problem, but too small is very common.....so, i know how big your speakers are, but how big is the room?

2) you need to be able to control the drive units propperly.

this depends on the speakers and 4 factors of them, they are;
a)most importantly the TRUE efficiency of the speakers-at its lowest point.
b)the MINIMUM impedence of the speakers
c)the f3 of the speaker (the point at which the bass is rolling off by 3db. NOT the commonly refered to 'frequency range' as this means next to nothing.
d)this is a little complicated, but its essentially the force available through the magnetic field (bl and flux density) vs the suspended weight of the cone and voice coil- lets leave this for now- but this becomes vastly more important if you have a speaker that is under size for the room.

now if your room is small enough, you can get away with a valve amp...yes. because your speaker will not need to move much to energize the room as its quite big....a envious position to be in in the first place as in my opinion your ahead of the majority of people!- theres a price though- you will sacrifice the lowest of bass if you go with valves regardless of what your speakers are.

as mentioned earlyer, a SET valve amp is by nature VERY low power (6-12w) and if you did go this way - i whole heartedly plead with you to have a listen to a valve amp using 300b valves- the border patrol amp is a amazing example of this.

but if your room isnt tiny- just forget it- a SET valve amp will give you a vague, overly warm, muddy, bassless, guttless dynamicless mess.

for a regular-large room to run a SET amp, you need a speaker to have 95db/w + and because of the laws of physics, this speaker will be massive.

in short- systems are forced to conform to a style baised on the sise of room vs the size of speaker.

your speakers are large (good start) but are fairly average efficiency- you can run what you like -but will likely find you will need 20w+ (solid state for good low end) or you could sacrifice a little low end and have a higher power valve choice- say 30w+.

the reviewer of the pl300's would likely be a fan of valves and grasps at the oppertunity of running a hard cone on valves-which is very very rarely a do-able combination. (my magnesium cones are a typical example of 85/86db/1w- which just isnt a valve friendly load) in fact i can think of only one other hard cone speaker that is vaguely valve friendly- avalon acoustics.

if you do go for the higher power valve examples, they dont have the magic of the SET class A amps -so the advantage of valves becomes less clear.+ they take lots of TLC to keep the sound sweet over time and require replacement valves (like a lightbulb does)

whereas there is the option of the SET class A SS amps (not many choices here) and the jungson amp mentioned earlyer is a very very good example and the cheapest also!
 
Thanks. I think I'm beginning to understand.

Russell, I broke one on the cardinal rules I'm afraid. I bought the pl300s having never heard them!
I've owned lots of MA speakers, gold and silver series, and so felt I knew the family sound. All the reviews were great (I know, never buy on reviews) and I got a cracking deal.


IBS, thanks. I've done a search on the Jungson and not much is coming up. All I've managed to gather is that they are made in China. Who actually sells them in the UK?

Having bought the speakers 'blind', I defo need a home demo of any amp I may buy.

My room btw, is 18ft by 12ft and semi open plan to another room that's's 18ft by 15ft.

Thanks.
 
I'd suggest that you get some good suggestions on matching amplifiers, regardless of the technology used (so might well end up being solid state).

With simply average efficiency speakers (which it sounds like yours are), you might want to checkout some of the more powerful valve amps, e.g. units powered using some 6550 valves. I've come away impressed from a number of amps that I've heard using this valves. One of the better (at vaguely sensible price) was from World Audio (they have their own website sellings kits and fully assembled units).

Above all, do make sure that you get to have a listen to see how well the speakers and amp match up.
 
Getting valves to work well and produce serirous dynamics is straightforward it's all about efficient speakers and sufficient drive.

The highest ouput SET amps get to 12W or so. I think my 211 is 11W and these valves are nearly milk bottle size and require 1150V !! Use a 300B in SET you will be nearer 3W. Not a problem with a high impedence efficient horn ( circa 16 Ohm and 105 db/W) So a 100W amp into a 87db speaker needs only 3W into a 105db speaker ;)

To compete with 105db and 11W you will need over 300W and guess what the 11W valve amp will sound a lot louder (I don't know why maybe they manage much greater peaks for a given output)

Take all this into account and the cost of good valve amps and efficient horns and the space required to house the horns. Then you will need a very big room and a LOT of money. Would it sound awesome, my god yes. But done with no consideration for cost you could end up buying a Ferrari of two AND a good solid state home cinema :eek:

The Living Voice Olympian are simply awesome and 105db/W with the bass horns they go LOW and have dynamics that box speakers can only dream of, but........... don't ask the price

UK High Fidelity Loudspeaker Manufacturers | Kevin Scott | Living Voice
 
Getting valves to work well and produce serirous dynamics is straightforward it's all about efficient speakers and sufficient drive.

The highest ouput SET amps get to 12W or so. I think my 211 is 11W and these valves are nearly milk bottle size and require 1150V !!


There's always a few points to add.....firstly,SET's are not neccessarily low powered amps,and there are a few(hideously expensive) SET's offering up to 100w/channel.

Another simple way of increasing output,beloved of the 300B users,is to simply parallel the output tubes.

The major cost item for SET amps is the output transformer,and to design a good one,and build it,is a bit of a black art.

SETs are very sensitive to both load impedance and reactivity,and this means that with a load having wide impedance and reactivity swings,the frequency response is influenced to very large degree by the load,which in effect is acting like a rather crude tone control.

Here are a few references which may help...

Single-ended triode - Wikipedia, the free encyclopedia

WAVAC Audio Lab. Power Amplifiers (this is for anyone who thinks that SETs are solely low powered amps!...these things are staggeringly expensive,but it's worth a look just for interest).

Most of the truly high powered SETs use transmitter triodes such as the 211/845,and for real grunt,the rather monstrous 833.
The anode voltages on these things are well into the 1kV range as IWC Dopplel has already said,which adds another dimension to power supply and transformer design.

There is a school of SET thinking that holds the idea that the most linear triodes are the 2A3 which has an output of 2-3W,followed by the 300B with up to 9W or maybe more with some of the newer tubes,followed by the 211/845.
 
I have never heard of the 8033, looks interesting :eek:
 
I read that review a while ago and I don't recall any mention ofthe extreme low powered SET amps. He did say that low powered valve amps work best, but considering they used an icon audio MB845, a class AB 90watt per channel triode amp, I don't believe he was talking about the 10w SET amps mentioned earlier. Perhaps the reviewer was simply referring to the fact that the PL300 don't need alot of power, and valve amps are relatively lower powered.

And I'd agree with the reviewer, all the solid state amps I've tried with my MA gold series speakers (not too different to the plats), make them sound clanky and metallic. My audio research valve amp sounds so much more natural, they don't sound like metal driver speakers through this amp - apart from the awesome clarity.

Having said that I haven't compared the ARC amp to a similarly priced solid state amp, so it's a bit unfair to dismiss them. From what I've heard, plinius, musical fidelity and naim amps should work well.
 
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I did mention this in yet another of my threads, but should do so here also, as people have tried to be so helpful.

I tried a naim 282 pre and naim 250 power at home for a few days. What transpired was that my powermap (quad909) is up to the job.

The weak link was the quad pre (built in my cdp2). When I used the naim pre with my quad poweramp things were much much better. I had blamed the poweramp out of ignorance, but the transparency of the pl300's had revealed the shortcomings of the quality of the variable output of the quad cdp.

so, I have decided to keep the Quad 909 (maybe add another later for bi ampin) and concentrate on finding a dedictated stereo preamp.

Thanks:)
 
I agree SE Triodes are not for this speaker but are capable of great things. I have used them for over 20 years now but need to be used in the correct situation and some good info has been posted already.

211 / 845 you should be able to get more than 20w out of them, even a 300b should be capable of 8/9w though many might want to reduce these a little to drive the valve at the sweet spot.
 

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