Changing to a Valve amp, but what type?

Got my head and heart set on a change to a valve amp and have been looking at this one, partly because I like the look I must admit.

BUT, I know nuffin about valves. KT88, 300b, single ended, triode etc all of which are a mystery to me.

Is the amp I am looking at a good one? are their better types? what are the key things I need to be looking for? Any specific recommendations.

Probably an important factor is speakers, Any amp will need do drive a pair of Sonus Faber Cremona Auditors rate at 4 ohm and 88db

Also only need single input, the source will be turntable only, don't have a CD player anywho.

ANY advice suggestions appreciated





Thanks

 

what are you changing from ? your speakers are good so its hard to advise as you could go from a few hundred s/h to tens of thousands. in the reasonable price bracket (£1800) the Manley Stingray is well reviewed (and looks unique) but I am sure the more experienced valve users will have more useful opinions than mine. Puresound A30 again, well reviewed at £1100. there are literally hundreds out the at the mo.

 

Thanks

It was more the type of valves and the way it works ie push pull, single etc rather than specific recommendations of amps i was after.

 

sonus reccomend 40w+, and with the sensitivity you describe that sounds about right to me.

You could get something more poweful..but I would avoid low power valve amps with those speakers.

You mention different valves and topologies.

With the power you're looking for it will be ''push pull'' more than likely.

Also, you're likely to be looking at EL84,EL34 6550 or KT88 tubes. You may look at 300b, but this will be less common.

EL34/KT88/6550's are very similar tubes and in some amps interchangeable.

This is the kind of amp that will drive speakers of that sensitivity, but it's not a reccomendation, just a 'type' to narrow down to.

http://www.positive-feedback.com/Issue24/cary_sli80.htm
http://www.stoneaudio.co.uk/

 

Thanks bottle, very helpful

 

EL34s





Seem to be generally recomended

There seem to be plenty got at though.

Check out hotrox

http://www.hotroxuk.com/


for options.

A very informative guy there.

As for HOW they work.......I'm not sure. I must find out one day!

 

Links

Some good links here:

http://www.hifiwigwam.com/view_topic.php?id=25279&forum_id=1

M

 

Some excellent info and links there guys thank you. But it does leave me with one key question.

A few places I read Transformers are hugely imortant to a good amp. If that is true how do you tell if the transformers are any good or not.

Is it size/weight
Specification
something else


Any clues?

 

I have heard a 10W triode amp using cheap mains transformers sound pretty good. Didn't handle my then Monitor Audio Silver 9i's very well though - they had an odd freq response curve.

As part of a project build I aquired a 20W push pull using Swedish made Lundahl transfomers (same massive main transformer as the 10W) and this baby handles most loads.

More than enough omph for my ProAc D25's...

I am looking for a cheap 2nd amp for fun / 2nd room see other thread - has anyone heard these...

 

Oh God, that there is a whole other thread (and a very very long one at that). Apparently, all modern transformers are rubbish, according to the old-timers in the forum that are familiar with vintage tube amps. Modern SET transformers that do a half decent job are outrageously expensive.

To be honest, I don't see why you should get bogged down in the details about transformer quality for a £1k amp in a second system. I doubt they'll be anything special and you should focus on an overall balance of sound quality versus features, serviceability, reliability and ease of use.

DT

 

In the words of Gary Dews of Border Patrol

...and I loosely paraphrase..

"If you want to know what makes a good valve amp, look at the power supply. If you want to see what makes a bad amp perform poorly, look at the power supply!"

Alphatoner, the power supply of a valve amp is key. Some superb valve amps don't use output transformers, but those that do ..this is a key component.

If the heavy square blocks at the back of the amp weigh an absolute ton, this is a good start. If the power supply is valve rectified with a choke input, this is a often a good thing too.

Have a read of the border patrol site:
http://www.borderpatrol.net/psuind.htm

NB I did not mention Border Patrol because their most powerful amp is 20w. They are a massive sounding 20w with the biggest power supply however.

 

Once again thanks, makes sense, the second amp i was looking at weighs a total of 8.5kg as opposed to a lot of others which weigh in at the 18kg+ level so i guess that tell me all I need to know.

I do LOVE the border patrol kit, saw some of it at the Heathrow show. Sadly they have a hugely expensive price tag to go with it and with a max budget of £1k puts them firmly out of the picture even 2nd Hand.

 

I just like talking about valve amps, I've always loved them, always seem to come back to them.

Here's a few winners.

cheapish, and good stuff
http://cgi.ebay.co.uk/AUDIO-INNOVAT...ryZ14973QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

not bad, slightly dear perhaps.. but it is a shop, so you have some come-back.
http://cgi.ebay.co.uk/audio-innovat...VQQcmdZViewItemQQ_trksidZp1638Q2em118Q2el1247

big and powerful. Had a similar model myself once. better than the chinese stuff you'll get for the same money, and better than audio research of the same era IMHO.
http://cgi.ebay.co.uk/CONRAD-JOHNSO...ryZ14973QQssPageNameZWDVWQQrdZ1QQcmdZViewItem


a few thoughts.

if you buy second hand you may end up changing the odd resistor that may blow.

 

Just sent a message to the guy with the conrad johnson, one of his previous ads said he may deliver personally.

I've asked because I had a heart attack 10 days ago and I'm not able to drive at the moment, but if he will deliver I think i will give that one a shot.

 

Hi

Really sorry to hear about your attack. These things weigh a ton, so be really careful..

Its a great amp, I can't see you being dissapointed for £799. It would have been more like £2k new.

Just behind the EL34 tubes and in front of the output transformers (reassuringly heavy! ) are a couple of fuses.

When a valve goes 'pop' the amp will blow one of these fuses. If you buy the amp I would reccomend taking a fuse out, and buying some spares. This is because they take a bit of getting hold of, more so than a new valve that's for sure. It was a real PITA when they used to go and I didn't have a spare.

It is rated at 45w p/channel, so should be potent enough for your sonus fabers.

I hope you enjoy it if you go for it.

If not, it has to be worth 7-800 on ebay again!!

 

Thanks

I'll let you know what he says, or maybe see if i can get a lift somehow.

 

this is a bit newer, worth a look.

http://cgi.ebay.co.uk/ROGUE-AUDIO-S...VQQcmdZViewItemQQ_trksidZp1638Q2em118Q2el1247


http://www.uptownaudio.com/rogue/st90amp.htm

nb, you can swap it to 'ultralinear' - which basically doubles the power, for slightly worse sound. Otherwise the same power as the CJ

 

here is a Puresound, second hand at reasonable price - just click on ''stuff''...

http://www.definitiveaudio.co.uk/definitive-stuff.html

For £650, that's very reasonable, and nearly new so blown parts are less likely for a few years.

I will stop throwing spanners into the works now.

 

I have a Rogue Stereo 90. I recommend it highly, but then I'm biased.

 

I have the predecessor, the Rogue 88 and its bloody fabulous. Amazing vfm and oodles of driving power. Very highly recommended.