Speakers for Class A valve amp

orfalot

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Been thinking for a while about changing my speakers - and finally finishing my upgrade. Good job I put it off maybe as house move intervened so now have a bigger room.

My Audion Sterling EL34 Integrated is a relatively low powered (12 watts / 8 ohms) Class A valve amp. Web site for which says 89db or better efficiency.
Current speakers are Rega R3 (c.2002) which I only now spot are 6 ohm but they are 89db sensitivity (or was that efficiency?..). They have done me proud I'd say but would be nice to see what raising the bar can do.

Head scratching starts when thinking about impedance, efficiency (or sensitivity?..) and speaker power requirements. Then of course there's the thorny issue of 'aesthetics'...
Am not sure whether I can consider speakers of other impedances or more generally what characteristics I should consider given the nature of this amp.

Am always keen to get a deal and have seen a few ex-demo offerings which appear very tempting. As an example, have seem some Audio Physic Sitara 25.
These are 89db speakers but 4 ohms. The (distant) dealer assures me that say compared to some 4 ohm Sonus Fabers (a definite no-no according to him) the Sitaras would be compatible. (He tested both of them out with a similar spec amp btw).

My budget is in the order of £2K at time of writing (although as usual would prefer to spend less). All my other upgrade bits were bought used so thought I *might* buy new for a change. Would mean I can choose the finish etc. Of course if anyone has anything suitable going spare am more than happy to consider.

New room size btw is 20' x 14' (ceiling height 10'). The speakers are positioned either side of the chimney breast to 'fire' across the room.

Ta very much for your thoughts.
 

rabski

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The usual suspects: Audio Note, Snell, Living Voice, Klipsch, most horns, most single-drivers, Tonnoy concentrics, Heco, some JBLs.

Sensitivity rating is a starter, but it's not the whole story. A great many speakers look good on paper with lower-powered valves, but in reality need a lot more power to 'wake up' properly.
 

Lawrence001

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Does the amp have 4 ohm outputs? Many do. If not I'd stick above 6 ohm but bear in mind speaker sensitivity specs are usually nominal and can (and usually do) fall at low frequencies, often the reason valve amps are said to have loose bass. So impedance graphs are helpful here if you can find them. (German mags often include them and review Audio Physics quite often.

My usual preference for low output valve amps are speakers designed for such, Audio Note, horns etc.
 

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Ady

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There are some Klipsch Heresy 4 in Cherry currently on Ebay for your budget. Got to be worth a listen.
Cheers Ady
 

pmcuk

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A valve amp has an output transformer whose function is to "transform" the input impedance to the output impedance. It has a ratio of step-down between the Primary, or valve, side and the Secondary or speaker side. So it's not an "absolute" kind of component with a value like a resistor, it's a link between the valve and the speaker. Change the speaker impedance and this reflects back to the valve operating point. So it's not a case of the valve amp "not working" into speakers of a different impedance, what happens is that it changes the operating conditions of the output valve away from the design values.

So to take an example, if you used a Lundahl LL1623 output transformer with connection "C", the Primary the valve sees would be 5.6K with a 16 ohm speaker, 3K with an 8 ohm speaker and 1.6K with a 4 ohm speaker. So in simple terms if the Secondary goes down from 16 to 4, the Primary goes down from 5.6K to 1.6K. With a 16 ohm speaker the amp would give you rather nice controlled sound but at a lower volume, with a 4 ohm speaker the amp would be louder but looser sounding.

As previously said, speakers vary in impedance over their frequency range, so you'd basically just have to listen to the combination to see if it's to your taste. If you have different secondary settings like 4 and 8 ohms you can try both and see which you like better. There's not going to be so much difference between nominal 6 ohms and 8 ohms speakers, and in any case you'd just try combinations of amp/speaker to see how they work out.

I'm personally not a fan of horns, and I would only consider the usual kind of 2-way speakers with sensitivities of around 89db. If you have an amp that is rated 12 watts that should be enough for most small to medium rooms. You might just find that if you listen really loud it distorts a little. If it's unusual to play your system really loud then you might feel that the gain is sound quality of not using horns (i.e. if you don't like them) warrants setting up and optimising the system for "normal" listening levels. If you do like horns it's another story.

So with valve amps the bottom line is don't get too precious about slight differences in specified speaker requirements - think more about the operating point of the output valves.

Screen Shot 2022-04-27 at 14.13.42.png
 

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pmcuk

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Been thinking for a while about changing my speakers. My Audion Sterling EL34 Integrated is a relatively low powered (12 watts / 8 ohms) Class A valve amp. Web site for which says 89db or better efficiency. Current speakers are Rega R3 (c.2002) which I only now spot are 6 ohm but they are 89db sensitivity (or was that efficiency?..). They have done me proud I'd say but would be nice to see what raising the bar can do. Head scratching starts when thinking about impedance, efficiency (or sensitivity?..) and speaker power requirements. Am not sure whether I can consider speakers of other impedances or more generally what characteristics I should consider given the nature of this amp. Audio Physic Sitara 25...These are 89db speakers but 4 ohms. The (distant) dealer assures me that say compared to some 4 ohm Sonus Fabers (a definite no-no according to him) the Sitaras would be compatible. (He tested both of them out with a similar spec amp btw). New room size btw is 20' x 14' (ceiling height 10'). The speakers are positioned either side of the chimney breast to 'fire' across the room.
As a follow-on to previous post....
From what I can see there is only one speaker output on the Audion, assumed 8 ohms, but correct me if I'm wrong. For a 4 ohm speaker it would be best to have a 4 ohm tap, otherwise the sound will be louder but less focussed, because the Primary impedance would be lower than ideal for the EL34s. So a nominal 6 ohm or 8 ohm speaker would probably work best. If you like the sound into the Regas then your amps work OK into 6 ohms. The Sonus Fabers are probably a no-no because sensitivity is lower - the Sitaras are 89db which should be in the ballpark, though the 4 ohm spec may be more of a compromise. But why not try out your existing Rega R3 speakers in the new room before making a move? You say they've done you proud. You would also need to know if 89db sensitivity speakers work for you in the new room as a guide to the sensitivity you require in any new speakers. So be curious, but don't jump until you have more info! Everyone here is going to give you a list of speakers, but if you are buying without audition find out as much as you can about the basics of valve amp-speaker interaction first. Good luck.
 

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hearhere

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Been thinking for a while about changing my speakers - and finally finishing my upgrade. Good job I put it off maybe as house move intervened so now have a bigger room.

My Audion Sterling EL34 Integrated is a relatively low powered (12 watts / 8 ohms) Class A valve amp. Web site for which says 89db or better efficiency.

New room size btw is 20' x 14' (ceiling height 10'). The speakers are positioned either side of the chimney breast to 'fire' across the room.
That's a large room (280 sq ft / 2800 cu ft) for a 12 watt amp unless it's connected to a genuinely high sensitivity (efficiency is a misnomer) speaker.

You should be looking at speakers that match the Ohm figure shown on your amp's output connectors. Most valve amps offer nominal 8 and 15 ohm outputs. A speaker with a relatively flat 6 ohm impedance should be OK on the 8 ohm outputs, but best to avoid 4 ohm speakers unless your amp offers this.

I'd be looking for speakers with a minimum of mid-90s sensitivity with your amp, but closer to 100 much better if you ever want to turn up the volume - so basically horns. Some here don’t like horns, but I’d suggest they may not have owned or listened carefully to good ones. It’s easy to build bad horns (eg most DIY efforts) but a lot more difficult to build good ones that don’t “honk”!

So, I'd look towards either horn speakers with your existing amp, or change your amp to a good ss one with a respectable output, in which case you can vastly widen your speaker search as neither sensitively (within reason) nor impedance should be a determining factor.

You may find a used pair of AG Uno horns within your budget, but get ones with 10” bass drivers. These are 102 dB so will offer good sound at a decent volume with your amp. I had the choice of 6 watt PX-25 or 18 watt 845 based amps, but preferred the former on small scale music (female voice etc) but the latter for big orchestral stuff. I’ve now switched to a Class D amp with no regrets whatsoever.

PS - Sorry I miscalculated your room area in my earlier edit!
 
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rabski

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20 x 14 x 10 is 280 square feet and 2800 cubic feet, though the overall size is less important than the distance between speakers and listener. My listening room here is about 7000 cubic feet, with a very high vaulted ceiling that's good at diffusing sound. At the moment, I've got the review Audio Note Meishu plumbed in, which is quoted as 8 watts per channel. My Living Voice are stated as 94dB, but it's generally suggested they are a touch less. That combination goes more than loud enough.

Not that I've anything against the Avant Gardes, as I've come close to buying some on more than one occasion. It's simply that with 12 WPC, anything over 90dB sensitivity is likely to have no issues in the 'loud enough' area. It's more a question of how it goes loud, than of how loud it goes. As per my earlier post, it's not always as straightforward as just matching power and sensitivity, as some speakers will go loud enough, but not work that well.
 
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karlsushi

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I've been reading these suggestions with interest as I'm starting to look into the idea of higher sensitivity speakers.

First thing to say is most of these suggestions seem to have ignored the fact the OP is looking at 'new' speakers with a budget of £2k. Talk of Living Voice, Vandersteen and Avant Garde is therefore a little unhelpful.

I've done a bit of research on this myself and there's not a lot of high sensitivity options around that price range, so you're probably best looking at second hand, or saving up a bit more cash.

Wilmslow Audio (based near Leicester, not Wilmslow!) do a pretty wide range of DIY kits, but they also offer fully built versions of their kits and do some high sensitivity options within that price range.

Other than that, you're only other viable option might be an ex-demo Heco Direkt or one of the more budget options from the Klipsch range.

Not a lot going with high sensitivity within that price range sadly, unless anyone else can enlighten us.
 

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pmcuk

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From another thread.... "Hmm, I didn't know the Vandy 1's were that efficient...". "They aren't, rated at 90db, but only measured 87db in Stereophile review". So some manufacturers' specs may be slightly misleading.

The thread also mentioned Tannoy Mercury 4, 91db sensitivity. These are MTM (midbass-tweeter-midbass) and doubling up on the midbass units is one way of increasing sensitivity, so look for other MTM designs.



A lot more information on this forum: https://www.audioasylum.com/forums/hug/bbs.html

Information on MTM speakers here: https://www.diyaudio.com/community/threads/mtm-sound-characteristics.356684/

Amphion do some MTM speakers, e.g. this rated 90db https://amphion.fi/enjoy/products-h...1483020937940-673f4ff1-f7f91aef-8a4b443c-51d9

Also the Argon 7 rated 91db. You'd need to buy used in this case https://amphion.fi/enjoy/products-h...7940-673f4ff1-f7f91aef-8a4bd011-41e20226-52d2
 
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karlsushi

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Zu Speakers may be another option. Most out of price range, but the Omen II's might be achievable.

97dB at 12 Ohms, so a very easy load in theory.


An American company, but there are UK dealers I believe. Never heard them myself, but I'm intrigued.
 

rabski

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I've been reading these suggestions with interest as I'm starting to look into the idea of higher sensitivity speakers.

First thing to say is most of these suggestions seem to have ignored the fact the OP is looking at 'new' speakers with a budget of £2k. Talk of Living Voice, Vandersteen and Avant Garde is therefore a little unhelpful.

I've done a bit of research on this myself and there's not a lot of high sensitivity options around that price range, so you're probably best looking at second hand, or saving up a bit more cash.

Wilmslow Audio (based near Leicester, not Wilmslow!) do a pretty wide range of DIY kits, but they also offer fully built versions of their kits and do some high sensitivity options within that price range.

Other than that, you're only other viable option might be an ex-demo Heco Direkt or one of the more budget options from the Klipsch range.

Not a lot going with high sensitivity within that price range sadly, unless anyone else can enlighten us.
OP actually satetd 'might' look at new, so used is certainly in the ballpark, though I agree Avant Garde (and some others mentioned) aren't going to happen.
 
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tuga

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My Audion Sterling EL34 Integrated is a relatively low powered (12 watts / 8 ohms) Class A valve amp. Web site for which says 89db or better

I would look at:

a) high sensitivity (> ~96dB) due to the low power rating and to avoid the likely high levels of harmonic and intermodulation distortion when driven hard

b) easy load to avoid the frequency response being overly affected by amplifier/speaker interaction

Ideally you should be looking at horns with active sub-woofers (e.g. Avantgarde).
 

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Zu Speakers may be another option. Most out of price range, but the Omen II's might be achievable.

97dB at 12 Ohms, so a very easy load in theory.


An American company, but there are UK dealers I believe. Never heard them myself, but I'm intrigued.
The Zu Audio Omen Def speakers are featured in the Stereophile review of the Audion Sterling Anniversay edition in Absolute Sound. (2012 review by Dick Olsher.) Interesting review btw, describing the history of Audion from its days in an ex betting shop run by David Chessil having split from Erik Anderson (Audio Innovations) to a modern factory with transformer selfwinding capabilities in France under new ownership.

Jack
 

Non-Smoking Man

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I'm heavily committed to high efficiency systems as I find they suit my 'ear' and my priorities (effortlessness, air, timbre, life).

I run 2 such systems - one is a multiway active horn system and the other, more relevant here, is a conventiuonal TT/phono/amp/floorstanding speaker system (with subs).

The speakers will be of interest - Jantzen TQWT..read on..

Pete, I recommend you find the Troels Graveson website homepage and click on 'The Story behind the Seas JA8008 TWO34-WG Project'. There will be an essay there that details the story behind my speakers and, notably, the reasons for designing a 95 db/w bass/mid driver and handing over the work to the highly regarded Norwegian 'SEAS' company for the construction and production.

There is some excellent theory about driver design and driver matching including the reasons for selecting the particular Son Audax unit Jantzen finally ended up with.
Further, there are suggested applications for this duo - a double TQWT, an 'Onken' style cabinet and an open baffle option (some of these incorporating a larger sub bass driver to augment the bass - I found a pair of 18" Bastani subs a welcome addition in my system.)

Clearly it will be nigh impossible to find a pair of Jantzen TQWTs (short for 'rearloaded horn' haha..) second hand but having read the articles above you might be encouraged to go down the DIY route and buy the kit. You might opt for a pro cabinet builder if you dont fancy a selfbuild.

Unfortunately mainstream design, production and marketing people have little time and energy for High efficiency/Low (valve) power amp - type systems so the DIY route is one we are often forced down, be it with SET amps or HE speakers. We are not catered for, by and large..

Alternatively you could seek out the Odeon Rigolettos that were advertised by Bandit Pilot and sold to a Wammer. They are a professionally made and beautifully finished ringers for the Jantzens.

Or get a pair of Living Voice Auditoriums (Avatar edition perhaps) - I nearly did - or an old pair of Snell E's with refoamed bass/mid drivers - I did.

Jack NSM
 
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hearhere

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OP actually satetd 'might' look at new, so used is certainly in the ballpark, though I agree Avant Garde (and some others mentioned) aren't going to happen.
The OP shouldn't give up on Avantgarde quite yet. A couple of years ago I found a pair of 2006 AG Duos advertised for just £2200. That sort of bargain is rare and I spotted it minutes after its listing and bought them next day. I was specifically looking for Duos and set up alerts when new ads were posted. I suggested Unos as they are less costly and not a lot short of Duos in sound quality - comparing earlier generation with 2 separate horn tubes.
 

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I'm happy with my Tannoy Monitor Gold 3LZ. Work well with my Audio Innovations Series 500 Valve Amplifier with 17wpc... 👍 👍 👍 😎 😎 😎