Sugden A21 Signature Integrated Amplifier

Audio Space Galaxy 34 and Cayin CS-55A. They are great amps in their own right. I still have the Cayin and need to roll some EL34 tubes into it. Have only used the stock KT88's thus far so there could definitely be some improvement still to come.

I also have a pair of Von Schweikert VR-1 speakers. Min. impedance is 4.75 ohms. It will be interesting to hear the a21 try to run those speakers. I suspect, based on what Richard has said, that the Cayin will fare better with that match. But then again, with 89 db efficiency it's possible that the Sugden will have enough juice to handle peaks.

 

Have you guys not learned anything yet? If it's not Audio Note, it's no good.

 

I think it's important to know which ones - There are essentially two types of tube amplifiers. Push Pull and Single Ended. To say that tube amps work with the KEF is true - there are Push Pull 100+ watt tube amplifiers which are happy to drive 2 ohm loudspeakers and their are 100 watt SS amplifiers that will shut off trying to drive a 2 ohm load. Indeed, in the reviews of my old Sugden A48B the amp blew it's fuse trying to drive a 2 ohm load.

Most modern day push pull amplifiers all have and 8 ohm and 4 ohm tap. Most of the common tube amps for first time tube amp buyers are typically KT88 and EL34 based push pull types offering 30-80 watt per channel - and Rogue Audio and others like the KT 120 offering 100 watts per channel or more. And articles have been written where most end users feel that subjectively tube amps are the equal of SS amps at tripe the power so a well made 50watt tube amp has a subjective volume the equal of a 150 watt SS amplifier.

I think any of these Tube amps (all are push pull class A) will drive the KEF LS-50 just fine. Single ended amps SS or tube (so virtually all AN amps) are a poor choice for the KEF LS-50. You will get far better sound out of the KEF LS-50 with the $2000 LM 216IA than you will with the $3500 Sugden or $25,000 Whammerdyne or AN 2a3 amps.

The biggest problem for SE designs is a lack of power - it basically cuts off most speaker options.

This is why for years and years I always sound like a broken record recommending the same damn speakers over and over and over because to be blunt there just ain't very many very ease to drive options at a variety of price points. An Speakers at $800, $1500, $2000, $2500 etc etc up the line. The alternates tend to either be cheap horns that shout or ring or have phase issues or they are single drivers with no bass or treble or they start at like $10,000. Sure the O/96 is SET friendly but not their towers or their small standmount. There is Zu Audio, Acoustic Zen - I mean there are some speakers out there but not as mainstream or available as - well - the mainstream speaker companies most all of which are designed off SS amplifiers. Generally you just need to read the manufacturer's recommended power rating. 30 or 50 watts minimum. Ie; absolutely not designed for a single ended amplifier of 20 or less watts.

I come from the source first approach - where no matter how good the speaker it can't fix what it is fed. I used to be in the speaker is most important camp and then just get an amp that can drive it. Many still view it like this. I no longer do - when you can compare a really good SE tube amp with a speaker that doesn't push the amp into distortion then you can compare the SE amp sound quality versus a 100 watt or 1000 watt SS amplifier all operating fairly. Then you sort of have an epiphany that SE is rather substantially better and you then seek out the speakers that can take advantage of them.

Thankfully, there are way more easy to drive speakers out there these days like Volti and Pure Audio Project and Spatial and a lot more Single Ended tube amps but none of these are really mainstream.

 

Bingo!

 

ART and Helom - where have I pushed AN - I just said that AN would be a terrible match for the KEF LS-50. And recommended push pull tubes at higher power.

Anyway this is about Sugden and I didn't want people to get the wrong idea about the sound of Sugden because of gross mismatching of gear. Sugden and 3.2 ohms

Yes overall Audio Note is my favorite audio company. Something has to be. Shhh - I also have a favorite movie, shirt, pizza, soft drink, book, painting, co-worker, shoe, and seat on the shuttle bus to work.

OMG - One should be executed for having favorites.

 

Add Decware speakers to your list. I'm using Decware 25th Anniversary SE84UFO3 Monoblocks (2.7 watts per channel), and Decware HR-1 speakers and getting incredible bass (in part because I'm also using a Decware ZROCK2 EQ component). They have other models that offer even better synergy with SET amps, including their Monoliths, DNA and upcoming DNA2. . . . .

 

The VR-1 was designed for near wall positioning in mind as I recall - it is certainly a lot easier to drive than the KEF.

I'm not familiar with that particular Cayin - the models I heard in Hong Kong were the big bad monsters that look like this


Fun fact - LM hired the Cayin engineers to design ALL of the LM amps. You will see some similarities like a 300B driver stage to the 845 similar to the 219IA.

See the back


22watts per channel SET and also 51kg.

Cayin's problem seemed to be the importer having issues back in the day. I wish a US company would pick up a Cayin's parent company "Spark" because they are more affordable.

With impedance it sort of matters where the dip is and for how much of the frequency response it covers. But the VR-1 looks to be a respectable match. I wonder what VS recommends power wise.

 

Thanks for that - They look GREAT and I like HE speakers and they have a number of affordable offerings.

 

Most, if not all, of Legacy Audio speakers are HE too. I've been listening to a pair of their least expensive Studio HD speakers for a month and find them better then the KEF LS50s in almost all aspects. My Raven tube amp at 32watts PP handled the LS50s just fine and I really liked the combo. I do believe the match with the Studio HDs at 93db sensitivity is a better match however.

 

What does "HE" mean in this context?

 

HE = High Efficiency

 

so the sugden halves in power in 4 ohm. then its no question that the sugden just cannot drive the kef ls50 adequately.

as for richard obsession of SET, I suggest you listen to PP DHT.

 

Been there done that - unless you have specific brand and model that you think is worth considering.

 

Lol, really?

 

I prefer the Legacy Studio HD to my LS-50 as well largely because I like the dynamic ease and superior bass depth and drive. Higher efficiency speakers almost always have a more open less boxy sounding presentation. They typically have a more vibrant sound on attack. Most lower sensitive speakers often need to be pushed harder to get going and many cite speakers that need to be played louder to come alive.

BUT, note that while the Studio HD is 93dB sensitive it is rated as a 4 ohm speaker and the Sugden has no 4 ohm tap. 4 ohm is probably okay for the Sugden - but you'd still like to see the impedance plot - just to see how low it goes. 4 ohm rated speaker usually (though not always) imply they dip a fair bit below that.

 

In this thread please tell me where I told Art to buy an Audio Note anything for his KEF LS-50. Cheers

 

You certainly provided your usual spiel about how one is ultimately better off with HE speakers that can be driven with SET amps. Seriously man, you sound more like an AN rep than a pro reviewer.

 

Do we really need to attack Richard about AN? These attacks are almost more on cue at this point than his recommending AN. I really don't see the issue...he has discussed many brands. So he loves a particular approach (HE and SET). I like his passion for that sound and get why he has it. And you know what...it's kind of relevant in a thread about Sugden. And so what if he recommends AN? They make a great product. Let's get over this already.

That's the interesting thing. Min. 10 tube watts and 50 ss watts!! Doesn't bode well but the fact that it can be powered with 10 tube watts I am guessing means it's not difficult to drive. The min of 4.75 ohms is from 150-200 Hz (as per Audioholics review). I think it should be fine but it's not the ideal match.

 

There's nothing wrong with having favorites or liking a particular sound, but continually denigrating other's purchase choices is something else. It's an air of superiority in most of his posts - that us ill-informed are just chasing our tails.

Art has plenty of experience with gear. I'm sure he was well aware of the basic principles of component matching. It's not as though he's a complete newb - one reason I was interested in this thread.

 

Honestly I don't see where anyone attacked Richard. Helom just pointed out the obvious. Loving a particular approach is not a bad thing. Dragging every thread to the same place gets old. I started this thread and I am already sorry I did. I admitted that the Sugden sound, with the LS50's, did not work for me. I'm guessing based on my experience with A21 and a previous audition with the A21SE that Sugden is not a sound I get on with. I hoped I was wrong and I listened to a dealer who was enamored of the Sugden/LS50 match. Especially for a small room at reasonably low volume. My belief is that the dealer was sincere. Honestly, I think that the midrange forward sound of many of the SET and tube amps that I have listened to isn't a match for my ears. I like a sound that is organic and natural in tone with a little different balance. That's OK because I am buying products for my room and my pleasure. Alright, have at it.

 

There are many HE speakers that I recommend and suitable tube amplifiers that I recommend for said speakers. AN gets recommended the most for two simple reasons - 1) I own them and have the most experience with them and 2) because they are at available price points. The reality is most audiophiles on most forums are not in the $10k+ speaker budget range or the $10k+ amp budget range. Most people are usually in the $2k to $5K range. Then for me to make a recommendation of something that I would personally BUY myself the options are limited. Plus I can't hear everything - it's not like I live in my parent's house and sit around all day doing nothing living off dad's money. There is limited time to hear stuff fairly. There are a lot of internet only brands or small American makers who don't or can't sell in the Asian market.

It's real simple advice - don't push square pegs down round holes. I don't really care what a person happens to favour but it is basic logic that when you buy low sensitive AND low efficient loudspeaker(the KEF is both) that you buy an appropriately powered amplifier. IE; buy amps and speakers that are on the same page. Generally look at what gets partnered at audio shows. And while you may see the same commentary from me not everyone does. There are plenty of newbies who read forums but don't post. I am a bit surprised that I have to spell this out to veterans audiophiles who should know that the Sugden is woefully out of it's depth driving the KEF LS-50 - or if you wish to spin it the other way the KEF is so lazily designed so as to not be able to be driven by a Sugden A21a. The KEF owner can blame the Sugden but just as easily the Sugden owner could blame the KEF.


My preference is for HE speakers and horns in big rooms and very good tube amplifiers (usually Parallel Single Ended). But like most people I have a budget and can't drop $700,000 on such systems so we live in the land of compromises both financial and in terms of space. Some audiophiles have to make more and more compromises than others whether by choice or circumstances.

I am fairly certain that I would 100% agree with Art's view that the KEF LS-50 and Belles Aria is a better combination than the KEF LS-50 and Sugden A21a combination. But that may very well be the exact opposite stance if the speaker was say the Pure Audio Project Quintett 15 or Teresonic Ingenium or yes the AN E.

 

Oops, correct. I forgot no 4 ohm tap on the Sugden. I suspect it doesn't dip much lower than 4 ohm... but I haven't seen an impedance plot to know for sure. I'm definitely enjoying the less boxy presentation as you mentioned, along with better bass and dynamics. I'd really like to try a SET amp at some point.

 

And you know what's great about Von Sweikert - he clearly bothered to actually test his speakers with both tube and SS amps!

My preference for HE and SET is shared by a lot of very experienced audiophiles who began with Low Efficiency speakers and High power - when I began in audio I touted 500 watts per channel SS and Professional loudspeakers almost all of which were low efficiency. And waxed on about measurements. And there are several low efficiency high power systems that I genuinely do like - but I almost never get a chance to recommend them due to the price of entry.

 

This thread has been an interesting read to say the least. My takeaway is that component matching is a total crapshoot. It might seem like on paper the KEF/Sugden combo was not ideal, but then again lots of speaker manufacturers claim their speakers are an easy to drive. HE speakers like Zu and AN are obviously easy loads, but Harbeth also claims their 83db/6ohm P3ESR speakers are an easy load. Those numbers are both lower than the LS50, so of course it's going to become confusing for consumers to figure out an ideal match.

 

I believe Ayon tube amps were the ones that Legacy brought to the last show I attended - so they like tubes being mated. There are many kinds of SET amplifiers and a previous notion that they are fat in the midrange is just kind of wrong. It depends on which SET amp and even which tube type.

There is some notion that SET has a sound type - they don't. Ditto for PP tubes. There is a reason that manufacturers make a KT88 amp and an EL34 because it is very likely you may like one considerably more than the other. SET amps have camps within camps. The LM dealer in Hong Kong noted that the 300B is a "lady amp"" in that it is gentle and elegant and a little polite. The sound is quite often more distant relative to a 2a3 which in spite of similar watts has more grip and power and drive and is more upfront.

It is very possible to like one much much more than the other. It's also possible that it could be speaker dependent - where you might like the 300B on a speaker that is a bit up front itself and create good harmony where the 2A3 would be too in your face. But what everyone will hear is a quite substantial difference between the two even by the same manufacturer using the same parts quality.

And that's just these two tube types - a parallel 300B (two 300Bs per channel instead of 1) can sound markedly different again). And then there are 845s, 45s, 211s, EL84s etc.

And then you get into the actual tubes for the amplifiers which then change things again. It's actually a bit of a headache. At least with SS it usually all sounds close enough that no one can tell most any of them apart when the level is matched and they have their bias removed.

It's also possible to like all sorts of SET tube types for those things that each does well. So if you do decide to go down the SET path with the Studio HD - it will be important to research which kind of tube is suitable to both the speaker and perhaps the sort of music you like most.