SET 45 Amp Driving Dynamic Speakers

Many lesser solutions have their charms. People choose or settle for them all the time.

The merits can be argued subjectively only. Often that’s enough for many of similar mindset.

Its just one of those things that some may go completely gaga over for good reasons but probably not so much with those who care more about technical aspects or what works best together or not and why.

My approach is I want to be able to enjoy listening at any practical volume needed. The only way to accomplish this is to avoid clipping and distortion.

One might be satisfied with lower volumes only but if speaker amp integration is not done well one may practically have no other choice.

Also distortion usually sets in at subtle levels that may not be clearly audible well before one becomes aware of a problem.

One may certainly choose to not care about these things but they are real issues to consider and understand for best results in most any case IMHO.

Yes the main point is it is not "ideal" but yet another compromise with trade offs that some perhaps many might easily live with.

A watt or two can also go much further when highest and lowest octaves are rolled off. That’s a reasonable trade-off as well that some systems might offer over others. My decent sounding table radio works that way. :^) Midrange freaks can be in nirvana for not as much. you might even hear things in recordings not heard on many much larger and more powerful systems.

Or if size and cost of speakers is no issue, and you are not adverse to large horns (good ones are very pricey), then you should be golden in the end with just a couple precious watts. Now that’s an option I think I might definitely be able to live with in the right house/room designed with that in mind.  But its not where I am at currently.

My point is that with more efficient speakers you would like it more, as the more efficient speakers can bring out more of that that amp can do right.

That’s a very good way to put it and not just in this more extreme case (only a few good watts available) but in all cases amp/speaker integration is one of the most fundamental things to address and get right. Otherwise it may still sound good within limits but you may not be getting the most possible out of your overall sound investment  and you may not even know what you are missing otherwise.

IMO nearly  the entire endeavor of assembling an audio system is subjective

I started out that way because I basically knew nothing about how this stuff really works.   I even lost interest for years because my sound was not what I wanted and I was too lazy to figure out why. 

Things changed when I started to focus on really understanding what was going on.    I was on teh right path soon after and finally found a happy place after not too long.

There is a difference between what one likes which is subjective and the decision making process that gets one to their goals.   That is best driven by objective learning to meet ones subjective goals.

Everyone ends up differently as a result because we all have different goals but there are right and wrong approaches to most any undertaking.  

Tommy,

I’ve heard all forms of demos at shows also, including very expensive high quality SETs using similar very large efficiency horns (with correspondingly stunning results).

The best thought out and executed ones, SET or otherwise, always exceed those that are compromised in some way.

Because of the few watts used, the difference between the best (large GOTO custom horns and bass bins comes to mind) and worst (Zu Essence is one that comes to mind, fine for acoustic jazz, very meh for rock/pop) SET demos I hear are perhaps among the most extreme possible.

So the ante is upped whenever one device asks more of another. That can be a SET asking more of the speakers (be more efficient and an easier load) or the speakers asking more of the amp (give me lots of clean undistorted power please).

Lots of ways to skin the cat acceptably perhaps but only only a few ways to really do it right/best.

I feel I’ve done it pretty well the second way currently at home (compared to the stellar SET demo for example I have heard as a reference among others) and look forward to giving the other way a try someday starting with a separate system on a smaller scale that I can compare and contrast with my in home larger "reference" system.

In the end its all a matter of expectations and how well things are executed together to meet them.

Charles,

I suspect there is a significant sized yet small minority out there that do venture into SETs or their like initially for various reasons, but on a limited budget like most first timers.

FOr example Glow audio sells a very popular and stylish looking SEP amp, the Amp 1 that will look quite nice in many homes. I’ve heard it at shows and it works quite well with many speakers. Jolida has various low wattage tube amps (not set) that also sound quite nice, like the FX-10 that I ’ve also heard.

These are very viable but well "compromised" options like all the rest for similar cost that some newbies might consider right off the bat.

The thing is speakers for an uncompromised set system tend to be larger and quite expensive and not something that will appeal to many.

Whereas with newer Class D amp technology in particular, one can create a small, manageable and reasonably uncompromised system quite easily with many options and for fairly modest cost.

Again, its all a matter of expectations and what limitations one is able to deal with effectively.

When it comes to tube amps, for me the fewer tubes the better. That’s where a SET amp has appeal for me. Thing is my Class D based SS system sounds so good, I have little incentive to look elsewhere other than sheer curiosity and the fact that I think this stuff is fun. I’m very glad I tried the Class D option first. So is my power bill. I’ve opted for modern technology that is also more efficient and green (and also best match my speakers around which my system is built for best results) than older amp technology that is the exact opposite and requires things be built around it for best results. :^)

Either way is perfectly valid and of course neither will appeal to all which is what makes the world go round.

Larryi the Class D amps I own and have settled with currently are Bel Canto ref1000m in my main system and C5i integrated in my smaller setup.   Both are simply wonderful devices.  

Id like to add a third system built around either SET or OTL amps but space is limited.  

Charles yes I am with you on that.

The challenge will be space and budget  is limited at first and I will be going only with an integrated amp, not separates.

I am open for suggestions but the white GLOW Amp 1, which I have heard at shows,  is my leading contender at present.   Aesthetics and WAF will matter as well.  It would go into a smaller room and my intent is not to have to play it loud (my other systems cover that).  Adding powered subs may be an option if needed.

I will likely downsize my  home at some point in a few years so options for smaller great sounding systems are of interest.   The Bel Canto C5i is my most recent shot at that and I have been most happy with that unit.

gsm18439,

No doubt an integrated subwoofer or two in play would change the game significantly and offload most of the work (which is always in producing the lower bass frequencies) from the SET. That is a very good way for any owner of a low powered amplifier to go. I would probably consider doing the same if needed. I’ve done it in the past with a mundane 15 watt SS amplifier and solved the problem practically and easily and with  top notch results.

" harmonic overtones were more developed and fleshed out "

That could be the pleasant 2nd order harmonic distortion Atmasphere pointed out perhaps?

If so who cares really. As long as it sounds good. Nobody ever said accurate reproduction of music always sounds best. Just like there are many ways to enhance a photo to make it look better. HDR on iphone cameras is a good example.  I use it all the time.

The speakers I have lined up for eventual use with a SET or similar tube amp are Triangle Titus XS monitors which are quite small not not particularly extended in the bass but still marginally efficient. They are small but very good for their size and their sweet spot is playing at lower to moderate volumes.

As a result expectation is that a SET or OTL would excel with these perhaps more so than any SS amp. Those using these with tube amps report consistently excellent results. Adding powered subs (most use Class D amplifiers these days by the way)would likely provide what is missing, let the amp do the thing it does best (low distortion when not over driven) and make the system a true top performer.

Charles,

Well, based on my understanding from Atmasphere and others, that’s how SETs work. It has nothing to do with semantics.

So that piano you hear is either a result of the amp working optimally and having very low distortion or if it is being stressed at all (not hard to imagine) the introduction of some pleasant sounding second order harmonic distortion.

Also the thing is its impossible for all recordings to sound like any single live piano listening session because each recording is produced differently. Also each live listening session changes based on listening location, close or far for example from the piano.

So if all piano recordings are sounding more like that piano, there is at least a decent chance that is a result of the sound of the system playing the recording, not the recording itself.

In the end it doesn’t matter. All gear does its thing a particular way and different people will take to different sounds for whatever reasons they choose. Its all good in the end.

Another test might be to listen to electronic synthesized piano or other synthesized keyboards that are not necessarily as rich in harmonics as a string instrument like a piano in particular. If I get those extra harmonics that don’t belong there not to mention clipping (even soft clipping) to-boot, that’s a very bad thing for me because the music will sound notning like the real thing done well live. How many electronic music lovers levitate to SETs as opposed to those into mostly Jazz or Classical?

Maybe with a pair of good Class D powered subs though. Then you can probably have the best of both worlds, Class D for the best bass and SET for  mids and high frequencies.

larryi, your assessment of the Titus is spot on!

Technically on paper, I think I would prefer OTL over SET in that the use of a transformer when needed can only hurt and not help most likely.

Problem with OTL for me is all those tubes and the limited choice of speakers for best results.

Also WAF and size though not so much cost.

I decided to try newer amplification technology ie Class D before diving into tube amps and have been quite happy there for a number of years , but of course curiosity still always kills the cat. Thing is though I (and many others including the pro reviewers) have found Class D amps to top performers in most regards already, the technology is not yet fully mature and will only get better. My ref1000m amps are several years old already. The newer ref600m models are said to be even better and knowing the technology that would not surprise me. That Class D still has upside coming down the road as swtiching frequencies and bandwidth continue to improve is another reason I hesitate to make too big an investment in tube amps.

Charles, yes Atmasphere s-30 would be nice and I have considered but looking for a more compact integrated amp initially.   Still waiting to see an  Atmasphere OTL integrated amp.  :^).

This would be a third system  in a smaller room if I do it and I am not seeking a large investment to compete with or replace my main system at least initially.    If things work out and I retire to smaller quarters at some point in the not too distant future and decide to downsize, maybe.  It all depends.  We'll see.