Most suitable amps for Sadurni Staccato horns subwoofers

[spiritofmusic]

Guys and gals, soon to audition Sadurni Acoustics Staccato horns. The main horns (109dB/1m eff) will be powered by my Nat Audio SE2SE 211s SETs, but the dedicated subs (lower eff) will take a signal from the preamp, run thru an external digital x/over, the Behringer DCX, thence to a stereo power amp to fire up the subs.
The only requirement is 60W/ch minimum. I believe Sadurni demo well w/ Merrill Audio, but obv there is lots of choice.
What should I be considering? Class A? A/B? D?
What else?
Thoughts on brands and models, etc?

 

[flez007]

A good SET with will do for the horns I guess.

 

[spiritofmusic]

Fernando, I have the SETs for main horns (Nat Audio SE2SE 211s). It's the stereo amps of 60W-100W needed for the subs that I'd like advice on. I know Jorge favours Merrill, but I'm curious re alternatives.

 

[arthurs]

Hi, how do you find the NAT 211 amps? How do they tend sonically and are they quiet?

 

[bonzo75]

Hi, how do you find the NAT 211 amps? How do they tend sonically and are they quiet?

NATs are dead quiet. Low distorton. High transparency, separation, dynamics, and bass. Music notes tend to be more rounder.

 

[jdza]

I do not know the NAT amps but have significant experience with 211 based amps and very high efficiency horns:

I love the sound of a 211 SET and owned a very highly regarded model that I used on my low mid horns.I had previously used it on my 105db/W speakers where it was dead quiet. However on the 115Wb/W horns there was a faint hum that eventually drove me nuts. I had the amp rebuilt by a RF engineer. He managed to halve the hum levels(2mV to 1mV) but it was still objectionable. Wishing to stay 211 I wrote to a number of highly regarded manufacturers. Each and everyone of those replied that they would love to sell me their 211 SET amps but strongly dissuaded me from 211 claiming that it is impossible to get a 211 below 2mV of noise and that I should therefore look to other types of amps.

Just my experience in my system. No matter how good the sound ,hum in a horn system will eventually drive you mad.

 

[spiritofmusic]

JDZA, omg, those are drop dead scary beautiful horns. For my part I just love the aesthetic physical presence of horns which combines with the saturation of the room w/sound the best ones provide. I do have issues w/the tonality and mids-bass integration of a fair number, but that's a discussion for another thread.
I have to say that your reservation is highly relevant and a massive one counting against me going horns from my Zus.
My Zu Audio Definitions 4s are 101dB/1m efficient (ie well above the majority of box spkrs at 90dB) and one of their joys has been getting me into the world of SETs. But even at 101dB, hum/tube rush is audible (worse w/my previous Audion Black Shadow 845 SETs, less w/my current Nat SE2SE 211s), just within tolerable limits, and I know that going to the c.110dB hyper efficiency of Sadurnis (or Avantgardes/Animas etc) will bring this even more to the fore.
Additionally I have some hum issues w/my 8kVA balanced power transformer that adds to the noise mix.
Unlike others here, I'm not well connected re DIY solutions or mods to improve performance of my gear, so I may be stuck w/this level of noise (hoping to sort my transformer out soon).
One of the biggest issues against my buying the Sadurnis is impossibility of home trial, and so a hum free Sadurni-Merrill Audio SS demo (as will be the case if I audition them in NJ) may really not be replicated when set up in my home.
So having got into the aural Heaven of SETs-Zus synergy, I don't really want to contemplate going back to SS amps in order to make horns noise free.
Especially since in my many audio journeys in life, NO ss amp comes close to the Nat 211s. NONE, not even close.

 

[arthurs]

Thanks for the comments and insights. Hum is my concern in finding the right amplification for my Tannoy Weestminster GR. I'm looking to move into the 211 or 845 family, either SET or PSET version but many references I've read talk about some kind of hum and I'm never sure how exacerbated that would be with the Westies.

 

[bonzo75]

Hi Jdza is mostly right. Horns are best player with low wattage amps, you can have valves since you don't like SS. Whatever your choice of horns - sadurni, AG trio, Anima - a lot of low wattage amps Will sound good and you don't really need to search for sota now. A guy is selling his wavac integrated for less than 1500 quid, for trample, and that will make the Sads sing. A lot of UK and London foods will visit you with such amps when they come over to listen to your horns, and you can them choose.

For the sub, you can start with a crown pro gear digital amp that costs less than 500 quid and is excellent on subs. And then you can add whatever you choose.

 

[Maril555]

JDZA, omg, those are drop dead scary beautiful horns. For my part I just love the aesthetic physical presence of horns which combines with the saturation of the room w/sound the best ones provide. I do have issues w/the tonality and mids-bass integration of a fair number, but that's a discussion for another thread.
I have to say that your reservation is highly relevant and a massive one counting against me going horns from my Zus.
My Zu Audio Definitions 4s are 101dB/1m efficient (ie well above the majority of box spkrs at 90dB) and one of their joys has
been getting me into the world of SETs. But even at 101dB, hum/tube rush is audible (worse w/my previous Audion Black Shadow 845 SETs, less w/my current Nat SE2SE 211s), just within tolerable limits, and I know that going to the c.110dB hyper efficiency of Sadurnis (or Avantgardes/Animas etc) will bring this even more to the fore.
Additionally I have some hum issues w/my 8kVA balanced power transformer that adds to the noise mix.
Unlike others here, I'm not well connected re DIY solutions or mods to improve performance of my gear, so I may be stuck w/this level of noise (hoping to sort my transformer out soon).
One of the biggest issues against my buying the Sadurnis is impossibility of home trial, and so a hum free Sadurni-Merrill Audio SS demo (as will be the case if I audition them in NJ) may really not be replicated when set up in my home.
So having got into the aural Heaven of SETs-Zus synergy, I don't really want to contemplate going back to SS amps in order to make horns noise free.
Especially since in my many audio journeys in life, NO ss amp comes close to the Nat 211s. NONE, not even close.

Just as a point of reference- my Avantgarde Duo Omega G2 are 108 dB efficient and with my Lamm ML2 amps are DEAD quiet.
I mean absolutely quiet. With my ear to either tweeter or midrange horn, there is complete silence.
I think my preamp, Tron Syren Ultimate contributes to that, as well.
I have experimented with preamp disconnected from Lamms, and it is silent. With preamp connected, there is essentially no added noise.
Bottom line is- with the right choice of amps and preamp, even very high efficiency speakers can be completely quiet.
But aside from the background noise generated by components, you should be aware of the other possible noise sources- ground loops, RFI, EMI, etc.

 

[spiritofmusic]

Maril, nice work. I know Steve Williams here runs Lamms into his Wilsons and has zero tolerance for noise too.
My Nats show a certain low level hum and tube rush, and I'm relatively tolerant to all that. This is on 101dB eff Zus. My Audions were much, much worse.
Do you suspect going to 107dB eff will be a much stronger magnifying glass than 101dB eff?
Whatever, I will insist on listening to 211s thru the Sadurnis, as well as tt, not just digital, if I make the trial.

 

[bonzo75]

Impossible to get NAT demo in the US on sadurni unless you ship them over.

 

[spiritofmusic]

Bonzo, no need for the demo to be Nats into the Sadurnis. I know my Nats are a GREAT deal quieter than my previous Audions. As long as I can demo the Sadurnis w/211 SETs of some variety, I'll be happy.
I'm just about to max out my Zus to their full potential - finally the Duelund tweeter caps and Lundahl sub amp transformers are going in, getting rid of the SpkOn spkr terminals to go direct to spades, completing overhauled Sablon loom (new Reserva power cords, ic's and spkr cbls/scrapping my last Zu cbls, for 100% one brand loom holistic synergy), and upgrading all plugs and sockets to US spec/Paladium/non fused. This means that over July and August I will be hearing the Nats/Zus at their full potential, and will have the perfect comparison to the Sadurnis.
I know it's an understatement that you have no positive opinion of the Zus, but these changes may make you warm to them - halfway thru this flurry of changes, and imaging/dimensionality is already transforming, and bass agility/extension is a step beyond.

 

[Maril555]

Going from 101 dB to 107 dB is very significant
Probably 60-70% louder
10 dB is 100% increase in loudness level

 

[Maril555]

Actually, I should've clarified- though Lamms were quiet in stock configuration to begin with, I've made input voltage dividers to decrease gain, and that quieted it further down.
The issue of the whole system gain structure is frequently overlooked, which might be OK in average sensitivity system, but is crucial in high sensitivity one.

 

[spiritofmusic]

Well, I have a dilemma.
I'm going to have to make a decision based on demo in the US, not a home trial. Maybe extrapolate from another brand of 211 SETs into them.
Maybe this is like road testing a Ferrari on tracks I'm totally unfamiliar with, hoping for the best that she runs just as well on my local routes when I get her home.
In reality, this purchase will totally clean out my bank balance, I cannot stretch to more expense on different amps. Not at all.
Blue58, who runs 107dB/1m eff AG Duos from his quiet DIY build 45s SETs, is strongly warning me to think very seriously about the ramifications of tube hum going super efficient horns.
He has some hum, but it's tolerable.
Interestingly w/him, going to the trial Lampi GG w/DHT tubes introduced initially at least some unacceptable hum above and beyond.
Atm, hum on my system at 101dB/1m eff is acceptable, but I wouldn't want it any more obtrusive.
And my move to SETs has been so phenomenal, the synergy w/Zus so spooky, that I don't want to now ditch SETs to go horns if the only alternative to be sure of horns being hum free is ss only.

I have just emailed Jorge to get his thoughts on SETs/noise/horns considerations. He's been the very model of non hard sell w/me thus far, I'm confident he will give me an honest response.

 

[marslo]

"He has some hum, but it's tolerable."

Me too, but one can notice that only when no signal e.g. when music does not play.
I agree with Meril555 - it depends on several factors , I use some Acoustic Revive and Entreq tweaks to fight RMI,EMI . Very important are also the parameters of electric grid outside of home.
On the other hand the XA pre/power from Avantgarde which are special ss design were really DEAD quite during audition.

 

[spiritofmusic]

Atm, I'm reconfiguring new Sablon power cords, and going to US sockets on my bpt. Additionally the bpt is being looked at by the designer for some hum issues above tolerable. Re Entreq, I'm fully kitted out (S. Tellus/8 Apollos/S. Cleanus/Olympus Mini), but my hum is mot ground loops or rfi, more inherent to 211 SETs and the transformer itself. If this all bears fruit the Sadurnis will be a practical proposition.

 

[spiritofmusic]

Have just discussed tube hum w/Jorge, and while he admits this is an active issue to be careful about, he's never found in his experience things have been oppressive (other than an OTL w/poss rogue bottles). My Nats are a good deal better behaved than my Audions were, and once I get my bpt sorted, there may be less to worry about. He's listened to a lot of different tube amps, and personally doesn't run his horns via SS.
Atm, actively getting sorted to make the trip to Jersey. Considering making a week of it to NYC, visiting Sadurni install and Marty's DEQX dsp'd Spectral amp'd Pipedreams/JL Fathoms, both in in Jersey, and Oswald Mills Audio in Dumbo, Brooklyn (Imperias float my boat more than the Living Voice Olympians ever could do).
Demo in Jersey will be Sadurnis on the end of an Oswald Mills Anastase tt/Sony transport-Reimyo DAC/Oswald Mills SET amps/Merrill SS subs amps . The Sadurnis seem to have ousted previously owned Oswald Mills New Yorkers horns (no slouches themselves).
This is a fine system, and will I'm sure really show the Sadurnis of their best.

 

[jdza]

The hum issue I raised was specifically in very high efficiency drivers i.e. compression drivers. It only really becomes a problem in multi amped horn systems.If you are using most horn systems with a passive crossover it is unlikely to arise.The reason for this is simply that it is extremely unlikely that all components of such a system will have such high efficiency. Very few horn tweeters get to 110db/W and certainly no cone driver on a horn as seen in lower mid applications. The sensitivity of the vhe drivers are usually then padded down to meet the other drivers. At the usually resultant 109db/W (optimistic ) levels most well designed SET amps will not have a problem.


The real problem arise in multi amped setups with the individual power amp coupled directly to the speaker driver. In my case it was a low mid compression driver at 115db/W sensitivity. To reach 92db listening level that driver needs 0.05W. It is easy to see that not many of those milliwats must be noise before it becomes intrusive.


I personally would have no qualms marrying a 211/845 SET to a pair of Tannoy Westminsters. Some of my happiest memories were of 211 amps driving a pair of 105db/W Klipshorns-oh such a colourful albeit severly coloured sound.


A further issue with these very high eff drivers is amplifier choice. IME experience an amplifier that sounds good on conventional multi driver speakers may sound totally different when asked to deliver such low output over a limited bandwith into a single driver. Again my experience (as a dedicated tube fan) but sadly simple class A solid state designs works the best.