What are the Sonic Trade-offs in Using Low/ High and Tube vs. SS with High Efficiency Speakers?

[Jägerst.]

That microscopic tendency in horns is exactly why I would never use SS with them.

Again, my experience with horns (horn hybrids and all-horns) + SS amps has been most rewarding with actively configured setups, where I find amp principle matters less (and where they sound much better) than with passively configured speakers. Below 4-500Hz - at least IMHO and specific setup context with horn hybrid speakers - is really about sufficient power (i.e.: plenty of headroom) and driver control, or ~2.5kW combined here in my case to the mid bass bins and TH subs (100 and 97dB sensitivity respectively). Above that range I have 111dB sensitivity at hand coupled directly to 30W pure Class-A. In a passive setup sensitivity would have to be matched to the least efficient driver segment, and so a 111dB horn/driver combo being "throttled down" to, say, 97dB would need approx. 1kW to see the same output. Not to mention that passive resistors can only hope to make the least amount of damage to the sound. 30W to 111dB sensitivity actively may seem way overkill, but coupled that way the amp is given the best conditions delivering only a couple watts at most directly to the comp. driver, without any interfering passive cross-over and in a limited frequency span sans bass to lower midrange. That's extremely low distortion operating so far from the power ceiling, in a limited range and without using juice seeing into passive XO.

What may be sonically inherent to push-pull SS amps with negative feedback applied, certainly in pure Class-A, I don't hear it as detrimental in named context. Just my $0.02..

 

[Walter66]

Be Yamamura told me that in Japan a lot of owners of horn speaker use transistor amp because has no noise
Yamamura did amp transistor in current class A 30 watt and are fantastic

Technically, it often makes more sense the other way around. Woofers suck electrical power and need low damping factors. Those little watts the mids/ highs need can be delivered with a modern tube amp system, mostly a pure class A one, without additional noise.

Some have gone towards high SS powered woofers with digital DSP frequency dividing networks of the active speakers incl. room tuning for a flat response of the system. All possible today.

Thats a story of decades ago when most tube amps were noisy. Today, no problem to construct even a tube pre which had no difference in output noise when switched between phono or line level inputs.

 

[DasguteOhr]

I have passive horns with SET and active horns...with SET...I would never put a SS amp on them...again.

I have learned never say never
This omtec class a mono amps 25 watt sounds phantastic with horns.why?
i have never seen an amplifier that had such good measurements sounded so nice and was completely free of artifacts in the sound. with the high sensitivity of horns they bring all the noise to light this amplifier makes none. my tip used get a couple for 1000 €.
Exsample mains interference at 1 watt 1 khz at 8 ohm load

 

[morricab]

I have learned never say never
This omtec class a mono amps 25 watt sounds phantastic with horns.why?
i have never seen an amplifier that had such good measurements sounded so nice and was completely free of artifacts in the sound. with the high sensitivity of horns they bring all the noise to light this amplifier makes none. my tip used get a couple for 1000 €.
Exsample mains interference at 1 watt 1 khz at 8 ohm loadView attachment 97925
View attachment 97926

Have you actually tried them on horns?

 

[Jägerst.]

Have you actually tried them on horns?

Conversely I'd ask you (not to be polemic about this, but merely inquiring further into your dislike for SS amps coupled to horns), what your range of knowledge with SS amps coupled to horns covers; what type of SS amps and whether they were implemented passively or actively with the horns? I'm not asking for an exhaustive list of SS amps and different context in which they were used, but just a few examples perhaps which may illuminate the matter. Taste is also a factor, and you may be quite sensitive to aspects in reproduction that I (and perhaps also poster @DasguteOhr) am possibly not.

As I described in my earlier post, using a Class-A SS amp actively sans passive XO with a very sensitive horn/driver combo and freed from frequencies below 5-600Hz is really ideal conditions for it to perform its best. This may be a vital context assessing it against a scenario in which the same (or another) SS amp is used looking into a passive cross-over on the output side (with all that entails in load challenges), driving the speakers full-range and being "robbed" upwards of 10-15dB's in speaker sensitivity. My take is that the latter scenario can be instrumental in making an SS amp sound more "strident" and "SS-like."

Maintaining named advantages from the active configuration above and the specific speaker context it'd be interesting to use an SET or other tube-based amp, given low enough noise levels. That I haven't tried.

 

[DasguteOhr]

Have you actually tried them on horns?

No, today I only have tubes in the signal path, for me a more emotional sound. except for active bass, I just use transistor amps for more control. Knowing the Omtec with Klipsch, Acapella and Avantgarde horns was a very clean, silky tone, nothing sounded unnatural. definitely give it a listen they are not very expensive and can keep up with all the big names.a real alternative if you don't want tubes.

Link

Omtec CA-25 V2, letzte Version, gebraucht ,1Jahr Garantie / ON OFF Hifi

Top Zustand! Ein Paar der schon legendären Class A Monoblöcke in der letzten und klanglich deutlich verbesserten V2 Version mit innenliegenden ...

www.on-off-hifi.de

 

[morricab]

No, today I only have tubes in the signal path, for me a more emotional sound. except for active bass, I just use transistor amps for more control. Knowing the Omtec with Klipsch, Acapella and Avantgarde horns was a very clean, silky tone, nothing sounded unnatural. definitely give it a listen they are not very expensive and can keep up with all the big names.a real alternative if you don't want tubes.

Link

Omtec CA-25 V2, letzte Version, gebraucht ,1Jahr Garantie / ON OFF Hifi

Top Zustand! Ein Paar der schon legendären Class A Monoblöcke in der letzten und klanglich deutlich verbesserten V2 Version mit innenliegenden ...

www.on-off-hifi.de

Oh, but I WANT tubes

 

[adrianywu]

I am in a special situation. I am using a pair of Acapella ion tweeters with my compression mid-range and 15" bass in ported enclosure. Both drivers are field coil units. Each ion tweeter is powered by a TV sweep tube inside, and it has a high pass filter, but it still needs a high level signal. The input impedance is 600 ohms. The signal is meant to be taken from the main speaker before the speaker's crossover (Acapella speakers have passive crossovers), and they work as supertweeters. However, they sound much better if there is no overlap between the midrange and the ion tweeter (I cross over at 7kHz). I therefore use an active 3-way crossover, run the tweeters and the mid-ranges with two pairs of differential 300B amps, and the woofers with a Parasound A21+. A friend just built a pair of Nelson Pass's ACA mini MOSFET DIY amps. The cost is $125 each. Each amp (basically a circuit board and a SMPS) can be run as single-ended stereo or balanced mono. The frequency response is flat to 50kHz and it is rated at 10W mono (or 5W in stereo). I borrowed them to try with my ion tweeters and they work very well indeed. Having matched the levels, my system actually sounded more extended with the SS amps than with my 300Bs on the tweeters. I will order the parts to build myself a pair. I did not try them with my mid-range, but I bet they will work well too, given the very high sensitivity of my drivers (111dB/2.83V) and the benign impedance. Once the amps settle in, I will explore whether they benefit from a linear power supply, although the power supply will likely cost more than the amp modules !

 

[DetroitVinylRob]

Very late to the party but… with great success. I run 98Db 16Ω field-coiled Classic Audio T3s with Atma-Sphere MA1 Mk.3.3 mono block OTLs creating 140w@8Ω in a 1300 sq ft room, modestly acoustic treated, often playing at level about 75Db. Very low in distortion, with little compression, and crazy good transparency. System is on (2x) dedicated 20A service distributed by (2x) Shunyata Denali v2. There are 55 valves in play.

So I find this setup plays quite dynamically and life like with very rich tonal character with layers and layers of texture. The music presents pretty much effortlessly. For contrast, I have used 60w/ch. Atma-Sphere amps and find them most satisfying. But upon adding more than double the wattage an added level of overall control and energy and a (bit) of lower level authority presents, even given the relatively high efficiency of the loudspeakers.

So a lesson? I seem to take from this is that watt power matters, always.