Which 300b amplifier for Devore O/96

@essrand  The O/96 is a great speaker; 2dB less efficient than my Classic Audio Loudspeakers. This is just my experience, but the power of a single 300b is simply insufficient on *my* speakers. Unless you're in a small room or never listen with volumes past 80dB, IMO 7 watts just isn't enough power.

I find about 30 watts is a good minimum, if its clean power. I have a type 45-based amplifier (which is push-pull); it makes the same power as a 300b SET. Its simply not enough power on my speakers for a satisfying volume. Now SETs are different from most amplifiers in the way they make distortion; that distortion interacts with the human ear/brain system to make you think they are louder than they really are. As you turn the volume up, this distortion (higher ordered harmonics) first tends to show up on transients. This is why SETs are often credited with being 'more dynamic than their power would suggest'; a common paraphrase you see in SET reviews.

So if I were you, and you want a 300b-based amplifier, I would go with a push-pull 300b amp. It will be making about 30-35 watts which will really help out a lot. There are plenty to choose from.

Yeah its 5 not 4 amplifiers.

@atmasphere @jsautter you guys have given me fodder for thought.

I feel like my Coincidents were powerful enough. But now you are making me doubt that. Will put those amps back in, listen more and get back.

So I am guessing out of my choices your vote would be for the Nagra 300p (its a push-pull 300b, 20W).

@essrand If I were you I'd be open to more than just the Nagra, but out of your list that would be the one. I personally don't think 20 watts would be enough power though. I see 30 watts as a minimum on my speakers and 60 watts is a lot nicer. I did recently move though and my new listening room is slightly smaller and I've still not sorted out all its differences, but for now its more lively so 30 watts has been enough for now. I think if I can tame the side walls I'll be able to play easier with more power though.


The trick is to really have more power than you're going to need! With SETs, because of how they make distortion, this really means that to hear what they do properly you really shouldn't need to run them past about 20% of full power (otherwise the higher ordered harmonics become more audible). That means to take advantage of many SETs you need speakers that are over 100dB...

I once had the integrated version of the Nagra 300b. It didn't sound like a 300b..it was pretty linear if a 300b can be called linear. With that being said, it had a solid state pre section and the speakers were Stenheims. It was nice and reasonably dynamic within its power band. I like the combo but I haven't had seller's remorse like I have every time I've ever sold a Leben. LOL

Atmasphere 5-15-2019
The O/96 is a great speaker; 2dB less efficient than my Classic Audio Loudspeakers.

Ralph, if I recall correctly your speakers are 98 db/1 watt/1 meter, and the O/96 is indeed spec’d 2 db less than that, at 96 db. However John Atkinson’s measurements in Stereophile showed the O/96 to have a sensitivity of only 91 db/2.83 volts/1 meter. For its 10 ohm nominal impedance that would correspond to about 92 db/1 watt/1 meter.

Which would seem to give further credence to your (and JSautter’s) advocacy of more power than most SETs can provide.

Essrand 5-15-2019
I feel like my Coincidents were powerful enough. But now you are making me doubt that. Will put those amps back in, listen more and get back.

To state a fairly obvious point, I would just suggest that you make a point of including recordings having particularly wide dynamic range in your assessment. Such as many recordings of classical symphonic music, if you listen to that type of music. For a given average volume, recordings of music having narrow dynamic range and/or recordings that have been engineered with a lot of dynamic compression are of course less likely to reveal the issues Ralph and JSautter have referred to.

Good luck. Regards,

-- Al