Which high power SET

06-24-14: Edoit
To rephrase my question, which of the 3 on the list would be the best match for shindo masseto pre amp?

My suggestion is that a more important consideration is which of the three amps is the best match for the speakers. As you can see in the impedance plots for the SHL5 shown here, its impedance is in the vicinity of 6 ohms in the mid-bass and upper treble regions but rises to a peak of about 34 ohms at a little under 2 kHz, which of course is a particularly important part of the spectrum. The interaction of that impedance variation with the relatively high and also model-dependent output impedance of a SET will cause significant tonal balance variation as a function of which amplifier is used.

It follows from that, also, that a given SET amplifier will likely sound significantly different when used with your particular speakers than when used with many or most other speakers.

One more reason, in addition to those that have been mentioned, to try to audition in your system prior to purchase, and for why a SET might not be the best choice for use with your speakers.

Regards,
-- Al

I have heard the Wavac. I have also heard some other amps recommended in this thread. What is important to note is, SET or PP, the output tubes have a major contribution to the sonic signature. Most of the big tubes, especially 845, 805 etc have a certain "artificially big sound" about them. They lack the musical subtlety compared to the smaller tubes. This is true even with the bigger Wavac. You hear all the details and of course have lots of power but the sound is more mechanical. It is more "sound" vs music. In that regards I discovered that even a well designed Push pull amp sounded way more musically satisfying if the output tubes are one of the smaller tubes (2A3, 45, 300B, EL34, EL84, Kt88, 6L6GC, 6c33c etc). I have not heard a well implemented 211 tube based amp so I cannot comment on that. But 845 and 805, not for me.

I suggest you also look at Unison Research Performance amp. It is more like a high powered SET without using big transmitter tubes.

Hi Edoit,

You're getting a lot of great advice here from some smart audiophiles. The common threads appear to be: 1) don't become overly enchanted by the idea of any single topology; 2) your speakers are ill-suited for SETs.

SETs can sound great; they also have real limitations. I've been running a sweet 2A3 DHT SET into 99db speakers (easy 8-ohm impedance, compression drivers) since 1999. It sounds really good in small spaces for quiet near-field listening. In my critical-listening room, however, where vinyl rules and I want realistic SPLs, it pales. That's with speakers designed for low-watt tube amps. Your speakers are not.

SET lovers tend to be very passionate about their choices, and they're on to something, no doubt. There's an infectious immediacy about the SET sound. But sometimes the passion takes on a metaphysical character that seems to imbue the topology with the ability to transcend the limitations of mundane physics, like adequately powering inefficient speakers with challenging impedance curves.

If you're certain that SET amps are your manna, I'd suggesting thinking about the amps and speakers as a unit, a single purchase, without trying to retrofit amps to your Harbeths. That way you have a much better chance of hearing the magic a SET *system* can make.

Pani, don't agree with you. I have a VAC 300 watt push pull mono blocks and my Absolare 845 mono blocks are better in every way. Less mechanical, more open, and much more natural. The VAC is great don't get me wrong, but sounds a little veiled in comparison.

It hasn't been established that the Harbeth is incompatible, just speculation. Edoit is doing fine with his present 30 watt amplifier so a similar power SET is at the very least worth an audition. Either he'll like it or he won't. Listening is the only way to determine this. It could disappoint him or reveal a honesty and realism he's not heard before. Let the ears decide.
Charles,