SET for 88 dB 4 ohm loadspeaker

I use a 12 wpc SE tube amp to drive 88db/mtr efficiency speakers and can achieve quite high volume levels.

Regards
Paul

Monomithos,

Power requirements are so dependent on one's listening level and size of room, it is hard to say whether any SET amp will be sufficient for your needs. I would say don't overlook pushpull amps; many sound fantastic and some don't even give away any of the "magic" of SET (just ask those who listen to ruinously expensive, but incredible sounding Western Electric amps).

Personally, I don't like most higher power pushpull amps based on pentodes, like the 6550, KT-88, etc. Some pentode amps based on EL-84s actually sound good to me, though they don't have that little something extra of low-powered SET amps.

My absolute favorite is low-powered SET amps (based on 45 or 2a3). But, my speakers are reasonably efficient (99 db/w, have a high impedance, and I don't play them very loud). I do think you give up something with higher powered SETs, but some are very nice sounding. A friend had a Wyetech that used 211 tubes that sounded very good.

Now, for something completely different. While I really do like the way SETs reveal fine textures and detail in an unforced manner, there is a quite different magic that is available from OTL amps. OTLs are incredibly dynamic and lively sounding. The compatibility issue there is that they work best with higher impedance speakers. Still, I've heard them on a wide range of speakers and really liked the sound too.

Pauly; it may not be very apparent in your system due to room size, music type, etc. but, the issue is usually frequency response and bass control. You may hear some frequencies really loud but, low power doesn't really control a 10in woofer well enough to move a room full of air appropriately.

Hi Pawlowski

My speakers respond well down to the 30’s (I believe the specs are –3db at 34Hz ) and the amp does provide a very deep and controlled bass. I have measured response down to the low 20’s, although that must be down 10-20db at those low frequencies.

The most critical thing for a tube amp is a speaker with benign impedance curve. Given that, you’ll be surprised how little in power is needed to provide high(ish?) volume levels.

I think 88db is a bit low for a 300B based set, but I am sure an 6C33, 805 or 845 based set will do well. I have a 22wpc 6C33 SET and it will blast my walls down if I turn it too high.

Regards
Paul

Thanx Paul. I stand corrected.