OTL Tube Amp for Maggie 3.6?

There are two ways to make an OTL work with 4 ohms really efficiently.

The first is to make it so big that 4 ohms is no worries (our MA-2 and MA-3 are examples of that- the MA-2 makes its maximum power into 5 ohms and the MA-3 makes its maximum power into 3 ohms). The second way is to use a set of ZEROs (http://www.zeroimpedance.com)

If you are planning to bi-amplify the latter method will allow you to use a smaller amplifier, which may well be just fine if it is only handling higher frequencies. The ZEROs can be a very effective solution for using smaller tube amplifiers on lower impedance loads.

We've had a lot of people use our MA-1s on the 3.6 to good effect. In fact the moderator of MUG (Magnaplanar User's Group) emailed me a few years back saying that the MA-1 was the best amp for that speaker.

However 4est makes a good point about power- in the 3.6, the sensitivity is 86 db. This spec is misleading since the speaker is 4 ohms and it is a line source. I think it is more valuable to know the efficiency of the speaker since that is a power rating and tube amps make power. The speaker is 4 ohms, causing the *efficiency* to be 3 db less. But the speaker is a line source so you add 6 db to that. IOW, the speaker is about 89 db 1 watt 1 meter. An amplifier that makes around 100 watts might be run out of gas at higher volumes, but a lot depends on the room and your listening taste.

Some OTLs cannot handle the load even though they make the power; a popular and effective solution is to use a set of ZEROs (http://www.zeroimpedance.com). Take it from me on this one- the use of such does not obviate the 'OTL quality' of the amp. With our MA-1 it is hard to say if the ZERO would help or not, I suspect you would have to try it and see.

A set of power tubes for a pair of MA-3s is $2000.

Wendal Diller told me once that the best he ever heard the MG-20.1s was with a set of MA-2s. Certainly MA-2s have no problem with 3.6s and the like! Years ago a friend of mine ran Tympany 4s with MA-2s- that worked really well too. IMO the trick is to keep the speaker cables short.

Audioquest4life, there is nothing about 6K- but he did say something about trying to keep it under 6 *figures* :)

We've got a lot of customers that like the combination so it must work...