Tube amp for "difficult" speakers,,,

Hi Mark, the trick to driving Accoustats is being able to deal with the load. A friend of mine had them- wicked low impedance- but we ran them with a set of M-60s and a set of our Z-Music autoformers to deal with the load. They sounded fabulous and could play any reasonable volume- we never ran the system out of power. He had an ARC too; it needed the autoformer as well!

These days you get a set of ZEROs (we don't make the Z-Music anymore) and a set of M-60s will do the job. You would need them even if you had MA-1s; Accoustats are a 'difficult' load, and the ZEROs can be looked at as a great problem solver for things like that. IOW a great way to get a tube amp to drive a problem load.

People often ask if there is a degradation, which is a sort of Red Herring; obviously if the amp can't drive the load 'without', and it does it great 'with', then the answer is 'no, it works great!'

Yep, its the load, impedance-wise on the 2+2's. I should have been clearer. When I talk here about driving a speaker, I tend to talk about impedance/sensitivity together, until I'm absolutely forced to talk about technicals. BTW, I still liked the MA-1s on them. Then again, I'm an SET guy these days, so dynamic compression doesn't bother me as much as most. What are those Dynaudios we are talking about here - 4 ohm load? That sounds familiar in my head.

I've got a second system with 88db (or, 89, I can't remember) sensitive LS3/5A's, but they are 15 ohms, so I can run them quite well with an Air Tight 300B 10W amp. You wouldn't think so, but its works quite well. No head-banging, but its not meant to be that way, can't be.

Anyway, 83db/4ohm speakers I think are going to suck up some serious real estate. To be honest, I think someone you wants those types of speakers should go for a Pass 200 watter and be happy that that's as close as he's going to get to SET, or OTL, mids, spacial rendition and harmonics.

I assume the sans-ZERO MA-1s could do the job, but, then again, he's coming off of 600W of Krell...

Hey, o Holter, what do you say about some big OTL's? Ralph Karsten is here and he's the man...OK, I'm changing my mind...anyone who has Krell on a 83db speaker and wants to go SET MUST be willing to get into the deep end, right?

Ralph, I hope I just helped you with a sale!

I am on holiday and not able to follow this thread so often, so this is just to say, thanks for more advice and suggestions, and also: I use the Aesthetix Io, so I am not exactly new to tubes.

O holter, understood. My apologies. So, then, what about that MA-1?!

They're no longer made, but you might look for a Mesa Baron. Here's one available on eBay.