I need a quiet tube amp

There are two things you need to keep in mind to match speakers and amp: sensitivity and impedance. The impedance dip are often overlooked.
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I prefer the Mac Mc240 driving the ProAc 2.5s. This is just my taste.

See my last entry. The 2.5s are an extremely easy load especially in a small room like mine (see my entry above!) although the 2A3 monos I owned a few years ago failed miserably. However, my Air Tight has more drive power than any other 300B amp I know and does great in my room with most types of music. However, I do hear buzzing/hum coming from speakers when being within 3-4 ft of them. I think it does have to do with some sort of grounding problem and am in process of checking things out through pre-amp company.

Also, phase angle also is very meaningful when choosing a partnering amp. I'm not real knowledgable about this fact but was able to find out the 2.5s have a begnin one and many speakers don't.

One thing, my experience with SETs (having owned four) is that the more efficient the speaker, the louder any noise in the system will be. I took my 2A3 monos to a friends house maybe three years ago and his Corner Horns were far noiser than any other one tried - they were the most efficient. By the way, I'm getting music as loud as I want with the volume control less than half engaged. Yes, when it's turned up beyond what I ever want to listen to (remember my small room) the amp's limitations become evident. However, this combo is the best I've used at home an that includes everything from another 300B amp (mono-blocks), 20wt 572 SET, 25wt OTL, 25wt S/S, 100wt S/S, and a 135wt P/P tube.

Elevick, thanks for the offer but this is the best SET I've ever heard and I'm keeping it even if something replaces it.

Tomyran,
You have probably explored this option, but on my Wright Mono 10's I used a 3-into-2 prong adapter, and the hum disappeared almost entirely. With his 3.5 SET amp monoblocks, I found that the hum through the speakers had mostly to do with the quality of the 2A3 tube I was using. When I found an excellent NOS tube, the hum was reduced dramatically.

If those suggestions--and the ground loop check--don't work, I would take the amps to a tech and have them checked out. If there is no issue with the amps, it may be a problem worsened by the 2A3's being used.

Hope my amateur advice helps.

All the best,
Howard

Tom: What's your price range? I have had two different ASL integrateds: An MG si15 and a FOX Ki22, neither of which would be a good match for your Proacs. However, they make some other very powerful amps, but the 200 watt hurricanes are about $5k!

You simply don't have enough headroom with a 300b amp (about 8 watts). With your speakers, I would want something like a VTL ST-150 or a pair of Rogue 120 Magnum monos. That's a lot of juice, and I'm willing to bet you a burrito that your Proacs will let you hear things that you never thought possible!

Tomyran, I don't have issue with Sun Audio SV2A3 in my setup ( I borrowed this amp from a friend of my ) Definitely no buzz or any noise. with my Citation I preamp.
I'm using it with Jensen coaxial speakers and they sounded fine except for the bass. I prefer deeper and larger volume of bass from that 2A3.