When I owned the SHL5 I was originally using Quicksilver V-4 mono blocks (120 watts per channel) to run the them. As much as I loved the Quickie's with my Vandersteen's, I was not happy with the sound they made with the Harbeth's.
I ended up switching to a Primare 30.1 solid state integrated (100 watts per channel) with much better results. I have since moved to the SHL5+ and I am now using an Ayre AX-7e integrated. On paper not a great combo, 60 watts per channel, but in my system it's an amazing combination that brings out the best in the SHL5+'s. The Primare is still my backup. The SHL5+ is a very different speaker than the SHL5 so I recommend you try any amp that you can with them before you buy.
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I have not been able to find a tube amp that I like with any Harbeth I have tried. This is just my opinion and YMMV. Good Luck!
I ended up switching to a Primare 30.1 solid state integrated (100 watts per channel) with much better results. I have since moved to the SHL5+ and I am now using an Ayre AX-7e integrated. On paper not a great combo, 60 watts per channel, but in my system it's an amazing combination that brings out the best in the SHL5+'s. The Primare is still my backup. The SHL5+ is a very different speaker than the SHL5 so I recommend you try any amp that you can with them before you buy.
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I have not been able to find a tube amp that I like with any Harbeth I have tried. This is just my opinion and YMMV. Good Luck!