WTD: Amps for Tannoy HPDs

[montesquieu]

Very interesting indeed, thanks for posting this.

Seems very good value - only $649 in the US ... Shame there is no UK dealer as I would fancy trying this with my 12" HPD's for sure!
I take it you were using it with a valve pre as I would be?

Yes EAR 912. £11k pre into £650 power amp but in this case not a mismatch.

[JohnJo]

Sorry didn't get that. Explains why you need the extra welly. 15in HPDs really do take a bit of driving and controlling.

One thing you could look at - my Radford will be going for a makeover soon to RAdford Revival - new paint job, boards, a ground-up overhaul - and I've been playing with alternatives to use while that is away. I have an NuPrime STA-9 here at the moment, 120w x 2 / whopping 290w monoblocked. Uses a JFET as input which functions much like a triode to give a very nice, valve-like sound, while the Class D element isn't 'classic' class D at all but uses a high switching rate and an analogue approach to generating the waveform, an evolution of the same approach used in the earlier (more musical) Lyngdorf amplifiers and not the peeling wallpaper fully digital Class D of old by any means.

I chose the STA-9 because of the monoblock option, but am swapping it for a single ST-10 at a little more than twice the price (or a shade more than two monoblocks), as I feel with the 12in HPDs I don't need the extra power and the ST-10 has a shade more transparency (I'm told), I think it's a tough call though but a lot of the stuff I listen to is delicate/nuanced lieder and chamber music, if I was a rock fan or into electronica or even big orchestral stuff I might well jump the other way. I've been very impressed I have to say - there is no UK dealer or distributor but perhaps Rene at Dimex in Belgium will let you try out the STA-9 I'm about to send back? If you like it (and I think you might) another one is easily purchased. For 700 Euros it's a no-brainer and I can categorically say that in my system it is better than some £5k valve amps I've had a listen to. Don't be put off by how cheap it is.

I'm hoping to hear either the high-end evolution of this approach either the Reference 20 monoblock or NuPrime's and coming statement product the Reference One which might be listenable in prototype by the time I visit Taiwan in April. £6k+ a pair though!

Nuprime are the split off high-end division of Nuforce, bought out by the brand's founder (the lower end stuff went with Optoma and are now Optomoa Nuforce) and by all accounts streets ahead of the Hypex nCore competition as they aren't focused on mass market module making for others to OEM, but rather only on making high-end finished kit (all in their own factory).

Very interesting. Not what was on my mind at all but look to be well made. Never heard any class D amps (know nothing about them!)

[Sherwood]

Very interesting indeed, thanks for posting this.

Seems very good value - only $649 in the US ... Shame there is no UK dealer as I would fancy trying this with my 12" HPD's for sure!
I take it you were using it with a valve pre as I would be?

I can endorse the Nuprime STA-9 amp. I have two configured for monoblocks operation. As good as the STA-9 is in stereo mode (it actually drove my Magneplanar 1.7 speakers very well which is no mean feat) it is a very different amp in monoblock mode. Not just louder and with better bass extension and control, but a more etched sound with better detail resolution. The already low noise floor completely disappears in monoblock mode. I also considered the ST-10 integrated which I heard on a trip to the USA just before Christmas but still prefered the two STA-9's which are about the same price. Another advantage I have found with the STA-9s is that they respond well to using XLR balanced interconnects with very short speaker cable runs.

Geoff

[JohnJo]

Bump. Anything out there?

[lewis]

PM sent.

[anubisgrau]

Did Nuforce/Nuprime sort all the DC leaking issues they had in the past?

[montesquieu]

Did Nuforce/Nuprime sort all the DC leaking issues they had in the past?

I'm in the process of trying to send back the STA-9 ... unfortunately there's no way to listen to the ST-10 in the UK on demo, or to get hold of another STA-9 to try the twin monoblocs, without acutally making a purchase. I'm reluctant to shell out the difference in cash, in the absence of a dealer prepared to put demo kit where their mouth is .... so back to valve amps.

Sad as there's a possibility it might well have been the way forward - the STA-9 remains a bargain for £700, and I stand by what I said about it being better than some £5k valve amps, the musicality and ambience is very good indeed though it lacks ultimate detail which is why I was trying to hear the ST-10. If Nuprime are serious about market development then they need to have dealers with demo kit in the European geography.

Anyway - to be frank - I am sorry for what I posted above, I had no idea the Belgian dealer would play it this way - he doesn't seem to have heard of the EU distance selling regulations, so I'm struggling for a refund. I definitely take back any recommendation!

[Ninanina]

John am I correct in saying that the Tannoy 15" HPD385s are rated at about 92dB?

If so I cannot see why they need so much power... maybe they are a tricky load for the amp for some reason or you have quite a large room..

Otherwise I would have recommended this Audio Note amp which is about 10w: http://www.ebay.co.uk/itm/Audio-Note...4AAOSw2xRYjPam

[montesquieu]

Trust me, won't do the job at all ... Tannoy 15in DCs (especially the HPDs) need a fair whack of current up them (and a decent damping factor) to control those 15in cones. HPDs in particular have extra mass in the cone that Monitor Golds don't have. Single ended amps (which usually have bugger all damping factor), don't cut it at all, 10w push pull (like the Audio Note) will drive them but sound no better than 'ok'. I would say a minimum of 40w push pull .. the ideal here is a 70w KT88/KT90 amp, anything short of that while it might sound pleaseant enought will NOT cut the mustard with 15in HPDs.

John am I correct in saying that the Tannoy 15" HPD385s are rated at about 92dB?

If so I cannot see how they need so much power... maybe they are a tricky load for the amp for some reason or you have quite a large room..

Otherwise I would have recommended this Audio Note amp which is about 10w: http://www.ebay.co.uk/itm/Audio-Note...4AAOSw2xRYjPam

[Ninanina]

Trust me, won't do the job at all ... Tannoy 15in DCs (especially the HPDs) need a fair whack of current up them (and a decent damping factor) to control those 15in cones. HPDs in particular have extra mass in the cone that Monitor Golds don't have. Single ended amps (which usually have bugger all damping factor), don't cut it at all, 10w push pull (like the Audio Note) will drive them but sound no better than 'ok'. I would say a minimum of 40w push pull .. the ideal here is a 70w KT88/KT90 amp, anything short of that while it might sound pleaseant enought will NOT cut the mustard with 15in HPDs.

Oky doky... They are obviously more tricky to drive than their 92dB would suggest... I have no idea as I've never owned a set or 15" HPD's