Harbeth Speakers and (digital power amplifiers) T-amps

[sam-fi]

I most interested in Red Wine Audio (RWA) 30.2 and Virtue Audio M901.
We are talking about the p3esr in a small room but I would obviously like to know any impressions you have with all t-amps. This will be a general discusion of Harbeth use with t-amps.

Thanks,
Sam-fi

{Moderator's comment: T-amps = TriPath company???? Are they still in business???}

[godlau]

http://www.google.com/images?hl=en&c...ed=0CCoQsAQwAw

these?

[hifi_dave]

You'll have no problems driving the P3ESR or any other Harbeth speaker with such an amp but will you enjoy the results ? Personally, I find these amps cold and uninvolving and would prefer a conventional budget amp like a Rega Brio-3 which is altogether more satisfactory to my ears.

Obviously you need to try the combination yourself.

[Gan CK]

Yes agree with hifidave that the class-t amps are uninvolving. Had compared the Red Wine Audo 30.2 directly against my LFD LE III & the 30.2 fell flat to the ground immediately after the LE III.

[kittykat]

like to know any impressions you have with all t-amps.

Sam-fi, This will probably not answer your question and it is not intended to, but should at least set you off on your journey in finding an amplifier which suits you. You have to do some work for this. You are spending your money.

Simply, amps of different topologies have their own unique characteristics including digital ones. There is a list of amps here …

http://www.soundstagemagazine.com/in...d=17&Itemid=19

…which have been measured by Canada’s National Research Council. I suggest you spend time picking out groups and topologies of different amps and comparing the charts and graphs of frequency responses and distortion. I know this is boring compared to reading Shakespearean write ups in glossy magazines of what are really only bits and pieces of electronic parts joint together by solder. A pattern will emerge when you have looked at enough charts on this webpage, that much i dare to guarantee you. Stereophile also measures including Australian hifi.

I understand that bel canto no longer uses tripath but ice, but please have a very close look at the distortion curve (and freq response) which is quite typical of a digital amp here…

http://www.soundstagemagazine.com/me..._eone_ref1000/

and then compare that with a conventional amplifier here….

http://www.soundstagemagazine.com/me...ston_b100_sst/

Then please try to pick out a tube amplifier and look at how they perform. ..

http://www.soundstagemagazine.com/me...ch_topaz_572b/

Hatbeths have a beautiful top end and are very low in distortion (almost electrostatic like). I personally couldn’t see why that performance would consciously be restricted by amplifier choice.

{Moderator's comment: a really excellent and appropriate post for the HUG. Can you help us by extracting some conculsions please?}

[kittykat]

my personal interpretation.,,

Digital amps – At performance extremities, where the boundaries are being pushed, distortion generally increases multifold. So if you want a digital amp, you’ll need a high powered one, not because you need the power to drive your speakers, but because you do not want situations where you approach that edge. This is perhaps why a well known manufacturer of digitals makes extremely high powered ones to give that “breathing” space. If you have a low powered one and push it, you’ll probably be able to hear it when it starts to crumble. The frequency response curves of digitals are quite unique as well; they are generally quite far from being flat. Some of them almost mimic tubes, I can’t tell if this is an inherent characteristic of the chip, or if it is a characteristic introduced by the designer. You might like this sound…buyers choice.

Transistors (non full bias class A) in general are pretty much text book amplifiers in the true sense. This is technology which has been perfected for decades now… a bit like the internal combustion engine. Transistors are flat and will break up more gradually. A good one generally has no “give” and will reflect whatever the input is. I think this is why some people don’t like them. It’s like a mirror. Good ones sound extremely transparent and will go loud (in a “soft” way meaning you can still have a conversation with someone else) to the extent it will affect your hearing because the distortion is so low. It takes time to appreciate a good transistor amp.

Tubes are far from flat. They sound “sweet” because, imo, they emphasise the parts of the spectrum which appeal to humans the most eg voice (please have a look at the response curves) and the highs start tapering off earlier (you seldom find people calling them shrill etc). They generally start distorting (relatively to other topologies) from the word go, all the way to the performance edge, so most of us have already “normalised” this shortcoming. Tubes, watt for watt (against transistors for example) may sound “loud” and “rich”, not because they are more “powerful”, but imo think because we are listening to the density and “thickness” of the harmonics and distortion within it. Tubes are very easy to like (some love) from the word go.

I have extensively swapped a tube and transistor amp in and out since HUG has become moderated, given the free time to tinker. There are charms in tubes, no doubt, but personally find that to bring out the true beauty and craft of the SHL5’s (for myself namely the low distortion and transparency), a decent, low distortion, low harmonic, relatively flat response (under load) and sufficiently powered amp will do the job extremely well. And the best thing is, you do not need to spend a lot of money to find such an amp. There are plenty to choose from, but what is required is a bit of hardwork.

Finally, if you can, just select simple conventional cables. Anyone please correct me if im wrong here. The more esoteric it is, and you could just be introducing dimensions such as capacitance into the equation where you completely loose control of the variables you are trying to manage the outcome for ie. s simple system which gives the best possible sound. If you choose to take the esoteric path, you choose a path of pain, in multivariables and unknowns. You’ll just find yourself swapping cables, spikes, stands constantly because you don’t know what you are controlling. In fact you start loosing confidence in yourself, then your dealer and then the whole industry. Just keep things simple.

[denjo]

I use a T-Rex digital amp to power some cheap Axiom speakers and my experience of the potential of these amps is quite different from some of the posts here! The amp is only about 10 to 12 watts but it can drive the speakers to deafening levels I would imagine. My Axioms are rated at about 91 dB at 8 ohms. I won't have any experience of whether they would drive the P3ESR as well as they do the Axioms!

[kittykat]

Hi Denjo, did you mean a T-amp? I suspect they will do well enough for the application in the setup you mention. That's why imo its hard to discern the differences in amplifier "sound" and its only when they are driven to their performance limits by material or choice (which we seldom do in a domestic environment) that the edges start to show.

There’s a technical evaluation of the sonic t amp here…

http://www.stereophile.com/budgetcom...ic/index4.html

Under load, in the frequencies where it matters the most, the T amp is basically pretty flat, but further up the spectrum you can see it swing 1.5dB. This particular example has only 6-7W of clean power. If anyone has had a looked at a VU meter while playing music in their living room at a pretty high level, we can see it hitting peaks of 10W quite often. Again for this digital amp, distortion is low where it matters most up to 1000Hz. (the high range of the human voice is around here). This chip does have a bit of harmonics though, and some people might actually like it, describing it as rich and warm or mistaking it for “power” given the “wall of sound”.

[denjo]

Kittykat, I actually meant the Kingrex T20U (apologies)! It pumps about 20w into 8 ohms and the "U" designation has a USB input (suggesting a built-in DAC within). My computer is connected to the amp and listening to IORadio Jazz, I am simply amazed with the audio quality. Very nice sounding!

[groovybass]

While not a Class T amp, I do use a class D Wyred4Sound STI-500 integrated amp with my Compact 7ES-3s. It's 250W/channel and the sound is anything but cold and uninvolving. I have a Naim CD5X/Flatcap2X front-end and everything seems to get along quite nicely.

[micron]

Hi there

I don't know if the ice power amps is matching with this subject... I use ice power amp with SHL5 and I think i'm on the right way. If is anyone interested we can make a new thread about ICE Power amps.
Best regards

{Moderator's comment: What exactly are 'ice power amps'? Is that a brand name or a technology?}

[Spindrift]

Hi there

I don't know if the ice power amps is matching with this subject... I use ice power amp with SHL5 and I think i'm on the right way. If is anyone interested we can make a new thread about ICE Power amps.
Best regards

{Moderator's comment: What exactly are 'ice power amps'? Is that a brand name or a technology?}

ICEPower is both a brand name and a description of a certain Class D circuit. B&O founded the (now separate) ICEPower devision & research-programme to develop their own, unique class D amplification circuits for active loudspeakers, 2- or multi-channel amplifiers and high quality car stereo systems. Over the past decade, ICEPower has been implemented by companies such as Rotel but also in niche-market designs from John Stronczer's Bel Canto, Jeff Rowland, PS Audio and Wyred 4 Sound. John Stronczer started out designing and building tube-amplification, specialising in Single-Ended Triode (SET) types. Later, Bel Canto would introduce some of the first 'audiophile' Class D amplifiers, using Tripath technology (in it's most basic form commonly referred to as a 'T-amp'; the BCD EvO design was much more elaborate than most T's).

Today, Class D amp circuits in general and ICEPower as a multinational effort (including Sanyo) has evolved into a mature technology. The best implementations of ICEpower can give surprisingly good performance and as Micron points out, can give fine results esp. with loudspeakers that are as transparent as they are musically involving, such as Harbeths or QUAD ESLs.

[jessie50]

I'm was using a Virtue 2.2 amp to drive my Harbeth C7's. Very good results. Recently, I added a Dared SL-2000A tube preamp and made the Virtue 2.2 a dedicated amp. Excellent results.