Amplifier selection for your Harbeths (general, not specific Harbeth models)

[danrubin]

Sadly, completely untrue.

Ah, so it's untrue that power is balanced in UK. Here is a description of the balanced power devices I referred to, which I am borrowing from someone's Internet post:

Balanced power (best for front end stuff not necessary for amps) splits the AC potential in two. Instead of 120V between the the hot blade (of the plug) and the (nominally zero) neutral blade (plus your ground of course) it splits it so that there is +60 V from one blade to ground, and -60V from the other blade to ground. You still get 120V between the two plug blades, but the blades are always opposite polarity relative to ground. So any noise carried in the line (mostly hum but also RFI) is self-cancelling. Studios have used balanced power for years, but it was only UL approved for consumer use about 8 years ago.

[A.S.]

... it splits it so that there is +60 V from one blade to ground, and -60V from the other blade to ground. You still get 120V between the two plug blades, but the blades are always opposite polarity relative to ground. So any noise carried in the line (mostly hum but also RFI) is self-cancelling. ...

This sounds perfectly plausible - in the UK/Europe the voltage would not be 120V but 230V, which is why an electric shock in Europe is often fatal.

However - and I'm on the very edge of my knowledge here - the system described above could only balance-out the hum and RFI (if there is any) between the power conditioner and the hifi equipment. Since that is only a few feet of cable compared to the perhaps hundreds of miles of cable back to the power station don't the undoubted theoretical benefits seem a trifle diminished by distances involved?

[A.S.]

Something strange has happened here ..... Kevint I seem to have overwritten your message. Sorry. The point you made was that uSA 120V being half the UK voltage would draw half the current.

If you would like to resubmit your message I will try and work it into my answer. Sorry again.

[kevint]

My original message was saying power stablity is more an issue in 110V countries. I experienced flashing light whenever the motor of dryer or air conditioner start running there. And I don't experience this problem in my home country where is 220V. So I guess 110V country has more power stablity concern than we have in 220V country, at least here in Hong Kong.

[airdavid]

Hallo,
have you ever tried Naim Nait 5i with Monitor 30?
thank you,

David

[Frihed89]

I have come into contact with a small spec/custom tube amplifier mfr. He can make me a push-pull amp at 2x40 or 75 W/channel or a single-ended triode (he hesitates to call it an SET) that is at a max at 28 Wpc. The preamp is triode based. These amps are extremely detailed and musical, with the single ended being "smoother" in the mid-range.

Now the $64 question: If i intend to buy the C-7 at a later date (i have Audiovector 2.5 ways and Quad 12Ls, now), do i dare buy the Single Ended power amp? Or should I play it safe?

I have auditioned the C-7 with Audionote Lexus speaker cables. The perceptible diference is that if you listen to a single guitar, it gives the notes a little warmth without losing the detail. I also hear this on various wind instruments in the mid-range. These cables also take a bit of the sharpness out of the Quad 12L which is a pretty amazing feat. I am a non-silver fan when it comes to the "BB-sound".

[compozor]

I am running ES7s with Cary 300SE LX-20, a single-ended design with a 300BXLS (20w) output tube. I have a small room and listen in the nearfield (and only rarely to large-scale orchestral works). In this context the Harbeths are simply marvelous and seem quite happy with the single-ended amps.

[Frihed89]

That is pretty much my situation. Most of the music i listen to is basically vocals with small bands, alt.country, indie, acoustic, blues. Maybe it will work. This is a very interesting single ended amp that uses "sweet tubes". They are high efficiency, high voltage, low cost triodes designed for TVs.

[Frihed89]

Has anyone seen the impedance-freq curve(s) for the C-7? If so, what is the lowest impedance of the C-7 and at what frequency? Or perhaps you can give me a url or post a pic of this relationship.

I want it to help make my amp decision. Thanks.

I got an offer for a new Quad 99 preamp + new 909 power amp, both demos, for a total of about 1100 quid. Is that a good deal?

The easier, softer way.

[Don Leman]

For the C7 impedance, go to the Harbeth webpage for the C7. There is a "Z" link at the very bottom with the curves you are looking for. The minimum is around 6 ohms.

[Frihed89]

Thanks Don. I feel a little stupid.

[Bruce]

Now the $64 question: If i intend to buy the C-7 at a later date (i have Audiovector 2.5 ways and Quad 12Ls, now), do i dare buy the Single Ended power amp?

Here's a review of M30's driven by 3 watt SET monoblocks off the Harbeth website.

http://www.harbeth.co.uk/hifispeaker...ownups-M30.pdf

[shseto]

I am using Arcam CD72 and Spendor S3 speakers (plan to move to Harbeth C7 in the future)

but now i need to upgrade of my amp first.

Been having my eyes on Naim Nait 5i and the Sugden A21A. It seems to me that the Nait is better for jazz and the sugden will do better with classicals.

how do they compare ? and other suggestion at this price range? anyone?

[A.S.]

Hello - well, we have used both Sugden and Naim at shows around the world, and Sugden is being used here in Guangdong to drive Harbeths. Both are fine companies although somewhat different in size; Sugden is a small, family business and run along very solid traditional lines.

Don't forget one important thing about equipment selection and purchase generally that has nothing to do with sound quality - true long term cost of ownership. A little more money invested at the beginning can save a vast amount in the long run, let alone the peace of mind and missed pleasure of listening. This is a general point and not related to the two fine brands that you mention here.

[Hu]

One Harbeth P3ES-2 user once tried Sugden A21a and Naim 5i, he said with Naim sounds more exciting, probably with Sugden more smooth and softer, finally he chose Naim 5i, so I think that dependes what music you listen to more and what kind of sound you like more.

Hu

[shseto]

Don't forget one important thing about equipment selection and purchase generally that has nothing to do with sound quality - true long term cost of ownership. A little more money invested at the beginning can save a vast amount in the long run, let alone the peace of mind and missed pleasure of listening. This is a general point and not related to the two fine brands that you mention here.

thx Alan, hm...... I think I am investing for the long term , the amps I plan to replace now, we have used it in our family for some 15 years now and it is still working fine but I just think that its time to replace them as I worry that I am missing something from my newer equipment by partnering them with these old amps.

Your comment of 'little more money invested at the beginning' is indeed very good advise, the sugden cost more than the naim. does this have anything to do with your comment?

[shseto]

One Harbeth P3ES-2 user once tried Sugden A21a and Naim 5i, he said with Naim sounds more exciting, probably with Sugden more smooth and softer, finally he chose Naim 5i, so I think that dependes what music you listen to more and what kind of sound you like more.

Hu

i listen to jazz and classical.

My personal expereince and feeling is that jazz and classical demand different sound. this is giving me big headache as i love both type of music.

i like classical sounding warm and smooth with lots of air while jazz should sound exciting and dynamic.

[ClaudeP]

Shesto,

I listen to classical (50%), jazz (25%) and other stuff.

I drive my Compact 7s with Naim amplification and just love it - Naim excels at reproducing the timbre of acoustic instruments (just like Harbeths do) and the famous PRaT (pace, rythm & timing) does magic for any kind of music.

I am not familiar with late Sugden products, sorry.

Claude

[Ned Mast]

This thread regarding amplifier choice I find very puzzling. I have long been of the persuasion that an amplifier's task is to amplify the signal given to it as accurately as possible. I think any number of modern amps will do this well, since they provide flat frequency response, inaudible levels of noise and of distortion. Hence, a recording will sound 'exciting' or 'smooth' or whatever quality you care to use, if that quality is in the recording. To try to use an amplifier as a glorified 'tone control' seems to me to be traveling down a slippery slope - and an expensive one at that! Just my opinion. . .

Just for the record my amp is not particularly exotic, but has great specs, and provides all the musical excitement or smoothness I could ask for - provided it's there on the recording. Also, I would add that I spent some hours over a weekend trying different placement of my SHL5's until I found a location where they have a relatively flat frequency response. With a little judicious eq, they are virtually flat from 40 Hz up. Something basic to consider, perhaps, before tweaking electronics. . .

Ned

[A.S.]

T... I think any number of modern amps will do this well, since they provide flat frequency response, inaudible levels of noise and of distortion. ...

Hello Ted,

Whilst you and I are in agreement, it is a fact that even a benign load like the SHL5 (or indeed any Harbeth) does interact with the amplifier and this does produce variations in sound pressure response ("frequency resonse") to a greater or lesser extent. For example, at the all-critical development stage of a new speaker when reference measurements have to be made of the 'raw' drive units sans crossover it is essential to elimianate the amplifiers load dependence. This is done by using a two-channel analyser, one channel of which measures the voltage at the amplifier's output and the other the signal from the microphone. By maths division the speaker's response can be normalised to that of a perfect amp.

The errors measured may be of the order of 0.3 to 0.5dB from true at various frequencies with a solid state amp - probably rather more with a tube amp - if this cross-correlation is not implemented. Whether one considers this important or not in subjective quality is a matter of opinion but it is a measurable fact.

Interesting to note that the earlier current dumping QUAD amps, of which we have many, are quite different in their load sensitivity. From memory the least sensitive is the 405, the later 606 is rather more so and the rack-mount pro version (520) has to be used with caution.