The Harbeth integrated amplifier

[STHLS5]

..
Had I for example been a well established amplifier manufacturer, I would have been highly delighted that even the loyal members of the Harbeth User Group argued amongst themselves, in public, unmoderated in the brands own forum, about whether Harbeth should or shouldn't enter the amplifier market and I'd have used those observations to prepare my counter-marketing offensive against Harbeth long in advance. What you don't see from your side as a consumer, is that business is war. Survival and growth in the tough global economic climate demands total brand management.

Frankly, it never crossed my mind. Now, I can see the bigger picture and now I understand what transpired a month ago wasn't a trivial matter in a very competitive commercial environment. I learned something new. Thanks

ST

[A.S.]

Great news. Thank you for your understanding. One thing you can be reliably assured of is this ... we (I) always have a good reason to act they way we (I) do. The Harbeth brand is so precious (to us all) that we have to walk a fine line between being open and frank (which by nature is how we want to respond) and putting the Harbeth baby at risk of predators.

I'm really pleased to see that we have you on-side again.

[chefre]

The problem with general-purpose tone controls is that they almost never control the frequencies you need them to. Usually the "bass" and "treble" controls start at 1kHz which is the perfect compromise; they don't work well for anyone.

More shelf-like bass adjustment below 300Hz would be a much better starting point, combined with one fully parametric eq setting for the bass to help correct the biggest room mode (there usually is one that is the most dominating).

{Mod: corrected K to k}

[thurston]

What happened to the amp-project?

By the way: i use a quad preamp with tone controls and find those very useful, therefore i believe it is a good thing to have them in any amp.

{Moderator's comment: a long sad tale of a small number of hostile concept critics. This is as dead as the Dodo. We learned a valuable lesson not to discuss future product concepts in public before launch. Pity}

[thurston]

Sad story.

I really would have liked to see this amp come to live.

[Don Jr]

If I may ask a question. Was this to be an amplifier or an integrated amplifier? I read a lot of information on this forum regarding amplifiers and I agree that for the most part, an amplifier is an amplifier (these days). I know that's not the case with an integrated. Every integrated amplifier has its own character and even the least critical of listener can discern the differences.

[A.S.]

...Every integrated amplifier has its own character and even the least critical of listener can discern the differences.

If that is a provable truth, you sir missed your chance to win a pair of M40.1s free of charge!!

I'm curious to know what aspect of an integrated amplifier would/could/may be responsible for the degradation of sound quality (at least, introduces some 'character') compared with a separate pre-power amp. In terms of circuit design, all that an integrated pre-power amp is, (compared with a separate power amp), at the very least, the addition of a volume control, a few connectors for alternative inputs, some switch method to select one input amongst others and, at the minimum, two transistors, and about six resistors and capacitors in the audio signal path in the same case as the power amp. I'm scratching my head wondering how so few, basic components (which could/will/may be identical to those in the power amp circuit itself) when placed inside the power amp case can introduce a change in sound quality. How? Why? The world needs to know!

It may well be that the practical execution of an integrated amp design places other priorities (size, cost minimisation) above those of sonic or technical excellence, but that need not be the case. Our doomed integrated amp was completely modular - you could clearly identify the preamp PCB, the power amp PCB, the power supply PCB, the remote control PCB, the input selector PCB - all very neatly wired together using good quality interconnects and easy to service on a swap-out basis requiring no in-depth technical skills. That is a very different experience to the typical integrated amp where there is one very big, complex circuit board. So nothing can be assumed or taken for granted in audio design.

Incidentally, we found ourselves dining this week adjacent to a table of engineers from the local nuclear reactor. It was on the tip of my tongue to introduce myself and ask them if they could pass a comment on room tuning crystals, CD isolators, speaker cable bridges, biwire links and the like. I didn't because folk who understand atomic physics and how the real world works in miniature (and who have our lives literally in their hands here) would obviously not appreciate the finer points of extreme audiophilia. It would have made me an object of utter ridicule. I kept my mouth clamped firmly shut.

[Labarum]

. . . Our doomed integrated amp was completely modular . . .

I do wish a way could be found of resurrecting this project, even if the product came to market with a different name.

A well constructed no nonsense amp would surely sell.

[Gan CK]

I do wish a way could be found of resurrecting this project, even if the product came to market with a different name.

A well constructed no nonsense amp would surely sell.

My sentiments exactly!

[EricW]

Me too - I know that Harbeth were a bit shell-shocked by some of the responses to amplifier proposal. But it was such a good idea, and remains a good idea. It would surely sell. Perhaps now that the dust has settled, the project could be (quietly, if need be) brought back to life?

[jair44]

Me too - I know that Harbeth were a bit shell-shocked by some of the responses to amplifier proposal. But it was such a good idea, and remains a good idea. It would surely sell. Perhaps now that the dust has settled, the project could be (quietly, if need be) brought back to life?

Yes a Harbeth amplifier would be fantastic, especially if it incorporated useful tone controls and an mp3/ipod input/remote control. I'd buy one if it could be done for under £1000.
The Harbeth name alone would go a long way towards giving it credibility.

[A.S.]

Yes a Harbeth amplifier would be fantastic... The Harbeth name alone would go a long way towards giving it credibility.

Ummmmm. Strangely enough, my wife and I met Derek Hughes and his wife here in Cumbria today as we are both coincidentally on holiday in the county - and Derek spontaneously mentioned the Harbeth amplifier, unaware that the concept has been reactivated here over the last days.

I have a definite sense that now the dust has settled on the amp concept, and that a decent time interval has passed, that there may be some mileage in the project again. But I have (mentally) moved on somewhat, and if we are going to reactivate this then I would really like to make it easy to combine it with some sort of room/speaker correction system. That racks up the mental complexity of the project, although not necessarily the circuit complexity (much) but moves the onus onto me to fully anticipate all user issues. This really has to be bullet proof. What is a little concerning is that although I recently laid out a list of key design decisions for the DSP(/amp) project, I can't recall any feedback*. That is concerning. I do believe that we should, wherever possible, sensitively and empathetically harness the technology that is now cost effective to take home audio listening to the next level.

Frankly, I have just cleared some space in my schedule to make a second pass investigation in the DSP area and I see that I need to make some more time to dovetail the DSP into a Harbeth amp. This will need six months to complete the investigation, so please don't expect any useful feedback from me this year. But I am, as always, listening.

* You may be interested to note that when I made that posting listing the 13 key decisions, I advised our DSP partner to monitor the thread and use it as a barometer of commercial interest. They presumably still are monitoring this.

[Labarum]

This gets more exciting. Such an amp would by it's nature have digital inputs. Analogue inputs would be by ADC and presumably RIAA would be in the digital domain.

This NAD referenced by me in another thread

http://nadelectronics.com/products/h...-DAC-Amplifier

would seem to be a model, but it runs the digital domain right into Class D power amps.

[Kumar Kane]

if we are going to reactivate this then I would really like to make it easy to combine it with some sort of room/speaker correction system.

There are plenty of good, robust and well specified 2 channel amps in the market for a lot less than 1000 GBP, so why would Harbeth be successful in the brand extension attempt? It would sound no different from capable competition, if well designed and built. Would just the Harbeth name be enough of a USP?

Unless, it offers an effective DSP tech that truly takes care of the quoted.

A caution for DSP too. Typically, DSP introduces some delay in the signal. Which is fine for a stand alone system, but can be a problem where someone wants to add on something like Sonos to the home for multi room audio, where the delay gets in the way of the necessary perfect sync across different zones/rooms, when that kind of music in perfect sync is desired.

[Labarum]

why would Harbeth be successful in the brand extension attempt?

A custom designed Harbeth amp with DSP could implement in the digital domain:

1. RIAA correction for playing vinyl (if needed)
2. Complex EQ (tone controls)
3. Room Correction
4. Active crossovers

All but 1. has got me very interested, and 4. has me seriously interested.

The thought of a new range of Harbeth speakers, based on the established range, that could be actively driven from a Harbeth amp is tantalising.

The DSP could be dealer or even user programmed to drive the particular two way speaker to which it is wired. There are of course issues - how do you protect the loudspeaker drivers from faulty programming or wrong connection? You don't want to send the wrong signal to a speaker driver. Proprietary plugs and sockets could solve that - multi-pole speakons might do it. Because some Harbeths are three way there is the issue of how many power amp modules you can house in the box and how you power them - but this is accomplished in AV receivers. Maybe the standard amp could have four amps for driving a pair of two ways; but if someone buys a pair of more expensive three ways they also have to buy an extra two channel amp which, with it's own power supply would furnish the extra power and complexity needed for the bigger speakers.

My mind is racing ahead, and I must stop - tantalising - absolutely tantalising.

Brand extension? No, re-writing the industry standards. Bring it on!

[DSRANCE]

I do feel that an amp that is sensibly made and easy to work on in future years would be ideal. I also feel that this could well lead into fully active operation for the speakers which although could open another can of worms, I feel the radial drivers are more than great enough to respond magnificently should this option ever be considered again (the now very middle aged HHB Circle actives that have found their way into domestic use are well loved too and I think "we're" way beyond that level of performance now )

As for DSP, I'm way behind on this, still looking for conventional ways to fine-tune the room and system, but I genuinely await possible future developments with keen interest.

Alan, thanks for your seemingly eternal patience in "us/me," allowing us to catch up with future possibilities.

[chirhonix]

Hi, Alan,

please keep us informed. I would be very interested in your ways of integrating a DSP into your amp.

Regards,
Peter

[hifi_dave]

IMO, this is going to be a nightmare can of worms.

Harbeth make some of the best speakers on the planet, hugely popular and respected with orders stretching into next year and beyond. Do we really need an amplifier, with all the attendant problems ?

A high quality, robust, simple amp is one thing but getting into DSP and goodness knows what else is an entirely different matter. I for one, would not be interested in all the digital gizmos and I know my customers feel the same. Maybe a few forum goers would relish such a project but the 'real' customer is not. I can just see it now, pitted up against a Yamaha, Rotel, Panasonic, Sony or whatever home cinema receiver with a gaggle of electronica and coming out worse because of the pricing.

Please leave gadgets and gizmos to the giants and concentrate on simple and good.

[davidlovel]

Good to see this open-minded approach to a possible Harbeth amplifier.

As the main limitation on the quality of sound that most Harbeth users experience probably comes from their listening room, could I suggest that the first priority be to address this? A DSP module to provide room correction with digital in and out (able to handle audio up to 24/192 resolution) and no other functions (DAC, gain etc etc) would be a very valuable first module for the proposed Harbeth amplifier electronics.

[Gan CK]

IMO, this is going to be a nightmare can of worms.

Harbeth make some of the best speakers on the planet, hugely popular and respected with orders stretching into next year and beyond. Do we really need an amplifier, with all the attendant problems ?

A high quality, robust, simple amp is one thing but getting into DSP and goodness knows what else is an entirely different matter. I for one, would not be interested in all the digital gizmos and I know my customers feel the same. Maybe a few forum goers would relish such a project but the 'real' customer is not. I can just see it now, pitted up against a Yamaha, Rotel, Panasonic, Sony or whatever home cinema receiver with a gaggle of electronica and coming out worse because of the pricing.

Please leave gadgets and gizmos to the giants and concentrate on simple and good.

Well said hifidave. Can't agree more on that. Simple and good has always been highly prized on british amps. Don't wish to see any change in that tradition. Even more so for a specialist brand like Harbeth.