• Welcome to the all-new HUG. All content has been converted from the old system, and over the next days we will re-style HUG in a more familiar way.

Tube Amp for Harbeth SHL5 - Minimum Power

Status
Not open for further replies.

A.S.

Administrator
Staff member
Can do it with Parametric EQ in Roon. It can be switched on and off during playback. Testing, testing, 1, 2, 3 ...
You must be registered for see images attach
Oh that's brilliant. Grand.

Have you listened to the EQ in/out?
 

A.S.

Administrator
Staff member
I love this thread, especially given my drive-by experience with the Primaluna (and its speaker counterpart, the Paradigm 3F).

If I may, again, expand on amplifier ideas:

In addition to using Hegel amplifiers in demos, I do believe I've heard Alan suggest an inexpensive Yamaha might be a reasonable choice (presumably based on manufacturing quality and warranty, as well as predictably linear behavior). Here's a listing for one. There are two models in the line with more/less power-


.../QUOTE]
Yes, I bought the Yamaha as a back-up for the Hegel at the Bristol show. I've just wandered into our stores and found it: a A-S701. We used it as a replacement of one of the Hegels when it had a mishap ....

Observation: no obvious change in sound quality v. Hegel 360 but a very big difference in maximum loudness, exactly as you would expect from the wattage specs. Nicely built. Plentiful features. Best usage case? Listening room of perhaps 4m x 3m max., playing 2m from the speakers and with neighbours who prevent playing *really loud* - which does rob some of the fun from rock music.

Interestingly though, whereas vistors (who often first look at the electronics, then the speakers, and finally become aware that music is playing) would make no or a warm comment about the presence of the Hegel, the Yamaha needed some explanation.
 

ssfas

Well-known member
Oh that's brilliant. Grand.

Have you listened to the EQ in/out?
Using Bluesound Node 21 and P3ESR. First up was a Mozart quartet, the big bump is at the higher end of the violins mainly and a hint of a difference. Then went to woodwind, an album called Roots by the brilliant Martin Frost, clarinet, recorder and transverse flute, and there does appear to be added warmth, which detracts from the "reediness" of the clarinet. Need to do this later on the Devialet/SHL5+40th. Fortunately Roon lets you add in the EQ profile on any device at a click. Very clever software.
 

MikeM

Active member
There was a list given (not by A.S. admittedly but by a significant contributor to HUG) in #110.
Yes, and one of the Brands on that list (that I owned until a few weeks ago) was derided in a previous amplifier discussion by some members and my dealer (same one as contributor in #110) will confirm that he often has a hard time with some on here with other brands on that list.
 

ahofer

Member
Interestingly though, whereas vistors (who often first look at the electronics, then the speakers, and finally become aware that music is playing) would make no or a warm comment about the presence of the Hegel, the Yamaha needed some explanation.
Audiophiles tend to have a real problem with mass-market brands, regardless of build quality, measurements, and sound. Yamaha has offered pretty high quality stuff for decades, AFAIK.

The other interesting question is whether one of the professional amps (crown, Yamaha...) would do the trick. Lots of power/price there, and usually quite durable and well-supported. Plus many of them are more amenable to, or have built in, EQ/DSP. They tend to have somewhat higher noise, although arguably inaudible, unless you are a young person living in a rural temple.

e.g. https://www.crutchfield.com/p_859XLS1502/Crown-XLS-1502.html

independent measurements and comparisons here:

 

Milosz

Active member
Yes, I bought the Yamaha as a back-up for the Hegel at the Bristol show. I've just wandered into our stores and found it: a A-S701. We used it as a replacement of one of the Hegels when it had a mishap ....

Observation: no obvious change in sound quality v. Hegel 360 but a very big difference in maximum loudness, exactly as you would expect from the wattage specs. Nicely built. Plentiful features. Best usage case? Listening room of perhaps 4m x 3m max., playing 2m from the speakers and with neighbours who prevent playing *really loud* - which does rob some of the fun from rock music.
It doesn’t surprise me at all since Yamaha A-S701 is another example of a neutral solid state amplifier (straight wire with gain), just like the Hegel, that just wasn't conceived to color the sound produced by the speakers in first place. Below is a graph presenting Yamaha’s frequency response under load, so you can see it’s flat:
You must be registered for see images attach


Yamaha A-S701 is quite powerful too, even though published specs are somewhat confusing as it’s often the case with mass market Japanese amplifiers. However, measurements clearly indicate that it produces 2x128W into 8Ohms which isn’t much less than current dumping Quad’s power amplifiers.
You must be registered for see images attach


What makes them different though is that Yamaha apparently has more modest power supply than the Quads as it is only capable of providing 2x130W into 4Ohms, which is just 2 watts more than its power into 8Ohms, whereas Quads are normally able to almost double the power delivered into 4Ohms. For example 909 Stereo is rated at 140W into 8 and 250W into 4 Ohms. As most Harbeth models stay in the 6Ohm region across most of the frequency range, it means that Quad 909 will pump about 200W into Harbeth speakers while Yamaha A-S701 will only produce 130W with Harbeths, just like it does with 4 and 8Ohm load.

Hegel 360 is also a completely flat straight wire with gain:
You must be registered for see images attach

and it produces significantly more power than either Yamaha or Quad. According to the graph below it’s 245W into 8Ohms and 450W into 4Ohms, above which the distortion increases instantly and THD+N exceeds 1%. So it’s about 350W into 6Ohm Harbeths. Very powerful amplifier indeed!
You must be registered for see images attach



Tests are taken from a well respected Polish audiophile magazine “Audio”. They are available only in Polish but you can use Google translate to read the contents. Focus on the “laboratory” section only. It’s all I ever read in audiophile magazines anyway because measurements tell all I need to know about any amp.

You can now see Alan’s frustration when he has to answer same questions over and over when all high-fidelity amps are flat and practically the same (this is very definition of hi-fi) and everyone has tools at hand to draw their own conclusions and make their own “amplifier short lists”. Use the fishing rod instead of crying for the fried fish served on a golden plate right away. It’s more fun if you do part of the job yourself!

Having said that though, you can also take an alternative approach and try to adjust the sound to your liking by way of purchasing electronics that are not flat. However, if your goal is different than neutrality and you want to deliberately color the sound rather than keep it true to the source, you won’t get a good advise from anyone else but you, because no one can decide for you what kind of sound you like. If you choose that path you’re on your own, and you will surely need a lot of patience and deep pockets. You can’t have both neutrality and colored sound fit to your liking so you need to make a choice. It’s even a philosophical question as I see it.
 
Attachments only viewable to members
Last edited:

A.S.

Administrator
Staff member
March amplifier:

The specs are not very comprenshive (I can't see an input sensitivity for the power amp) but these two parameters are interesting:

You must be registered for see images attach

Now, it would not be obvious at all to the non-technical reader but the walk through I gave in my post #129 above actually relates to these two. It is likely that the reason the tube amplifier analysed by Stereophile has such a frequency response is almost certainty because it has an output impedance that is a significant proportion of the speaker load at any frequency. You don't really need to know much more than that - it's a rule of thumb.

Now look at the March amplifier spec above. The amp's output impedance is quoted at 1.5 thousandths of one ohm! That's so low that it is difficult to measure. Amazing really. And as a consequence, I would fully expect that were Stereophile to test it, it would show a ruler-flat dB output across the audio band. So the very low output impedance is a really useful parameter to look out for.

As a matter of comparison, the tube amp invariably drives the speaker through an output transformer. And this transformer, rather than the tubes themselves, is where the challenges really are for the tube amp designer. The output transformer works by taking the instantaneous audio electrical signal in the windings of the transformer primary and converting it to a instantaneous variable magnetic field, inducing that field in a secondary coil in which the magnetic field induces a voltage. So the speaker is at the end of an electrical > magnetic > electrical converter. And obviously that secondary coil has resistance - quite high resistance, not thousandths of ohms but often an ohm or more. That means the tube amp's impedance match to the speaker is radically different to the solid state amp, and hence, the problems we see about load sensitivity.

There is no such thing as a neutral transformer. The electrical > magnetic > electrical converter aka output transformer always imparts its own nature on the signal passing through it.

On the basis of what I read above, I would have no concern oredering a March amp - I wonder who the UK importer is? Anyone know? Perhaps he'd make a special Harbeth branded one.
 
Attachments only viewable to members
Last edited:

Milosz

Active member
Can do it with Parametric EQ in Roon. It can be switched on and off during playback. Testing, testing, 1, 2, 3 ...
You must be registered for see images attach
We called that kind of frequency response “a smile” because it has enhanced low and top end to make music sound more impressive and attractive to the ear. When I was younger almost everyone set graphic equalizers in their amps that way, but all those years ago we mostly listened to pop and rock music only, that can benefit from such equalization and is a product of the studio anyway, often so much processed and played on non-acoustic instruments that it’s hard to say what’s natural anymore.

With classical or even jazz music played on acoustic instruments such kind of equalization in my opinion is not desirable, but of course everyone has their own ears and taste. For sure such manipulation will be very audible though, for any ear, trained or untrained.
 

ahofer

Member
March amplifier:

The specs are not very comprenshive (I can't see an input sensitivity for the power amp) but these two parameters are interesting:

You must be registered for see images attach

Now, it would not be obvious at all to the non-technical reader but the walk through I gave in my post #129 above actually relates to these two. It is likely that the reason the tube amplifier analysed by Stereophile has such a frequency response is almost certainty because it has an output impedance that is a significant proportion of the speaker load at any frequency. You don't really need to know much more than that - it's a rule of thumb.

Now look at the March amplifier spec above. The amp's output impedance is quoted at 1.5 thousandths of one ohm! That's so low that it is difficult to measure. Amazing really. And as a consequence, I would fully expect that were Stereophile to test it, it would show a ruler-flat dB output across the audio band. So the very low output impedance is a really useful parameter to look out for.

As a matter of comparison, the tube amp invariably drives the speaker through an output transformer. And this transformer, rather than the tubes themselves, is where the challenges really are for the tube amp designer. The output transformer works by taking the instantaneous audio electrical signal in the windings of the transformer primary and converting it to a instantaneous variable magnetic field, inducing that field in a secondary coil in which the magnetic field induces a voltage. So the speaker is at the end of an electrical > magnetic > electrical converter. And obviously that secondary coil has resistance - quite high resistance, not thousandths of ohms but often an ohm or more. That means the tube amp's impedance match to the speaker is radically different to the solid state amp, and hence, the problems we see about load sensitivity.

There is no such thing as a neutral transformer. The electrical > magnetic > electrical converter aka output transformer always imparts its own nature on the signal passing through it.

On the basis of what I read above, I would have no concern oredering a March amp - I wonder who the UK importer is? Anyone know? Perhaps he'd make a special Harbeth branded one.
Full PDF specs of the amplifier module are here, under "downloads" (pdf)



There is a calculation of 6.61 dBu at using rated power 250W, Load 4Ω, Gain 25.6 (balanced)

Other stats are impressive, although you'll note the gap in continuous output power vs. many AB amps. Not an entirely realistic music scenario. Alan March has some videos on his youtube site showing him run his amps at full power, stable, and taking temperatures off of the case.

You must be registered for see images attach


Note the scales below - tiny on the distortion Y, supersonic on the Frequency Response X.


You must be registered for see images attach


You must be registered for see images attach
 
Attachments only viewable to members

ahofer

Member
PS, there's something of a debate about what happens if very high frequencies (related to the switching power supplies) get output to the speaker. I'm not qualified to judge, but you can see some of the proffered answers to my questions on that below this post:

 

ssfas

Well-known member
March amplifier:

The specs are not very comprenshive (I can't see an input sensitivity for the power amp) but these two parameters are interesting:

You must be registered for see images attach

Now, it would not be obvious at all to the non-technical reader but the walk through I gave in my post #129 above actually relates to these two. It is likely that the reason the tube amplifier analysed by Stereophile has such a frequency response is almost certainty because it has an output impedance that is a significant proportion of the speaker load at any frequency. You don't really need to know much more than that - it's a rule of thumb.

Now look at the March amplifier spec above. The amp's output impedance is quoted at 1.5 thousandths of one ohm! That's so low that it is difficult to measure. Amazing really. And as a consequence, I would fully expect that were Stereophile to test it, it would show a ruler-flat dB output across the audio band. So the very low output impedance is a really useful parameter to look out for.

As a matter of comparison, the tube amp invariably drives the speaker through an output transformer. And this transformer, rather than the tubes themselves, is where the challenges really are for the tube amp designer. The output transformer works by taking the instantaneous audio electrical signal in the windings of the transformer primary and converting it to a instantaneous variable magnetic field, inducing that field in a secondary coil in which the magnetic field induces a voltage. So the speaker is at the end of an electrical > magnetic > electrical converter. And obviously that secondary coil has resistance - quite high resistance, not thousandths of ohms but often an ohm or more. That means the tube amp's impedance match to the speaker is radically different to the solid state amp, and hence, the problems we see about load sensitivity.

There is no such thing as a neutral transformer. The electrical > magnetic > electrical converter aka output transformer always imparts its own nature on the signal passing through it.

On the basis of what I read above, I would have no concern oredering a March amp - I wonder who the UK importer is? Anyone know? Perhaps he'd make a special Harbeth branded one.
It'll cost you just over £500 ordered online direct from Australia, so you won't be paying distributor or dealer margins.
The guy who makes them has a discussion thread about his amplifiers here:
With such a branding option he'd probably send you one for free!

It is a Hypex NCore amplifier, of which there are many, the less middle-men the cheaper.

A popular seller in Europe is Hattor/Khozmo, otherwise known as Arek. He's well known for his step attenuators and I had one of his balanced dual mono 64-step passive pre-amps. The only pre-amp I ever owned. Sold it to a HUGster.
Arek does mono blocks that appear to be the same NCore unit, but with a more sophiciated power supply. Listed at $600 each, but he does deals.

My own amplifier site says:
"There are multiple advantages to hybrid amplification. Output impedance remains constantly below the 1 milliohm threshold across the entire bandwidth. The resulting damping factor guarantees total control of any speaker on the market. Exceptional audio performance is achieved without special selection or peering of components. Performance is replicable from one device to another, sustainable and guaranteed by engineering."

There is a huge database of amplifier measurements measurements here, including damping factors:
The chart of damping factors for the Class A/D hybrid Devialet Expert 130 shows that for a quality hybrid digital amplifier the damping factor remains very high even at very high volume levels. The summary report that much of the distortion was below measurable levels, and very low at high frequencies any power, give me a warm glow that I bought the right product (I have the 250 model - twice as powerful). The downside is that I if the 130 had been available when I bought my 250 (which it wasn't) I could probably run the 130 with Harbeth SHL5+ at high levels with negligible distortion.
The damping factor for the Hegel 360 is not quite as impressive, but it is a Class A/B amplifier, but the 390, the same price and similar functionality to the Expert 130, is probably better.

The PS Audio M700 is a Class D ICE amplifier, again pretty good, but quite a lot of high frequency distortion well below its max power rating.

I think this shows how good Class D amplifiers can measure over Class A/B in terms of damping factor and distortion, and that there is further gains to be made from more sophisticated products like the Devialet compared to the PS Audio. One of the main factors of the former is it's proprietary power supply, besides being a hybrid A/D rather than just a Class D amp.

The Audio Research VS55 60w valve amplifier has the same dummy speaker load profile as the Prima Luna Alan reviewed above.
 
Last edited:

MikeT.

New member
I realise the debate has moved on a bit since I’ve been away, but, on this particular point, if the PrimaLuna clips at 35w, isn’t it supposed to? It’s rated at 35w, so at that point it maxes out - and clips.
I have no quarrel with an amp clipping where the manufacturer says it will per the design. I bought into the “tubes are best” camp and while it sounded good, I now have a solid state amp at triple the wattage, a third of the price and it doesn’t overheat my smallish listening room.
 

witwald

Active member
So, how will the average consumer understand if an amp color the speakers or not?
It's not that difficult really. An amp with low distortion, high damping factor, and reasonable power output (e.g. at least 80 WRMS into 8 ohms), would probably do the job.

Harbeth could do a "Preferred amp list" per speaker so we at least can save money and time and get closer to the best match
That's unnecessary, and would probably do a bit of disservice to good amplifiers that aren't on the list. Keeping up with new models would be a lot of work.

Myself is trying to read tons of reviews and personal feedback now trying to find the needle in the hay in order to find a neutral, powerful amp that doesn't cost me a fortune. Tough task..
There is a plethora of amplifiers that are neutral, powerful, well built and that don't cost a fortune. It really isn't that hard a task. Lots of brands and styles to choose from.
 

A.S.

Administrator
Staff member
I wonder if it is fully appreciated how humans consider a sound 'colored' or not.

We use the adjective 'colored' to describe what our brain/ears tell us is a surplus or weakness of energy in an audio band. The technical measurement of coloration (excess/deficiency of energy) is not a matter of debate but the sensitivity of an individual listener to the presence of coloration is. For example, play a violin made of chipboard to an Amazon native with no prior contact with the outside world, and he would readily accept the sound as his reference. Subsequently, play him a Stradivarius, and compared with his chipboard reference, he would perceive the sound as horribly shrill, bright and resonant.

So, we can appreciate why the earliest audio pioneers nearly a hundred years or more ago invented audio measurement equipment and connected that to their audio systems. Those instruments did the job of the ear. They identified and excess or weakness of audio energy in octaves, part octaves and by individual notes and frequencies.

That is all there is to 'coloration'. So it must follow that the logic behind applying test instruments to audio equipment is to save us the stress of needless auditioning of audio hardware when we can prepare a short-list of candidates by reviewing technical measurements well in advance of actually listening.

Of course, this is a purist's approach, where reducing coloration to the absolute minimum is the driving motivation. But, equally, there will be those who positively want to add-in coloration to their system, as some like to turn-up the colour controls on their TV. For those, interpretation of the technical measurements is equally valid because they can look for particular characteristics in the technical graphs that would likely add the sort of coloration they seek. As an example, someone with an age-related or occupational hearing defect might eliminate 'flat', uncoloured audio equipment, and seek-out components with a boosted output in the high frequency range. As audiologists tell us, the trained listener can (just about) detect a level boost/cut of a dB or so, so a consumer who wanted or needed a brighter top could find such a speaker by studying the technical measurements from the comfort of his arnchair before making his short list.

Technical measurements are our friend in allowing us to match our needs to the most appropriate hardware.

You must be registered for see images attach

1932 audio test equipment - the same functionality of dB v. Hz is used today.
 
Attachments only viewable to members
Last edited:

MikeM

Active member
Of course, this is a purist's approach, where reducing coloration to the absolute minimum is the driving motivation. But, equally, there will be those who positively want to add-in coloration to their system, as some like to turn-up the colour controls on their TV. For those, interpretation of the technical measurements is equally valid because they can look for particular characteristics in the technical graphs that would likely add the sort of coloration they seek. As an example, someone with an age-related or occupational hearing defect might eliminate 'flat', uncoloured audio equipment, and seek-out components with a boosted output in the high frequency range. Technical measurements are our friend to the best system for us.
This is a very good example that mirrors the subjective vs objective debate in Hi-Fi Circles. Almost every family member and friend that I know has their TV colour fairly badly oversaturated. They can readily look outside to very easily get a grading reference for how green grass should look to be as natural as possible but, just as some do in photography, they love to see the colour pop! Natural looks too flat to them. And this is the point I think, most of these audiophiles know they are introducing colouration and less than neutral fidelity but it suits them - I was one of them until it finally did dawn on me only 4-5 years ago that I did not want my electronics to spoil my P3ESR's.

One final point. I am willing to bet that most of those who are fanatical about their technically flawed electronics are the ones that DO tune their TV colour as near natural as possible.
 

allthumbs

Member
So if you had 10 eminent speaker designers and each of the designers were given the same drivers for a two way bookshelf speaker say, as well as identical pre-built cabinets and the same test equipment but they were allowed to build their own crossovers with a predetermined budget cost (not too tight and not too loose) would the outcome be that they would all sound roughly the same, or completely different?

I'm kinda thinking of those comparison paintings of Van Gogh and Gaughin when they were living and working together in Arles and painting the same scenes and locations but interpreting them differently although one can recognize the same elements in both painter's renditions but given different emphasis and accents, framing of the subject etc.

If you were to hold up a photograph of the same scene it could be seen as a reference and Paul and Vincent's efforts as wildy coloured interpretations, fictions in fact so to speak, but as Francis Bacon would say returning the very fact more "violently" more alive back to the viewer.

With speaker designers my expectation would be that given the technology and the limits of the physical elements the speakers would sound very roughly the same. But in real life that doesn't appear to be the experience. It's easy to say we all hear differently, perhaps we all taste food differently but a restaurant manages to make the same recipe for it's meals every day on the basis that it tastes the same, despite the change in particular ingredients due to shortages of a particular vegetable from one supplier rather than another, or a different brand of pepper etc etc.

Think of the longevity of the Big Mac? Now that's science and marketing blended perfectly.
 

A.S.

Administrator
Staff member
So if you had 10 eminent speaker designers and each of the designers were given the same drivers for a two way bookshelf speaker say, as well as identical pre-built cabinets and the same test equipment but they were allowed to build their own crossovers with a predetermined budget cost (not too tight and not too loose) would the outcome be that they would all sound roughly the same, or completely different?
...

With speaker designers my expectation would be that given the technology and the limits of the physical elements the speakers would sound very roughly the same. But in real life that doesn't appear to be the experience. It's easy to say we all hear differently, perhaps we all taste food differently but a restaurant manages to make the same recipe for it's meals every day on the basis that it tastes the same, despite the change in particular ingredients due to shortages of a particular vegetable from one supplier rather than another, or a different brand of pepper etc etc.
That's a really interesting question. I think I should move it to an existing thread on that very issue. I just don't know how to do that in the new upgraded HUG.
 

March Audio

New member
Amplifier specifications - our very best friend. An explanation for the non-technical teenager.

Rather than return to the office after our break, I'm going to have one, hopefully final attempt to convey the essential point about amplifier sonics. It's a fair point reported earlier thin this thread that 'ordinary folk can't understand the Stereophile technical graphs', so let see if we can demystify them.

CAVEAT: I have used as data the two links that were posted by ordinary contributors in the thread above. I could have gone hunting for any number of alternatives, but this saves time. So I cannot say, and will not say, whether these are typical of what's available in amplifier land nor pass comment on their designer's philosophy or commercial acumen; I'm just recycling what went before.

We start with cleaning up the printed technical graph of the tube amplifier (Graph A) to simplify for the non technical reader. It looks like this now:

You must be registered for see images attach

Hi Everyone :)

I was made aware of this thread and decided to pop in and say hello and hopefully help in answering any general technical questions. I will try my best to keep this technical/genearalised and not a sales pitch.

First thing it have to say how refreshing it is to see Alans (this could become confusing as I am also Alan) no BS approach. There is soooooooo much BS in hifi with customers being totally misled by marketing rubbish. My approach is very similar to Alans and hence I do have a bit of a tendancy to rub ardent audiophiles up the wrong way when I point out their audio beliefs have no basis in fact :)

Im replying to Alans post above because it clearly demonstrates an issue found with tube amps. In fact I had a fascinating exchange in another forum on precisely this a couple of days ago. I would like to relate it.

The thread was about class D amplifiers. I sell Hypex based units and Im about to release a Purifi based unit. Bruno Putzeys designed both. Inevitably a poster came along and said (Im paraphrasing) "how much better an Acoustic Research tube amp sounded than a Hypex NC400". I probed a bit more and found they performed the comparison sighted, without accurate volume matching and listened to the respective amps on different days! So in essence, their conclusions were hopelessly flawed.

Thats not the real story though. I decided to dig a little deeper and see if there would be any other genuine reason for the perceived difference. I wasnt familiar with the AR Reference 250 amp, but stereophile had measurements for its lower power sibling, the Reference 150. (Note the Reference 150 is about $20k AUD and the 250 is about $32k AUD - yes really !)

If we look at the frequency response we see that into resistive loads it is not flat. Into a speaker load it is all over the place. (the black squiggly line)

You must be registered for see images attach


This level of FR excursion is quite audible. The other point to note is that this amp will sound different with every speaker. Its frequency response will vary dependent upon the specifics of the speaker load. As Alan rightly said due to the high output impedance and the behavior of the output transformer.

re the output impedance of my amps, its measured at the module output terminals so in reality by the time it gets through the banana posts it will be a little higher, but its a fundamental trait of good class D.

I then looked at distortion. Frankly horrendous. There should only be one signal there, the far left one. No amp is distortion free but good ones will probably have those harmonics 120dB plus down.

You must be registered for see images attach


Intermodulation distortion (being directly related to THD) was equally bad. There should only be 2 signals at 19 and 20kHz

You must be registered for see images attach



So this tube amp in my opinion really did sound different, but thats because its abysmal technical performance renders it horrendously coloured. Due to the bias created by the tube technology, the brand and massive price tag it was perceived as sounding better. It most certainly sounds different, but not for any good reasons.

So this is the fundamental reason behind valve amps sounding different. Most will suffer with these effects. Now if any individual likes the ultimate sound that comes out then I dont really have any criticism, thats up to them, but HiFi it most certainly aint. I did joke that the perceived "air" around the instruments on the 250 (a quote) was just all the intermodulation distortion that surrounded each and every note. Also that it would have been far more cost effective to buy a cheap amp, a graphic equaliser and a guitar fuzz box. The owner of the amp became quite irritated at this point.

So compared to the new Purifi module - is it any wonder they sound different? :)

You must be registered for see images attach
You must be registered for see images attach


You must be registered for see images attach



If anyone has any questions about this, class D or other areas Im happy to try and answer. :)

cheers

Alan
 
Attachments only viewable to members
Last edited:
Status
Not open for further replies.
Top