What would be interesting is if Hifi Critic could review one of the amplifiers designed by Elektor Electronics.

If they were to review the design and perhaps suggest tweaks - specific resistors, capacitors, wiring change etc., this would allow people to build and hopefully have a lower cost unit that is a pleasure to build and listen to.

Regards,

Richard.

Edited by user 06 October 2011 16:47:56(UTC)  | Reason: Not specified

Hi Jan,

Wow it looks great. But it's only 50W, this is really what i'm talking about, this may be a very good amp, but it cannot be considered world class if it doesn't drive all speakers.

I have inefficient stand mount speakers and i need power, 100-150W................................

mat.

frank, are you saying that designs that are 'too good' get automatically pushed up in price (and casework)?

Indeed, if it were so easy to produce these things (i.e. setup a production facility with the supply and backup to produce consistently good and reproducible product with little production variation), then everybody would make their own.

Edited by user 07 October 2011 16:44:50(UTC)  | Reason: Not specified

I don't really know how you'd find out. HiFi mags mostly do non-blind non-randomised testing (most of them as a matter of principle) and their reported results are hopelessly compromised by expectation based on price, physical build, reputation and often the supposed design principles espoused by their designers. There are probably some truly excellent budget amplifiers made by the likes of Sony, Denon, etc, where the only compromises are in the bits that don't actually affect the sound - front panels, knobs, styling etc. But as a private individual it is very hard to do any true comparisons of sound without being affected by all the above factors, or even have access to competing products to find out. Or indeed have any way of knowing, even if blind listening does identify real differences, which are nearest to the original sound.
About all you can say is that if you have reasonably kindly speakers in terms of impedance and sensitivity then there are lots of good amps, some bearing "HiFi" names, others not, which are utterly indistinguishable from the top price articles in terms of sound. I except single-ended-triode amps from this of course, whose performance is so utterly dreadful that you would have to be truly cloth-eared not to distinguish them, though of course you may actually LIKE their deficiencies.

Wonderfully prejudiced stuff, as usual from those that do not hear , do not wish to hear , or always know better even if they are far from expert in the field on which subject they are so free to give of their opinions ........

The Which series on hifi when the market was more important, routinely used DBT methods, as did much of the HI FI Choice A5 series multiple comparative test work that I undertook.

Of course there have many fine Japanese inexpensive amplifiers for which a consensus rapidly developed in the magazines , this when the Japanese companies took separates stereo audio seriously at every price level.

Classics such as the Rotel RA 820 series which were £150 and the like. Also the NAD 3020. There was also a lot of rubbish , and easily differentiated too.


Designers who understand and care about sound quality have had to struggle under the weight of EMC legislation which is mainly directed to thyristor controlled washing machines where the required counter measures readily degrade sound quality in audio electronics.

Such differences require additional costly parts and circuit revision to maintain sound quality, and not always with complete success.

I can hear the sound quality difference for a connected power amplifier between types of 1nf Y class mains suppression capacitors, eg PP and Paper on the mains input and there is a subtly different tone colour and clarity in the audio.

I wish it was not true , but there it is. I know which I prefer. Ferrite suppressors on power cables are easily heard in a compression of subjective dynamics , and have been for years from when TDK first introduced to the audio market.

Meeting EMC emission regs for CD players often requires compromised audio grounding , since a hierarchical ground may be too long for the RFI stoppers to work. You have to accept poorer sound to meet the specification or spend more money to make up the shortfall.

As I have said before double blind a single 4.7uf high quality PP cap into 20K at a power amp input. The die-hards say audibility of a single component , never mind any 'good' complete amplifier is impossible. I have done it and the capacitor was audible.


If you can hear one component how can the whole heap be rendered undetectable never mind the design and topology to boot?


Martin Colloms

Edited by user 10 October 2011 18:31:44(UTC)  | Reason: Not specified

What is your success rate in DBTs Ken, and what is your current listening/reference system?

Edited by user 10 October 2011 10:57:37(UTC)  | Reason: Not specified

The amps that come to mind are from middle sized companies; Rega Elicit, Creeks, Cyrus and Naim NAIT XS etc. They all make good sounding amps at the bottom of their ranges. In my yoof there was a greater range at the low end of the scale such as 3020, Sansui 217, Marantz's, Denons, Rotels etc (but then again I was more aware of every product in hi-fi back then and I had an opinion on everything....) in addition to Rega and Creek but now there isnt a world beater at £200 but more likely a musical amp at £1000.

I dont get too tied up with quality components, you need the right one in the right place. I remember reading an issue of Stereophile and they were raving about brand X mega amp having several Vishay metal film resistors in key places but a Rotel amp a few pages after being stuffed full of them but that wasnt being used as an indicator of quality.

The best way to get a world beating amp at real world prices is to buy second hand.

One trouble with DBT is you can always hear no difference "proving" there is no difference between, say, mains cables once you DBT. You dont have to listen very hard and your case is made. As often the cry from DBT enthusiasts is that once level matched and controlled most electronics sound the same this can give you the answer you wanted.

Good summary

Hi,

I have had no involvement with DBT - i assume that the people listening do not know what they are listening too (equipment hidden ???), and the people conductiong the experiment do not know who is the real test subject.

Can a DBT be continued over a long period of time ?.

I do think that perception is biased - so extended DBT may be the only way of scientifically proving that changes in equipment - such as a mains lead, can definitely be heard.

I don' think i have the capability to determine the difference (hearing wise), so i would have to rely upon the experiment to resolve this aspect.