Effects of metal enclosures on circuits

Only in as much as they are both Class A Ultra Linear output stages. The phase splitter arrangement is different & the A30 uses octal valves (6SL7 & 6SN7) rather than 83's and 82's. The A30 also uses valve rectification and a CLC power supply whereas the AI amps used silicon rectifiers and CRC.

 

What is the difference with this http://www.hi-end.on9mart.com/cart/Bewitch - 6550.html I know your amp was different from the original but they seem to be claiming this to be the same (in not so many words). I quote:-

"Embarrass your friend's GBP5000 big boy sound system with this GBP500 tube amplifier, this is one of the best pound for pound British designed Class A operation amplifier Bewitch 6550 by miles. It uses the mighty Russian Electro-Harmonix 6550 valves in an Ultra linear push pull configuration. The combination of sturdy power, clarity and modern looking are the distinguishing features."

 

Do you think tat's a bona fide advert Richard?

 

It's not Class A, it doesn't have 30W output, it has a different mains transformer, different o/p transformers, different biasing components (obviously), different feedback arrangement & isn't qc checked by me when it gets here.

It isn't 'British Designed' either. They and a couple of other HK based sellers are simply riding on the back of some decent press I've garnered for the A30.

I've also been asked to repair a couple of them! Unsurprisingly that seller isn't really in a position to offer much in the way of advice or support should there be a problem.



Actually looking more carefully at that advert, they are claiming 60W per ch in UL which it will be. Its the same as the standard factory product & not Class A. You can't get more than about 30W from a pair of 6550's in class A.

The original attraction for me was the platform. Then I just had to persuade them to make me the amplifier in a configuration that I liked the sound of.

 

OK so its bullshit, good, but how do you counter it. I have had people want to make my amps in China or Taiwan or Malaysia, but as I said in earlier post on different thread "there is no business ethic" so you are onto a stufffing to nothing. I don't need that crap!

 

you counter it with branding, solid service and reliability and a big stick from a Chinese lawyer.

 

Bollocks! you just heard it from the horses mouth that it doesn't work otherwise he wouldn't having this crap!

 

I don't get too stressed about it tbh. I don't buy enough A30's to insist that the factory stops selling its 60W amplifier altogether. However, I can request that they don't sell the versions of anything made to my spec to anyone else. So far they haven't. I can also develop entirely new products with them & ask that they don't sell those elsewhere. So far they've been good to their word in that regard aswell.

Beyond that, I just have to try & make sure that what I do sell is reliable & fully supported.

 

The thing is, this will happen no matter what. If you protect your interests and designs, you are only one second-hand purchase away from someone cloning your product. Almost no-one in this business makes products impossible to reverse engineer.

It's not a question of 'if', it's a question of 'when'.

 

Richard, no need to be rude.

Guy doesn't have the lawyer with the big stick, maybe a little lawyer with a chopstick....

 

You miss the point. I have already had two do it, one in Germany (for fun) and one in China who now advertised what is supposed to be my amp PCB on Ebay. The first I don't mind, anyone can try for their own use. The second is all wrong and he (I presume) lost the plot as the circuit is not what an amp is about believe it or not. With transistor amps the layout and component selection is equally if not more important. With Puresound it is different, it is *the same*, same chassis, same looking layout, and valve amps are so simple it is easy to copy. What is missing is his expertice and tweaks, and OK they are playing it straight now, but at any moment if they want more business or think they can get away with it they will - there is no business ethic.

With my circuit and design, cloners will always get it wrong or different, but with Guy they make it! that is why I will never let a Far Eastern company make it.

 

Stop being an idiot (with you that would be like stopping breathing) and there would be no need. If you can't even read the mans post you deserve to be dissed.

And talk about the pot calling......... etc. People only need to read the archive. You seem to live on a different planet to me thank goodness.

 

The other thing is that they, the factory, know that I can go elsewhere if need be. As a result of dealing with them, I'm forever getting offers from other similar companies. It'd be a hassle for me to change but not one that's insurmountable. They aren't that huge a company & I imagine wouldn't want to lose the work I do put their way.

Not only have they not done the dirty so far, they've also been quite willing to undertake new projects, initially at their expense.

I have had quite a bit of experience in trying to get particular items made in the UK recently. That's certainly far from straightforward with many suppliers being either much less co-operative or indeed incapable of making what I want.

 

Joke, typo or Freudian slip, Richard?

 

Well all I can say is the best of luck! as you know we have completely different ideas as to business model, but I think we have much in common on the musical model.

 

Layout aside, aren't most amplifiers on the market copies of others gone before?

Has anything truly different appeared recently?

As an outsider it looks extremely difficult to protect an amplifier design.

 

Or take the longer view. The quality of components may have increased in recent years, but has any useful design innovation occurred since Quad's Current Dumping?

(Digital switching amps remain controversial!)

 

New technology does mean we are able to do things we haven't done before - for example the diyhifisupply lux mono max uses an old western electric '91 schematic as it's base

http://www.audiosharing.com/archive/western/we_amp/pdf/No.91-A.pdf

..but then uses a 'film cap power supply'. This wouldnt have been possible in the same way years ago, some things can be made better now, and therefore new innovations are possible.

'' a twist on the old'' is the new.

from electrostatic speakers to class D amps, it's old-tech by and large.

 

I'd say that what David Berning has done is fairly unique. I'm not the biggest fan of the way they sound but I appreciate the ingenuity of the approach.

 

The nearest to new are Class XD (which is Class AB with the crossover distortion point moved) and Class ADH (which is a small Class A amp with a larger Class D in current dumping mode). Before that was IcePower, Tripath and gainclones.

Unfortunately, real clean sheet design takes research budgets that are beyond most amp manufacturers. Remember, the likes of RCA started working on solid-state amp designs not long after solid-state was announced, but didn't release anything until after stereo happened. That's a dozen-year R&D period.