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Puffin
07-01-2017, 11:39
When browsing today I noticed that we have in our midst some that either have or still work in the electronics industry or have been reviewers of equipment.

I think that it would be beneficial (if they were willing) to have a section where they could share their history and experience and their take on Hifi/Audio equipment. With their experience they could tell us what is manufacturers bullshit and where money is best spent and any tweaks that are worth doing etc?

Joe
07-01-2017, 12:20
Having seen the stick engineers often get on here for suggesting that some beloved tweaks are a waste of time because they simply can't do 'what it says on the tin', I doubt you'll be getting many takers.

Puffin
08-01-2017, 14:28
Yes Joe, you may be right. What I am more interested in is their take on the hifi industry, you know things like "is the new MAGICAL FIGELITY amp really much better than the previous incarnation, or is it just a styling exercise, that sort of thing.

Arkless Electronics
08-01-2017, 14:32
Having seen the stick engineers often get on here for suggesting that some beloved tweaks are a waste of time because they simply can't do 'what it says on the tin', I doubt you'll be getting many takers.

Correct. Apparently the impossible happens every day in hi fi and the Laws of Physics don't apply in this "post-truth" world so count me out...

Marco
08-01-2017, 14:48
What I am more interested in is their take on the hifi industry, you know things like "is the new MAGICAL FIGELITY amp...

Is that the one for perennial fidgets? ;)

Marco.

User211
08-01-2017, 15:10
Correct. Apparently the impossible happens every day in hi fi and the Laws of Physics don't apply in this "post-truth" world so count me out...

It isn't only hi-fi. That's the annoying thing. Another version of the truth is prolific just about everywhere. Most annoyingly in the workplace, which is just too close to the bone to be comfortable with on so many occasions.

Joe
08-01-2017, 15:33
Yes Joe, you may be right. What I am more interested in is their take on the hifi industry, you know things like "is the new MAGICAL FIGELITY amp really much better than the previous incarnation, or is it just a styling exercise, that sort of thing.

With reviewers, much will depend on whether the manufacturer/distributor has taken out a full-page advert in their publication.

struth
08-01-2017, 15:36
Not nessessarily. It,ll depend on many factors, like life i guess.

Jac Hawk
09-01-2017, 18:25
Sounds like a bit of a hot potato this one, the main problem with Hi Fi is everyone has their own opinion, i know what you're getting at Rob for trade members to act as like a "bullshit" filter and advise where clever marketing has been employed by the manufacturer, however i also understand where Jez is coming from, as soon as he gives his opinion there will be folks out there saying he has an ulterior motive or some such nonsense because he's in the trade.

As this is an enthusiasts forum, i would have thought the insight given by any member is worth taking into account.

Puffin
09-01-2017, 18:43
As this is an enthusiasts forum, i would have thought the insight given by any member is worth taking into account.

Absolutely Mike. I just thought that some with more technical knowledge than I might enlighten us more.

Arkless Electronics
09-01-2017, 19:48
Sounds like a bit of a hot potato this one, the main problem with Hi Fi is everyone has their own opinion, i know what you're getting at Rob for trade members to act as like a "bullshit" filter and advise where clever marketing has been employed by the manufacturer, however i also understand where Jez is coming from, as soon as he gives his opinion there will be folks out there saying he has an ulterior motive or some such nonsense because he's in the trade.

As this is an enthusiasts forum, i would have thought the insight given by any member is worth taking into account.

Precisely. Also the OP mentions tweaks etc and I'm apparently barred by site ethos from saying what I really think about the majority of tweaks.....

Marco
09-01-2017, 20:12
Not barred; as long as you say what you think once, and then let others who disagree do what they like afterwards, without being endlessly 'spanked' like silly schoolboys! ;)

Marco.

Reffc
10-01-2017, 09:04
Having seen the stick engineers often get on here for suggesting that some beloved tweaks are a waste of time because they simply can't do 'what it says on the tin', I doubt you'll be getting many takers.

This.

Plus, please be mindful that most of us still active in the hifi design and construction business would find it unpalatable offering criticism of others' work...the right minded amongst us simply wouldn't take part in offering such opinions on a public forum. There are many ways to skin a cat and there are many companies and individuals doing things their own way.

Now where there was a blatant example of marketing trying to deceive by lies or by claiming that magical nymphs power their box of tricks, it would be only too fair to point out that nymphs don't exist (sorry, block the eyes of any children reading, but neither does Santa) and to perhaps offer the truth behind a claim rather than to rubbish a statement outright. It is dangerous ice to tread on though. A little re-thinking might help. Perhaps something like a section to share technical articles or personal thoughts on design might be more appropriate?

Firebottle
10-01-2017, 09:49
I'll take up the cudgel (oops, sorry – thread) on this one.

Having an enquiring mind in matters of a technical nature I'm always keen to try to understand what causes changes to the sound we listen to.
One aspect that has puzzled me is the differences caused by valve rolling, after all the valve is usually being replaced by one of the same type/designation, though usually a different make.

I'll try to keep this simple so everyone can understand my thoughts.

Firstly some basics, no components are perfect, if they were there wouldn't be any difference in the sound of X, Y or Z amplifier models.
If only 'a straight wire with gain' was something that could be achieved, sadly not.
Gain in this instance is another word for amplification

The gain of a valve stage is dependant on the conditions it is operating under, primarily what voltage is across the valve.
The problems arise from the fact that it is not just the characteristic that determines the amplification (gm) that is non linear compared to the voltage across the valve, the 'equivalent internal resistance' (my terminology) of the valve, known as ra, is also non linear with respect to the voltage across the valve.

A resistor is a basic building block in all electronic circuitry, perhaps one type approaching 'perfect' being the Z foils, at affordable prices; http://www.hificollective.co.uk/components/car_resistors.html

Now combine what may be a near perfect external resistor, the load resistor on the valve anode, with the non linear internal ra and differences can easily arise.
To quote from Keith Snook,
'The complex interdependencies changing internal gains and impedances within a triode amplifier as Va Ia and Vg change dynamically cause all kinds of distortion and colouration ~ Simply isolating one cause of distortion such as the non linearity of the Ia/Vg transfer function cannot fully explain the differences between the sound of similar or even the same type of valves'.

Full article is here: http://www.keith-snook.info/amplifier-buffer/amplifier-buffer-pcb-graphs.html

There are design techniques that can mitigate most of the non linearity of valve characteristics, used to great effect by the likes of Tube Distinctions (AnthonyTD of this very parish) and Shindo to name but two.

A majority of valve amplifiers may well use supply regulation to good effect but that only goes part way to negating the valve amplification stage non linearity, hence different sounds when valve rolling.

I use various techniques in my own design amplifiers, probably why they sound as good as they do :)