Introductions

[phase_accurate]

Dear fellow DIYers

I take this chance to introduce myself.

I live in the vicinity of Berne, the capital of Switzerland.

I started my apprenticeship as a radio and TV technician 25 years ago.That's when I also started with DIY in the audio area.
I later changed to (and still am with) the datacomm busines since the income is much better here (and most of the stuff you get into the repair shop is chepo stuff anyway and veeeeeery seldom real fancy equipment).

Some years later I graduated from a school of engineering. So I am now one of those EEs.
BTW: The subject of my thesis was a "PWM amplifier with resonant-mode PSU"

Apart from audio electronics my hobbies are:

Music ( I am playing the bass guitar and the flute, though not very active anymore)
Sailing
Travelling

When it comes to audio engineering I am neither religious nor fanatic. I simply belive that the best amplifier, the best loudspeaker etc doesn't exist (even though sales-people and high-gloss brochures try to force you to believe the opposite).
In every technical area there are a lot of compromises to be made and there is always the one solution that is not the best of them all but THE BEST SUITED for a given task.
This is specially true for audio electronics where also personal taste is an important factor (music is an intellectual AND emotional thing after all).
Apart from facts: Life would be boring if the perfect audio reproduction chain had already been invented !

Below my opinions on some often discussed subjects:

Tube amplifiers:
I likle their sound but don't use one

Transistor amplifiers:
They have reached a performance level nowadays that can be called "blameless" (to cite Douglas Self) and unproblematic.

Class A:
Amazing sound quality but I don't like the waste of power and material (as I also dislike equipment that is switched on all the time waisting immense amonts of precious energy because it is perfectly posible to design equipment that 1.) suffers little from switching on and off and 2.) reaches optimal bias within reasonable time, with some intellectual effort).

Switching amplifiers:
This is a very interesting working principle and I believe that these amps will play an important role in the future, specially in the low and middle priced HiFi range as well as in the professional area. Their performance will continue to improve but I don't think it will ever exceed the one of the very best conventional amplifiers. One of my main concerns is the necessary output filter that is restricting the output bandwidth (this can be overcome a little bit by using a parallel configuration of a conventional and a switching amplifer).

Horn Loudspeakers:
Effortless and natural dynamics (no matter whether subtle or "brutal"). I actually once owned something like a Klipshorn copy where the separation between low frequency and mid/high was done actively. I still own a speaker using a JBL biradial horn (2344) and find it fun to listen to.

Broadband drivers:
Excellent imaging and voice reprodiction (see below !)

Reflex enclosures (i.e. vented):
The best compromise when it comes to achieve a low cutoff frequency and good SPL (with low THD) whith a reasonably sized cabinet. The JBL thing mentioned above is vented in the LF area, as well as another two-way speaker I am currently using which is consisting of Dynaudio 17W75LQ and D260 drivers.

Closed box:
The best solution when it comes to perfect pulse response with a reasonably sized cabinet (see below as well).

Active speakers:
For me this is definitely the way to go. There is no other solution where the designer has so many things under his control. As a bonus, the power amplifiers have to meet less stringent requirements for a given performance.

"Voodoo":
As long as it doesn't cost a fortune I am positive about any form of tweaking. Even if there is no apparent scientific reason (it might just not have been found yet !) considered that much of it can be a simple matter of taste anyway.

I am currently developing an active system that is using the Manger bending wave transducer (MSW) paired with an LF driver, made by Audio Technology of Denmark, in a closed box. It will use a subtractive crossover (called analog computer crossover by John Watkinson:www.celticaudio.co.uk), like the ones introduced on Nelson Pass' homepage, in order to achieve perfect transient AND amplitude response. Although I will use a very standard asymmetric subtractive crossover (3rd order lowpass/1st order highpass) I did some thinking and came to conclusions how symmetrical subtractive crossovers could be made or very simple three-way ones. If at least more than just three persons are interested, then I will of course supply more details on this subject.

So I hope I might contribute to this forum in a positive way, and my opinions will NOT help to find the absolute truth (which I am convinced that it doesn't exist at all) but to encourage different ways of thinking.


Regards

Charles

[mrfeedback]

Welcome.

Regards, Eric.

[capslock]

How's your Manger project progressing?

[planet10]

Originally posted by phase_accurate
It will use a subtractive crossover (called analog computer crossover by John Watkinson:www.celticaudio.co.uk), like the ones introduced on Nelson Pass' homepage, in order to achieve perfect transient AND amplitude response. Although I will use a very standard asymmetric subtractive crossover (3rd order lowpass/1st order highpass) I did some thinking and came to conclusions how symmetrical subtractive crossovers could be made or very simple three-way ones. If at least more than just three persons are interested, then I will of course supply more details on this subject.

This is an interesting subject. I have started a new thread.

dave (diyAudio regular hat on)

Active Subtractive XOs

I took the liberty of adding posts on the subject from another thread that was wandering off-topic.

dave (moderator hat on)

[roddyama]

Hi Charles,

Welcome, of course.

Definitly interested in the active subtractive XO's. I will checkout the other thread.

Regards,
Rodd Yamas***a

[UrSv]

phase_accurate,

When and where for Swiss High-End fair?

/UrSv

[trigon]

Welcomen.

Trigon.

[trigon]

Yaaa nuturlih.

Trigon

[cocolino]

Yaaa nuturlih

tats amost pörfect - a bittle mor ant we kan toak in German!

[planet10]

The excellent discussion on Mangers has been given its own thread:

http://www.diyaudio.com/forums/showt...&threadid=5787

dave