Hi
2nd Channel is working the same as in post above. same working amp like post 155.
that is fine. 😊
i am happy to say that this amp is now ready for a case and listening...never hear a BJT amp.🤔
open issue...
chris
2nd Channel is working the same as in post above. same working amp like post 155.
that is fine. 😊
i am happy to say that this amp is now ready for a case and listening...never hear a BJT amp.🤔
open issue...
- is the switch on pop...i see about 2Volts peak on scope.....i will recheck.
- build a thiele network for the 2nd channel
- LT spice..OLG...i think i am really a noob...🙄
chris
Hi Chris,
i wonder what "Thiele Network" is meaning....if i look at such a network i think Zobel/Boucherot is the same ? Or is there any difference ?
Your BJT Amp is running now ? I had my fingers crossed that you can solve the problem...😉
Greetings
Peter
i wonder what "Thiele Network" is meaning....if i look at such a network i think Zobel/Boucherot is the same ? Or is there any difference ?
Your BJT Amp is running now ? I had my fingers crossed that you can solve the problem...😉
Greetings
Peter
I always thought like this:
"Thiele Network" = this is an electrical circuit L/R
"Zobel" = his is an electrical circuit RС
"Bouchero" = French mathematician's equation L/R=RС
when pulled wires across the Atlantic at the beginning of the 20th century - they all researched the same thing somewhere in the physics section to improve the quality of signal transmission...
Later, the applied value of these circuits appeared with the development of audio amplification.
Attachments
Yes. 🙂
Both the Zobel circuit and the Thiel circuit are used to a large extent in acoustic systems to increase linearity - this is relevant there. In amplifiers - of an applied nature only.
the Thiel circuit protects the feedback circuit from the capacitive nature of the load, and the Zobel circuit corrects the increase in output resistance due to the current through the coil flowing in the opposite direction.
Hi,
found this, but in german language, month ago. https://www.elektroniktutor.de/analogtechnik/zobel.html
I had, think i wrote, problems with oscillation in the old Elektor Mini Crescendo . I had to learn that a speaker is a generator too.
The capacitor in the zobel filter was to small..Easy to solve, if you know...i learned by comparing with other schematics...tested and voila...
But i wont hijack this tread....
Hennady, thanks a lot for helping and let me understand something more
Peter
found this, but in german language, month ago. https://www.elektroniktutor.de/analogtechnik/zobel.html
I had, think i wrote, problems with oscillation in the old Elektor Mini Crescendo . I had to learn that a speaker is a generator too.
The capacitor in the zobel filter was to small..Easy to solve, if you know...i learned by comparing with other schematics...tested and voila...
But i wont hijack this tread....
Hennady, thanks a lot for helping and let me understand something more
Peter
The author wrote, everything seems to be correct, but he forgot to attach the Thiel coil to understand how the Zobel circuit works.
Also began to write well with the study of wires, but I created a model for analysis unsatisfactorily; it was necessary to compensate for the linear resistance of the wire in order to study the influence of the linear capacitance and inductance of the wire.
article at the link - "befriedigend" ))) in general terms it seems normal, in a specific case it’s not entirely clear.
Hi
Because i do not find the other 3R3 for the Thiele Network 2nd channel i have to change it to 4R7 for both channels...
so i have got more damped network.
next step is to use the M2 chase where i have the defetct ecdor transfomer. i want to listen to this different (edcor vs Hammond 109N)audioformers then i will use this housing for the AA14.
chris
Because i do not find the other 3R3 for the Thiele Network 2nd channel i have to change it to 4R7 for both channels...
so i have got more damped network.
next step is to use the M2 chase where i have the defetct ecdor transfomer. i want to listen to this different (edcor vs Hammond 109N)audioformers then i will use this housing for the AA14.
chris
A resistor parallel to the inductor in the Thiel circuit must be connected to the outside of the turns.
There should only be air inside the inductor of the Thiel circuit.
Hendrik Ohldag from the Stanford Synchrotron Radiation Laboratory at SLAC , believes otherwise, he claims that non-magnetic materials (in particular carbon) on the surface can have a magnetic moment equal to that of magnetic metals, which is observed even at room temperature. This depends on the hydrogen-containing impurities in this non-magnetic material.
Perhaps in amateur radio practice it is not necessary to know such subtleties from physics, but it also does not hurt to have the practical skill of not soldering inside the inductor any (even non-magnetic) resistors.
Any magnetic carbon isn't going to have any significant effect in the real world.
https://physicsworld.com/a/the-magnetism-of-carbon/
https://physicsworld.com/a/the-magnetism-of-carbon/
Ou yes, the real world consists of simple recommendations, for example:
"When winding an inductor coil, it is necessary to take into account that dirty hands can significantly reduce the quality factor of the coil, so the wire should be held through a piece of cotton fabric when winding. It is even better to wind with thin cotton gloves."
Who is this written for? and who needs it? 🤔 the main thing is that it is not magnetic, the rest is out of this world....
Hi
after nice cycling summer i have to inform you that my AA14 is up and running and works very well! 😉
putting into operation was 1 mnth ago and compare with oter amps.(my nuvista 600 and my brothers M2OPS amps)
because of BJT transistor decided to use a solid state relay- i choose the XRK SSR (can handle a big Class AB am up to 80V rail !)
SSR by XRK and Jhofland
output BJT´s are well in the temperature frame 50°C after hours. voltage on my rails is about 23V. i use 2x300VA 2x18VAc sec by sedlbauer. CRC is the PSU v3 with 8x33mF. housing is the 4Ux400mm complete alu. bias is starting with 1,5a and goes down after warming up about 1,36A, not bad.
i very happy with the sound. it is my first BJT class A! its a very clear and punchy sound, deepness and fundamental in bass are very good. vocals and instruments are very neutral -i like that amp!
to do´s to make it better?:
transformer mounted up...
change VAS transistors- actually not possible because i solder the pin header with the VAS transistor at the beginning of searching month ago.🙄
kr
chris
after nice cycling summer i have to inform you that my AA14 is up and running and works very well! 😉
putting into operation was 1 mnth ago and compare with oter amps.(my nuvista 600 and my brothers M2OPS amps)
because of BJT transistor decided to use a solid state relay- i choose the XRK SSR (can handle a big Class AB am up to 80V rail !)
SSR by XRK and Jhofland
output BJT´s are well in the temperature frame 50°C after hours. voltage on my rails is about 23V. i use 2x300VA 2x18VAc sec by sedlbauer. CRC is the PSU v3 with 8x33mF. housing is the 4Ux400mm complete alu. bias is starting with 1,5a and goes down after warming up about 1,36A, not bad.
i very happy with the sound. it is my first BJT class A! its a very clear and punchy sound, deepness and fundamental in bass are very good. vocals and instruments are very neutral -i like that amp!
to do´s to make it better?:
transformer mounted up...
change VAS transistors- actually not possible because i solder the pin header with the VAS transistor at the beginning of searching month ago.🙄
kr
chris
