RMI-FC100, a single stage audio power amplifier

Do you want me to make an amplifier that will smash mine?

ahahahaha... this one was already terrible!...ahahahahah

Now talking serious..... for sure, not doubts will be a top performer...you made a winner.

I have Found 9 milivolts, but it is easy to adjust into resistances...this was not the problem..had not problems..only exploded because some transistors i have used were not good...

heheheh..inverted they do not like to work, and short into the board use to produce fire and smoke.

Happy new year.

I will be concentrated into my own amplifier Mihai, i had already loose my focus for a week long...now back to the job.

Also you do not need big Charlie to tell it is good..you already know, a lot of folks already know that... and there are many hidden inside their shells.... let them move and show themselves to us.

regards,

Carlos
 
Re: Do you want me to make an amplifier that will smash mine?

destroyer X said:


I have Found 9 milivolts, but it is easy to adjust into resistances...this was not the problem..had not problems..only exploded because some transistors i have used were not good...


Did you match for Idss input jfets? I had only 0.5mV offset ...
How much current did you use in LTP CCS and in common reference folded cascode CCS?
 
Negative.... i have not matched.

I know your amplifier is well designed, and will measure perfect..also sound very good.

I do not bother with those details.... all i wanted was to listen the input and to compare.... if 0.5 milivolts or 22 milivolts, to me is almost the same, as we can adjust and match parts if we need that result.

To me, those things are alike headache... we eat pills, drugs...do not matter if the headache is in the frontal head or lateral pain.... i use to let those milivolts in peace, as they do not disturb and i have control on them...i can reduce them to zero into the moment i decide.

Will do comparison in the future, when Precision II was released.... not to publish, just for my pleasure and curiosity

I will be focused on my amplifier from now on.

bye and good luck to your nice thread.... i will be selfish and will be concentrated into mine amplifier.

Carlos
 
Sorry Mihai, we are from different worlds, i use to force things to work

And you make them to be precise not needing adjustments...this is boring to me, as i turn myself unusefull...not needed tweaking.

Also i do not bother myself with things that do not sound...as some milivolts into the output.... this is something do not matters to me... we can fix and finish those milivolts...just a very small and non important detail...say nothing about the amplifier, only that the designer made good calculations and the transistors are behaving exactly as the data sheet and the constructor,builder, have used matched transistors.

I am in the other extreme of the production line...you may be the designer, the Enginneer that complain saying those folks downstairs use to replace resistances to "adjust".... the circuit do not need adjustment!!!!

I am the guy into the production line, a manager i think... i will tell, those kids, young enginneers always think the components obbey what they have readed into the data sheet..... if we were not around that thing would explode!!!

Ahahahaha....

Just that.

Will not publish comparison...will tell you directly if your amplifier was the winner...if you amplifier lost...you will never know, because i hate to bring bad news.

Also, there are another brand, another man that produces the best possible sound...that can eat my amplifiers easy, laughing, and falling down from the chair.... Aspen amplifiers...... he has models that eat mine without any effort...so.... if i will decide to compete... for sure i will compete by the second place...as he makes the better ones.... when you switch on and music starts to play you feel the quality... soft, undistorted, not harshing, not annoying...have class...not sterile, not undefined, not screaming sound.... class....charm...other thing compared with my huge bass punch!

You questions, seems to me alike that folk that asked me if i have placed matched transistors.... then i said i made that...one was 550 and the other was 546.... and this means nothing into sound and offset...and the guy start to say that i made a terrible mistake...they have to be 550 and 550....or 546 and 546.... this is matching!

Yeah.... it is really matching.... for theories .... go to measure and to listen and they will means nothing.

My best wishes...you are very good designer, even destroying your schematic, tweaking everything, using other transistors, operating class AB...well...it continues sounding great...so..it is great!

regards,

Carlos
 
Roender i already have output transistors and others Tosh hard to find here, so it's on the way for me.

I will build exactly like yours....But...There always a 'yes but' ...héhéhé


I have problems with your Gerber files with my equipment for PCB and i don't want to untune my software that controlling it for compliance with your files, so i will redraw your amp in Altium DXP and if someone want it , it will be available in another format.
 
Excelent Monsieur, allors Mihai will feel good

Building it following the schematic...... great!

regards,

Carlos
 

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DRZ1 said:
Roender i already have output transistors and others Tosh hard to find here, so it's on the way for me.

I will build exactly like yours....But...There always a 'yes but' ...héhéhé


I have problems with your Gerber files with my equipment for PCB and i don't want to untune my software that controlling it for compliance with your files, so i will redraw your amp in Altium DXP and if someone want it , it will be available in another format.

Hello Denis,

Please make your Altium version following closely my board. I have past through four PCB versions, one of them with bad sound, until the published one.

Happy New Year,
Mihai
 
Re: prototype

loek said:
I made this board with a millingmachine.
Now collecting parts.Happy 2008,
Loek

Hello Loek,
Don't worry about outside PCB dimensions holes. Two of them are from drivers, mje15034/mje15035, and are not in use.
I'm not sure if it is safe to implement ground plane. In the first stage, when you start the amplifier, try to not connect the plane to ground. See how it works and after that try to find a good point to connect such a huge plane to GND, maybe in main starground. Use a scope to track possible oscillations

Good luck and
Happy New Year!
Mihai
 
Re: Re: prototype

roender said:


Hello Loek,
Don't worry about outside PCB dimensions holes. Two of them are from drivers, mje15034/mje15035, and are not in use.
I'm not sure if it is safe to implement ground plane. In the first stage, when you start the amplifier, try to not connect the plane to ground. See how it works and after that try to find a good point to connect such a huge plane to GND, maybe in main starground. Use a scope to track possible oscillations

Good luck and
Happy New Year!
Mihai
Speaking of ground planes and amplifiers -- I had some board made up for the LM4702 and LME49810 -- on one set I used a dual star system -- allowing the ground for the driver to be separated from the power ground by a small value resistor, for the second I poured copper. The THD+N% for the board with ground plane is measurably inferior to the dual-star system.