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Old 26th October 2004, 11:46 AM   #21
MikeB is offline MikeB  Germany
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Hi carlos !

A small sidenote...
Just to give you some imagination how sensible feedback is:
In my latest amp i only changed/shifted some caps, not really
changing much, but suddenly my amp mutated from some
"Idontknowwhybutidontlikethesound" to a "wowwhataperfectsoundihaveneverheardthisbefore "...

So changing small things in an amp, especially regarding feedback
and the compensating is critical !

Mike
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Old 26th October 2004, 11:48 AM   #22
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Default Duo and Epupa.... i am turning crazy, trying to reach the unreachable

This is the second madness stage; as the first is get married....and i did that twice....hummmmm!.... thinking in do it the third time.

That's the reason why i never pass in front of Menthal Disease Hospitals.....they can capture "Big Charlie"...will be funny...ahahaha....maybe 3 or 4 to hold me, i am too much strong.

First was the Danish red hair...... hummm, cold.

Second is my Spanish Beauty, wonderfull, but talk too much.

I am thinking in a Brazilian Indian.... may be better... for them, the husband is something over the king!

Yes, amplifiers distorts....no common to compress...but i could change the compression, moving the differential bias and removing the stop resistors...... the double barreled .12 gauge is ready to a "circuit Murderer" goes to work hard....... hummmm, the output (expensive) is outside the board.....hehehe.....boooom!

That circuit, dear Epupa, was made in the eigthies, by Japanese engineers....and they told worderfull words related the "Special phase shacking tone control"..... the name they gave to that thing may be so astounding as the one i wrote....even better than the one i wrote hear. And they were congratulated!....and we runned to buy...... the same as today...... just entering the "time machine" and you can see.... now people is making double simetrical, fet, controled, error corrected, double balanced, mirrored, CCS, long tailed, many darlingtons....terrible sounding devices too.

I found one 1960 design...make from someone that came from Europe...... Epupa neighboor i suppose...scaping from the communism maybe..... Mr. Esdrenerewsky made the TATERKA LINEAR here....hehe...... i could get one new......and i am copying the astounding and magnificente circuit...hehehehe....... will show you when ready.....will hear too.....output is condenser...hehe 1000 uf (my GOD!... so shocking!...how deer them!)... a lot of trimpots to adjust thing not to "kaput"....having fun only.

Guys, you could not make that damn thing good....i also could not...hehe.....boooooom!

I will put my gun "ausgang" into the board (eingang)... and booooom!


regards friends,

Carlos
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Power supply; ripple, filter, noise, stability and the use of capacitance multiplier... Portuguese and English; https://www.youtube.com/watch?v=sSm0ku1eIgg
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Old 26th October 2004, 02:56 PM   #23
thanh is offline thanh  Viet Nam
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carlos! perhaps I also try to build a amp with current mirror. I like the sound of Sony television .It is very "cold" but a bit dirty (perhaps the speaker is not good)
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Old 26th October 2004, 08:20 PM   #24
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Default My dear very very old friend thanh..hehehe..hohohoh...who is that lady

My special friend Thanh.....my dear...hehe....my old fellow...ahahaha....

Who is that lady?

My God!

Incredible!

Magnificent!


Astounding!


Who needs an amplifier if can look that beauty everyday.....thanh!!!....WHAT A LUCKY GUY YOU ARE!!!!!!!!!

Remenber poor devil charlie......little charlie....lonely...... has she one sister.

If you daughter or wife....hehe...I AM OUT...MOVED FROM THE ADRESS.....GOING TO MARS!!!

Carlos
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Old 27th October 2004, 12:21 AM   #25
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Default MIKEB, i made a node on my tongue to spracht Gütersloh

Quiltersloh...Quil...from quilty?....one day i will say ausrufunkstzeichen....one day...it exclamation signal isnt'it?.

My God!...it seem to me that someone is sending my mother to hell or worst thing....but i like.....strange language...funny is swedish...really funny language...i like very much.

Mike, i already had the experience with special components...special materials, special (tuned) values, and some strange connections.....and i am already sure that those things makes difference.

I could hear one man out of the tone.... a bad singer in the middle of many, the music was Wagner.... and the piece was something alike "receiving friends to a party"..... there was a Coral of many singers.... the resultant singer tone is something alike young people singing....teenager singing.....and i could see that one was completely full of "Schnnaps!"..... and i could hear with one special amplifier, the one is full of tricks.... the amplifier with one capacitor enormous under the board...it seems one small airplane carrying one "Jumbo" aircraft....i laugh a lot when the Designer said that "the protude thing" was special...he dislike that i called the part a "suppository"... some medicine with "grossen" vaseline to put medicine using the back....hummm back...... exit....or entrance in the case of the medicine used...not injection, and not pilules....you know.... the protude...hehe.

But removing the protude, the guy out of tone disappeared....was hard to perceive, and i was with all my attention, as i had already heard the guy... the change i made from the special one,for a common Capacitor resulted in no way to perceive....returning the "white protude Whale" condenser.... there's the bad singer again...a detail.....some magic...i could see..no more doubts i have about those things.

But used the same cap in other amplifiers and could not perceive.
I asked my friends.... 16 people hearing with me.... only 2 could perceive, of course, the others said we were been drinking too much.... really, but only Coke Cola... the American drinking.

regards,

Carlos
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Old 27th October 2004, 09:43 AM   #26
MikeB is offline MikeB  Germany
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Hi carlos !

Hmm ,you have a lot of german speaking people around haven't you ?
Guiltysloh, thats funny...

Yes, it's funny how simple changes to an amp have great audible
effects. But be aware, if an amp reveils many details you normally
don't hear it's possible that it in fact distorts, exaggerating details.
Typically this is IMD, this issue is called "false trebles". If you make
extensive listeningtest you will find another passage where this
wonderful detailing shows it's real ugly face, distortion...

I had this just yesterday, i removed some resistors that where
intended for a flat openloopbandwidth. Suddenly, wow these details !
You can hear so many things... Wow, quick, insert next disk... ooops,
damn it, it was the tim-trap ! It seems to me, that tim can improve
the sound on old/bad recordings, making the music more alive/fresh.
But with good detailed recordings you suddenly recognize something
beeing wrong... So Mr.Tim has 2 faces, the one can please you, the
other is a ugly evil one.

Mike
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Old 27th October 2004, 10:13 AM   #27
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hi carlos
you have a pseudo-integrator after rails connegted to output transistors- and these caps may unload too fast- biggerwould be better.
i think that lowering rails a change the biasing of a diffirential stage and so there is some signal dynamics comresion.
for me it is an ideal situation when you supply output transistors and diffy+vas with separate rail voltages( say +40V to diffy and +-35V to O/P).
you may also have the diffy stage rails regulated.
as you cannot modify your circuit tooo much change filter capacitors and pseudo-integrator capacitors
this may help
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Old 27th October 2004, 10:40 AM   #28
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Default MikeB and Darkferinz, thank you both

Mike:

Yes, i had a Uncle, and now two German cousins...Herbert Schrool from Bayern (Bavária... the Bayerichen Motoren Werke place), now my cousins Herbert and Friederich decide to live inside some florest....they love the country, they are retired.

Also my country have a lot of German imigrants towns.... the houses are made alike your houses....they dance the same, and use the same "chucrute", unt einzbein....do not know to write the pig leg articulation well cooked and well condimented. They speak Portuguese and German.... special schools....good people... very small violence index.....pretty blonde people.... they are serious, work hard and have enormous sense of hierarchic models and respect. We do not mind they made Germany inside our country.... we like that...do what you want is our rule....the flag, the law and the feelings are the same.... they love chucrute, i think is a damaged potato....but this is not a problem...they cook frite potatos for non Germany too... they are my people...sorry, not more your people.

I agree with you.... that kind distortion is agreable to us.... this way i am returning to the past...trying old amplifiers now...because they had not the intention to "clear" all distortions...may be better...take a look in JLH, and AKSA design...old fashioned models.....JLH from sixties...AKSA from early eigthies...the basic design, of course was upgraded.

Darkferinz:

Your people and neighboors, gave me always the idea, that you had very good Universities in your country.... the knowledge appear always, and easy to detect that many of you not juniors enginners.... easy to respect to, the impressive know how that you have been bringing to us.

I thank you, but must say that i have to read again with calm... to understand better....not english the problem.....my theorethical know how is poor....i thank you to put some ligth in my darkness.

regards,

Carlos
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Old 27th October 2004, 10:51 AM   #29
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Hey Carlos,
Just got round to looking at your circuit. In addition to comments so far:

1) I wouldn't put the tone circuit in the NFB path. Big no-no. This path needs to be physically short to prevent noise pick-up and parasitic feedback. You don't really want the dynamic response of the amp to vary with the tone setting.

2) You have no RF filter on the input. Put a 470pF polystyrene across the 100k input resistor.

3) Replace the 8.2k resistor with a CCS or you'll modulate the differentiator current (and thus gain) with the input signal.

4) Check your grounding to avoid any ground loops.

Good luck!
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Old 27th October 2004, 12:59 PM   #30
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Default Traderbahn, thank you, have a question to you.

The 470pf capacitor, and other values people had been using, in dependence of the input impedance.

I was understanding this one just as a RF low impedance patch in earth's direction... have it another responsability...alike some needed load capacitance to the pré-amplifier output, or anything else.

Some people is asking us to avoid any capacitor in the signal patch.... and you say opposite, i think you have a good reason.

Please, let me know the reason why, as the only damn Radio Amateur in my region are myself.... the one can generate the annoying problem is "Big Charlie"..i will not operate radio with amplifier running...hehe...no way with or without capacitor...very strong magnetic field in my shack when tube linear amplifier is running and turning blue, resulted of electrons flowing hard....needles move if you touch your finger point in some electrical meter terminal...it swings a little with my voice modulation, your body turns one aerial.....bad guy i am?...not so bad, as i normally do not use all that power...only to call very distant guys...in Siberia or other difficult place... having the contact and tuned on each other, i always reduce my power to 100 watts PEP.

regards,

Carlos
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