Carlos, i was always there, following your "DX amplifier"... (I think you should give it a real name)
About the more complicated symasym, i haven't build it, but it should show that low distortive can sound excellent, but you definitely need to define "low distortive".
Do you really see my symasym as complex?
Mike
About the more complicated symasym, i haven't build it, but it should show that low distortive can sound excellent, but you definitely need to define "low distortive".
Do you really see my symasym as complex?
Mike
Good to see you here, Mike..
No that "f" didn't jump , it was just there.
There's a limit to what someone can investigate, even a fanatic builder like me
Care to share some of your thoughts related vas-transistors, even for a humble builder ?
I didnt like the highspeed-devices sofar, but my experience is very limited.
I don't have anything against the symasym btw, just didn't get around to build it
Regards,
Klaas
No that "f" didn't jump , it was just there.
There's a limit to what someone can investigate, even a fanatic builder like me
Care to share some of your thoughts related vas-transistors, even for a humble builder ?
I didnt like the highspeed-devices sofar, but my experience is very limited.
I don't have anything against the symasym btw, just didn't get around to build it
Regards,
Klaas
A friend asked me a very cheap amplifier, to use with standard 18 plus 18 AC trafo.
Every 200 watts transformer will fit this Dx junior amplifier.
It uses low parts count..to be cheap, to be simple and to be small.
It may be very stable...well...i have not assembled, but my friend will do 6 channels and i will know how stable it will be.
Small condensers....not too big rail condensers...excluded zener, excluded trimpots, and very cheap transistors.
The output are TIP142 and TIP147, those darlington switching transistors will fit.
Power will not be bigger than 60 watts RMS each channel, and this is over 4 ohms and 25 plus 25 DC volts.....of course not more than 30 unclipped over 8 ohms
If someone decide to construct..i want to tell you that those darlington loves to oscilate...reason why i have placed 470 picofarads from base to colector.
Amplifier not constructed real life...just to show you another one...not the standard Dx amplifier...this may be Dx junior after testings.
A capacitor, say 1uf will be a good idea, interconnecting darlington transistors bases.
Do it under your own risk.... not constructed amplifiers, simulated or calculated ones may explode in real life!
regards,
Carlos
Every 200 watts transformer will fit this Dx junior amplifier.
It uses low parts count..to be cheap, to be simple and to be small.
It may be very stable...well...i have not assembled, but my friend will do 6 channels and i will know how stable it will be.
Small condensers....not too big rail condensers...excluded zener, excluded trimpots, and very cheap transistors.
The output are TIP142 and TIP147, those darlington switching transistors will fit.
Power will not be bigger than 60 watts RMS each channel, and this is over 4 ohms and 25 plus 25 DC volts.....of course not more than 30 unclipped over 8 ohms
If someone decide to construct..i want to tell you that those darlington loves to oscilate...reason why i have placed 470 picofarads from base to colector.
Amplifier not constructed real life...just to show you another one...not the standard Dx amplifier...this may be Dx junior after testings.
A capacitor, say 1uf will be a good idea, interconnecting darlington transistors bases.
Do it under your own risk.... not constructed amplifiers, simulated or calculated ones may explode in real life!
regards,
Carlos
Attachments
The last schematic, that Dx Junior amplifier, contain errors.
That crazy Multisim 2001 simulated it perfectly.....but once....when i tried second time...no way...and presented simulation errors.
Very crazy those simulators...mine was installed again.
Here is the correct circuit.....but i do not guarantee without testings will be made.
This is only a simulated model...may not work fine.
I hate simulators!
regards,
Carlos
That crazy Multisim 2001 simulated it perfectly.....but once....when i tried second time...no way...and presented simulation errors.
Very crazy those simulators...mine was installed again.
Here is the correct circuit.....but i do not guarantee without testings will be made.
This is only a simulated model...may not work fine.
I hate simulators!
regards,
Carlos
Attachments
Looks like a nice simple low-power-option, Carlos.
Darn, one of the channels just popped a rail-fuse, due to an intermittent connection of the bias-diodes.
maybe i should take a soldering-course.
Thankfully nothing fried except the fuse
Was just enjoying Simon & Garfunkel live in Central Park on dvd,
despite the kind nature of the amp (it doesn't shout in your face) very good resolution, makes you wanna dance
With kind regards,
Klaas
Darn, one of the channels just popped a rail-fuse, due to an intermittent connection of the bias-diodes.
maybe i should take a soldering-course.
Thankfully nothing fried except the fuse
Was just enjoying Simon & Garfunkel live in Central Park on dvd,
despite the kind nature of the amp (it doesn't shout in your face) very good resolution, makes you wanna dance
With kind regards,
Klaas
Simon and Garfunkel are fine....I like them too
Nice music together nice sonics make us move the body.
This is the sound quality meter....the more you shake your body when feeling the music, the better will be sound.... sound is not only to be listened, it can be something you feel...traveling with it.
Another hiper old group...older the Simon and Garfunkel:
Credence, Clearwater and Revival.....also nice if you accept the old recording quality...things our ear/brain can "adjust" in a matter of minutes.
That "junior" amplifier can be constructed very small...a tiny amplifier..i am curious to know how this one will sound...hummm, not so good i think...those TIP in the output...those ones never made a good sonics when used to output, well, at least here in my home...but they sound great when used as drivers.
I will go down the building, the party saloon is in the first floor...my daugher party..her birthday party is now!
regards,
Carlos
Nice music together nice sonics make us move the body.
This is the sound quality meter....the more you shake your body when feeling the music, the better will be sound.... sound is not only to be listened, it can be something you feel...traveling with it.
Another hiper old group...older the Simon and Garfunkel:
Credence, Clearwater and Revival.....also nice if you accept the old recording quality...things our ear/brain can "adjust" in a matter of minutes.
That "junior" amplifier can be constructed very small...a tiny amplifier..i am curious to know how this one will sound...hummm, not so good i think...those TIP in the output...those ones never made a good sonics when used to output, well, at least here in my home...but they sound great when used as drivers.
I will go down the building, the party saloon is in the first floor...my daugher party..her birthday party is now!
regards,
Carlos
HMMMMMMMMM cake!!!!!!!
Uncle Charlie, if you don't get to drunk at the kiddies party, won't you mind checking the position of C14 (5pf), it is nearly 1cm from Q3 on the Raj board, would they not need to be closer?
I also think C3 and R11 should swap positions... if you could relay to Raj....
Uncle Charlie, if you don't get to drunk at the kiddies party, won't you mind checking the position of C14 (5pf), it is nearly 1cm from Q3 on the Raj board, would they not need to be closer?
I also think C3 and R11 should swap positions... if you could relay to Raj....
This small capacitor is to be used only with low speed transistor, alike TIP41
Having others, it is more safe to substitute to 20 picofarads...also the feedback capacitor (12pf) will be better if you replace them to 20 picofarads,
Raj is tracking the thread, he knows everything dear Nordic.
You are welcome to the cake...but....come fast...kids will make big magic...cake will disappear.
regards,
Carlos
.........................................................................................................
Thank you Klaas.....beautifull party we had...good food and pretty people...i have made 234 images.
regards,
Carlos
Having others, it is more safe to substitute to 20 picofarads...also the feedback capacitor (12pf) will be better if you replace them to 20 picofarads,
Raj is tracking the thread, he knows everything dear Nordic.
You are welcome to the cake...but....come fast...kids will make big magic...cake will disappear.
regards,
Carlos
.........................................................................................................
Thank you Klaas.....beautifull party we had...good food and pretty people...i have made 234 images.
regards,
Carlos
Attachments
One of my Son's birthday cakes.
Took much more than a soldering iron to make that for my dear wife to make that.
She once made a cake of Roland Rat, the TV puppet with big ears.
I took it into work to show my mates - went round a corner - OOPS - one flat ear -
- as Homer would say - Doh !!!
Took much more than a soldering iron to make that for my dear wife to make that.
She once made a cake of Roland Rat, the TV puppet with big ears.
I took it into work to show my mates - went round a corner - OOPS - one flat ear -
- as Homer would say - Doh !!!
Attachments
I like your decision dear Nephew Nordic.... as you will realise how much different
those transistors will sound.
You will be surprised with the result.
TIP41 is interesting because it cannot oscilate into high frequencies, the unit in unable to do that.
regards,
Carlos
..........................................................
Nice cake Graham, that one i have shown disappeared
as magic....in a matter of minutes...hehe
Those old turntables used ceramic pickups...hehe...old days.
I had one alike this one you are showing down the fifties
regards,
Carlos
those transistors will sound.
You will be surprised with the result.
TIP41 is interesting because it cannot oscilate into high frequencies, the unit in unable to do that.
regards,
Carlos
..........................................................
Nice cake Graham, that one i have shown disappeared
as magic....in a matter of minutes...hehe
Those old turntables used ceramic pickups...hehe...old days.
I had one alike this one you are showing down the fifties
regards,
Carlos
Attachments
Sparkle, the resistor you have suggested was included in the amplifier schematic
I was trying to avoid to install it there...to reduce parts count and not to have things alike Aksa.
But many guys suggested, and RAJ included that one in his board, this way, as final board is cooking for a while, the modification was included.
thanks Sparkle.
.......................................................................................................
Observe the TIP41 Ft ..... this is what make it so interesting, unable to oscilate, having big losses above 3 Megahertz, it will not like to oscilate...in the reality, it is very difficult to put it into oscilation when you want it to produce beat oscilators to SSB reception...even something alike 550 Kilohertz is hard to make it work....
This defect, or effect, or quality...this is what make it reliable to audio amplifiers.
Slew rate will be bad...but our ear plus brain slew rate is awfull...sensor cells are electro chemical, and those reactions took time to run....inside ear sensitive cells your slew rate will be awfull...and any square wave will turn "rounded".
regards,
Carlos
I was trying to avoid to install it there...to reduce parts count and not to have things alike Aksa.
But many guys suggested, and RAJ included that one in his board, this way, as final board is cooking for a while, the modification was included.
thanks Sparkle.
.......................................................................................................
Observe the TIP41 Ft ..... this is what make it so interesting, unable to oscilate, having big losses above 3 Megahertz, it will not like to oscilate...in the reality, it is very difficult to put it into oscilation when you want it to produce beat oscilators to SSB reception...even something alike 550 Kilohertz is hard to make it work....
This defect, or effect, or quality...this is what make it reliable to audio amplifiers.
Slew rate will be bad...but our ear plus brain slew rate is awfull...sensor cells are electro chemical, and those reactions took time to run....inside ear sensitive cells your slew rate will be awfull...and any square wave will turn "rounded".
regards,
Carlos
Attachments
Guys, those cakes make me hungry !
I remember those old record-players, you could put the next record on top for continuous play, ending up with a pile of records on the platter.
Most of them had a needle or cartridge you could flip over to play those old 78 rpm records.
Done some tidying-up :
The bd243c i use as vas has the same low ft, 3 mhz.
According to the st-datasheet at 1 mhz hfe is already down to 3, at 1 khz it 's 20 !
Running off to the refrigerator now
Best regards,
Klaas
I remember those old record-players, you could put the next record on top for continuous play, ending up with a pile of records on the platter.
Most of them had a needle or cartridge you could flip over to play those old 78 rpm records.
Done some tidying-up :
The bd243c i use as vas has the same low ft, 3 mhz.
According to the st-datasheet at 1 mhz hfe is already down to 3, at 1 khz it 's 20 !
Running off to the refrigerator now
Best regards,
Klaas
Waiting for delivery is the worst, especially if it's the last tiny bit
you need to complete a project.
I'm afraid to tell you my situation concerning local availability of parts -it's basically parts-heaven overhere- you may pick up Carlos' double-barelled and shoot me now Nordic
With kind regards,
Klaas
you need to complete a project.
I'm afraid to tell you my situation concerning local availability of parts -it's basically parts-heaven overhere- you may pick up Carlos' double-barelled and shoot me now Nordic
With kind regards,
Klaas
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