I am sure you will be happy.
Diy is really a great fun!
Now a days we are in party time....the world cup is a big party for us, despite we are living internal problems related government.
Girls are using special make up, people using green and yellow shirts.... we almost stop everything because of world cup.
regards,
Carlos
Diy is really a great fun!
Now a days we are in party time....the world cup is a big party for us, despite we are living internal problems related government.
Girls are using special make up, people using green and yellow shirts.... we almost stop everything because of world cup.
regards,
Carlos
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hi dx you,re lucky for the world cup to be hosted in your country . all the best and post more photos
My source of inspirations was these Gradiente models
Gradiente does not exist anymore....operated from 1960 to 1986.
This factory have used a transistorized Super A simplified version...i have assembled and tested and i found not very stable, then i decide to make it in a more simple way.
regards,
Carlos
Gradiente does not exist anymore....operated from 1960 to 1986.
This factory have used a transistorized Super A simplified version...i have assembled and tested and i found not very stable, then i decide to make it in a more simple way.
regards,
Carlos
Attachments
Dx Super A optimized for audio purity competition
It is a Dx Super A with the Dx Super A feature switched off, current adjusted to 70 mA per rail, 25V supplies (from 20 to 30 volts), can put ou 25/50 watts RMS at 8/4 ohms, made to the highest possible audio quality.
Total harmonic distortion is 0.000145% ..... much less than the usual 0.003%
Circuit is attached and also i am posting the link to the video made in Portuguese language...but it is a result of Simulator images...of simulation...so... real language is electronics, instruments and waveforms and you can forget the language and you gonna understand...for sure you will...you can even switch off the audio.
https://www.youtube.com/watch?v=9EqC7E4o9MU
regards,
Carlos
It is a Dx Super A with the Dx Super A feature switched off, current adjusted to 70 mA per rail, 25V supplies (from 20 to 30 volts), can put ou 25/50 watts RMS at 8/4 ohms, made to the highest possible audio quality.
Total harmonic distortion is 0.000145% ..... much less than the usual 0.003%
Circuit is attached and also i am posting the link to the video made in Portuguese language...but it is a result of Simulator images...of simulation...so... real language is electronics, instruments and waveforms and you can forget the language and you gonna understand...for sure you will...you can even switch off the audio.
https://www.youtube.com/watch?v=9EqC7E4o9MU
regards,
Carlos
Attachments
I see a few changes.
Although my opinion is not valued, these changes look as though they have gone in the right direction.
So a question or two.
Have you had a chance to listen yet?
Does it sound the same as the earlier circuit?
Does adopting 10uF in conjunction with the Rin=56k produce a good quality bass?
Although my opinion is not valued, these changes look as though they have gone in the right direction.
So a question or two.
Have you had a chance to listen yet?
Does it sound the same as the earlier circuit?
Does adopting 10uF in conjunction with the Rin=56k produce a good quality bass?
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Here you have the "invincible", made for competition
with some amplifiers... supply voltage reduced, stand by bias reduced due to the enclosure used (no ventilation holes)... supply voltage reduced to obtain small power for comparison and some tuning made.
Capacitor cannot be smaller than 100pf in this schematic...for the compensation....or you gonna have unstabilities.
Enjoy folks...video is in portuguese..but electronics are international language and you gonna see some schematics:
https://www.youtube.com/watch?v=XNL7qBrsGBw
regards,
Carlos
with some amplifiers... supply voltage reduced, stand by bias reduced due to the enclosure used (no ventilation holes)... supply voltage reduced to obtain small power for comparison and some tuning made.
Capacitor cannot be smaller than 100pf in this schematic...for the compensation....or you gonna have unstabilities.
Enjoy folks...video is in portuguese..but electronics are international language and you gonna see some schematics:
https://www.youtube.com/watch?v=XNL7qBrsGBw
regards,
Carlos
Attachments
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Here are the illustration on the board of where the changes are
Dx Super A Invincible, 20V
C40 = 100nF
R7 = 1K8
R4 = 150 ohms
R5-R6 = 10 ohms
R13 56K with a 3.3pF cap in parallel
C37 = 220uF
C38 = 10uF audio signal input cap
C13 = 100pF
R30 - jumper is bypassed
R16 = 350 ohms
R9-R8 = 68 ohms
R35 = jumper is bypassed
Q31 = TIP35AG
Q35 = TIP36AG
Regards
Juan
Dx Super A Invincible, 20V
C40 = 100nF
R7 = 1K8
R4 = 150 ohms
R5-R6 = 10 ohms
R13 56K with a 3.3pF cap in parallel
C37 = 220uF
C38 = 10uF audio signal input cap
C13 = 100pF
R30 - jumper is bypassed
R16 = 350 ohms
R9-R8 = 68 ohms
R35 = jumper is bypassed
Q31 = TIP35AG
Q35 = TIP36AG
Regards
Juan
Attachments
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Vargas,
have you read this Thread?
http://www.diyaudio.com/forums/solid-state/256412-multichannel-amplifier-internal-ground-loop.html
It tells you to make small loop area for current to flow around.
It tells you that large loop areas for the current flow make for bad interference pick-up.
All your layouts have large loop areas.
have you read this Thread?
http://www.diyaudio.com/forums/solid-state/256412-multichannel-amplifier-internal-ground-loop.html
It tells you to make small loop area for current to flow around.
It tells you that large loop areas for the current flow make for bad interference pick-up.
All your layouts have large loop areas.
Thank you Juan....very fast.
Give it a try dear Juan, sounds different.
I would like to know what you feel about it.
regards,
Carlos
Give it a try dear Juan, sounds different.
I would like to know what you feel about it.
regards,
Carlos
I was yesterday thinking to make another different layout a simple one for Dx Super A Invincible, 20V "this is (only) me not official" 🙄
I saw a Russian layout and the guys was nice to share the layout he gave me the file and is really interesting how he place the parts maybe I can do something similar to the Dx Super A Invincible, 20V I was placing parts and brainstorming
for a while but still not sure, here are the images of the Lanzar Mini and my first attempt, any way I don't think is necessary because Dx Super A PCB can be easily mod it, any way is good to try out different stuff 🙂 don't mind about the numbers is just a draft ok lol 😛
Regards
Juan
I saw a Russian layout and the guys was nice to share the layout he gave me the file and is really interesting how he place the parts maybe I can do something similar to the Dx Super A Invincible, 20V I was placing parts and brainstorming
for a while but still not sure, here are the images of the Lanzar Mini and my first attempt, any way I don't think is necessary because Dx Super A PCB can be easily mod it, any way is good to try out different stuff 🙂 don't mind about the numbers is just a draft ok lol 😛
Regards
Juan
Attachments
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Good...... Russian style is fine
What happened is that i have assembled an unit to amplify satelite receiver from my cable TV...and even without any modification (Dx Super A - 42V) i found the sound very nice, even operating 20 volts using series pass regulator.
Then i have simulated and what a surprise!.... even lower THD...... because of that surprise i have checked using Scope and found the slew rate wonderfull, also nice the harmonic distribution.
I have decided to tweak a little to see if could result even better and then the distortion fell down to 0.00009123%...and this is much better THD compared with the 0.002 to 0.003% i was having.
The need to tweak is because a Brazilian forum folks asked me a deep comparison review in between the LM1875 compared with the Invincible Dx Super A model...same supply..... same conditions...same load.... same speaker...same sensitivity.
Because of that i have published the results...this does not mean the Dx Super A standard is not good...it is awesome...but this one, i have perceived, since first time i have listened, the sound is even better..... the treble is special....i use to be under strong emotions while listening...it is really awesome.
You do the layout you want dear Juan....i set you free to try whatever you want....i would ask you to test the layout...to assemble, to listen and to inspect it using scope........OR....if do not want to test, or if cannot do that, then tell folks the layout was untested...just that...to be transparent...the way we use to be.
In the first moment it was made to my daugther boy friend.... i have offered too much late, then he bougth a home theater.....then i have used the unit together my satelite receiver....you can see the video link below.
regards,
Carlos
What happened is that i have assembled an unit to amplify satelite receiver from my cable TV...and even without any modification (Dx Super A - 42V) i found the sound very nice, even operating 20 volts using series pass regulator.
Then i have simulated and what a surprise!.... even lower THD...... because of that surprise i have checked using Scope and found the slew rate wonderfull, also nice the harmonic distribution.
I have decided to tweak a little to see if could result even better and then the distortion fell down to 0.00009123%...and this is much better THD compared with the 0.002 to 0.003% i was having.
The need to tweak is because a Brazilian forum folks asked me a deep comparison review in between the LM1875 compared with the Invincible Dx Super A model...same supply..... same conditions...same load.... same speaker...same sensitivity.
Because of that i have published the results...this does not mean the Dx Super A standard is not good...it is awesome...but this one, i have perceived, since first time i have listened, the sound is even better..... the treble is special....i use to be under strong emotions while listening...it is really awesome.
You do the layout you want dear Juan....i set you free to try whatever you want....i would ask you to test the layout...to assemble, to listen and to inspect it using scope........OR....if do not want to test, or if cannot do that, then tell folks the layout was untested...just that...to be transparent...the way we use to be.
In the first moment it was made to my daugther boy friend.... i have offered too much late, then he bougth a home theater.....then i have used the unit together my satelite receiver....you can see the video link below.
regards,
Carlos
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