Thanks very much thimios for that report 
Struth gave a pretty convincing argument a few pages back that the Baxandall diode and associated components are probably useful here. Thimios, you are very fast with your work, and I was wondering if you wanted to see how the amp performs and sounds with these components removed? I would try it myself but I've been pretty busy with family commitments.
If you are up to the challenge then please refer components in the BLUE box in the schematic below:
- Remove D8 and C9
- Replace R19 with a wire link.
Very keen to hear your thoughts.
Struth gave a pretty convincing argument a few pages back that the Baxandall diode and associated components are probably useful here. Thimios, you are very fast with your work, and I was wondering if you wanted to see how the amp performs and sounds with these components removed? I would try it myself but I've been pretty busy with family commitments.
If you are up to the challenge then please refer components in the BLUE box in the schematic below:
- Remove D8 and C9
- Replace R19 with a wire link.
Very keen to hear your thoughts.
Finally there isn't any problem,this hum was a matter of gnd loop.
I spend some time listening Patricia Barber cafe blue.
No original disk not a flac either,just in mp3 from youtube.
I'm surprised from the vocals and crystal clear and strong cymbals.
This simple amplifier have something magic. You must listen to this!
Time to build it then
Hi Dave
No group buy has been suggested so far. A couple of years ago, I did a layout and sent off for some boards based on an old revision of the circuit. My amp is pretty close to the current schematic under discussion but I've had to do perform some surgery to these original boards to accommodate the changes.
Fast forward to very recently and two members, Prasi and thiagomogi have independently laid out and posted the PDF files for their layouts, which reflect the current schematic. So far thimios has built Prasi's version. The designers of these boards might be prepared to post the Gerbers for their layouts, you would need to ask them.
Hi Dave,
Gerbers posted at http://www.diyaudio.com/forums/soli...imentary-mosfet-amplifier-34.html#post4765108 . Thiagomogi has also posted his two-three posts before that. Mine is a bit crowded, Thiago's is a bit spacious. Choose your flavor.
But some values may change as per Thimios's testing.
reg
Prasi
Gerbers posted at http://www.diyaudio.com/forums/soli...imentary-mosfet-amplifier-34.html#post4765108 . Thiagomogi has also posted his two-three posts before that. Mine is a bit crowded, Thiago's is a bit spacious. Choose your flavor.
But some values may change as per Thimios's testing.
reg
Prasi
Boards are ordered
Hallo Friends.
Some days back i have ordered prasis nice PCB by kikipcb, who's prefering by
vargasmongo Juan- with shipping to Germany 10 Boards only 26 $.
Patrick i will send you a pair when received here, if you like- send PM.
Thank you to ALL ! ! here, extra special Thank to Thimios for his quick work-
this time you have beat Terry.
If Hugh is spending Time and knowledge here it only could be a good sounding one, i know, because meanman sells the FetZilla Boards here.
The FetZilla impressed me with very relaxed magically sound- a different
transparency and clearness with wide presentation, than other Amps do.
I am inquisitorially now.
Bangla.
Hallo Friends.
Some days back i have ordered prasis nice PCB by kikipcb, who's prefering by
vargasmongo Juan- with shipping to Germany 10 Boards only 26 $.
Patrick i will send you a pair when received here, if you like- send PM.
Thank you to ALL ! ! here, extra special Thank to Thimios for his quick work-
this time you have beat Terry
.If Hugh is spending Time and knowledge here it only could be a good sounding one, i know, because meanman sells the FetZilla Boards here.
The FetZilla impressed me with very relaxed magically sound- a different
transparency and clearness with wide presentation, than other Amps do.
I am inquisitorially now.
Bangla.
Bangla, I'm watching like a hawk........
I have spent 20 years trying to figure out the connection between the schematic and the (subjective) sound quality and I have heard an almost identical Ranchu amp in the past, along with many of my own design.
The 'magic' you refer to is distortion. When you measure this amp, it's around 0.05% or even higher, but 98% of this THD is H2+H3+H4, all musical harmonics.
It is possible to design an amp with this harmonic profile with high THD but with clarity, musical presentation, and with depth of image. There are people like Pass who can do this stuff pretty easily, but in fact not many people can do it. I was disappointed with the FetZilla because it lacks any depth of image, something I worked hard to achieve with my commercial amps.
There is a quality of a quasi amplifier which is elemental; it is very difficult to recreate the sound quality using complementary output stages.
Ciao,
Hugh
I have spent 20 years trying to figure out the connection between the schematic and the (subjective) sound quality and I have heard an almost identical Ranchu amp in the past, along with many of my own design.
The 'magic' you refer to is distortion. When you measure this amp, it's around 0.05% or even higher, but 98% of this THD is H2+H3+H4, all musical harmonics.
It is possible to design an amp with this harmonic profile with high THD but with clarity, musical presentation, and with depth of image. There are people like Pass who can do this stuff pretty easily, but in fact not many people can do it. I was disappointed with the FetZilla because it lacks any depth of image, something I worked hard to achieve with my commercial amps.
There is a quality of a quasi amplifier which is elemental; it is very difficult to recreate the sound quality using complementary output stages.
Ciao,
Hugh
Hi all potential builders,
I have been thinking about mounting Q4 properly on Q6. Here is what I think is most practical. Note that by mounting Q4 on top of MOSFET, you create a gap between PCB and Q7 (2SC5200N) on the otherside. This needs to be filled in by use of a suitable spacer.
Hope the two attached pictures say two thousand words.
reg
Prasi
I have been thinking about mounting Q4 properly on Q6. Here is what I think is most practical. Note that by mounting Q4 on top of MOSFET, you create a gap between PCB and Q7 (2SC5200N) on the otherside. This needs to be filled in by use of a suitable spacer.
Hope the two attached pictures say two thousand words
.reg
Prasi
Attachments
The 'magic' you refer to is distortion. When you measure this amp, it's around 0.05% or even higher, but 98% of this THD is H2+H3+H4, all musical harmonics.
It is possible to design an amp with this harmonic profile with high THD but with clarity, musical presentation, and with depth of image
That's it!
It is the depth of image that we can't measure but we can clearly hear.
It is the depth of image that surprised me in this amplifier,cymbal isn't flat,vocal isn't sterile
As for distortion.....0.05 ?
Closely near to what i measure.
Amplifier is on the left chanel when on the right channel is the sound card loop(in to out) for comparison.
Now i will go for the second channel and this time i will remove parts according to Ranchu recommendations.
Attachments
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Hugh the watching Hawk.
Hallo Hugh.
I have registered that it needed very long time and inspiring thinking with fundamental basics in electronics, wich i not have, to find very well working
parts in detail in an Amp and other Raffinement short PCB tracks .
You have wrote to Bigun to his new TGM ideas.
There are people here with excellent detailled knowledge, that gives me great
respect and shows me my little basics.
For differnet reason, one is actual health i don't can spent more time and money in equipment and on other hand i feel i learn slowly with understand in little steps.
Parallel it cost time to read and write- also slow- it seems i could be Mister Slow
like Top Gear !
And Mr. Pass is in my Eyes the absolut Genius, The Guru- the Master of our Desaster, he knows in his long period creating Amps who every single part is working and working together in circuit.
I all ways must shake my head 2 stage SE or PP or Transformer coupled and
so on. Hiss KISS maxime.
If you do not have to look to power consumption you can enjoy every day with the robust stable working Amps.
My first one finished was F5- who impressed very much and clone F4.
So i was infected with Pass Fever.
My wish, if i can, would be that my grey brain is working faster and learned
quicker what i visualize and read- but it is not.
The Audio Hobby brings movement in my mind and i like it, but i can not discuss here with my basics.
My ears are my tool to scale out the Imaging sound of Amp in depth and wide and separation.
For that what i am understand some ideas make me inquisitively.
The Elvees cheap Circlophone is one of this ideas..... so many other.... so i
am busy.
2008- HiFi Musicworld Gelsenkirchen a real Loudspeaker, named Schmitti
Memorial.
To all here Bangla.
Hallo Hugh.
I have registered that it needed very long time and inspiring thinking with fundamental basics in electronics, wich i not have, to find very well working
parts in detail in an Amp and other Raffinement short PCB tracks .
You have wrote to Bigun to his new TGM ideas.
There are people here with excellent detailled knowledge, that gives me great
respect and shows me my little basics.
For differnet reason, one is actual health i don't can spent more time and money in equipment and on other hand i feel i learn slowly with understand in little steps.
Parallel it cost time to read and write- also slow- it seems i could be Mister Slow
like Top Gear !
And Mr. Pass is in my Eyes the absolut Genius, The Guru- the Master of our Desaster
, he knows in his long period creating Amps who every single part is working and working together in circuit.I all ways must shake my head 2 stage SE or PP or Transformer coupled and
so on. Hiss KISS maxime.
If you do not have to look to power consumption you can enjoy every day with the robust stable working Amps.
My first one finished was F5- who impressed very much and clone F4.
So i was infected with Pass Fever
.My wish, if i can, would be that my grey brain is working faster and learned
quicker what i visualize and read- but it is not.
The Audio Hobby brings movement in my mind and i like it, but i can not discuss here with my basics.
My ears are my tool to scale out the Imaging sound of Amp in depth and wide and separation.
For that what i am understand some ideas make me inquisitively.
The Elvees cheap Circlophone is one of this ideas..... so many other.... so i
am busy.
2008- HiFi Musicworld Gelsenkirchen a real Loudspeaker, named Schmitti
Memorial.
To all here
Bangla.Attachments
Great!, looking at the pin-out of Q4 in the photo on PC monitor, just request you to re-check again as per schematic.
reg
Prasi
What do you see prasi ?
This on the monitor is the tested and working first channel.
New channel is sitting on the keyboard
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What do you see prasi ?
This on the monitor is the tested and working first channel.
New channel is sitting on the keyboard
Pin out is ECB for bd139 (Q4). looking at the picture of my post # 409, in your case is emitter going to the base?
it may just be a display problem, I am not able to exactly make out.
reg
prasi
Surely I am going to build it but will require some time. I am not as good at etching my own boards as Thimios or Terry here, takes me many attempts
. reg
Prasi
If Dave or someone has excess boards, I will buy from him. (At a special discount hopefully
). Just kidding!
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