Re: phono pcb
Konnichiwa,
Only if you want that design. It will have sonically and all very little to do with my own. It stars by using a Dual Op-Amp making it virtually impossible to actually use any Op-Amp that stands a chance to sound good in this circuit, omiting all sorts of bits and then makes it imnpossible to use the high quality components I specify for very sound (pun intended) reasons.
So thanks for mthe effort but NO WAY to the layout.
Sayonara
Konnichiwa,
johnny555 said:bravo to steen and Gnuz for that, it makes life easyer for newbees!
Only if you want that design. It will have sonically and all very little to do with my own. It stars by using a Dual Op-Amp making it virtually impossible to actually use any Op-Amp that stands a chance to sound good in this circuit, omiting all sorts of bits and then makes it imnpossible to use the high quality components I specify for very sound (pun intended) reasons.
So thanks for mthe effort but NO WAY to the layout.
Sayonara
Konnichiwa,
Just a comment in general.
Please be aware that using a PCB in the traditional way is not conductive to sound quality. not only does using a PCB mean you get on average double to tripple the solder joins neccesary, the PCB traces typhically have relatively high parasitic capacitance to any ground plane and so on.
Making a tight layout on a simple 2.54mm grid hole pattern board, making sure to use as little wire other than the component leadouts is a better choice. Even better is the "dead bug" style with all components in air.
AND (here it comes), I found the differences between PCB Materials (Aralon, FR4, Pertinaxe etc.) the more pronounced the lower the operating levels of the circuit. Don't ask me for a comprehensive theory to the why, it is merely an observation.
My vote for absolute quality of sound quality (and if you are $ 25 Op-Amp's and Polystyrene capacitors etc. you might as well shoot for the best sound quality) thus goes to a piece of solid copper and dead bug style.
The layout is easy as long as you think three-dimensional and use a few sets of grid paper to draw different versions. usually, the parts used and circuit will take one natural form that follows their function best.
Sayonara
steenoe said:
Just a comment in general.
Please be aware that using a PCB in the traditional way is not conductive to sound quality. not only does using a PCB mean you get on average double to tripple the solder joins neccesary, the PCB traces typhically have relatively high parasitic capacitance to any ground plane and so on.
Making a tight layout on a simple 2.54mm grid hole pattern board, making sure to use as little wire other than the component leadouts is a better choice. Even better is the "dead bug" style with all components in air.
AND (here it comes), I found the differences between PCB Materials (Aralon, FR4, Pertinaxe etc.) the more pronounced the lower the operating levels of the circuit. Don't ask me for a comprehensive theory to the why, it is merely an observation.
My vote for absolute quality of sound quality (and if you are $ 25 Op-Amp's and Polystyrene capacitors etc. you might as well shoot for the best sound quality) thus goes to a piece of solid copper and dead bug style.
The layout is easy as long as you think three-dimensional and use a few sets of grid paper to draw different versions. usually, the parts used and circuit will take one natural form that follows their function best.
Sayonara
Schematic Errato (Thanks Carsten)
Konnichiwa,
A minor drawing error was spotted by an avid reader, one "ground" sign was missing in the output section, here the corrected version:
Sayonara
Konnichiwa,
A minor drawing error was spotted by an avid reader, one "ground" sign was missing in the output section, here the corrected version:
An externally hosted image should be here but it was not working when we last tested it.
Sayonara
Kuei Yang Wang said:
I think that if you do PCB, teflon would do just nicely -- and you could run up the national debt at the same time. See Bob Pease's article "What's all this femtoAmpere Stuff Anyway?" at National Semi. But nothing beats "air". The only thing I can think of which might detract from "dead-bug" is that JFET's like to have their feet planted.
Any problems with thermal drift, btw?
Konnichiwa,
Non that appear to prejudice performance.
After all the J-Fet headamp is capacitor coupled and the Op-Amp has little offset drift.
As for planting the J-Fet's little feet, the traditional solution is to solder it to the RCA Socket and run two wires from there to the main assembly where the Supply, Drain load resistor and coupling capacitor tend to reside....
Sayonara
jackinnj said:
Non that appear to prejudice performance.
After all the J-Fet headamp is capacitor coupled and the Op-Amp has little offset drift.
As for planting the J-Fet's little feet, the traditional solution is to solder it to the RCA Socket and run two wires from there to the main assembly where the Supply, Drain load resistor and coupling capacitor tend to reside....
Sayonara
A little drawing for the less experienced solder artists to give you an idea of how to build this little gem.
Enjoy,
Carsten
An externally hosted image should be here but it was not working when we last tested it.
Enjoy,
Carsten
Konnichiwa,
Not if you like Valve Audio.
The AAPhono/ElCheapo is meant to be a "minimum performance standard design", in other words the minimum performance I'm willing to live with.
The Valve El Cheapo does better what valves do better, more 3D, more natural and airy and smooth, not hugely so, but appreciable.
Sayonara
garp said:
Not if you like Valve Audio.
The AAPhono/ElCheapo is meant to be a "minimum performance standard design", in other words the minimum performance I'm willing to live with.
The Valve El Cheapo does better what valves do better, more 3D, more natural and airy and smooth, not hugely so, but appreciable.
Sayonara
Thorsten, any chance you could post a picture of your 2"O"6 version?? I am working on a strictly "cubistic" version at this point,
its not gonna look like a dead bug, but the soldering is the same Trying to figure this one out, I try to recall the Atomic-sculpture in France, you know, the one from the world-excebition, many years ago
Hey, Carsten, thanks a lot for your contribution!!!
Steen
its not gonna look like a dead bug, but the soldering is the same
Trying to figure this one out, I try to recall the Atomic-sculpture in France, you know, the one from the world-excebition, many years ago Hey, Carsten, thanks a lot for your contribution!!!
Steen
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.