You've got it.(...) I'm not sure if I'm more intrigued by the phono or the presentation
The circuits of the old masters of the 60s and 70s are more interesting.
I actually find these passive stories the least interesting. The whole theater is somehow dependent on the mood.
Let's build a SUPRA, the ancient Elektor circuit or ...
You could also simply use all four well-known network topologies in a switchable way, in the hope of finally finding the ideal today.
Or once again a kind of SRPP.
Bye,
HBt.
Attachments
With the quick design "Haudegen_3" we could perhaps promise ourselves /belive to lift the internal npn-pnp output stage of the TL (there is a 128Ohm series resistor just at the ...) into a quasi class A single-ended operation.
With the so called "better sounding" passive network and two fairly high gain stages 2*sqrt(1000). That's not really how it's done wisely, but in this case it works and with a bit of luck you might even achieve an SNR > 80dBc. And that's good enough. My grandma was already happy with > 70dBc and with her DUAL-Turntable.
If we also weight the noise, then we achieve better Numbers to publish.
BTW.
I like both OPs.
With the so called "better sounding" passive network and two fairly high gain stages 2*sqrt(1000). That's not really how it's done wisely, but in this case it works and with a bit of luck you might even achieve an SNR > 80dBc. And that's good enough. My grandma was already happy with > 70dBc and with her DUAL-Turntable.
If we also weight the noise, then we achieve better Numbers to publish.
BTW.
I like both OPs.
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1. Stage:
Now that the project is clearly outlined and we are all just boiling water, I decide on the first stage.
I will use the NE5532 as the operational amplifier, U1a for the left channel and U1b for the right channel. The result should be absolutely inexpensive and small in form factor. All the components required can usually be found in any standard range /boxes.
You can play with the component dimensions for the purpose of optimization. Feedback regarding any errors is welcome.
HBt.
Now that the project is clearly outlined and we are all just boiling water, I decide on the first stage.
I will use the NE5532 as the operational amplifier, U1a for the left channel and U1b for the right channel. The result should be absolutely inexpensive and small in form factor. All the components required can usually be found in any standard range /boxes.
You can play with the component dimensions for the purpose of optimization. Feedback regarding any errors is welcome.
HBt.
Attachments
A short excursion into reality:
5mV(rms) multiplied by 100 is equal to 0.5V(rms), which corresponds to a peak of 0.707Vp.
We could also calculate with the infamous 2V(rms), I have done this countless times, always with the same result. Given a load (our input resistance of the preamplifier, for example) of 10kOhm +/-j0Ohm. Our last stage of the Haudegen project should now be able to supply a current of 0.0707mAp. With R_load=1kOhm it is 0.707, we generously round up to 1mA.
Any operational amplifier can supply this current virtually undistorted.
If you compare the internal output stage of an NE5534 with the classic JLH class A amplifier, for example ... you'll go crazy with excitement.
The gimmick of an additional, flange-mounted push-pull power amplifier is normally nothing more than a gimmick.
I will, however, also give the TL072 a small afterburner, but for other reasons - even if the additional circuit is actually nonsense.
I don't want to build a headphone amplifier at the moment.
More on this later ...
Regards,
HBt.
(depending on the load, the quiescent current could be in the range of 353µAdc and 3.53mA - and we are still talking about class A. The most common extremes are included in this average estimate)
5mV(rms) multiplied by 100 is equal to 0.5V(rms), which corresponds to a peak of 0.707Vp.
We could also calculate with the infamous 2V(rms), I have done this countless times, always with the same result
. Given a load (our input resistance of the preamplifier, for example) of 10kOhm +/-j0Ohm. Our last stage of the Haudegen project should now be able to supply a current of 0.0707mAp. With R_load=1kOhm it is 0.707, we generously round up to 1mA.Any operational amplifier can supply this current virtually undistorted.
If you compare the internal output stage of an NE5534 with the classic JLH class A amplifier, for example ... you'll go crazy with excitement.
The gimmick of an additional, flange-mounted push-pull power amplifier is normally nothing more than a gimmick.
I will, however, also give the TL072 a small afterburner, but for other reasons - even if the additional circuit is actually nonsense.
I don't want to build a headphone amplifier at the moment.
More on this later ...
Regards,
HBt.
(depending on the load, the quiescent current could be in the range of 353µAdc and 3.53mA - and we are still talking about class A. The most common extremes are included in this average estimate)
2nd stage now:
Now the output stage looks completely normal, just like in the textbook - and it will work perfectly. The prototype will ultimately show whether minor adjustments are still necessary. The only thing that interests me personally is the distortion spectrum and of course the noise.
HBt.
Now the output stage looks completely normal, just like in the textbook - and it will work perfectly. The prototype will ultimately show whether minor adjustments are still necessary. The only thing that interests me personally is the distortion spectrum and of course the noise.
HBt.
Attachments
The only thing missing is a suitable power supply unit and, of course, the usual charging capacitors and blocking capacitors. Frequency response compensation will then follow on the object itself, but this does not affect the RIAA network. In our case a passive divider. I will add two suggestions, one of which is already available in this thread.
Let's hope our storyteller Haudegen doesn't suddenly fall into a coma and start dreaming crazy stuff ... something with triads who simply copy his idea and make a PCB ... that would be too nice, he reads his name on colorful circuit boards: "Haudegen" the universal MM-Phono-EQ.
Let's hope our storyteller Haudegen doesn't suddenly fall into a coma and start dreaming crazy stuff ... something with triads who simply copy his idea and make a PCB ... that would be too nice, he reads his name on colorful circuit boards: "Haudegen" the universal MM-Phono-EQ.
The final center:
The initial situation is now ideal: source resistance almost zero, no load on the complex voltage divider!
Without exception, only standard components are used. The resulting approximation is amazing, no fiddling is necessary.
Here is my final proposal, now the three groups just have to be plugged together ... It's all very simple.
The overseas client can consider his catalog of requirements fulfilled, but it is doubtful whether our CEO will be satisfied. He can't win a flower pot within his Rotary club friends with this circuit. Alois Lederhose, the boss, will go berserk, but Haudegen couldn't care less.
What SNR will this project achieve?,
HBt.
The initial situation is now ideal: source resistance almost zero, no load on the complex voltage divider!
Without exception, only standard components are used. The resulting approximation is amazing, no fiddling is necessary.
Here is my final proposal, now the three groups just have to be plugged together ... It's all very simple.
The overseas client can consider his catalog of requirements fulfilled, but it is doubtful whether our CEO will be satisfied. He can't win a flower pot within his Rotary club friends with this circuit. Alois Lederhose, the boss, will go berserk, but Haudegen couldn't care less.
What SNR will this project achieve?,
HBt.
Attachments
Alois calls Haudegen into his room to intimidate the little boy, does he want to pull the seat of his pants tight?
"What did I tell you? How am I standing there? No coupling capacitors between the steps, not even a hidden one."
Alois has been casting a disapproving eye on Haudegen for a very long time, the brat is always late for work and just does what he wants.
Haudegen desperately tries to have a technical discussion with the CEO about the necessary lower limit frequencies, at least to focus on the important things.
It doesn't help, the CEO Alois Lederhose is ultimately omnipotent and omniscient, a narcissist. He prefers the submissive upstarts.
The boss lets his employee step away and announces a late afternoon meeting with the other members of the lower floor.
Haudegen knows the big boss wants to show him up and get him down! This is really too stupid for him, but it's not new territory.
In the small meeting room:
At the tiny oval table sits the master precision mechanic, some other banger from the electronics lab and, of course, our disgraced hero.
The receptionist brings her master's green tea and announces: "His Highness is still on the phone, but he'll be right in."
Ok, the usual game, everyone involved knows this stewing ... The metal man is already looking forward to the upcoming thrashing and Haudegen is bored.
Alois triumphantly enters the tiny room, 45 minutes late. Two hours later (as usual and empty of content), everyone leaves the interrogation room.
It was agreed that Haudegen would supply the circuit and the master of aluminum would make a great housing with a blue LED. He is happy to leave the pencil sketches of the great Zampano to the metalworker. He prefers not to say a word about the minute-taker.
Next meeting, next week Thursday evening.
The tea service was still on the table the next lunchtime, the mouse had already called it a day.
And with that, the fringe story fizzles out. A new day in the lab begins.
HBt.
"What did I tell you? How am I standing there? No coupling capacitors between the steps, not even a hidden one."
Alois has been casting a disapproving eye on Haudegen for a very long time, the brat is always late for work and just does what he wants.
Haudegen desperately tries to have a technical discussion with the CEO about the necessary lower limit frequencies, at least to focus on the important things.
It doesn't help, the CEO Alois Lederhose is ultimately omnipotent and omniscient, a narcissist. He prefers the submissive upstarts.
The boss lets his employee step away and announces a late afternoon meeting with the other members of the lower floor.
Haudegen knows the big boss wants to show him up and get him down! This is really too stupid for him, but it's not new territory.
In the small meeting room:
At the tiny oval table sits the master precision mechanic, some other banger from the electronics lab and, of course, our disgraced hero.
The receptionist brings her master's green tea and announces: "His Highness is still on the phone, but he'll be right in."
Ok, the usual game, everyone involved knows this stewing ... The metal man is already looking forward to the upcoming thrashing and Haudegen is bored.
Alois triumphantly enters the tiny room, 45 minutes late. Two hours later (as usual and empty of content), everyone leaves the interrogation room.
It was agreed that Haudegen would supply the circuit and the master of aluminum would make a great housing with a blue LED. He is happy to leave the pencil sketches of the great Zampano to the metalworker. He prefers not to say a word about the minute-taker.
Next meeting, next week Thursday evening.
The tea service was still on the table the next lunchtime, the mouse had already called it a day.
And with that, the fringe story fizzles out. A new day in the lab begins.
HBt.
Lower corner frequency:
However, we can make excellent use of the criticized capacitor (47µF/63Vdc + 1µF MKT) in the feedbackloop of stage one.
We determine four values for four cut-off frequencies, 5Hz, 10Hz, 15Hz and 20Hz. We make the scenario switchable and call it a soft subsonic filter, the last setting we call IEC/RIAA.
@Chestnutspread
I am glad that you like the project. Your comments are very kind. Should I make a complete circuit diagram to summarize the topic and actually conclude it?
Perhaps a gifted CAD/CAM user can then create a PCB for all of us.
Everyone feel free.
However, we can make excellent use of the criticized capacitor (47µF/63Vdc + 1µF MKT) in the feedbackloop of stage one.
We determine four values for four cut-off frequencies, 5Hz, 10Hz, 15Hz and 20Hz. We make the scenario switchable and call it a soft subsonic filter, the last setting we call IEC/RIAA.
@Chestnutspread
I am glad that you like the project. Your comments are very kind. Should I make a complete circuit diagram to summarize the topic and actually conclude it?
Perhaps a gifted CAD/CAM user can then create a PCB for all of us.
Everyone feel free.
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I somehow get a picture of a sausage in Lederhosen as the CEO - well played!
Regarding the Phono Pre I would like to see the project in it's final form.
Up till yet snippets are fine for explaining but the entire network may clarify the last bits.
A well performed layout would be nice - after checking the typical measurements it would be nice to have a competition between well remarked approaches.
I assume the noise will be better than granny was used to 😉
Beer and Pretzels for the storyline!
Regarding the Phono Pre I would like to see the project in it's final form.
Up till yet snippets are fine for explaining but the entire network may clarify the last bits.
A well performed layout would be nice - after checking the typical measurements it would be nice to have a competition between well remarked approaches.
I assume the noise will be better than granny was used to 😉
Beer and Pretzels for the storyline!
Let's see how our story ends,
Haudegen will only present a basic overview of the circuit at the next meeting. His direct colleague (a black holeof cozy mind ) looks at him in love -
"everything is self-explanatory". Leberkäse arrives, sits down, leafs through his personal notes and bites his fingernails. Nobody says a word.
Haudegen wants to bend down and ask Daddy to help him with, he is itching at..!
But he shows him the basic circuit diagram of the MM-Phono-EQ concept but that's not really what interests the boss.
The usual two hours later, Haudegen has to start all over again, Alois Lederhose has a new idea.
It's hopeless, the CEO seems to have an inferiority complex, the white sausage army is willingly behind him, no wonder he knows everything better.
Haudegen thinks about giving up, should he give in? He still has the CEOs private project "FlashGordon" on his cheek and that might be ****.
Overview of the EQ:
As promised, a complete circuit overview of the equalizer can be found in the file attachment.
Of course, this is not yet the final version, but everything that follows are marginal (and yet important) details.
Questions are welcome, as are suggestions or even cooperation.
Best regards,
HBt.
Haudegen will only present a basic overview of the circuit at the next meeting. His direct colleague (a black holeof cozy mind ) looks at him in love -
"everything is self-explanatory". Leberkäse arrives, sits down, leafs through his personal notes and bites his fingernails. Nobody says a word.
Haudegen wants to bend down and ask Daddy to help him with, he is itching at..!
But he shows him the basic circuit diagram of the MM-Phono-EQ concept but that's not really what interests the boss.
The usual two hours later, Haudegen has to start all over again, Alois Lederhose has a new idea.
It's hopeless, the CEO seems to have an inferiority complex, the white sausage army is willingly behind him, no wonder he knows everything better.
Haudegen thinks about giving up, should he give in? He still has the CEOs private project "FlashGordon" on his cheek and that might be ****.
Overview of the EQ:
As promised, a complete circuit overview of the equalizer can be found in the file attachment.
Of course, this is not yet the final version, but everything that follows are marginal (and yet important) details.
Questions are welcome, as are suggestions or even cooperation.
Best regards,
HBt.
Attachments
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Dear Chestnutspread!
So Haudegen would have wished for that in his stormy youth, just to get Alois to boil.
HBt. doesn't really care, he has already implemented countless projects and compared them with each other. But if it's fun, he's happy to do it.
Perhaps a comparison between the famous Pearl 1, 2 and the Salas Ultra. You shouldn't compare yourself with the fantastic Pearl 3, which also has a two-stage design, but such a passive/active concept should also only be compared with an equivalent split RIAA, for example the 1980s PREAMP from Elektor.
But Haudegen also competes against every other concept and it will hold its own.
So try double blind to identify your own favorite equalizer. If none of the candidates makes mistakes and they are all equally loud, the experiment will produce astonishing results.
HBt.
Psst.
I'm adding a symmetrical power supply unit to give the project another boost.
LM317 and LM337 will also do the job.
But Technics had once built a controller that I liked, oh, we'll copy the main features of it now.
Do you have something like the picture in mind as a test setup?
There are other DIY-style structures in my photo album.
Mounted on a wooden board it's the most fun - I used the kitchen extensively, until my first analog oscilloscope complained about the frying fat.
And now for the riddle: which commercially very successful equalizer is in the picture?
There are other DIY-style structures in my photo album.
Mounted on a wooden board it's the most fun - I used the kitchen extensively, until my first analog oscilloscope complained about the frying fat.
And now for the riddle: which commercially very successful equalizer is in the picture?
Attachments
Haudegen
No better and no worse than any other approach.
Disclaimer
This material contains ideas only. They are freely available to any user. Nobody can be held responsible for any damage except the self-builder himself. All similarities with existing publications are purely coincidental.
No better and no worse than any other approach.
Disclaimer
This material contains ideas only. They are freely available to any user. Nobody can be held responsible for any damage except the self-builder himself. All similarities with existing publications are purely coincidental.
Attachments
I do have a question regarding the RIAA network.
Probably I'm missing something but I got the 820//100nF but for the 300nF the parallel 10.6Ohm is missing.
For my understanding the 10k in series - if not part of the feedback/gain of the first stage - is probably misplaced in the drawing?
Somehow I need to get my whiteboard back to calculate 2/4pole networks again in a proper way.
Probably I'm missing something but I got the 820//100nF but for the 300nF the parallel 10.6Ohm is missing.
For my understanding the 10k in series - if not part of the feedback/gain of the first stage - is probably misplaced in the drawing?
Somehow I need to get my whiteboard back to calculate 2/4pole networks again in a proper way.
Lunchtime
Our hero drives with his old companion, whose name must not be mentioned, to the best and dirtiest Chinese restaurant around the corner. They want something to eat. Both are furious about the CEO's weekly harassment. What's more, a young employee has her eye on Haudegen's companion. She doesn't let up and flaunts her alluring femininity.
Desperate and worried about his friend, Haudegen forgets his circuit diagram in the kitchen of the Asian snack bar.
That night he will have terrible nightmares, haunted by countless bags of 100nF capacitors, all calling out to him.
Months later, a product from a seller in the Pacific region appears in the electronic collection bay, called eBay. Black housing, blue LED (this is very important), gold-colored terminals - wasn't that even his idea? Crazy company name and so far
Haudegen thinks about a career change, hermit in the Wudang shan.
Our hero drives with his old companion, whose name must not be mentioned, to the best and dirtiest Chinese restaurant around the corner. They want something to eat. Both are furious about the CEO's weekly harassment. What's more, a young employee has her eye on Haudegen's companion. She doesn't let up and flaunts her alluring femininity.
Desperate and worried about his friend, Haudegen forgets his circuit diagram in the kitchen of the Asian snack bar.
That night he will have terrible nightmares, haunted by countless bags of 100nF capacitors, all calling out to him.
Months later, a product from a seller in the Pacific region appears in the electronic collection bay, called eBay. Black housing, blue LED (this is very important), gold-colored terminals - wasn't that even his idea? Crazy company name and so far
Haudegen thinks about a career change, hermit in the Wudang shan.