Something like this:
https://calvins-audio-page.jimdofree.com/projekte-projects/phono-vinyl/all-jfet-se-phono-1/
It's inverting and therefore I add an inverter behind the mu-follower. If you like, I can share the schematic, but it's off topic, I think.
https://calvins-audio-page.jimdofree.com/projekte-projects/phono-vinyl/all-jfet-se-phono-1/
It's inverting and therefore I add an inverter behind the mu-follower. If you like, I can share the schematic, but it's off topic, I think.
I'm no expert, but I thought a SRPP don't use the capacitor to drive the upper FET?
Maybe you are right, I don't know. I thought the mu-follower has this capacitor driving the upper gate and the SRPP not.
Thanks for the simulations and the explanation/recommendation. In fact I can have higher voltages if necessary. I'm still in the design phase.
Yep you just use a same old typical known op amps for low noise, gain and RIAA
Mystically magical high distortion discrete circuits, don't do much but make distortion.
So comical from small signal to high current to speakers. There is so many lost concepts to engage in.
Complicated circuit. Aside from power supply decoupling.
1 cap 2 resistors = done Anything from .001% THD to .00006% little bit below -60 dB LOL!!
What is next to add to Overthinking longer solutions for easy problems a 18 month permit process to start building nonsense audio.
Mystically magical high distortion discrete circuits, don't do much but make distortion.
So comical from small signal to high current to speakers. There is so many lost concepts to engage in.
Complicated circuit. Aside from power supply decoupling.
1 cap 2 resistors = done Anything from .001% THD to .00006% little bit below -60 dB LOL!!
What is next to add to Overthinking longer solutions for easy problems a 18 month permit process to start building nonsense audio.
Thank you for your fruitful contribution to this topic. Again, I know that an operational amplifier can be ways better and I'm used to work with them in other circuits. And yes, I know that there is a reason why most circuits today are based on integrated circuits and the manufacturer of them had done a great job providing great solutions since 1958.
With two mu-follower I have a lot of gain and need a feedback to reduce it, or do I understand something wrong.
I'm pretty sure you already knows
https://www.ti.com/lit/an/snoa620/snoa620.pdf?ts=1737831833497
where you can find this type of amplifier on page 5. If I got you right, you mean something like this
https://www.valvewizard.co.uk/mufollower.html
without the extra DC offset at the upper gate?
I am not a tube guy.
But I guess you are using something like the Ultra High Gain Audio Amplifier in P.5 of TI AN-32.
Then Av = Yfs / Yos / 2 of the lower JFET
If you choose a JFET like MMBF5456, you will have a gain of 50 or less.
You can further reduce the effective Yfs by adding a source resistor to the lower JFET, right ?
http://www.geofex.com/article_folders/foolwfets/foolwfets.htm
It also helps to give you a more manageable bias current.
The upper JFET and the source follower don't have to be the same as the lower JFET, right ?
Patrick
But I guess you are using something like the Ultra High Gain Audio Amplifier in P.5 of TI AN-32.
Then Av = Yfs / Yos / 2 of the lower JFET
If you choose a JFET like MMBF5456, you will have a gain of 50 or less.
You can further reduce the effective Yfs by adding a source resistor to the lower JFET, right ?
http://www.geofex.com/article_folders/foolwfets/foolwfets.htm
It also helps to give you a more manageable bias current.
The upper JFET and the source follower don't have to be the same as the lower JFET, right ?
Patrick
Last edited:
Hi,
"I looks like highly nonesensical to me, but I' ve done way more stupid things in life so who am I to judge it?"
Exactly! Before dismissing other´s designs with stark wording rather think about them in depth.
It´ll prevent You from appearing arrogant if not foppish, especially when You seemingly haven´t ´got´ the reasoning behind the design decisions.
back to #36: I came up with these circuits after having seen Alex Nikitin´s designs for Creek (OBH-series) and his contributions here at DIYaudio.
My part was basically having translated his bipolar and hybrid-bipolar-JFET designs into a JFET-only world.
Along this process it became quickly clear why the cap needs to be large ... at min in a medium 1-digit µF range.
So, yes, it makes sense.
As for the gain=-1 buffer application: You could omit with it by just connecting the pickup inverted .... or, if You don´t believe in ´absolute phase´ 😉
jauu
Calvin
"I looks like highly nonesensical to me, but I' ve done way more stupid things in life so who am I to judge it?"
Exactly! Before dismissing other´s designs with stark wording rather think about them in depth.
It´ll prevent You from appearing arrogant if not foppish, especially when You seemingly haven´t ´got´ the reasoning behind the design decisions.
back to #36: I came up with these circuits after having seen Alex Nikitin´s designs for Creek (OBH-series) and his contributions here at DIYaudio.
My part was basically having translated his bipolar and hybrid-bipolar-JFET designs into a JFET-only world.
Along this process it became quickly clear why the cap needs to be large ... at min in a medium 1-digit µF range.
So, yes, it makes sense.
As for the gain=-1 buffer application: You could omit with it by just connecting the pickup inverted .... or, if You don´t believe in ´absolute phase´ 😉
jauu
Calvin
The question is whether one stage amplifier with say Gain of 500 is lower in distortion than two stages with gain of ~22 each.
Patrick
Hi @Calvin. Thanks for joining here. As already said, I like you design proposals and you are right, this high value capacitor is necessary and the performance is great, at least for me.
What do you think about the difference to SRPP and/or mu-follower. What's the officialy definition. I guess it's driving of the upper device?
https://en.wikipedia.org/wiki/Push–pull_output
What do you think about the difference to SRPP and/or mu-follower. What's the officialy definition. I guess it's driving of the upper device?
https://en.wikipedia.org/wiki/Push–pull_output
Here a quick example. It's not the same circuit, just quick and dirty with some random components and a riaa network. Notice, that the capacitor C is places at another position. The three results are for 220n, 3.3u and 68u.
This can be true, right. And I prefer film as well. But if you like a totally flat gain the big cap is one thing to check. For sure, you also have to check the new issues, the elco may generate.