Same/similar circuit, other parts/values; there are many options with this circuit.
To me red light indicates error or alert, so I use green LEDs in the current sources. 🙂
To me red light indicates error or alert, so I use green LEDs in the current sources. 🙂
This is something I don't know but think I've read: There is some physical property with red LED's that make them particularly suitable in these kind of circuits. I can't say what though.
What I don't know either is if the current is high enough for the LED to actually emit light?
Perhaps you are thinking of this thread: https://www.diyaudio.com/community/threads/some-noise-measurements-for-leds-and-zener-diodes.35821/
LEDs emit light directly proportional to forward current. Its laser diodes that only lase above a threshold (and burn out readily if much above that threshold(!)). Laser diodes still emit light at lower currents, they are just special LEDs with an optical cavity and carefully engineered quantum well(s) to create a population inversion.
LEDs emit light directly proportional to forward current. Its laser diodes that only lase above a threshold (and burn out readily if much above that threshold(!)). Laser diodes still emit light at lower currents, they are just special LEDs with an optical cavity and carefully engineered quantum well(s) to create a population inversion.
Hi! I may be a little ahead of myself now, but is this one of the options (more or less) that is possible at the moment? I did not use the last buffer from catd because I could not figure out all the details. Should the PSU be integrated on the PCB or be external? Note that the added components have random values of my choice to make a complete schematic. Please disagree! And the RIAA network is from Aladdin....
🙂 morten
🙂 morten
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You don't want to cause any trouble on my pitch, Nico R.
Don't you?
(...)
best regards,
HBt.
The KiCad schematic corresponds 100% to the idea, my core with catds Diamond wish, really great.
I don't think the PCB has to include a PSU, then the rebuilder would be stuck with exactly this PSU and perhaps lose a degree of freedom if he wants a different PSU.
C301 consists of two 3.3nF FKPs connected in parallel, and C302 of 10nF in parallel with 10nF.
R301 should have an AC coupling, i.e. a capacitor in series, so that you have the option between DC and AC coupling. 470µF to 1000µF in parallel 1µF MKS.
Perhaps an AC coupling option on the input side ..!
Dear Morton,
Thank you very much for your commitment, it's great to have you on board.
fire free
greetings,
HBt.
I don't think the PCB has to include a PSU, then the rebuilder would be stuck with exactly this PSU and perhaps lose a degree of freedom if he wants a different PSU.
C301 consists of two 3.3nF FKPs connected in parallel, and C302 of 10nF in parallel with 10nF.
R301 should have an AC coupling, i.e. a capacitor in series, so that you have the option between DC and AC coupling. 470µF to 1000µF in parallel 1µF MKS.
Perhaps an AC coupling option on the input side ..!
Dear Morton,
Thank you very much for your commitment, it's great to have you on board.
fire free
greetings,
HBt.
An option request:
A jumper that allows the RIAA network to also /alternatively be placed on the emitter node between Q105 & Q106.
Either the last stage is only a buffer or a component of the negative feedback ---> this results in two completely different equalizers (the issue with the internal resistors comes into play here).
A jumper that allows the RIAA network to also /alternatively be placed on the emitter node between Q105 & Q106.
Either the last stage is only a buffer or a component of the negative feedback ---> this results in two completely different equalizers (the issue with the internal resistors comes into play here).
Now I'm just commenting on the possibility of having a part off the PCB "detachable" like @catd did for the input load selection part of OREAD. I think that is an elegant solution. If you don't want the PSU you can saw that part of the PCB off. (Sorry for my poor English)
On a PCB, I would also recommend the option of using coupling capacitors at the input and output of the buffer.
Depending on the choice of parts and values, such as the actual current gain factor hfe of the transistors, a larger DC offset may occur there.
When simulating only the buffer of the last circuit in post #44, I got input/output DC offsets of about 1 volt.
All this tinkering for vinyl is a superfluous luxury. For this reason, perhaps it should also be possible to use several paralleled input transistors. 🙂
Depending on the choice of parts and values, such as the actual current gain factor hfe of the transistors, a larger DC offset may occur there.
When simulating only the buffer of the last circuit in post #44, I got input/output DC offsets of about 1 volt.
All this tinkering for vinyl is a superfluous luxury. For this reason, perhaps it should also be possible to use several paralleled input transistors. 🙂
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One more thing! Capacitor pin spacing. Is 5mm in general ok? Maybe 3,5mm for small polarized and 30-40mm for output?
🙂 morten
🙂 morten
That's completely in the spirit of DIY and the joy of creating your own work of art.
dimensions:
5, 7.5, 10, -> 2,3,4 times 2.54mm is very fine for FKP, MKS, MKP s
#
Later, in reality, there will be no offset problems - nevertheless, the input/output AC coupling is preferable and should be provided for.
##
I know it Morton 😉, Without the DC blocker, it's perfectly fine, but we want more freedom ..!
If you don't connect the big hummer with its negative electrode to the GND potential, then you can include it in the negative feedback - as you can see, this is very easy to do.
kindly,
HBt.
That's not a good idea, because then we might as well just design a new layout for the original 1982-Supra-MM-MC-EQ.
SUPRA2024 is based on a different initial idea - which I will reveal later, if it is not already recognized in the meantime, but this supra should also provide one practical proof.
Please don't forget later that all BJTs have to be selected.