@@MarkYoshimotoNemcoff thank you. The 2555B capsule is great and the OPA circuit is really transparent with a very high dynamic range so you hear the capsule.
Outstanding job as per usual! your work is an excellent cuasi scientific reference for all of us, DIY enthusiast, live sound producers and curious people alike, THANK YOU!
@@SoundSleuth Can you clarify if you mean the unmodded version or the modded version won't clip? I suppose I should just build the original and try unmodded, can always make a second with the mod if needed. Thanks for replying, I do love your work @soundsleuth.
And what if the task is the opposite: raise, make a louder level, increase sensitivity? For example, a microphone with the same preamp board, but with different caps, has a very different output volume level, and I want it to be approximately the same. I soldered 220 pf to a 1 gig ohm resistor, with a TSC-1 capsule and the level weakened by -10 db. And with the JLI-3413AU01 capsule (without the DC-DC Hex Inverter board), the level is initially very weak, somewhere 17 db quieter compared to the tsc-1 capsule (without 220 pf). Soldering the wima capacitor with other values for greater attenuation (330, 470 pf) I'm afraid there will be high frequency losses. Maybe try to change the value of the resistor in the feedback R6, R7 to increase the volume with an electret capsule, what do you think?
The TSC-1 with hex inverter is pretty sensitive. The JLI3413 is -44db about 11dB lower. Add in the 2-3dB that running it at 75VDC vs the 60 the default sensitivity was calculated with.
Nice warm, tight, and dark. These OPAs really punch way above their weight, can the Alice circuit accept a large diaphragm? or would it need modification? Thanks love your content
Great video, i love your opa builds. By the way I am new to this and I have really wierd question, on your opa alice circuit you used 1G ohm resistor but i don't have the access to it, highest i can get is a 10M ohm 0.25 watt, so if i put 100x10M ohm in serise will it work? Thanks.
The capsule and 1G are already in parallel. One end of both is tied to ground. Thus putting the padding capacitor across the 1Gig puts it in parallel with both.
@@zanzeoo From an AC and signal perspective the Capsule is in parallel with the 1Gig. We are adding in the the additional capacitor to pad the signal. The capsule is approximately 50pf. The additional 220pF cap then attenuates the signal roughly 47/(47 + 220) or about -15dB. From a DC perspective one end of the capsule is at ground, The other end is tied to the 1Gig and the input of the opamp, which is a very high impedance FET input and the other end of the 1Gig is aprox 6VDC. As far as AC goes, it and full 0V ground behave the same way.
This is very imprssive. Great devolpment. Thank YOU, SIR!🙏💪👏
Thank you!
That sounds great! Your Alice mics really deliver the goods on everything.
@@MarkYoshimotoNemcoff thank you. The 2555B capsule is great and the OPA circuit is really transparent with a very high dynamic range so you hear the capsule.
Outstanding job as per usual! your work is an excellent cuasi scientific reference for all of us, DIY enthusiast, live sound producers and curious people alike, THANK YOU!
Thank you so much!
Very nice. I'm planning an Alice build and am thinking this might be a good mod for grand piano as well, they always seem to clip with condenser mics.
They will not clip on a piano. And will sound great
@@SoundSleuth Can you clarify if you mean the unmodded version or the modded version won't clip?
I suppose I should just build the original and try unmodded, can always make a second with the mod if needed.
Thanks for replying, I do love your work @soundsleuth.
@@genghisbunny the original will work without clipping. If you really close mic you may want the padding.
And what if the task is the opposite: raise, make a louder level, increase sensitivity? For example, a microphone with the same preamp board, but with different caps, has a very different output volume level, and I want it to be approximately the same. I soldered 220 pf to a 1 gig ohm resistor, with a TSC-1 capsule and the level weakened by -10 db. And with the JLI-3413AU01 capsule (without the DC-DC Hex Inverter board), the level is initially very weak, somewhere 17 db quieter compared to the tsc-1 capsule (without 220 pf). Soldering the wima capacitor with other values for greater attenuation (330, 470 pf) I'm afraid there will be high frequency losses. Maybe try to change the value of the resistor in the feedback R6, R7 to increase the volume with an electret capsule, what do you think?
The TSC-1 with hex inverter is pretty sensitive. The JLI3413 is -44db about 11dB lower. Add in the 2-3dB that running it at 75VDC vs the 60 the default sensitivity was calculated with.
Are you sure you need the pad? The mics i built using opamps can take considerably more spl than regular fet mics.
Yes they can! For a close snare they do. The cool thing I found is it also drops the ambient noise level too.
Nice warm, tight, and dark. These OPAs really punch way above their weight, can the Alice circuit accept a large diaphragm? or would it need modification? Thanks love your content
Absolutely! www.instructables.com/True-Condenser-OPA-Mics/
Great video, i love your opa builds.
By the way I am new to this and I have really wierd question, on your opa alice circuit you used 1G ohm resistor but i don't have the access to it, highest i can get is a 10M ohm 0.25 watt, so if i put 100x10M ohm in serise will it work?
Thanks.
You could techinically but physically it would be huge. DIgiKey and Mouser carry them www.digikey.com/en/products/detail/ohmite/MOX200001007JE/705445
@@SoundSleuth Thanks for the help
I'm trying to figure out how 100 resistors would fit in a tiny circuit like that lol
@@dillpereira250 smd
@@dillpereira250 smd resistors on serise, placed it on the other side of the mic body, no problems so far.
wow! Very Impressive! Which Capsule this microphones are using? are from JLI too? Thanks! I love your content!
Yes the JLI2555B
The capacitor is not really across the capsule but in parallele with the 1g resistor , i was wondering how the signal could be attenuated this way ?
The capsule and 1G are already in parallel. One end of both is tied to ground. Thus putting the padding capacitor across the 1Gig puts it in parallel with both.
@@SoundSleuth in your schematic , the capsule is connected between GND and V+ , then the 1G is connected between V+ and Vcc/2 (6v)
@@zanzeoo the “6V” is a virtual ground. So it all works.
@@SoundSleuth Yes, 6v is a virtual ground, but are you agree that one end of the capsule is connected to GND (0V) ? and not the 1G or the 220pf cap
@@zanzeoo From an AC and signal perspective the Capsule is in parallel with the 1Gig. We are adding in the the additional capacitor to pad the signal. The capsule is approximately 50pf. The additional 220pF cap then attenuates the signal roughly 47/(47 + 220) or about -15dB. From a DC perspective one end of the capsule is at ground, The other end is tied to the 1Gig and the input of the opamp, which is a very high impedance FET input and the other end of the 1Gig is aprox 6VDC. As far as AC goes, it and full 0V ground behave the same way.
40 / 5 000
What is the name of this superb drummer?
His name is Winton. And he is great!
I'm new to DIY stuff but I have a question. Is there a nice way to add a switch (like a GT22MABE) to the pad without messing the PCB layout?
Yes you just wire a DPST switch with the capacitor in paralell with the resistor when in the on position.