amir hossain
Member
Thank you,
So i am guessing there is no way to amplify sound on the circuit with out any audio interface
how can i increase sound in circuit Opic and opa alice
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So i am guessing there is no way to amplify sound on the circuit with out any audio interface
amir hossain
Member
Interesting, thank you.
Btw, can i replace n5532 with opa1642 (because i have 8 more laying around) or i HAVE To use n5532.
1642's fine, i'm sure. Especially if it's not a fake one...
amir hossain
Member
@Khron sorry to bother you again, need some help.
https://sound-au.com/project122.htm
Found this preamp page, i read the whole page but can not understand it fully or have doubts.
Like, is this a pre amp that
1) i need a preamp like opa alice+capsule?
2) opic/opa-alice powering with phantom power then the output from that goes to this preamp.
(Assuming i need no.2)
Also in the schematic (out and ground) is that mic output that goes in audio interface or audio jack?
Sorry for being annoying.
https://sound-au.com/project122.htm
Found this preamp page, i read the whole page but can not understand it fully or have doubts.
Like, is this a pre amp that
1) i need a preamp like opa alice+capsule?
2) opic/opa-alice powering with phantom power then the output from that goes to this preamp.
(Assuming i need no.2)
Also in the schematic (out and ground) is that mic output that goes in audio interface or audio jack?
Sorry for being annoying.
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Last edited:
rogs
Well-known member
The 'single sided' OPIC circuit is simply an impedance converter. It has no gain. The 'differential output' OPIC circuit will provide 6dB of gain.
You can increase that output further by increasing the value of R3 on the OPA1642 schematic. (That will also add a little bit of extra noise as well.)
(That will make the signal levels different on each leg of the output, although that should not affect the impedance balance).
The problem of using that extra gain - when connecting an XLR lead that has a 3.5mm jack at the other end - is that the signal to the jack may only be taken from pin 2 of the XLR. So the differential signal - with it's extra gain - will be lost.
The simplest (and probably cheapest ) way to connect a single sided OPIC mic is to use the type of interface suggested by K. Brown in post #20.
That USB powered device will provide both phantom power and amplification for use with a single sided OPIC.
The phantom power is specified as 48v. In reality it's less than that, but will still power an OPIC circuit OK.
The output can be connected directly into the mic or line input of a computer sound card.
No need for a separate phantom power supply or mic pre amp.
This type of mixer can be found quite cheaply on Aliexpress....... See here: https://www.aliexpress.com/item/1005005925478301.html
You can increase that output further by increasing the value of R3 on the OPA1642 schematic. (That will also add a little bit of extra noise as well.)
(That will make the signal levels different on each leg of the output, although that should not affect the impedance balance).
The problem of using that extra gain - when connecting an XLR lead that has a 3.5mm jack at the other end - is that the signal to the jack may only be taken from pin 2 of the XLR. So the differential signal - with it's extra gain - will be lost.
The simplest (and probably cheapest ) way to connect a single sided OPIC mic is to use the type of interface suggested by K. Brown in post #20.
That USB powered device will provide both phantom power and amplification for use with a single sided OPIC.
The phantom power is specified as 48v. In reality it's less than that, but will still power an OPIC circuit OK.
The output can be connected directly into the mic or line input of a computer sound card.
No need for a separate phantom power supply or mic pre amp.
This type of mixer can be found quite cheaply on Aliexpress....... See here: https://www.aliexpress.com/item/1005005925478301.html
Last edited:
amir hossain
Member
Thank you for all the informations above, i will definitely look into it.
amir hossain
Member
Big success, changed R3 resistor with 10k, changed xlr to 3.5mm jack's internal wiring. Previously it was pin2 singnal, (pin3+ pin1 ground)
I changed it to (pin 2 no connection), pin3 signal and (pin 1 ground)
Now its loud, how much loud Don't know. But i am happy with it
I tried my best to explain but my english not good. Sorry if i could not explain it correctly.
rogs
Well-known member
Changing R3 from 2k2 to 10k will increase the signal on that output by just over 13dB....
