Arduino+PGA2311 Ultimate PreAmp with OLED and IO switching

[zdr]

T

In your picture (#1) you can see PE0 and PE1, and only the atmega328pb has these pins
they are unused

Those boards can't be found any more on Aliexpress. They were with atmega328PB. But it seems that Atmega328PB allows use of ADC6/7 as digital pins according to datasheet, unlike 328P. Therefore it could be possible to expand I/O by two, if you manually replace Atmega328P with Atmega328PB on Nano and upload new bootloader.

 

[Micha_0910]

I now have 328p and 328pb in possession
I ordered the one under your link , they arrived yesterday
I've built it now, with changes
for example PGA2310 with +/-15V

 

[zdr]

I forgot I am using A7/A6 as an error condition (CLIP/OTW) detection from my class D power amp, so it's a no go for me for 6 inputs. But tape monitor and 5 inputs is doable with one sacrificed output which I have no use for anyway. I already ordered some boards. It will take around 1 month to arrive.

The new boards will use NCV1117-ADJ to bring down input voltage to 5.4V, which then will feed NCP699 for 5V rails and TPS72301 for -5V. Or you can use your own power supply and feed higher voltages to analogue part.

 

[zdr]

I now have 328p and 328pb in possession
I ordered the one under your link , they arrived yesterday
I've built it now, with changes
for example PGA2310 with +/-15V

Ha, they have PB variants again! But the prices have doubled as well 🙁

 

[Micha_0910]

test pcbway ,
I waited 10 days
http://www.pcbway.com

 

[aditya]

I forgot I am using A7/A6 as an error condition (CLIP/OTW) detection from my class D power amp, so it's a no go for me for 6 inputs. But tape monitor and 5 inputs is doable with one sacrificed output which I have no use for anyway. I already ordered some boards. It will take around 1 month to arrive.

The new boards will use NCV1117-ADJ to bring down input voltage to 5.4V, which then will feed NCP699 for 5V rails and TPS72301 for -5V. Or you can use your own power supply and feed higher voltages to analogue part.

Hi did your new boards arrive?

I am having some form of Hissing noise when the volume increases above say 3db as per the PGA serial data value, though it's not very loud, it is heard when my ears are next to the tweeter and the volume is full without input?.

I have used the mark Hennessy design (OPA2134) but used an opa2132 for input to pga2311 ( i had those OPA's).

For the supplies, there are 2 different winding on the transformer 1. 12 0 12
2. 0 12

so the 0 - 12 is used for relays and controller, and 12 - 0 - 12 is used for PGA and OPA with 7805 / 7809.

would it help to switch to LM317/337?

 

[Micha_0910]

I have PGA2310 and OPA on the same symmetrical power supply +/- 15V , BD140 + BD139 with TL431,
I tried OPA2604 and OPA2134

 

[aditya]

I have PGA2310 and OPA on the same symmetrical power supply +/- 15V , BD140 + BD139 with TL431,
I tried OPA2604 and OPA2134

Do u have a hiss like sound from the tweeters.

 

[Micha_0910]

Do u have a hiss like sound from the tweeters.

no

But I also have 2 transformers,
first transformer for 5V and 3.3V
and second transformer for +/-15V

 

[aditya]

no

But I also have 2 transformers,
first transformer for 5V and 3.3V
and second transformer for +/-15V

This is my board, on lower left is Bluetooth diff to single ended circuit. So one relay is sourcing that.

 

[olixman]

Hi.

Will i get the firmware too if i buy the PCB and shipping?
Asking because i can`t seem to find the firmware in the links provided in the first post.

Thanks!

 

[zdr]

I finally found some time to complete the board with tape monitor. Still need to iron out some quirks in the firmware.

 

[aditya]

I finally found some time to complete the board with tape monitor. Still need to iron out some quirks in the firmware.

Are you using the pga upto 0db or are you using with internal gain, since in my board I am having the infamous hissing from tweeter when I go into the 5db gain (internal)

 

[zdr]

Are you using the pga upto 0db or are you using with internal gain, since in my board I am having the infamous hissing from tweeter when I go into the 5db gain (internal)

Please open a new thread for your board and discuss it there.