Hello here on ASR.
This is my first post here, so I do hope I success in creating a nice readable post
Some year's ago, around fall 2022 I started getting really interested into diy measurements of mostly audio-stuff. I soon realized that I needed some kind of interface to plugin between the DUT's (Device Under Test) and the ADC, hopefully making it easier to make measurements.
Sadly or NOT sadly, because It's a very learning and fun project this one; there was not anymore any interface/autorangers available anymore so I needed to do my own.
I was inspired by PMillett's and the L|A Autoranger interfaces back then.
The version I show here, is the 3. working prototype.
It consist of a "motherboard" and a plug able "outputcard". The microprocessor is an ESP32 Devkit programmed with Arduino.
IN / OUT is CombiXLR/TRS plugs.
3 PCB's : Motherboard, Outputcard and PSU.
Box is Hammond.
A quick view of the capability is shown below. Measurement is taking wih Victors oscillator into ---> Cosmos ADCiso, Cosmos APU [998Hz -38dB Notch] and the SuperRanger.
The Victors oscillator, CosmosADC + the APUNotch is the best equipment I have, so comparing the SuperRanger to this is my reference.
Target can be hold pretty close to the ADC's sweet spot in the 64 [1 unity + 63] gain steeps:
What it can do or more like what my intention is, but I do think it's working pretty good now ::
This version of the SuperRanger, just finished a month ago, the former version was more or like the same one, but I used a OLED screen on that one, and it's a nogo, as the chargepump inside the OLED makes some nasty noise down -160dB or so.
OLED noise in RED (Former version SuperRanger):
Well...
I figured out, that an old fashion LCD is not making this kind of noise, but it's more difficult to have it behave nicely, as it's much more slow than the OLED one's.
But changing the code some, did the trick. So now the LCD is working very good.
The newest V2.0 [LCD] looks like this:
The "Menu" section is like this:
Schematic:
PSU:
Pictures of the machinery:
I will properly post some more stuff, if there is any interests here
Jesper.
This is my first post here, so I do hope I success in creating a nice readable post
Some year's ago, around fall 2022 I started getting really interested into diy measurements of mostly audio-stuff. I soon realized that I needed some kind of interface to plugin between the DUT's (Device Under Test) and the ADC, hopefully making it easier to make measurements.
Sadly or NOT sadly, because It's a very learning and fun project this one; there was not anymore any interface/autorangers available anymore so I needed to do my own.
I was inspired by PMillett's and the L|A Autoranger interfaces back then.
The version I show here, is the 3. working prototype.
It consist of a "motherboard" and a plug able "outputcard". The microprocessor is an ESP32 Devkit programmed with Arduino.
IN / OUT is CombiXLR/TRS plugs.
3 PCB's : Motherboard, Outputcard and PSU.
Box is Hammond.
A quick view of the capability is shown below. Measurement is taking wih Victors oscillator into ---> Cosmos ADCiso, Cosmos APU [998Hz -38dB Notch] and the SuperRanger.
The Victors oscillator, CosmosADC + the APUNotch is the best equipment I have, so comparing the SuperRanger to this is my reference.
Target can be hold pretty close to the ADC's sweet spot in the 64 [1 unity + 63] gain steeps:
What it can do or more like what my intention is, but I do think it's working pretty good now ::
- Outputvoltage (target) can be set somewhere between 0.5Vrms and approx. 8Vrms.
- The attenuation part can be adjusted in software to properly fit the target e.g. when shifting to -6dB from -0dB could be done from around 1Vrms to 6Vrms.
- It can take more than 70Vrms with the correct inputcapacitor of cause.
- Attenuationsteps 0dB, 6dB, 12dB, 18dB, 24dB, 30dB, 36dB and 42dB. The Input impedance should be around 20k.
- With the outputcard, there are 64gain steps (0db to approx 25dB or so).
- Clipping detection, input overload warning etc... in the software, along with information on the LCD screen.
- Easy to choose between SE input or Balanced input.
- Choose between manual or autoranging.
- Etc...
This version of the SuperRanger, just finished a month ago, the former version was more or like the same one, but I used a OLED screen on that one, and it's a nogo, as the chargepump inside the OLED makes some nasty noise down -160dB or so.
OLED noise in RED (Former version SuperRanger):
Well...
I figured out, that an old fashion LCD is not making this kind of noise, but it's more difficult to have it behave nicely, as it's much more slow than the OLED one's.
But changing the code some, did the trick. So now the LCD is working very good.
The newest V2.0 [LCD] looks like this:
The "Menu" section is like this:
Schematic:
PSU:
Pictures of the machinery:
I will properly post some more stuff, if there is any interests here
Jesper.
Last edited:
