V2164 Tester / Mixer

Simple board to test V2164 chips. Follows the application example in the SSM2164 datasheet.

Can also be used as a 2 channel stereo mixer.

Status

Ok.

v0.1 Test results

• It works ✅
• Pot direction reversed - CCW turns gain up 😒
• right side ouput label should be "3+4" 🤷‍♂️
• Resistor divider - one would be enouth

v0.2 not tested / will not test / should be ok.

• twisted Pot directions
• changed right out label
• added version label

Gimmics

For cleverness sake, chip adapters can be used.

With R1/R4 and R14/R15 the range of the pots can be limited. For testing u can just short these. In theory 0V is 0dB and then the gain factor is -33mV/dB with a max range of -120..+20 dB, that equals 3.96V=-120dB to -0.66V=+20dB.

Ask your favorite chat bot for a voltage divider fitting your needs.

To design a voltage divider with three resistors in series between +12V and -12V that meets your specified voltage requirements, we'll follow these steps:

### Given:
- **Supply voltages**: +12V (top) and -12V (bottom)
- **Middle resistor (R₂)**: 10 kΩ
- **Desired voltage at top of R₂ (V₂)**: +3.96V
- **Desired voltage at bottom of R₂ (V₃)**: -0.66V

bla bla bla...

### Final Resistor Values:
- **Top resistor (R₁)**: **17.4 kΩ**
- **Middle resistor (R₂)**: **10 kΩ** (given)
- **Bottom resistor (R₃)**: **24.55 kΩ**

### Practical Considerations:
- You may need to use standard resistor values close to the calculated ones (e.g., 17.4 kΩ ≈ 17.8 kΩ or 18 kΩ; 24.55 kΩ ≈ 24.9 kΩ or 25 kΩ). 
- For higher precision, you can use a potentiometer or combine resistors in series/parallel.

Or use the experimental falstad circuit.

BOM

References	Value	Footprint	Quantity
C5, C6, C7, C8	560p	603	4
C2, C3	220p (100p+)	603	2
R2, R3, R5, R6, R7, R8	33k	603	6
R10, R11, R12, R13, R16, R17	470	0603	6
R1, R4, R14, R15	5k see notes	603	4
R9	7.5k for class A or open for class AB	603	1
U1	SSI2164	DIP-16 7.62mm or SO-16 + Adapter	1
U2	TL074 or any such 4x OpAmp	DIP-14 7.62mm or SO/SOP/TSOP-14 + Adapter	1
RV1, RV2	10k see notes	9mm Potentiometer Vertical	2

Schematic

Reference from DS

Also read the datasheet, just search for "V2164 pdf" or "SSM2164 pdf".