JLE RTA Soundcard Interface Pre-Soldered SMT PCB 1pc

Includes pre-soldered SMT parts, ultra low noise post regulators, and balanced input / output capability. Uses INA1651 IC (pre-soldered)

****

Large signal input protection and simple attenuator for low THD+N audio soundcard / interfaces / ADC like Motu M4 or UltraLite-mk5 or E1DA Cosmos ADC. Protects the soundcard's ADC from large AC inputs and potential DC voltages from the device that's being tested. Ideal for production runs or repair shops, running quick tests before shipping out the amplifier. Or for DIY audio enthusiasts, to check if the amplifier is good and within the specifications.

The I/O of the interface has 600V input coupling caps, which will protect the ADC input from DC voltages. INA1651 input section has an ESD protection (TPD2E007) and voltage divider switch that accepts floating input up to 60Vrms.

The input has a pre-attenuation switch -0.1dB (divided by 1.01), -14dB (divided by 5), and -24dB (divided by 16). For example, if the device under test's output signal is 1Vrms, the resulting output of the interface can be switched to ~991mVrms/200mVrms/62.5mVrms respectively (SE, 2x for BAL out).

After the initial DIV 1.01/5/16attenuation, the DUT signal can be further attenuated by a volume pot knob to the desired soundcard's (sweet spot) input. For example, if the DUT's output signal is 2Vrms, the output of the interface can be adjusted anywhere from 1.99Vrms down to ~0Vrms. Can also be called a "manual ranger".

For measuring device under test (DUT) output signals up to 9Vrms, set the attenuator switch to DIV 1.01, then adjust the interface's volume pot knob which will reduce the output of the interface to the desired input level of the soundcard. For DUT output signals higher than 9Vrms and up to 60Vrms, flick the switch to DIV 5 or to DIV 16 attenuator, and then turn down the interface's volume knob pot to set the output of the interface to desired soundcard input level.

Output voltage limiter is adjustable through an onboard pot. The relay will disconnect the output if the AC signal going to soundcard is higher than the preset Vrms output. You can set the relay trigger to the desired voltage going to the ADC, so you don't need to measure the voltage output of the JLE interface. Slowly increase the volume knob until the relay clicks, then back down a little to re-engage the relay.

The interface has a 5V to +/- 15V isolated DC-DC converter with ultra low noise post regulators. The module can be connected to a 5V usb power bank.

With correct wiring, the module is not sensitive to interference and can be used as is, without copper shield or a metal casing.

Package Includes
1 pc Soundcard Interface Mono Blank PCB
BOM and schematic via email.
All SMT parts are already pre-soldered
Through hole parts are not included, you need to buy and solder the through hole parts separately

Features
For low THD+N soundcard or professional sound interface
Can accept output from SE/BTL/PBTL audio amplifiers up to 60Vrms
Adjustable output going to soundcard through potentiometer. With relay limiter.
DC protection, overload protection for soundcard*
Powered by isolated DC-DC converter 5V to +/-15V
*Avoid ground loops by not connecting the speaker GND when measuring single-ended output power amps.

Specifications
Supply Voltage: 5V USB Power
Floating input voltage: 60Vrms
Output voltage protection: Adjustable
Input Impedance: 2.2KΩ
Balanced Line Receiver IC: INA1651
Buffer IC: dual opamp (not included)
THD+N @1kHz, 20kHz BW: -110dB (or better)