I was trying to figure out a way to make the 403 a bit more usable in the field and give me some flexibility of extra features. So This is my first drawing. Any suggestions would be super helpful.
In this design the wiring would break out to the front panel and also allow for O-Scope Outputs via some B&C “Y” connections on the + side of the inputs. Ive tested this and it doesn’t seem to change the measurements that much. The THD goes up a little, but certainly not enough to be bothered with. Thanks for the suggestions.
Output A (L) would be one XLR and output B would also be one XLR as would input A/B. Basically, you have twice as many XLRs as you’d need. You could also have a pair of ‘scope outputs from the generator (I often send the inverted output to the ‘scope if I’m only using the non-inverted output (SE). The ‘scope outputs you have suggested will pull in noise depending on the output impedance of the connected DUT.
and I’ve been very happy with it, although after 3d printing it I redid it in aluminum because there’s a fair amount of torque with these connectors. The connections are extremely short and noise pickup is minimal. It does, however, exclude using the BNCs standalone.
The reason I doubled up on the xlr connectors was to give some flexibility. Ie on the input I often go to a high gain headphone amp to listen into the noise. This is a great technique for spotting noisy transistors in the circuit. The b&c outputs take the + side of each input so I can wire up a scope and see realtime info on waveforms…
I’ve got an update as I made it a 2u rack unit and would love to see if I can develop a dedicated scope output using the I2s port.
