Recommendations for a basic bench testing set up?

tvr2500m · 3906

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Offline tvr2500m

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on: September 14, 2023, 11:20:15 AM
I've got the stuff to do electronics work and projects, like building Bottlehead kits. Soldering station, nice multimeter, hand tools, consumables. I would like to have a more complete, basic bench set up to do testing, measurement, troubleshooting. It looks like today there are more choices than ever for equipment. From vintage, to hand-held, to computer-based, ??

Recommendations? The Audio Precision suite, or something like it, looks great, but a bit pricey. What are the most basic pieces needed? Oscilloscope, powersupply, frequency generator, distortion analyzer... ??


Offline Thermioniclife

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Reply #1 on: September 14, 2023, 02:54:51 PM
The only thing you would want would be a variac if your mains voltage is higher than 120 vac if you live in north America. for instance my home usually has an average of 123 Vac which can alarm some builders as the extra 3 Vac will increase the voltages spec'd on the voltage check's. Having said that just measure the wall voltage and if it a couple of volts higher or lower It will effect voltage checks.
The resistance checks are very important so make sure you pass them first. So a Variac is not needed if you really think about it, but
it can be useful if you are designing a scratch built circuit.

Lee R.

Offline tvr2500m

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Reply #2 on: September 14, 2023, 03:47:35 PM
Thanks. Good one. A variac. How did I forget that one?

Offline Paul Birkeland

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Reply #3 on: September 14, 2023, 04:19:34 PM
The Audio Precision is really nice and gathers its data very quickly but they are very expensive.  You can use a computer with Arta and a decent soundcard to get a sample of the waveform coming out of your amp to do distortion measurements, then use an oscilloscope to get an accurate measurement of the amplitude of the output.  This kind of setup doesn't work well to measure burst power, but with class A SET amps, there is no burst power, so it works great!  Generally the bandwidth of these USB pro audio cards is limited as well, so your THD measurements up at high frequencies will not be particularly accurate.  Do also keep in mind that the sound card will want just a small sampling of what's at the speaker posts, so put a low value resistor in series with your 8 ohm dummy load, then grab the signal from that junction and send that to the sound card microphone input.

If you add a signal generator into the mix, you can get a much better measurement of high frequency roll-off. 

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man

Offline ssssly

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Reply #4 on: October 27, 2023, 10:50:03 PM
I'm a big fan of my Analog Discovery 2 with the BNC shield for signal gen and oscilloscope duty. Not the most accurate oscilloscope you can find, but pretty difficult to find a better one near that price. And it's very convenient.So much so I haven't used my bench oscope in some time.