Pro Audio Design Forum

Hi All
My APIB USB ADAPTER that drives System One, System Two & Cascade under ApWin 2.24 that runs OS from XP, Vista, Win7, Win8, Win10 has been verified under Win11. It also works with ATS2 using Ver 1.5, not V1.6 (this has AP’s USB code installed).
Duke
duke.aguiar@ieee.org

Phase reversal is very common in most FET IC when over driven. Try a non FET IC
Duke

The power line may have had a big voltage spike. Lost the netural first (I lost a VCR in smoke)? Did some other devices fail? Check if surge protectors are GOOD.
Duke

The THD% in resistors that are shown in the table maybe misleading. What frequency & power levels did he use in testing the THD? During the development of the ATS2 (the first all SMD AP) I had 0.0006 THD% until the 10Hz test when it went sky high. At first I thought it was oscillating. Probing a...

Hello AnalogJoe I have an APIB USB ADAPTER that drives the System One. System Two & Cascade under ApWin 2.24 that runs OS from XP, Vista, Win7, Win8 & Win10. My next batch is due from my assy. house 31 Aug. I should have some overages after filling my back orders in Sept. http://www.sound-lo...

Hi Brian

If you have access to an Audio precision the RIAA curves & tests are part of the software tests.
Duke

Hi AnalogJoe The AP S1 has Tantalum only as pass modes and they are common failures. Sometimes the 15 volt trace also opens on the SINP assy. When I repair/service them I replace them with Panasonic low ESR parts. Tantalum’s is also prone to failure where ripple currents are present. When we develop...

In Pro Audio I would not use rail to rail op amps. Look @ the THD/SPECTRUM of the output as output level increases. Many op amps will go nonlinear when the output gets near to 3 volts from the rails voltage. To get clean 8v rms the op amp rails need to be slightly larger than 15 vdc.
Duke

The HP3582A was a great instrument years ago, however with 25kHz BW and 70dB dynamic range almost any Sound Card will be a better instrument for today's jobs and much smaller.

Wayne

What about placing the BIG TX into a 5 Gal steel paint can? This may give you another 10-20dB reduction.