MiSTer FPGA Forum

I'm using a MiSTer in a custom arcade cabinet (ie. CRT TV with arcade controls, etc) but I'm using a car speaker amplifier connected to speakers.

Here is the setup:

MiSTer -> Extron SW4 VGA/Ars Switcher -> Volbox inline audio volume -> JBL DA4002 Amplifier -> 2x Speakers

Everything works perfectly except there is a loud pop when I turn the MiSTer on or off and when I switch cores.

I've searched for this issue and it sounds like it's common for car audio setups but the on/off relay typically turns the amplifier on or off before the stereo to prevent this.

Can anybody give me any advice or info to solve this problem?

Try running the audio directly to the amplifier to see if the problem is caused by any of the inline equipment. From what I recall, my MiSTer pops too, especially with my subwoofer turned on.

Are you using the analog audio jack on the IO board? The solution is to instead use the optical output (from the same port) and run it through a DAC.

See viewtopic.php?f=29&t=2049

Thanks so much for the information ... That's the exact issue I'm having. I should have searched better before posting.

Did you find a DAC that eliminates the popping? You mentioned in that thread you still have the issue, but somebody commented later on recommending the FiiO D3?

EDIT: Jotego also seems to recommend this PROZOR 192KHz Digital to Analog Audio Converter DAC? (only $12.99 on Amazon)

I confirm that the DAC is indeed removing the pop sounds between core loading.

I have also the PROZOR version and it works like a charm.

sofakng wrote: ↑Tue May 25, 2021 5:04 pm Can anybody give me any advice or info to solve this problem?

From the old Atari MiSTer forum:

Sorgelig wrote: Different cores have different zero level making the capacitor charge at some level and then discharge when other core is loaded.

https://www.atari-forum.com/viewtopic.p ... 98#p354698