Im using my Parasound Zamp v.3 for my computer audio system. The chain goes to the computer, USB isolator, USB DAC, ZAMP, and Monitor Audio Silver 2 bookshelf speakers. The amp has always had a hum/hiss with no inputs, but it went away with the DAC so I never though much about it. I recently upgraded my DAC, and the new DAC goes idle after a few seconds, essentially shutting off the output, resulting in the ZAMP humming/hissing. I swapped amps with a Yamaha M-45 and the old Yamaha is silent with in the exact same setup. You can even unplug the RCAs from the back and the Yamaha stays silent.
I'm thought it might be floating inputs that the Zamp doesn't like. I checked the resistance between ground and signal, found it to be 19.5kohm (the Yamaha measured 20.4kohm) so that doesn't seem to be an issue. The ground checks out (and the Yamaha doesn't have issues), so I don't believe it is a ground loop issue (I even ran a separate ground to the chassis of the amp and tried a cheater plug). The Zamp also has the option to lift the ground, and that has no effect. I opened it up Zamp and didn't see any obvious issues with the caps.
The Yamaha is a tank, and I don't have room at my desk for it. How do I get the Zamp to be quiet? I tried an app called Sound Keeper, which keeps the DAC from sleeping, it works but that seems like a Band-Aid solution and doesn't fix the real issue. Is this just normal for a Zamp? Does it need a recap job (or just bad design)? Is it time to upgrade to one of the new TPA3255 chip amps?
Thanks!
I'm thought it might be floating inputs that the Zamp doesn't like. I checked the resistance between ground and signal, found it to be 19.5kohm (the Yamaha measured 20.4kohm) so that doesn't seem to be an issue. The ground checks out (and the Yamaha doesn't have issues), so I don't believe it is a ground loop issue (I even ran a separate ground to the chassis of the amp and tried a cheater plug). The Zamp also has the option to lift the ground, and that has no effect. I opened it up Zamp and didn't see any obvious issues with the caps.
The Yamaha is a tank, and I don't have room at my desk for it. How do I get the Zamp to be quiet? I tried an app called Sound Keeper, which keeps the DAC from sleeping, it works but that seems like a Band-Aid solution and doesn't fix the real issue. Is this just normal for a Zamp? Does it need a recap job (or just bad design)? Is it time to upgrade to one of the new TPA3255 chip amps?
Thanks!
Seems to be a bad design - https://www.audiosciencereview.com/...ds/parasound-zamp-v-3-amplifier-review.11872/
Sure got a bad review. Shame , it has a hefty linear supply. I'd throw a quality DIY tripath PCB in it !
Edit - I thought it was a little class D. That amp is WAY to small to be (decent) 60W class AB amp !!
It has 45-47V supplies running with 50V caps , and almost no thermal dissipation area.
My old Sonance 60W has two large heatsinks and 4 devices per channel. Hard to believe Parasound would market
something like this !
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