Hello people, my first post to head-fi
My A1 arrived this morning and I have to say, I'm rather disappointed
I ordered it with the Tung Sol tubes. My intention is to use it as a headphone amp at work hooked up to my PC via an AlienDAC kit.
First issue was only the right channel worked, the left was very quiet (faint sound). I popped the lid off and checked all the cables were seated and gave the tubes a gentle wiggle. This fixed the issue but I'm not clear how it fixed it. My best guess is one of the tubes wasn't seated right or had worked loose during shipping.
Putting the lid back on there were issues with the case. The holes in the lid didn't line up with the holes in the case. I had to pull gently on the speaker terminals to make the holes line up. A couple of the screws won't tighten properly, I think the threads are damaged, I suspect because the case was forced on in the factory. The unit doesn't sit flat either, it rocks slightly. I'm not sure if it was like this before I popped the lid off or if it's a result of opening the box.
None of the above worries me much, the real issue is the sound. There is a persistent hum/buzz in the background. It's not very loud, but loud enough to be annoying if I'm listening to quiet music.
Testing the unit at work today with the volume up a little the PC/DAC/A1 combo worked fairly well. Taking the unit home this evening I'm struggling to use it with my laptop. When I connect the DAC/A1 to my laptop there is a terrible background noise/interference. When I disconnect my laptop from it's power supply and run on batteries it's ok. I suspect some kind of ground loop or similar. I get the same issue if I remove the DAC and connect directly from the headphone jack on my laptop to the A1. Again, disconnecting the laptop power supply sorts the issue.
At the moment my intention is to leave it running over night (once I can find an audio source that doesn't cause excessive hum) and see if it sounds any better in the morning once the tubes have been run for a couple hours.
What's the feeling here, do I have a dodgy unit or is this normal and I've brought a bit of a lemon?
Thanks,
Dylan