Hi,
This is my first post here, but I've been lurking around here a while. I've successfully built a few bit and pieces from kits, such as Frugel-horn speakers, a Whammy headphone amplifier and a couple of phono preamplifiers.
I'm very happy the things I've built so far, but now a problem has turned up which was caused by suddenly pressing the "Buy it now" button on eBay. So now I've bought and built a Zero zone ear 834 clone, which came with everything included apart from enclosure, tubes and build instructions.
The kit was surprisingly easy to build, despite the missing instructions. I turned it on for the first time yesterday and it seems to work as expected, and also sounds quite good. But there is a loud hum, and I'm at a loss about how to get rid of it. The hum is the same in both channels. If I turn it off while playing a disc the hum immediately disappears while I still can hear music for a couple of seconds, so I'm thinking this is related to the transformer and/or power supply and some kind of grounding issue.
The tubes are Electro-Harmonix 12AX7EH.
Can anyone point me in the right direction to solve the problem?
I'm having trouble attaching photos so I've upload some photos here: diyaudio - Google Drive
Thanks,
Trond
This is my first post here, but I've been lurking around here a while. I've successfully built a few bit and pieces from kits, such as Frugel-horn speakers, a Whammy headphone amplifier and a couple of phono preamplifiers.
I'm very happy the things I've built so far, but now a problem has turned up which was caused by suddenly pressing the "Buy it now" button on eBay. So now I've bought and built a Zero zone ear 834 clone, which came with everything included apart from enclosure, tubes and build instructions.
The kit was surprisingly easy to build, despite the missing instructions. I turned it on for the first time yesterday and it seems to work as expected, and also sounds quite good. But there is a loud hum, and I'm at a loss about how to get rid of it. The hum is the same in both channels. If I turn it off while playing a disc the hum immediately disappears while I still can hear music for a couple of seconds, so I'm thinking this is related to the transformer and/or power supply and some kind of grounding issue.
The tubes are Electro-Harmonix 12AX7EH.
Can anyone point me in the right direction to solve the problem?
I'm having trouble attaching photos so I've upload some photos here: diyaudio - Google Drive
Thanks,
Trond
Attachments
That thread is certainly a monster! I've read bits and pieces of it and I have now solved the problem. I grounded everything to a common point and it actually did the trick. It's now nice and quiet. Sound great too!
Thanks,
Trond
So what did you do?
Hi, I stumbled upon your thread while researching the same problem, a humming 834 build. I would appreciat any advice, pictures, etc on grounding. I believe my problem lies with grounding of the PSU, but I can't find any info.
Are you using the R-core transformer? Do you have a center tap from the heater coils, or any other means of grounding the heaters? Would love to get this thing quieter.
Thanks!
Hi, I stumbled upon your thread while researching the same problem, a humming 834 build. I would appreciat any advice, pictures, etc on grounding. I believe my problem lies with grounding of the PSU, but I can't find any info.
Are you using the R-core transformer? Do you have a center tap from the heater coils, or any other means of grounding the heaters? Would love to get this thing quieter.
Thanks!
I have not posted here much, but had the same problem. I found the RCA input jacks had a bad ground. Replaced both L and R inputs and that solved the problem. Used a pair of better jacks from an on line supplier
This is how I solved the issue. Phono preamp sounds great, used almost daily.
EAR834 small hum problem
EAR834 small hum problem
Hi,
Sorry for the late reply!
Take into consideration that I'm a complete newbie when it comes to electronics, but what I did was basically routing every ground connection between the power supply and the preamplifier board through a common point, which is also connected to the chassis. See all the green wires in the photos. For what its worth: it did the trick and my 834 is practically hum free. There is hiss when I crank up the volume of course, but nothing noticeable at normal listening levels.
As you can see from the photos I use a R-core transformer. I also took care to isolate the RCA-connectors from the chassis.
I bought everything as a kit with no instructions (apart from the chassis and some other parts), so I was actually surprised when I turned it on and it worked...
It sounds great, and I am very pleased with it so far.
Trond
