Newbie Troubleshooting Question

Rwwear and Dgaylin,

THANK YOU! for your responses. I tried the easiest thing first (swapping the left and right inputs on the amp). The hum moved from the right speaker to the left speaker so I guess that means the preamp has an issue.

I'll get it back to the person I bought it from. It seems like a nice preamp. If I knew about circuitry and things I would probably try and track down the issues because I only paid about $65 dollars for it but if it doesn't work right, it's not a bargain for me.

THANK SO MUCH for your helpful responses.

You bet, but note it could be as simple as the interconnect cable. Try replacing the one that seems to be indicated based on your swapping.

The saga continues
HERE

OK... So I got a $12 Kenwood preamp (no kidding) and even though it was more modern and quiet, the sound was not as good as the Hafler DH-101. Don't ask me to explain it but the Hafler just had a better sound. At any rate I think I want to keep the Hafler but it has a hum in the right channel that you can hear at low volume levels which is where I do most of my listening. It is only in the right channel. Also there is some hiss with the volume all the way down. Additionally the sound will not turn all the way down like maybe a bad pot or something. The balance was off which is part of the volume control but loosening a hex bolt and repositioning the knob took care of that problem. I have found some places on the internet that will go through the unit for $150 to $300 but I hate to pay somebody that much just to replace a resistor or capacitor.

My question... Does anybody have any suggestions on what I might look for or do to eliminate this problem? Is this a common problem with an easy fix? I could probably replace a resistor or a wire but even that would be at the far limits of my expertise. I always worry about getting electrocuted by a capacitor or something. Now I did open the case up the other day just to see if there was something obvious like a loose wire or something but didn't see anything. The unit did have a glass type fuse by the power supply which looked like it had a resistor inside of it. Never seen that before. So if any of you have any suggestions I would greatly appreciate it. I already tried the previously mentioned suggestions. (Thanks RWWEAR & DGAYLIN)
Thanks in advance for any help or advice you might have.

The capacitors in the unit are past the 20 year old mark by a very comfortable margin(going on 30). No doubt- Ripe for replacement. I'd start with the power supply caps. Were you provided with a manual when you bought the unit? If not- Buy one on eBay. That will give you a complete list of parts, and the full construction instructions that originally came with the piece. The circuit board was pre-assembled, but the parts layout, and schematic are included in the manual. Then too- A few people offered power upgraded power supplies for the 101. Some are still available. Here's something on eBay that may interest you: (http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=260359603612&ssPageName=MERCOSI_VI_ROSI_PR4_PCN_BIX&refitem=260350575646&itemcount=4&refwidgetloc=closed_view_item&refwidgettype=osi_widget&_trksid=p284.m185&_trkparms=algo%3DSI%26its%3DI%26itu%3DUCI%26otn%3D4%26ps%3D42) BTW: The S/N ratio was high enough that no hiss should be audible, especially with the volume turned down. I was the Hafler dealer in Orlando/Winter Park, FL for a few years, and used the 101(modded) in my demo system back in the day(early 80's). No noise at all would have tolerated in my audition room. RE: The power supply fuse- That's just what some slo-blo fuses look like. RE: Getting electrocuted by a cap- The voltages in a SS pre-amp are too small to worry about. If you can solder, you can handle the DH-101 upgrade. It would be a great way to get involved in the DIY electronics/modding hobby(It's highly addictive).