• Hello and Welcome to HiFiVision.com - an online community for the home entertainment and tech enthusiasts!

    If you would like to ask a question, participate in a discussion and view attachments please Register yourself.

Help troubleshooting Elekit TU-8500 preamp

Subscibe to HiFiMART Newsletter

asdlk33

New Member
Joined
Aug 27, 2016
Messages
2
Points
0
Location
Japan
Hi all, new to the forum, new to assembling electronics in general. I got an Elekit 8200 stereo tube amp kit and an 8500 preamp kit back in December which was my first project. I have an old-ish technics mk 3 turntable and a pair of JBL 4312 compact monitors hooked up to the amp. Everything sounded great and was working fine until last night. No sound! The main amplifier still works on its own.

After removing the cover from the preamp, I can see the heating elements in the tubes are lighting up, so I'm assuming they're fine. The fuse isn't blow, or doesn't appear to be anyway. Does anyone have any suggestions for how to go about troubleshooting the source of the problem? Like I said, I am pretty new to this and don't have much experience with electronics so I'm not even sure where to start.

Any help is greatly appreciated, Thanks in advance!
 

IndianEars

Well-Known Member
Joined
May 18, 2008
Messages
730
Points
63
Location
Mumbai
Hi,

1. It would be helpful if you could post a Circuit Diagram. Its not there ion the site at: https://www.tubedepot.com/products/elekit-tu-8500-stereo-tube-preamplifier-kit

2. If you have checked the connectors and interconnects and that the Power Amp is indeed working, its probably an electronics failure.

3. Since BOTH channels are not working, I would suspect the DC Power Supply ... Its the only section common to Both Channels. If you have a multimeter, please check the High Voltage DC after the High Voltage Rectifier.... & The Low Voltage DC.


There are 2 rectifiers just next to the Power transformer.... Check the DC output at both these.

The Tube filaments are probably driven directly by AC from the transformer, so they are glowing OK.
 

Attachments

  • PSU.jpg
    PSU.jpg
    37.3 KB · Views: 36
Last edited:

asdlk33

New Member
Joined
Aug 27, 2016
Messages
2
Points
0
Location
Japan
IndianEars,

Thanks a lot for the reply, I just got really busy at work so haven't had time to try your suggestions yet. I will reply when I have.

Thanks again!
 
Top