Hafler DH-500 Power Amp Repair III - Static Noise

This is a video about repairing a static noise for Hafler DH-500 power amplifier. It took me a while to figure out because there was no apparent cause or defective parts can be detected from my multi-meter or SG/Oscilloscope equipment. This unit was working fine but generated an annoying static noise. I started repairs by replacing electrolytic capacitors first. The noise was reduced but still there. It didn't completely go away until I replaced the driver transistor Q13. So I hope this video will help other DIY fan when dealing with the static noise in their amplifiers.

[@craigm.9070]

Thank you for sharing your troubleshooting! Sounds amazing now in the quiet, acoustic music sequences. Been a long time since I've seen the internal real estate of one of these...the good 'ol days!

[@VintageAudioFan]

Thank you for your comments.

[@pascalphase2556]

You're very patient to find out this static noise, bravo ! from France. Are you happy whith nichicon condensator ? personnaly i use panasonic, what do you think ?

[@VintageAudioFan]

I think Nichicon does improve the sound quality of the amp and I am impressed. I haven't tried Panasonic before. But I will try in the future. Thanks.

[@joelane7146]

Excellent video, sounds good!

[@VintageAudioFan]

Glad you like it!

[@theirritatedirishman5440]

How do think this amp would be with a good tube bass guitar preamp?

[@VintageAudioFan]

I haven't owned a tube bass preamp before so I can't give you any opinions. However, I used a Yamaha C-2 preamp in this video to do the listening test and it sounded very good.

[@AudiophileTommy]

Do you do repairs for others ? 👍 Thanks!

[@VintageAudioFan]

Please send your inquires to my email address which is listed under "About" in my TH-cam home page.

[@tofyvargashi-fi7326]

hello, could you help me, I have a hafler 500 and one channel sounds saturated, thanks for your help, greetings from Ecuador

[@VintageAudioFan]

There are some culprits are very common in this product. Also there are many versions in this product. So to give you suggestions, I need to know which version your unit belong to. You can send the photos of interior of your amplifier and PCB layout to my email which is listed under "About" in my TH-cam channel home page.