Hafler DH-110 Preamp - Fixing the Most Common Issue - 2023

[@srtamplification]

Glad to have you back on the air!!!

[@NickP333]

Again, it’s great having you back. I’ve learned so much from you over the years. Thank you, Mark.

[@kenfixes2908]

Amazing .thank you . I've been searching for the longest time to repair my DH 110. I have 2 and both have the same problem. Coincidentally left channels.

[@karecall3262]

Thank you!! I had exactly the symptoms described. Changed out the JFETS but left channel cutout persisted. Only cycling the power would bring that channel back. Changed out the LM393 and all is back to normal. I've enjoyed my Hafler components for 40 years, you rock!

[@roroseppel2077]

Good to see you back Mark 😀!

[@alrtgy9642]

Two videos in one week? Let's hope you can keep up the pace. Always your stuff>

[@rickclink9196]

I re capped quite a few of these preamps. The pot can be fixed by removing and wiping the carbon element with q-tip and alcohol. Not easy but normally yields good results.

[@midmodaudio6576]

Very useful and informative video. Welcome back !

[@crimsonghost6454]

Very good. Nice to see you again. It's been awhile

[@harbselectronicslab3551]

good to see you back....

[@morrisonAV]

So good to have you back, Mark. Is this just a one-off video or will you be getting more free time to make more content?

[@charlesabura472]

Impressed how you figured out the muting j-fets. I would have cleaned the switch contacts a hundred times😅

[@roberthaysley4245]

Welcome back

[@andydelle4509]

Funny story. I once replaced a bad video OPAMP in a Sony broadcast monitor. I too threw in an 8pin socket. It then was passing signal but oscillating! Problem turned out to be the socket causing it. Soldered the new chip in directly, problem solved. But I agree this is highly unlikely in audio circuits. Rack Mount DH220! Very rare. I still use DH220's and DH120s in my HT setup. No reason to change. Great amps!

[@williamwahl6464]

I had a friend who worked for an old electronics supplier say his repairman suggested to never turn off the system. That more damage is caused from it going cold to hot back to cold than just leaving it on. Ever hear of this? Just curious. Thank you for your suggestions on these Hafler 101's. Great sounding gear!

[@mrg21659]

I got the 110 it's performing well ...but my 101 is faulty playing mono only and volume / balance pot not working properly... pity your not in England UK ..I would send to you for help ..regards Neville

[@sabelli33]

Please, I would like to ask a question: would it be worth repairing a Hafler DH200 and pairing it with an AMC CTV 1030 preamplifier with a pair of Dynaudio 52 speakers and an Arcam cd73 CD player?

[@Mark-rw3kw]

Was that music you were testing with? I thought it was a noise generator.

[@chubbspeterson6161]

I have this same exact preamp that will not power on anymore any ideas?

[@cougar1861]

Thanks. What is the name, part # (and where does one find) the JFET (and I assume any three-terminal device?) socket?

[@Blueglow]

Added parts list in the comments

[@cougar1861]

@@Blueglow Thanks!

[@someperson4712]

One of the people whos houses I clean is getting rid of their late husbands entire set up, and its really nice but I dont got the room :( They got this pre amp, a tuner, cd player, equalizer/analyzer, and 3 amplifiers. And the speakers they use are HUGE extremely vintage speakers worth $5000!

[@davidsonneidert5523]

"Promo SM"