Apt Corp. Holman Preamplifier Repair And Test

[@MichaelAspras-jg5gr]

Great video; thorough throughout like all the rest. Best compliment in this one is we finally got to see Erik!

[@EriksElectronicsWorkbench]

Thanks for watching. I figured I could get in front of the camera at least once :)

[@DavidWahl-y5s]

You do excellent work, very professional. The video is thorough and very easy to follow.

[@EriksElectronicsWorkbench]

Thank you for the nice compliment!

[@martinkoskella3943]

Appreciate how thorough your repairs are. Very good pace, and you have an excellent command of language and technical explanations.

[@EriksElectronicsWorkbench]

Thanks for the kind compliments and for watching.

[@joeohara2623]

I owned this same pre. Late 1970's. FYI. Thomas Holman is the THX originator; he worked for George Lucas and created the THX standards etc. I heard THX stands for Thomas Holman's eXperiment. There was a matching power amp also that was built like a tank. Thanks for the video.

[@poormanselectronicsbench2021]

Thanks for a peek inside the Holman preamp! Years ago when I was doing my first system build, I considered one of those, but happened upon a used Threshold NS10 instead. FYI, you should consider using the "Delta" or "REL" function to zero test leads when checking for low resistance faults. It can be especially helpful if you are trying to troubleshoot a dead short without wanting to disconnect anything, as it will give you that ability to find the short by getting your test leads as close to the fault as possible with some point to point maneuvering of probes.

[@sms9106]

I have one too since the 70's and has similar issues. Have an upgrade kit to replace parts but not done anything yet. A great unit.

[@peterlarkin762]

That's a highly regarded preamp - I always wanted one. They don't come up for sale often as owners just never want to get rid of them.

[@robharley9838]

Really interesting Preamp Erik, thanks for the great run through. Never seen one of those guys, but it looks old school solid. Appreciate your process.-jrh

[@EriksElectronicsWorkbench]

Thanks for watching!

[@fluxjunkie6645]

Great work .love your attention to detail.I don't work on domestic HiFi much anymore not much around worth repairing.Gone to the Pro Video and audio side.i always check frequency response with a load of at least 600 ohms or sometimes 200 ohms depending on the output impedance.Old faulty caps show up immediately wish poor low frequency response

[@enzof9679]

Great video! Thank you for all the great information.

[@EriksElectronicsWorkbench]

Glad you found the video helpful, thanks for watching!

[@drdyna]

It should be a damn law that the manual and documentation is this good for everything. I've still got a Krell KSL sitting in my pile of shame because of how 0 documentation is available.

[@feds27]

I had a later year Tandberg 3008a preamplifier that was serviced by Holman. I wish I had kept it.

[@LorenzoRivaro]

Hi do you offer this service? Thanks for the video and for answering.😊

[@EriksElectronicsWorkbench]

At this time I am not taking in additional outside projects. Thanks for watching!

[@len9518]

My all time choices in a preamp, would be this one, and the Hafler DH-110. I don't think there has been anything better, before or simce.

[@bobdoritique7347]

Thank you, how did you clean the switchs please?

[@EriksElectronicsWorkbench]

I use the NTE p/n RX500-12 contact cleaner with lube. As mentioned in the video I was able to work the cleaner into the the switch through the hole by the latch mechanism basically flooding the switch with cleaner and then activating it many times.

[@bobdoritique7347]

@@EriksElectronicsWorkbench thank for the response. 👌

[@abeleski]

Thanks for the video. I would however prefer if you showed the unsoldering of the switch and cleaning it, removing the caps etc. Feels dry without it. Too clinical but still enjoyed it. Just my 2 cents. Thanks again for the video

[@EriksElectronicsWorkbench]

In some of my other videos I do show desoldering and soldering capacitors such as in the safety capacitor video kzbin.info/www/bejne/fXW3pnt6qK17fKM I use a Hakko FR-301 to desolder.

[@linjia9539]

Finally updated, I really like watching your videos👍