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ALPS Motorized Volume Pot- Repair (VTL 5.5 Preamp)

Hi,
Need some help diagnosing a strange problem with my VTL Preamp’s Volume pot. It uses an Alps motorized pot, that is controlled via the remote. When I turn on the VTL, the remote controls the volume normally for the first couple of minutes and then stops working. 

Manually the the volume pot works perfectly, smooth, precise and with no crackling. I’m guessing that there is something happening when the preamp warms up that cuts off the remote control of the pot.. any theories?

im pretty handy and would feel comfortable trying to perform a repair myself, but could use some experienced advice.

Thanks!!
arniespin

Showing 1 response by cedargrover

cedargrover
302 posts
 
Strange!

In the failure mode, have you put a meter to the motor driving the volume to see if it is getting voltage when you hit the remote button?  

If it isn't seeing a voltage maybe something power-supply related after warm up.  Does this unit use tubes in the power supply (like, is it tube regulated or solid state regulated), or just in the audio stages?  If so, have you tried replacing them?

Where's @almarg?  :)

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