Hoffman Amplifiers Tube Amplifier Forum

Other Stuff => Solid State => Topic started by: Tiny_Daddy on August 29, 2009, 01:01:38 pm

Title: Crown 3600 VZ FanFormer
Post by: Tiny_Daddy on August 29, 2009, 01:01:38 pm

Introducing the "fanformer": I notice Crown has been using the fan motor as a transformer to get 18V for the preamp. I have a Crown with bad fan bearings and in order to replace the fan with something ordinary, a small transformer will need to be added too.

Title: Re: Crown 3600 VZ FanFormer
Post by: PRR on August 29, 2009, 09:13:36 pm

> motor as a transformer to get 18V

That was a common trick with low-cost transistor record-players. There's ample flux in the motor stator. A few turns will steal some power. Commodity barbecue-spit motors have more than enough torque to spin a platter. It's not the most efficient plan, but it saves a part.

Title: Re: Crown 3600 VZ FanFormer
Post by: Tiny_Daddy on August 30, 2009, 06:41:22 am

Sounds fine for low-cost record players. But Crown preamps? Another issue is fan noise but changing or slowing the fan now becomes a problem.