Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: bigdaddydiesel on December 04, 2020, 08:47:17 pm

Title: Ampeg SVT-CL, 12vac fan off IEC input?
Post by: bigdaddydiesel on December 04, 2020, 08:47:17 pm: Hi, I have an SVT-CL. It's working well after some new tubes and repairing some bad solder joints incl. one that was causing a cathode resistor to lose connection and put the amp into fault protection mode. I've noticed that a lot of heat collects inside the head case and the stock fan on the front baffle isn't quite cutting it. I was kicking around the idea of mounting a second AC-powered PC fan on the rear grate and sneaking its 2-prong umbilical underneath the grate. However, I noticed there's a bit of space in the route for the power transformer leads on the top side of the chassis and got to thinking -- Would I be causing any issues by connecting a 12vac fan in series off the amp's IEC input?

I would of course also wire up a molex connector so the grate and fan can be disconnected when future service is required.

Thanks!
Title: Re: Ampeg SVT-CL, 12vac fan off IEC input?
Post by: sluckey on December 04, 2020, 09:00:11 pm: Quote
Would I be causing any issues by connecting a 12vac fan in series off the amp's IEC input?
yes
Title: Re: Ampeg SVT-CL, 12vac fan off IEC input?
Post by: bigdaddydiesel on December 04, 2020, 09:35:48 pm: Quote from: sluckey on December 04, 2020, 09:00:11 pm
Quote
Would I be causing any issues by connecting a 12vac fan in series off the amp's IEC input?
yes

Er, I meant parallel. :think1: Hot to hot, neutral to neutral.
Title: Re: Ampeg SVT-CL, 12vac fan off IEC input?
Post by: sluckey on December 04, 2020, 09:55:52 pm: Not gonna work.
Title: Re: Ampeg SVT-CL, 12vac fan off IEC input?
Post by: bigdaddydiesel on December 04, 2020, 10:09:17 pm: Quote from: sluckey on December 04, 2020, 09:55:52 pm
Not gonna work.

Thanks!
Title: Re: Ampeg SVT-CL, 12vac fan off IEC input?
Post by: AmberB on December 05, 2020, 12:05:14 am: You can use a 120 volt fan that way by tapping off the AC input. You would fry a 12 volt fan very quickly...