Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: TIMBO on March 20, 2012, 03:32:51 am

Title: Fixed Voltage VVR
Post by: TIMBO on March 20, 2012, 03:32:51 am

Hi guys, This may be trying to fix something that aint broke. I was unable to find a Fixed 250v regulator that i could use to drop the voltage for the ECL84 tubes.

The vvr was the best way to go and works well.
I measured the ohms on the two sides of the pot G-Z 426k and G-X 743k.
Has anyone modded a VVR to have it as a fixed voltage and can the pot just be replaced with resistors as shown Thanks

Title: Re: Fixed Voltage VVR
Post by: FYL on March 20, 2012, 03:45:19 am

Resistors are OK.

Title: Re: Fixed Voltage VVR
Post by: kagliostro on March 20, 2012, 04:11:46 am

I haven't do but certainly you can use a VVR circuit that way

you can use fixed resistors or a trimmer as to substitute the pot

an alternative is to use a Zener Follower circuit

(http://s2.imagestime.com/out.php/i673042_ZenerFollower.jpg) (http://www.imagestime.com/show.php/673042_ZenerFollower.jpg.html)

this will give a "stabilized" voltage, but is it necessary ?

Kagliostro