Great cross-line master volume trick

[Gaz]

I've never seen this online, so I thought I'd share this excellent trick.

A common complaint with a 'Matchless style' crossline master volume is that it works more like an on/off switch when using a 1M log pot. Using a 500kA pot helps with the sweep a little, but may cause slight attenuation, even when full up.

So, the trick is to add 100k series resistance on each side after the PI coupling caps, but before the crossline MV. Having this series resistance before the MV improves the sweep dramatically.

I've done a/b tests and found little effect on tone. Any loss in high end is usually negligible because most cathode biased amps that use this MV already employ a cut control.

Try it if you like!

[Philoffline]

Well, I'll bite if nobody else does. I'll try it the next time I have the amp open. Thanks for posting.

[jjman]

You could make the MV pot a "no load" when set to max, thus avoiding the partial attenuation at that setting. Here's a random pic of one. Ignore the cap.

[img:288:216]http://www.projectguitar.com/tut/potr/C ... HPAINT.JPG[/img]

[Masco]

You could make the MV pot a "no load" when set to max, thus avoiding the partial attenuation at that setting. Here's a random pic of one. Ignore the cap.

[img:288:216]http://www.projectguitar.com/tut/potr/C ... HPAINT.JPG[/img]

With a cross line MV, there's NC on that lug.

[jjman]

As with a tone control.