Sunn Beta Lead, no reverb on either channel

redhare · 01-13-2009, 12:45 AM

Hi!

I'm a forum n00b, so pardon me if this is not the right place to post this.

I have a Sunn Beta Lead with some issues. Many of the pots are scratchy. But also there is an occasional pop when adjusting some of the levels. Also, zero reverb effect on either channel, no matter where the reverb pots are set.

Where to start????

Thanks

RH

loudthud · 01-13-2009, 02:04 AM

If you can't get any sound by giving the reverb springs a thump with your finger, you have a bad reverb pan or a problem with the cable or a short at the footswitch jack. There are lots of 2.0 or 2.2uF non-polarized electrolytic caps in the preamp. If cleaning the pots doesn't clear up the scratchy sounds, I'd replace all those caps. There are about 20 of them.

Don Moose · 01-13-2009, 02:19 AM

The attached schematics have the schematics and layouts for the Sunn Beta line (Lead, Bass and I think a booster). The Lead schematic starts around page 14, IIRC.

Clean scratchy pots with POT cleaner, NOT contact cleaner.

Hope this helps!

01-13-2009, 12:45 AM	#1
redhare Junior Member Join Date: Jan 2009 Posts: 3	Sunn Beta Lead, no reverb on either channel Hi! I'm a forum n00b, so pardon me if this is not the right place to post this. I have a Sunn Beta Lead with some issues. Many of the pots are scratchy. But also there is an occasional pop when adjusting some of the levels. Also, zero reverb effect on either channel, no matter where the reverb pots are set. Where to start???? Thanks RH

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01-13-2009, 02:04 AM	#2
loudthud Supporting Member Join Date: May 2006 Location: Texas USA Posts: 796	If you can't get any sound by giving the reverb springs a thump with your finger, you have a bad reverb pan or a problem with the cable or a short at the footswitch jack. There are lots of 2.0 or 2.2uF non-polarized electrolytic caps in the preamp. If cleaning the pots doesn't clear up the scratchy sounds, I'd replace all those caps. There are about 20 of them.

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