Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Walrus on December 25, 2010, 02:03:27 am

Title: Noise in Stout
Post by: Walrus on December 25, 2010, 02:03:27 am

I am a newbie.  I just built a Stout and put it into a Valve JR chassis.  I used a full-wave rectifier, and chinese tranny's from Musical Power Supplies, Inc.  The build is not real clean as the chassis is small.  I had a few problems getting everything correct, but now it makes a lot of noise.  Plugged in without a guitar it buzzes real loud.  Not a hum, a buzz.  Put in a guitar with single-coils and the buzzing gets better.  Put in a guitar with humbuckers and the noise almost goes completely away.  I have built other small single-stage amps and they are almost completely without any noise.  I used shielded wire from the input to the tube. 

Does anyone have advice for me to reduce the buzz to lower levels? 

Thanx.

Title: Re: Noise in Stout
Post by: Shrapnel on December 25, 2010, 02:30:21 am

Is your input jack a shorting jack, and if so, do you have that properly wired to short out to ground when no cable is plugged in?
 (First place I'd check with your symptoms.)

Title: Re: Noise in Stout
Post by: topbrent on December 25, 2010, 03:01:57 am

The Stout is a known, working design.

Did you wire it true to the schematic/layout?

Re-trace every one of your steps.

It is all too easy to forget or overlook some small detail along the way.

Title: Re: Noise in Stout
Post by: PRR on December 25, 2010, 11:33:10 am

There's a missing or wrong-routed wire somewhere.

Title: Re: Noise in Stout
Post by: Walrus on January 03, 2011, 12:15:25 am

Thank you for the replies.  I am going to make sure that I have the shorting jack properly wired.  As far as I know, I wired it correct to the schematic.  I am looking for a wire that is misplaced.

Thank you again. 

Title: Re: Noise in Stout
Post by: Walrus on January 04, 2011, 06:17:32 pm

I installed a shorted input jack and the BUZZ quieted down.  It's still there, but much quieter.  Thanks for the advice.  I am going to try looking for the other two items.   

Title: Re: Noise in Stout
Post by: Tone Junkie on January 04, 2011, 11:40:21 pm

Walrus what happens to me is always I either miss a ground somewhere or have a bad joint to ground,
 always on a tight build of course so recheck all those solder joints.Bill

Title: Re: Noise in Stout
Post by: topbrent on January 05, 2011, 01:59:58 am

Can you post some pictures of your build? 

Great idea, stuffing a Stout into a VJr.  :smiley:

What transformers did you use?

Title: Re: Noise in Stout
Post by: Walrus on January 12, 2011, 08:03:31 pm

The tranny's are from Musical Power Supplies, Inc.  I used a SS rectifier.  The build isn't very pretty.  I'm getting better, though.  I had several Valve JR. chassis, some extra parts, and a mask for the Stout board.  The tranny's were originally purchased to do a Baby Will. 

How do I put a picture on this site?  I noticed some of the other guys have pictures.  I have several pictures of the build, and could post them if I could figure it out.