Was doing some experimenting tonight with the Express. I had a stranded cable with a 1K Grid Stopper coming off the volume pot going to the 2nd gain stage. Anyway whilst I was testing with the amp upside down with no cover I was obviously getting a lot of interference. So I thought for a laugh I'll remove my valve covers to see how bad I can make the interference.............well soon as I removed the cover from V1 the amp got quieter. I put it back on and there was additional noise. I think the noise is ground loop but odd that its caused by a valve cover? I'll try and get a recording uploaded.
Edit: Once it was back in the cabinet with the shielded bottom, it was the opposite. Quieter with the valve cover on. Odd. Must be a ground loop issue when its missing it's shielded bottom.
Valve Cover Interference
Moderators: pompeiisneaks, Colossal
-
johnnyreece
- Posts: 1072
- Joined: Thu Jan 26, 2012 2:05 am
- Location: New Castle, IN
Re: Valve Cover Interference
I'm sorry...my brain immediately went to automobile engines...I thought for a moment you got the idea to build an amp in an old valve cover...like, the part that bolts on to the head of an engine...I wonder if anyone's ever done that? 
-
Littlewyan
- Posts: 1944
- Joined: Thu Sep 12, 2013 6:50 pm
- Location: UK
Re: Valve Cover Interference
Haha no unfortunately not. But what an excellent idea!
Re: Valve Cover Interference
The reverse is true in the southern hemisphere as well 
Re: Valve Cover Interference
Yes, I saw one at the winter NAMM show. I believe it was built by the amp tech at Demeter.johnnyreece wrote:I'm sorry...my brain immediately went to automobile engines...I thought for a moment you got the idea to build an amp in an old valve cover...like, the part that bolts on to the head of an engine...I wonder if anyone's ever done that?
Pictures attached.
Henry
You do not have the required permissions to view the files attached to this post.
-
Littlewyan
- Posts: 1944
- Joined: Thu Sep 12, 2013 6:50 pm
- Location: UK
Re: Valve Cover Interference
Haha! That is awesome!
-
Reeltarded
- Posts: 10189
- Joined: Sat Feb 14, 2009 4:38 am
- Location: GA USA
Re: Valve Cover Interference
OMG!
Signatures have a 255 character limit that I could abuse, but I am not Cecil B. DeMille.
-
johnnyreece
- Posts: 1072
- Joined: Thu Jan 26, 2012 2:05 am
- Location: New Castle, IN
Re: Valve Cover Interference
I knew it was too good an idea to have not been done already!
Re: Valve Cover Interference
Do the tubes move up and down when it's on?
-
johnnyreece
- Posts: 1072
- Joined: Thu Jan 26, 2012 2:05 am
- Location: New Castle, IN
Re: Valve Cover Interference
OOH! Or, one could rig it with LEDs to make the plugs (tubes) "spark" to a rhythm, and increase as the volume knob is turned up, or something. Ah, the possibilities...rp wrote:Do the tubes move up and down when it's on?
I know, I know...it won't make it sound better, but sometimes I like to be a nerd, just because.
Does this count as a derail yet?
Re: Valve Cover Interference
What do you expect from a bunch of geezers? Cars, guitars, and tube amps and off we go.johnnyreece wrote:Does this count as a derail yet?
On that note, anode cap tubes (6J7, 807) instead of spark plugs?