Bare Knuckle Pickups Forum

Forum Ringside => Guitars, Amps and Effects => Topic started by: richard on July 21, 2013, 12:52:10 PM

Title: Redplating
Post by: richard on July 21, 2013, 12:52:10 PM

One of the two EL34s in my Cornford is redplating. Could this simply be a tube gone bad ?

Title: Re: Redplating
Post by: Dmoney on July 21, 2013, 12:59:35 PM

If it was me I'd swap the EL34's in the sockets and see if the problem follows the valve.
That said, it's a cathode biased amp I think (Roadhouse?) so in theory MAYBE there are less things to go sketchy than in a fixed bias amp but you should get some valves asap and really stop using it if it's redplating. If it pops it could cause some collateral damage to the amp at varying degrees of expense. If you're unsure then get it looked over, if nothing is wrong then it shouldn't cost much for someone to take a look and check and you'll have peace of mind.

Title: Re: Redplating
Post by: richard on July 21, 2013, 01:46:11 PM

Thanks, I've ordered some new valves from Hotrox and I'll wait for those to arrive before I start experimenting because the Roadhouse is a bugger to re-valve.

Title: Re: Redplating
Post by: Dmoney on July 21, 2013, 02:12:20 PM

Quote from: richard on July 21, 2013, 01:46:11 PM

Thanks, I've ordered some new valves from Hotrox and I'll wait for those to arrive before I start experimenting because the Roadhouse is a bugger to re-valve.

Oh really? How come? Do you mean in terms of tone or physically?

Title: Re: Redplating
Post by: richard on July 21, 2013, 02:26:33 PM

The valve sit horizontally and are behind the chassis which is mounted at the rear of the amp. Have to take the chassis out.

Title: Re: Redplating
Post by: jpfamps on July 22, 2013, 02:32:18 PM

The Road House 30 is indeed cathode biased.

If one of the valves in a cathode biased amp starts redplating, then it's usually due to the other having expired.

I would try changing the valve first.

Title: Re: Redplating
Post by: Keven on July 23, 2013, 03:21:26 AM

Quote from: jpfamps on July 22, 2013, 02:32:18 PM

The Road House 30 is indeed cathode biased.

If one of the valves in a cathode biased amp starts redplating, then it's usually due to the other having expired.

I would try changing the valve first.

Great advice man! i've had a few experiences of redplating and usually tossed the tube that was plating aside, so i guess now the "bad tube" is in my backup stash, gonna have to check that out...