New 6505+ two fuses blow in one month

[Skyweaver]

I picked up a new 6505+ and it's blown two fuses in one month

Last night at 3 hours into rehearsal - boom tha she blows, I keep a set of fuses with me now, but this is crazy.

Any idea's ???

I had it delievered from interestate, maybe the powertubes need replacing ?

 

[everybody's x]

my triple x was just doing that too, it was a bad tube, finding it is the tough part, just because it glows doesn't mean it's good.
look for power tubes with white spots inside the glass at the top

 

[everybody's x]

or a bad speaker cable

 

[Skyweaver]

Thanks mate, the speaker cable is planet wave dual jobby, so I'm guessing its one of the power tubes,

they've all got Ruby written across them, so I might just replace the lot and see if the shop will re-imburse me for them

 

[everybody's x]

mine had stock sovtek 6l6's in it, they all lit up just fine but the fuse kept blowing and I had a brand new cab and cable so I knew they were OK. It finally blew the fuse inside the chassis. I grabbed a single good 6l6 and switched each one until I found the offender. problem solved

......Then I switched to El34's.

 

[hogan666]

Got the same problem with my MK1 a few months ago.
It was caused by bad tubes. My Amptech told me that a few tubes couldn't handle the higher voltage inside the 5150. Especially the cheap ones I tested.

Now this issue is fixed. Bought four quality tubes :Smug:

Cheers, Hogan

 

[Skyweaver]

hmm so theres a few its happened to, I'll do a search and see what the best replacement for the powertubes are for the 6505.

they first cracked at 5 on the volume, since then I've kept it low, happened at the worse time, got to gig on Thursday night...

Its a hassle to get them biased, shame I can't just put them in

 

[greyskull]

you cant really bias 5150's without a mod! although it could indeed be the fuse..
however check the fuse type against the original.
Is it slo blo?
should it be?
that can make all the difference

 

[Skyweaver]

yep the original fuse was slow blow and so the replacements are, just hoping I will get through a gig

 

[nwright]

You don't have to get the 5150/6505's (or II's or +'s for that matter) rebiased when you replace tubes. The tubes necessary for a 5150/6505 are
6L6GC's. The amps are biased so cold that you can replace tubes with the same type without the need to rebias. Get some new 6L6GC's and pop them in there.

 

[Skyweaver]

Cool ! picking up a set today and getting them in.

With the JCM800 I was told I always needed a tech to do it,

thanks !

 

[nwright]

FWIW, The 6505+ is said to be "adjustable bias", but the trim pot still keeps the amp within a safe bias at it's highest setting. The 6505 series is biased at around 16 milliamps from the factory, which is pretty low, some say it's because EVH preferred the crossover distortion heard when the bias is that low. With a bias mod, a lot of people will bias it up to around 30-32 milliamps. Supposedly, doing this gets rid of all the bad stuff you hear about the amps (cold, lifeless sterile, SS soudning, buzzy). I like the amp where it is, personally.

 

[Skyweaver]

put a new set of Mesa 6L6GC's in, now shes off and running again - I'm just hoping to get through thursday nights gig with no problems.

The guy in the shop tried to charge me $98 a tube ?? I almost dropped a stump, after arguing with him, when he checked again it was $40 a tube, dont you love it how music shops will do their best to rip you off

The sound of the 6505 - wipes the floor with the JCM800 (which I'm now selling).

Thanks Guys !

 

[Nebulous]

Haha. Nice work on the price dude. Though, I'm still sort of puzzled by the price you got. I thought it should only work out to be $30 per tube, based on internet prices. I can't say i've actually seen a shop stock tubes, so I don't know, maybee I was jsut dreamnig with that price.

 

[Skyweaver]

was desperate for the tubes so went down to store, couldn't wait for the internet ones, interested to know of any good online stores for picking up gear

 

[Nebulous]

I can only remember Eurotubes off the top of my head. I remember there was a thread which had a good online shop about a week back.