PT100 Fuse Blowing?

Rayneman

Rayneman

Well-known member
Some guitar buddies and I were fooling around with some amps yesteday. We had my PT100 hooked up to a Marshall 4x12 with Greenbacks. We were playing LOUD.

So, for giggles, one of the guys (John4021 from this forum) turned the gain way down on the 2nd gain channel and turned the level of that channel up to around 8. One strum and BLAM! that was it. Tubes and LEDs still lit but no sound. The 2a fast blo was scorched (I think it was 2a - the one in the twist-off fuse holder, not the one inside the power module or whatever its called). A quick trip to Radio Shack and the amp was up and running again. But, is this right? This is nearly a brand-new amp. I had fuse issues with an OD100 SE+ I had awhile back, in fact a gig ending fuse failure (I didn't know about the fuse inside the door of the power module thing at the time, but the other fuse was fine?!?). So, yeah, I will always be armed with extra fuses, but shouldn't I be able to turn the amp up to 8 and NOT have it blow a fuse? Yes, silly volume, but still.

OR, could this have something to do with the cab loaded with Greenbacks? My understanding is that those speakers can hold up to an excess of 100 watts, but who knows.

Any thoughts? I wonder if it was a coincidence at that volume, or if I always have to worry about blowing fuses.

Perhaps oddly enough, but I've never ever had a fuse blow in any other brand amp I've owned.
 
.......the girlfriend came over today and blew my fuse....
But I didnt need to go to Radio Shack :LOL: :LOL:
 
Well the problem is not the greenback cabinet. If you are throwing more watts that it can handle you would start turning the volume knob more and more without noticing any change, and the speakers would get fucked up. But not the fuses...
 
,,,<<<<<<< hides under mommies skirt.
Hey where big John on this fuse issue? I didnt know your other OD100 popped fuses too :confused:
 
northern1":244oxxni said:
Possibly a bad power tube(s)?? Tubes and fuses are designed to blow before a transformer is well done ;)
Click to expand...

+1. Usually a shorted or arcing power tube will cause a fuse to blow.....check that first.
 
The HT fuse should be Slo Blo 2 amp or 1 amp, not a Fast Blo. When you hit the strings like that and the master up higher like that, the mains filter caps experience a large voltage spike and it can cause the HT fuse to blow. If it's a fast blow, basically that fuse has lower tolerance for handling high voltages, and the slow blo's are a higher tolerance. If you're still blowing fuses after that, then it's probably a tube issue like Jerry said. If there is something wrong with the amp, it will blow fuses if the values are correct.

If an amp is blowing fuses and it was working soundly previously, it's more than likely that the tubes are bad.
 
Thanks for the replies. The amp has been ok since then. Not that its a big deal :scared: , but I've now had 1) OD100 SE+ that failed, a 2) PT100 that blew a fuse so "maybe" it has bad tubes (and the amp is new) and 3) NOW, my Suhr Std's 5-way switch went south at an open mic shindig but I was able to borrow a mexi-strat (oh joy, oh embarassment AGAIN).

Damn, if it weren't for my Koko boost (which I am watching closely) I would have a 100% failure rate for every Suhr/CAA item I've owned (fail is probably a strong word, but each piece of gear has been rendered inoperable until repaired, whether its a fuse or new switch). ARS.... :confused: I wonder if these tubes aren't so reliable, but I thought they were stock for CAA and Bogner, too?
 
Bad luck? I have had many Suhr products. Never head a problem. Some people that have had some minor issues post about it, and after they call Suhr u see a "resolved" in an updated tread... And how they couldn't be happier.... Just make a call. They will fix you up


Happy and a PROUD owner of a Badger 30 and a PT50 Prototype, Suhr Pickups and Pedals.

Matt V
 
Rayneman":18re9f6v said:
Thanks for the replies. The amp has been ok since then. Not that its a big deal :scared: , but I've now had 1) OD100 SE+ that failed, a 2) PT100 that blew a fuse so "maybe" it has bad tubes (and the amp is new) and 3) NOW, my Suhr Std's 5-way switch went south at an open mic shindig but I was able to borrow a mexi-strat (oh joy, oh embarassment AGAIN).

Damn, if it weren't for my Koko boost (which I am watching closely) I would have a 100% failure rate for every Suhr/CAA item I've owned (fail is probably a strong word, but each piece of gear has been rendered inoperable until repaired, whether its a fuse or new switch). ARS.... :confused: I wonder if these tubes aren't so reliable, but I thought they were stock for CAA and Bogner, too?
Click to expand...


If you use tubes in an amp eventually they will fail
Not if but when, we brutalize our tubes before shipping but sometimes things are out of our control.
If you have any fault in your cab wiring you will stress the output section, this includes, cab wiring and cables.
Other than that you always have a crap shoot with tubes.
As far as the 5-way, it is the same 5way used by every other major manufacturer out there. Did you contact us? Was it ever rewired? got a serial number?
Please use us for support, we are easy to get a hold of, in fact I believe this same thread has been posted elsewhere or you already contacted us?
 
boneyard":3eo10see said:
Bad luck? I have had many Suhr products. Never head a problem. Some people that have had some minor issues post about it, and after they call Suhr u see a "resolved" in an updated tread... And how they couldn't be happier.... Just make a call. They will fix you up


Happy and a PROUD owner of a Badger 30 and a PT50 Prototype, Suhr Pickups and Pedals.

Matt V
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Yeah bad luck I guess. Also, as I tend to get nearly 100% of my gear used, I don't feel I am owed anything by the manufacturer, hence I why I posted on a forum. In any event, and as pointed out by John, tubes are just waiting to die. So my takeaway from this is that I should likely purchase a new set of tubes for my PT100 and get them biased up and assume that will take care of it. Further, I imagine some contact cleaner or at worst, a new switch for the guitar. Not the end of the world in either case. I suppose I might have thought that Suhr guitars used special hardware made in Germany by specially-bred uber-engineers or something. :)

Yes, I do have serial numbers, does it matter?

PT100: 2010759
Std: 9872

I did also post on the Suhr board.
 
get the tubes from Suhr. The current tubes should have some hand written numbers on them... if you call Suhr with those numbers, they can get you some tubes that will be just drop in.... no re-bias required (for the power tubes)

Thx, Matt
 
boneyard":31w9miur said:
get the tubes from Suhr. The current tubes should have some hand written numbers on them... if you call Suhr with those numbers, they can get you some tubes that will be just drop in.... no re-bias required (for the power tubes)

Thx, Matt
Click to expand...

Really? <runs off to amp room>

Why yes. There are two hand-written numbers on each of the ARS branded JJ/Tesla EL34s. Each tube has a different set of numbers...like 28.2 / 5.18 & 27.7 / 5.00...etc. These current tubes sound fine and don't show any strange goings-on as far as I can tell (i.e. no super red glowing tubes) it was just that one incident of the fuse.

Winged -C- tubes were recommended as well and I have a buddy with one of those whiz bang bias rite things (can you tell that the extent of my tech knowledge is limited).
 
Rayneman":2fgodjag said:
boneyard":2fgodjag said:
get the tubes from Suhr. The current tubes should have some hand written numbers on them... if you call Suhr with those numbers, they can get you some tubes that will be just drop in.... no re-bias required (for the power tubes)

Thx, Matt
Click to expand...

Really? <runs off to amp room>

Why yes. There are two hand-written numbers on each of the ARS branded JJ/Tesla EL34s. Each tube has a different set of numbers...like 28.2 / 5.18 & 27.7 / 5.00...etc. These current tubes sound fine and don't show any strange goings-on as far as I can tell (i.e. no super red glowing tubes) it was just that one incident of the fuse.

Winged -C- tubes were recommended as well and I have a buddy with one of those whiz bang bias rite things (can you tell that the extent of my tech knowledge is limited).
Click to expand...
Bias points that are superior to any kit are already built in to the amp
All you need is a generic digital multimeter and send us an email for bias instructions
 
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