Amp died tonight...

edbolivar

Sitting down with large glass of red now, pondering a) what could be wrong? b) who can fix it?

Just bought a Fryette Power Station today, plugged in my Phil X Friedman amp to the power station so that I could crank the X amp without killing my neighbours, and it turns out they are fine, the amp not so much.

After 5 mins of it sounding glorious, I heard a small crackle, and the amp died..
No sound, no glowing tubes I n the amp, no power light on.

Did the obvious, changed the fuse, changed the kettle lead, took out the fryette power station and nothing, no power light, nothing.

subsequently used the Fryette with a Cornell amp and no problems, so suspect its not that.

Any help much appreciated, including any recommendations to solid amp techs in SW London or Surrey.

hoping not the transformer...

olafgarten

It looks like the fryette might not be powerful enough for a cranked 100w amp, it says in the fryette manual that it can take up to 150w of input power, but a 100w amp can technically put out almost 200w of power when distorted. 

Unfortunately it does sound like the transformer has blown if there is no power at all, but it could be something else. 

@jpfamps is in London. 

edbolivar

On 4th large glass of red now, and getting far less worried...
thanks @olafgarten ;
had not considered that aspect, that said was not fully cranked on the X amp, but about 2/3 up.
off to the cellars (garage) to grab another bottle

Cirrus

When you say you "changed the fuse"... are you sure there's only one fuse to change? For example, my AC30 had a fuse in the power socket, and 3 fuses underneath.

DJH83004

Looking at an image of the rear of the amp, there is a HT fuse which you have checked, however the mains fuse is built into the IEC mains socket, which I suspect has blown, it is 20mm fuse, to access it, you prise open the bottom cover with a terminal screwdriver. I suspect the transformer will be ok, if the correctly rated mains fuse is fitted.

edbolivar

Music to my ears, will try and find this mains fuse now

SunDevil

As long as the Power Station is providing a correct impedance to the amp, any excess of power would effect it rather than the amp - The resistive element of the PS would get hot.

I'm not claiming to be an expert here, but I suspect that cranking the amp has caused a power valve (don't know if it's valve rectified?) to fail and that's taken the fuse with it and if you're lucky, nothing else

edbolivar

Thanks to all of you for your help and particularly @DJH83004. Found the mains fuse (didn't see it yesterday) and took it out and it has definitely blown as it is a mess of blackened glass.

i guess I should check the amp over before replacing the fuse, otherwise it could just go again

ecc83

Just your mother here! PLEASE peeps, don't go any further than external fuses when checking amps when pissed!

Dave.

CarpeDiem

ecc83 said:

Just your mother here! PLEASE peeps, don't go any further than external fuses when checking amps when pissed!

Dave.

The advice from @ecc83 is spot on, particularly with valve amps where the residual voltages remain for some time after the amp is switched off.

DJH83004

If you feel confident enough, remove the output valves, replace the mains fuse with the exact type, and power up again, and check if the 'power on' indicator lights up. I suspect one of the output valves may have 'flashed over' as you were driving the amp quite hard at the time. If it blows straight away, you have a power supply problem, if not, suspect one or more of the output valves has an anode to grid / heater short. Generally if an output valve does go short it blows the HT fuse, but not always, so worth a try.  

edbolivar

Thanks for all your help, but I think I will now look for a good tech in SW London /Surrey, as I want to make sure it gets a full MOT and gets sorted properly.
My tool kit consists of a rusty spanner, one screw driver and a hammer. So definitely not the man for the job.
Any recommendations gratefully received.

SunDevil

It'd be worth changing the fuse as has been suggested first - the fuse may we'll have done what it was meant to and save any further damage.

If it's stable with the new fuse, popping in some new power valves would be a sensible next step, but it it fails after that, @jpfamps would be your nearest forum tech. Frank is in Denmark st

GuitarAid are in Putney - never used them myself and Amp Wizard is Horsham (Don't think he has any real magic though..)

rico

I'd recommend the guys at GuitarAid. Greg and Adam are your guys.

Modulus_Amps

Contact Jon at Dickinson amps, he does stellar work and will look after your amp well