Hughes and Kettner Warp X - Help

[mikeboone]

Anyone have a schematic or at least know the value of R20 in this amp? R20 is a 5W dropping resistor in the power supply.

I searched the internet for a schem and didnt find anything.

[Jazz P Bass]

Try getting in touch with Yorkville Sound.
They are the H&K distributors.

[gtrplayr1976]

It isn't marked on the resistor ?

[mikeboone]

It isn't marked on the resistor ?

No, unfortunately not... None of the dropping resistors have anything written on them.

The folks at Yorkville were no help at all and H&K never answered my inquiry.

H&K is not doing themselves any favors. Its got pretty lights though.

[gtrplayr1976]

Is the resistor bad ? Are there any others like it ? Do you have a meter to check it ? It may take days for them to reply if they're like other companies..if they ever reply.

[mikeboone]

The resistor is open. I have a meter.

[gtrplayr1976]

Yeah, I can't find that schematic either. Some of the others ,but not the Warp series. Is there another resistor like that one in there in the same ,or another channel ?

[Jazz P Bass]

Anyone have a schematic or at least know the value of R20 in this amp? R20 is a 5W dropping resistor in the power supply.

I searched the internet for a schem and didnt find anything.

Got an EMail from Herb @ Yorkville Sound, USA.
R20 is a 1.0K/ 5 watt wire wound cement resistor.

[gtrplayr1976]

Jazz comes through in the clutch

[mikeboone]

Funny... They must be wondering why they got an email about the same thing from two people... They replied today with a schematic. I have got some 1K/5W from my last EL34 build.

Thanks guys for everything!!!

[mikeboone]

Schematic Hughes and Kettner Warp X

For future users...

[Jazz P Bass]

I would think about what took out that resisitor.
Something wanted more than 5 watts of 440Vdc.
That is the B+ rail.

[mikeboone]

I am thinking that first filter cap or possibly a bad power tube. None of the dropping resistors downstream have any signs of heat fatigue and all measure within 10%(out of ckt). I am going to replace the cap anyway just for good measure while I have it opened up.

Thanks again guys!!!

[mikeboone]

The outcome of this was a power tube drawing too much current. No tube tester so I fired it up with the new resistor running through my amp meter and it was instantly drawing nearly 1A which didnt make sense because the HT fuse is 500mA. Someone before me put a 2A fuse in it masking the issue. So I put a .5A fuse and it blew right away which is what I would expect. I pulled the power tubes out and replaced them one at a time until the fuse blew. I replaced that one with a spare 6L6 that I had and everything worked just fine. So now it has a new quad and all is well with the world.

Thanks guys...