FUSES

[jak3y]

Hey there everyone

I own a RM100 and I have got a tube failure light coming up on tube one.. the tube it still glowing and they are glowing all even.. this prob means just my fuse has blown right???

Now I know these particular amps Use the 250mA Fast Blow fuses.. but i am unsure what size they are either M205, 2AG, 3AG.

could someone please specify this for me??

Cheers in advance

 

[kc2eeb]

The fact that the tube is still glowing does NOT mean it is OK. The .250 ma fuse is on the HV plate voltage, not the heater voltage which is in the 6 volt area. (The heaters are what make the tubes "glow.") The fuse size you need is GMA type, 5x20mm. You can use .312 amp (312 ma.) In fact, that is probably better than .250 amp (250 ma) fuse. If you replace the fuse and it blows again, it's probably the tube. You can swap it out with one of the other tubes, just to check. Hope this helps! Pat L.

 

[jak3y]

Well the EL34's are totally gone and I have ordered two matched pairs of kt88's and I have .312 6 pack of fuses ordered.. So i was wondering for each matched pair where I place them.. do i place one matched pair in 1,4 and the other in 2,3?? your help is greatly appreciated

 

[khingpynn]

1-4 2-3

 

[jak3y]

Ok so I got my Kt88 tubes in and changed all the fuses.. as soon as I warmed them up and then flicked the power stage on everything glowed nice. but the readings were really low.. and then one tube started glowing real hot and the meter rushed up and popped a fuse.. it is running really cold and I'm too scared to bias hotter maybe I need to burn the tubes in more?? and then bias cause at one stage the bias screw wasn't doing anything at all :/