[bbchem]

 
 Hi Guys, I have a tube amp question. I have a Rogue 90 tube amp. It has 4 6550 tubes with fuses for each one called V1 V2 V3 V4. Rogue recommends 1/4 amp fast blow fuses.

#1. When I touch one of the 6550s the fuse blows? if I just move the socket a little
#2. Can higher amp fuse be used safely?
#3. The real weird one as I am a tube novice, is that the other day V1 and V3 blew as the bias was zero and the both channels still played??? Does this mean that the two tubes are for each channel of the output so if one blows it still plays???

Thanks, Tube Noobie

[Ericus Rex]

Sounds like a possible short somewhere.  Take that baby in for a check-up.

Do NOT use a higher amp fuse.  You risk blowing up something else not so easily replaced.

For each channel, one tube handles upper half of waveform, the other handles the lower.  So yes, you can blow a fuse for one tube and still have some signal coming out.

Again, take it in to an experience tech.

[bbchem]

Thanks much!!!

Sounds like a possible short somewhere.  Take that baby in for a check-up.

Do NOT use a higher amp fuse.  You risk blowing up something else not so easily replaced.

For each channel, one tube handles upper half of waveform, the other handles the lower.  So yes, you can blow a fuse for one tube and still have some signal coming out.

Again, take it in to an experience tech.

[JerryM]

A Rogue Stereo 90? Nice amp. 

However, it requires a 2/10 amp slow blow fuse on each tube, pursuant to the fuse values listed in the Owner's Manual. A fast blow fuse would definitely suffer quick problems in a circuit requiring a slow burn.

Have fun,
Jerry

[bbchem]

A Rogue Stereo 90? Nice amp. 

However, it requires a 2/10 amp slow blow fuse on each tube, pursuant to the fuse values listed in the Owner's Manual. A fast blow fuse would definitely suffer quick problems in a circuit requiring a slow burn.

Have fun,
Jerry

? Here is the paragraph from mine and your manual>>"Tube will not bias ? If the meter provides a reading but the tube will not bias, the
tube is probably bad. If no meter reading can be attained, check the fuse (1/4
Amp fast blow). If the fuse is bad, replace the fuse and then set the bias. If the
bias will not maintain itself and the fuse blows again, the tube should be replaced"

[JerryM]

A Rogue Stereo 90? Nice amp. 

However, it requires a 2/10 amp slow blow fuse on each tube, pursuant to the fuse values listed in the Owner's Manual. A fast blow fuse would definitely suffer quick problems in a circuit requiring a slow burn.

Have fun,
Jerry

? Here is the paragraph from mine and your manual>>"Tube will not bias ? If the meter provides a reading but the tube will not bias, the
tube is probably bad. If no meter reading can be attained, check the fuse (1/4
Amp fast blow). If the fuse is bad, replace the fuse and then set the bias. If the
bias will not maintain itself and the fuse blows again, the tube should be replaced"

Darn, that's a quandry, huh?     Slow blow fuses are listed in the fuse values just several pages down...  I'd call Rogue Audio and ask them exactly which type of fuse you're supposed to be running.

Good luck,
Jerry

[bbchem]

A Rogue Stereo 90? Nice amp. 

However, it requires a 2/10 amp slow blow fuse on each tube, pursuant to the fuse values listed in the Owner's Manual. A fast blow fuse would definitely suffer quick problems in a circuit requiring a slow burn.

Have fun,
Jerry

? Here is the paragraph from mine and your manual>>"Tube will not bias ? If the meter provides a reading but the tube will not bias, the
tube is probably bad. If no meter reading can be attained, check the fuse (1/4
Amp fast blow). If the fuse is bad, replace the fuse and then set the bias. If the
bias will not maintain itself and the fuse blows again, the tube should be replaced"

Darn, that's a quandry, huh?     Slow blow fuses are listed in the fuse values just several pages down...  I'd call Rogue Audio and ask them exactly which type of fuse you're supposed to be running.

Good luck, Jerry

Thanks,just emailed them
Bill

[JerryM]

Cool.

If told that 1/4 amp fast blow fuses are fine, I'd reply "So why do they keep blowing?" You may parlay this into a cool good-customer-service story! 

Have fun,
Jerry