KT 88 Biasing query

[jak3y]

Hey guys thanks fo your help over the course of last year and I hope ya had a good new year!!

Now to the point.. I have installed some kt 88's into my randall rm100.
I have tried to bias these tubes but one jumped off the scale and popped a fuse I swear my tubes are only now running at 10mVs or so but I really need them at 50mV right?? I'm having trouble getting the tubes to that level they seem to be glowing extremely hot at anything over 20mV's.

I'm really hoping I don't keep blowing fuses.. they are cheap but i would rather get each pair stable and up to 50mVs any help would be grand!

 

[Nrrrk]

Yeah. I have em' at 50mV. They should work properly, maybe a tube is bad or something.

 

[jak3y]

i just brought them brand new.. maybe i didn't put the pairs in matched properly??? could that do it..

 

[jmgman70]

The RM100 has bias on all 4 sockets so would that matter?

 

[JKD]

It's more than likely a defective tube or tubes surely...unless your RM100 has the wrong fuses in.

 

[jak3y]

Well the bias rotaters were not working for some tubes so could that be a internal Fuse problem that is effecting the bias section?

 

[jmgman70]

Well the bias rotaters were not working for some tubes so could that be a internal Fuse problem that is effecting the bias section?

Are you getting a zero reeading on your meter on those sockets?

 

[jak3y]

no I was getting a reading of 10mV's or so and I couldn't change it for some tubes...

 

[jimosity]

Are you positive you've got the meter set correctly and the amp in the 'on' positive and all those little details?

 

[jak3y]

Are you positive you've got the meter set correctly and the amp in the 'on' positive and all those little details?

I set the Multimeter to "20M" on the V side and it read 9-10 Have I selected the wrong reading?

 

[jmgman70]

Set it to 200m and check back.

 

[jmgman70]

Dude you must have cranked those tubes a bit!

 

[jak3y]

Haha Holy **** I was running them at 80mV's so when i came to play it was pushing over 100mV's no wonder I fucking blew a fuse or 10

Now they are settling at 50mV's and are peaking just under 100mV's when i'm playing I'm very happy with the tone it's absolutey amazing.. 4 x kt88's!!! I highly reccomend

 

[jmgman70]

Sweet!You almost had a nuclear meltdown :shock:

 

[Nrrrk]

Haha Holy s*&t I was running them at 80mV's so when i came to play it was pushing over 100mV's no wonder I f&*king blew a fuse or 10

Now they are settling at 50mV's and are peaking just under 100mV's when i'm playing I'm very happy with the tone it's absolutey amazing.. 4 x kt88's!!! I highly reccomend

true,
KT88's sound fucking awesome in the rm100.