question about power tube bios

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drsakky
RM20
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Joined: Mon Jun 20, 2011 3:46 am
Location: Australia

question about power tube bios

Post by drsakky » Sat Jul 09, 2011 11:05 pm

Hi,
This is probably a silly question, It looks pretty simple to bios the rm100 I saw a video on it on youtube.
What I want to know is when biosing the amp can you do it with the amp on just standby or do you have to plug into a speaker box and have the amp fully on ?
The video does not show this.
Thanks

BigBrewtus
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Post by BigBrewtus » Sat Jul 09, 2011 11:27 pm

Yes your amp needs to be plugged into a cabinet and standby on play. Be sure your master is completely off.
Amps: RM4, RM50H, Lynch Boxes: Production #1 RM50 & RM100
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Lots and lots of trades, buys and sales on this forum.

GuitarGod87
RM100
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Post by GuitarGod87 » Sun Jul 10, 2011 12:51 pm

I made the mistake of not flicking the the standby switch to on the first time I tried to bias my head. I bought the amp used off of ebay and when I saw no voltage on my volt meter, I saw red thinking someone ripped me off a few hundred bux, lmao. But yea, both switches have to be on and make sure you have the head plugged into the cab.

drsakky
RM20
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Joined: Mon Jun 20, 2011 3:46 am
Location: Australia

Post by drsakky » Mon Jul 11, 2011 4:15 am

Thanks for replies, I asked because on the video the guy hasnt got a speaker lead plugged in.

Exoticwood
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Location: Ontario Canada

RM100 Bias

Post by Exoticwood » Wed Jun 04, 2014 2:29 pm

what do you guys like to Bias your power tubes to, and why?
Ibanez Exotic Wood Series USA Custom (Mace Baily) Eventide DPS 4500
Randall RM 100 Jaded Faith Ubersonic, SnakeBite, Texas Special, SG After life, Breakneck, Salvation Camerock, Markus, Mamba.

webrthomson
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Re: RM100 Bias

Post by webrthomson » Wed Jun 04, 2014 3:48 pm

Exoticwood wrote:what do you guys like to Bias your power tubes to, and why?
Hey - it depends on the type of tube in question (actually the tubes watts dissipation rating) and the plate voltage of the amp - for the technical stuff see the eurotubes generic bias link here:

http://www.eurotubes.com/eurotubes-Gene ... rshall.htm

Randall / egnaters suggested bias's are as follows (for the RM100/RM50/Mod100/Mod50):

6L6/5881 28mV to 35mV
EL34/6CA7 30mV to 38mV
E34Ls 35mV to 45mV
6550 35mV to 45mV
6V6 (JJ Only) 18mV to 22mV

(KT88's are bias'ed as 6550's)

From the RM100 manual here:

http://geartunes.s3.amazonaws.com/gear/ ... manual.pdf

And the Mod50 manual here:

http://www.bandslink.com/randall/Egnate ... (3-07).pdf

Hope that helps - any questions let us know

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