#1
getting some EL34s to go in my randall, so i'm gonna have to bias them more than likely to get the right warmth going in them. amp is running 6L6s right now, so it's not just a plug-in-and-play situation. already have my multimeter. the amp has self-biasing points on the back to make it more simple and i'm assuming a little less dangerous.

what i need to know is just general tips and what the voltage is supposed to be set to for EL34s?

not taking it to a tech b/c prices are just stupid, i've been inside and out all my amps i've owned and know how to be very cautious. this won't require me dissassembling anything fyi, just using the bias points in the back.

thanks for any advice.

slash_edit: tubes are JJ brand if that helps at all.
My MAIN Gear
____________
"They call him the 'Sand Spider.' -Why? -Probably because it sounds scary"
*Agile AL3000 Les Paul w/ Alnico IIs
*Randall RM50
*Dunlop CFH
*fellow LEO feel free to give a shout out
Last edited by slash_rocks2005 at Feb 5, 2009,
#2
Look up biasing videos on you tube that helped me when i needed to know stuff.
Although my amp had a bias switch so i didnt have to correct anything so i never learned how to use a multimeter.
LIFE IS TOO SHORT NOT TO LET YOUR MIND SPREAD WINGS AND TAKE FLIGHT

Quote by KeepOnRotting
+Infinity. This dude knows good metal.
#3
yea i feel a lil dumb now b/c with a lil bit more research, i found some very helpful articles online. though i still like tips from guys who've done the biasing themselves on UG.

i've been gone for a lil while on UG and getting back into the swing of things
My MAIN Gear
____________
"They call him the 'Sand Spider.' -Why? -Probably because it sounds scary"
*Agile AL3000 Les Paul w/ Alnico IIs
*Randall RM50
*Dunlop CFH
*fellow LEO feel free to give a shout out
#4
Hey, I have a RM100 and the best way to make sure nothing goes wrong is to follow this procedure;

I read somewhere to turn the bias setting all the way to 0 for the tubes because it will vary with different tubes for example you could have it set to 35mV for the 6l6s but when you change the tubes this could spike to 50mV which wouldn't be good for your tubes or your amp, not 100% on where I read this but it seems logical, better off safe than sorry anyway.

Once the bias setting is all the way counter clockwise go ahead change the tubes over then follow the procedure outlined in manual:

1) The amp should be on, standby in the “PLAY” position and all knobs all the way down.
2) Turn the meter on and set for reading DC millivolts. Consult the meter instructions for how to do this properly. Since all meters are different it is extremely important that you thoroughly understand what you are looking at on the meter display.
3) Insert the Black (Negative) meter lead into the panel hole labeled “COMMON”.
4) Insert the Red (Positive) meter lead into the panel hole marked “TEST POINT 1”.
5) You typically will observe a reading between 25mVDC (25 millivolts DC) and 45mVDC (45 millivolts DC). Some meters may read .025 volts to .045 volts. Be sure you understand what your meter is telling you.
6) With your screwdriver, turn the “BIAS ADJUST” control to obtain the proper reading for your tube type from the chart below. Write this number down.
7) Next, move the red meter lead to the hole labeled TEST POINT 2. Write down the value. Both readings from steps 6 and 7 should be within the range shown on the chart. Readjust if needed to get both tubes into the proper range of readings.
8) Lastly, keep the red test lead in the TEST POINT 2 hole and move the Black meter lead to TEST POINT 1. You should read
less than 5mVDC (5 millivolts DC) or .005VDC. If the reading is greater, this indicates the tubes are not very well matched. It doesn’t necessarily mean they are defective, just not matched. If the reading is greater than 8mVDC (8 millivolts DC) or .008VDC, we recommend replacing the pair with a closer matched set.
9) After completing the adjustments, allow at least 5 minutes for the tubes to warm up and stabilize. Then recheck and readjust if needed. Lower settings will typically sound a bit cleaner and harder while higher settings tend to be a bit more compressed and softer. Find a range you prefer.

EDIT: Heres the range they reccomend for a few different tube types;

BIAS READINGS:
6L6/5881 28mV to 35mV
EL34/6CA7 30mV to 38mV
E34Ls 35mV to 45mV
6550 35mV to 45mV
Gear:

Ibanez RGT220H
Schecter C1 Elite
Ibanez EWC30
Maxon OD-808
Framus Cobra
Peavey 5150 MK1 Block Letter
ENGL E530 Preamp
Mesa Boogie Standard Rectifier 4x12

Music:

http://www.myspace.com/morethanthisuk
Last edited by chrism3006 at Feb 5, 2009,
#5
Are you sure your amp has a switchable bias?
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CELESTION
#6
Quote by Van Noord
Are you sure your amp has a switchable bias?


Yes, the RM series has the most user friendly biasing system I've ever used.
Gear:

Ibanez RGT220H
Schecter C1 Elite
Ibanez EWC30
Maxon OD-808
Framus Cobra
Peavey 5150 MK1 Block Letter
ENGL E530 Preamp
Mesa Boogie Standard Rectifier 4x12

Music:

http://www.myspace.com/morethanthisuk
Last edited by chrism3006 at Feb 5, 2009,
#7
*thanks Chrism, i found that article after a lotta searching and wanted to kick myself in the head for wasting forum space. but alas, i've found yet another RM user!!

what modules do you use?

i had mine as a metal/hard rock amp since i got it over a year ago (spent 9 months KIA), and just recently decided to turn it into a Marshall wannabe . 'Brown' and 'Clean' combo atm, hopin' to get a plexi to replace the 'clean.'
My MAIN Gear
____________
"They call him the 'Sand Spider.' -Why? -Probably because it sounds scary"
*Agile AL3000 Les Paul w/ Alnico IIs
*Randall RM50
*Dunlop CFH
*fellow LEO feel free to give a shout out
#8
No worries! I have mine set up for pretty much for hard rock/metal; a modified clean, Ultra XL, and soon an Ultra lead. Not had it for too long bout a month but I'm loving it so far and as you said the best thing is that If you want a new sound just buy a new module, its great!
Gear:

Ibanez RGT220H
Schecter C1 Elite
Ibanez EWC30
Maxon OD-808
Framus Cobra
Peavey 5150 MK1 Block Letter
ENGL E530 Preamp
Mesa Boogie Standard Rectifier 4x12

Music:

http://www.myspace.com/morethanthisuk