#1
I did a quick search and I couldn't find any tutorials about retubing !
I need to re-tube my Marshall TSL-602 but I have no idea how
( I have to do it myself )
Does re-tubing mean swapping every single tube in the amp ?
Can someone please give me hand in re-tubing my amp ?
I head something about biasing, whats that ?
Guitar : Cort X-TH ( EMG 81-85 )
Amp : Marshall TSL-602
Effects : Boss MT-2, Boss NS-2
#2
well, it's rather easy. if you know which tubes to get, it's like replacing a light bulb...

except you don't twist the tubes in, you push it into the corresponding pins holes... and ya. don't stress out, it's not that hard of a modification.
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#3
you might have to rebias though. do those need biasing shot?
Jumping on dat gear sig train.
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#4
no amps "require" biasing unless it's some radical tube change. as long as the amp require 12AX7s and EL34s, if you put in 12AX7s and EL34s, no need to really change the bias. most amps are biased on the safer side. it's not gonna blow up or anything cuz you put in new tubes. so as long as you use reliable tubes that are up to par in the electronic specifications, it'll be fine.


what are you gonna do if a tube dies during a show, and you have tubes to shove in there? are you gonna tell the audience to wait because you need to rebias ur amp? no, you just stick them in and fire them up... or so i hope?
Call me "Shot".

ShotRod Guitar Works

Custom Hand-wired Amplifiers and Effect Pedals.

Est. 2007


Source to everything I say about Guitars, Pedals, and Amplifiers: I make them.


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#5
for just retubing all you do is slide it in, very very easy
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#6
Quote by ECistheBest
no amps "require" biasing unless it's some radical tube change. as long as the amp require 12AX7s and EL34s, if you put in 12AX7s and EL34s, no need to really change the bias. most amps are biased on the safer side. it's not gonna blow up or anything cuz you put in new tubes. so as long as you use reliable tubes that are up to par in the electronic specifications, it'll be fine.


what are you gonna do if a tube dies during a show, and you have tubes to shove in there? are you gonna tell the audience to wait because you need to rebias ur amp? no, you just stick them in and fire them up... or so i hope?


carry 10 amps. duh.
Jumping on dat gear sig train.
PRS Hollowbody II / BKP Warpigs
Strandberg OS6T / BKP Aftermath
Strandberg OS7 / Lace Poopsticks
Skervesen Raptor 7FF / BKP Warpigs
Skervesen Raptor 6 NTB / BKP Juggernauts
Hapas Sludge 7 FF / Hapas Leviathan
Anderson Baritom / Motorcity Nuke BKP Sinner Anderson H2+
Warmoth Baritone / BKP Piledriver
Ibanez Rg2120x / BKP Nailbomb

Blackstar ID:Core Beam
#7
It's best to have a spare set of tubes in the same heat range so you can re-tube without worrying about bias.
Not all power tubes are matched...some much hotter, some much colder.
With my stock tubes, the amp came biased at about 30mA..pretty cold. I adjusted to 38.5mA.
Upgraded to JJs, and the bias was back down to 32mA. Had I NEVER checked bias, even though I replaced 6L6s with 6L6s, my bias would have been somewhere around 24mA. These amps (and the peaveys they are based on)give only "crossover distortion" until you get above 34mA.
I'm told an amp producing crossover distortion can not produce a good warm clean tone to start with. It also causes the amp to be sluggish and lack dynamic response.

Get you a probe, and a multi-meter, and bias your amp if it's adjustable...if it isn't, get your bias reading, and contact eurotubes.com and they will set you up with tubes that will match your amp properly...kinda like a hard way to bias, but gets the job done none the less.
Ibanez RGR421EXFM, Michael Kelley Vex NV, Ovation Celebrity. Carvin V3
Peavey 412M w/Eminence Wizards & Swamp Thangs, Rocktron Hush Super C, Furman PL-8C,15 band EQ, Boosta grande, ISP Decimator, Dano EQ, Ibanez TBX 150,TC Elec Polytune
Last edited by Vinson at May 29, 2010,
#8
Somewhere in Marshall forums I read that the correct bias for TSL-602 is 80mV.
What does that mean ?
Does mV means milli Volts ?
How can I calculate this bias thingy ?
Can I Increase the gain of my amp by changing the tubes to something else ?
Do I have to open the amp to change the tubes or can I just pull the tubes out ?
should I change all the tubes or just a few that are faulty ?
Guitar : Cort X-TH ( EMG 81-85 )
Amp : Marshall TSL-602
Effects : Boss MT-2, Boss NS-2
#9
Knicked from elsewhere:

MARSHALL SERVICE BULLETIN

SUBJECT: Bias Info/Procedure for JCM2000 series Marshall amplifiers

THEORY OF OPERATION: We are setting the bias using the current method instead of cross over distortion method. The Bias PCB assembly is as follows:
PR1: Bias mini-pot adjustment for pin1 which is one side of the push pull amp (two output tubes in a 100watt amp and one output tube in a
50watt amp). Pin1: Connected to the cathode of the output tube(s) which then goes through a 1 ohm resistor then to ground. Pin2: ground reference.
Pin3: Same as pin1 but for the other side of the push/pull amp. PR2: Bias mini-pot adjustment for pin3, the other side of the push/pull amp.


PROCEDURE:
1. Make sure amplifier is connected to a load with the proper impedance
selected. 2. Power up amplifier on STANDBY and let the circuit stabilize for a couple of minutes.
3. Locate the male three pin molex connector (CON2) with the two mini-pots (PR1 and PR2) on both ends found on the bottom of the tube bay. 4. Connect DMM (set to read mV) with alligator leads, reference common lead to center pin (pin2) on molex connector CON2 and positive lead to pin1 on CON2.
5. Take amplifier off of STANDBY with no signal, adjust mini-pot (PR1) closest to pin that the positive lead from your DMM is connected to and set it to the mV voltage that is listed in the chart below. 6. Repeat steps 4 & 5 for pin3 and until both pin1 and pin3 mV are the same.

BIAS CHART mV SETTINGS
(pin1 and pin3)

DSL50 45mV TSL60/1/2 80mV
DSL100 90mV DSL401 1.375V
TSL100/122 90mV DSL201 .675V
Gilchrist custom
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#10
Quote by Philosophient
Somewhere in Marshall forums I read that the correct bias for TSL-602 is 80mV.
What does that mean ?
Does mV means milli Volts ?
How can I calculate this bias thingy ?
Can I Increase the gain of my amp by changing the tubes to something else ?
Do I have to open the amp to change the tubes or can I just pull the tubes out ?
should I change all the tubes or just a few that are faulty ?


Some bias probes read in mV (millivolts), some read in mA. Knowing which type of probe you have will tell you what it will read.

Got to eurotubes.com they even have videos explaining how to bias, and what is going on when you bias (probes reading mV or mA is covered)
Ibanez RGR421EXFM, Michael Kelley Vex NV, Ovation Celebrity. Carvin V3
Peavey 412M w/Eminence Wizards & Swamp Thangs, Rocktron Hush Super C, Furman PL-8C,15 band EQ, Boosta grande, ISP Decimator, Dano EQ, Ibanez TBX 150,TC Elec Polytune
#13
Quote by denied
www.eurotubes.com

Read everything on that website.

It's a really simple process, and you should have some basic knowledge about tubes and maintenance if you are going to own a tube amp.

I will definitely do that
Thanks
Guitar : Cort X-TH ( EMG 81-85 )
Amp : Marshall TSL-602
Effects : Boss MT-2, Boss NS-2
#14
Eurotubes.com

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#15
+1
Ibanez RGR421EXFM, Michael Kelley Vex NV, Ovation Celebrity. Carvin V3
Peavey 412M w/Eminence Wizards & Swamp Thangs, Rocktron Hush Super C, Furman PL-8C,15 band EQ, Boosta grande, ISP Decimator, Dano EQ, Ibanez TBX 150,TC Elec Polytune
#16
If you're gonna retube it I'd say do them all at once, it's a bitch to do one every couple of months rather than doing 4 or 5 every two years, It's better to have them age all at the same time (like strings).
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#17
Necrobump much?
Gilchrist custom
Yamaha SBG500
Telecasters
Randall RM100 & RM20
Marshall JTM45 clone
Marshall JCM900 4102 (modded)
Marshall 18W clone
Fender 5F1 Champ clone
Atomic Amplifire
Marshall 1960A
Boss GT-100


Cathbard Amplification
My band