carvin Carvin V3M, Carvin V3 Carvin V3M (bias)

How to bias:

V3M

Rev A

9/22/2011

www.carvinservice.com

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Only a certified technician should bias Carvin amps, this is very
dangerous, you can get hurt, please be very careful when working
with any tube amp!

If you have changed the tubes make sure they are a matched set.

-The Bias for the V3M, V3MC should be 80mA at 50W setting, with 120VAC.

STEP 1

These are the tools you will need:

1. A flat head screw driver “small”.

2. A multi-meter, w/ milli amp

reading.

3. Banana to clip leads.

4. Drill

5. Amp stand (optional).

STEP 1A

STEP 2

You have to remove the bottom cover by
removing the screws as indicated. It’s a total of
10 screws.

Set it in an amp stand. Be very careful with the
tubes they can break.

NOTE: If you don't have an amp stand then
support the chassis on some blocks of wood so
that the power tubes are not touching anything ­they get very hot

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STEP 3

STEP 4

Plug in speaker to output 1 or 2, they are
both the same, both jacks are in parallel.

NOTE: For speaker setup click on
“Troubleshooting” and “Speakers”.

IMPORTANT: Do NOT turn on the
amplifier without a speaker plugged in!

Make sure the OHM setting is correct.

STEP 5

Improper setting will result in damage to
the amp!

NOTE: On the back is where you will
find the OHM setting, make sure the
speaker matches the OHM setting.

Set the switch in the back to 50W.

NOTE: This step is very important, if
you don’t set this to 50W setting you will
not get the correct bias setting when you
adjust it later in the procedures.

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STEP 6

STEP 7

A) Lower the volume down on All channels.
B) Unplug your guitar cord from the input of the amp.

NOTE: If you have signal going through
the amp, it will not be the true reading,
when you set the bias.

A) Connect the leads to the meter. B) Set your meter to the milliamp (mA) position.
Make sure the fuse inside is good. Set meter to DC Current, not AC current.

NOTE: If the Fuse inside your meter is open, the meter will never work. It will
always read 0mA. In the meter above, mA and COM is selected, you have the
option to plug in the lead on (A) but because the setting will be set to 80mA it’s
best to use mA.

STEP 8

1. 2.

Connect clips from meter to Standby Switch. It’s easier to clip the leads to the
wires that go from the standby switch to the main circuit, see picture above.

IMPORTANT: Never power the amp ON before connecting the leads, you will

get a big spark, you may blow the fuse of the Meter and or damage the amp.

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STEP 9

STEP 10

Plug in AC Cord.

NOTE: Sometimes when the AC Cord is
new it does not want to go in all the way.
Push firmly to force it in, if that is the
case.

STEP 11

Turn the Power Button ON. Wait 2
minutes for the amp to get hot, after the 2
minutes you should see the meter read
current. Your Meter will start low then
increase up to 80mA, adjust it accordingly.

NOTE: Do Not turn ON the Standby
switch, leave it on STANDBY.

Check your meter at this point, if it goes
over 80mA, lower it by turning the bias
potentiometer with the screw driver, clock
wise, if it’s under 80mA bring it up by
turning the potentiometer the other way.

Bias Potentiometer above.

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It is OK and normal for the bias reading to fluctuate a little bit and may not be
exactly 80mA but as close as possible.

IMPORTANT: Set your meter to DC Current, your meter should read (mA)

Good Bias

STEP 12

Power down Steps:

1. Turn OFF the amp

2. Disconnect the meter leads.

3. Unplug your AC cord and wait for the tubes to cool down, so that you can put
back the bottom lid.

IMPORTANT: During biasing and normal amp operation if there is a burning smell

or loud crackling noise that comes from the speaker, you should turn off the amp as
your may have a bad tube. The same is true if your meter reads higher that 150mA
or goes into overload. The tubes should never glow RED on the gray plate material,
the largest metal part inside the tube. This indicates a major problem and extremely
unsafe condition. If this happens turn off the amp immediately!

IMPORTANT: The tubes get very hot! Don’t touch them, you will burn your

skin if you do. If the amp is ON the tubes will get hot, even if you are not
playing the amp, wait 30 minutes before handling the unit to ensure the amp
cooled down.

IMPORTANT: This is not the only way to set the bias on this amp, this is the

Carvin Approved method which is used on the Production line in the San Diego,
California Factory.

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NOTE: If the tubes are getting hot and 3 to 5 minutes went by and you don’t see
any reading on your meter check your meter, you may have the leads connected to
the wrong place in your meter or the fuse on the meter is open.

EXPORT(230-240VAC 50Hz): Follow the same instructions.

Comments or questions email us at [e-mail]

www.carvinservice.com

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