Frequently Asked Questions

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Can I use the MF350 power amp with another pre-amp?

Yes, follow these simple steps:

Connect the output of your pre-amp to the MF350 FX RETURN jack socket. Turn GAIN to MINIMUM on AMP 1 and AMP 2

Turn the FX LEVEL to maximum on AMP 1 and AMP 2

Insert a jack plug into the INPUT jack socket to release the automatic muting facility. Note: You can use the footcontroller to select either the AMP 1 or AMP 2 power amp

configurations.

Can I connect any cabinet to my MF350 head?

Yes, so long as the total impedance into the amplifier is equal or more than 8 Ohms (check the impedance selector on your cabinet). Please be aware that the MF350 can deliver 350 Watts and if, for example, your cabinet is only rated 280 Watts, there is a chance that you might damage your speakers by playing at high volume.

Can I run my amp without a speaker cabinet connected, while doing silent recording for example?

Yes, unlike a valve amplifier the MF350 allows you to do this. We recommend however that you turn the MASTER VOLUME to minimum, as it does not affect the output level on the EMULATED OUTPUTS.

What does emulated out mean?

This means that the line output is emulating the sound a good quality microphone located in front of your cabinet would produce. This allows you not only to record silently, but also provides an easy and reliable way of getting a good sound through a P.A.

Can I use headphones in the EMULATED LINE OUTPUT?

No, the LINE OUTPUT is a mono signal, whereas you would need a stereo output for headphones.

Where is the best place for connecting my effects, front end or in the effects loop?

Please refer to the section entitled Parallel to Series Effects Loop (page 8) for detailed explanations.

What instruments can I use with my amplifier?

The MF350 has been designed for use with an electric guitar, including baritone and detuned guitars.

Can I disconnect the fans for recording when using the speaker cabinet mic’ed up?

No, there are no user servicable parts in the MF350 and the fans are extremely important for the reliability of this product. The fans are the quietest available, but if you want to minimise any residual fan noise during your recording we recommend applying the favourite studio technique of buying a long speaker lead and connecting the head in a different room to where the cabinet is mic'ed up.

What would happen if I connected a single 16 Ohm speaker cabinet to loudspeaker output II of the Mode Four?

No damage would be caused connecting a single 16 Ohm cabinet to output II or connection of a single 8 Ohm cabinet to output I. However, the damping would be mismatched and this would have a negative effect on the sound.

TONE TIP: Damping refers to the amount of feedback applied to the power amplifier of the MODE FOUR from the speakers. It is important the damping is correctly matched to the load impedance used for optimum sound.

Troubleshooting Guide

Before calling the service department, check the following:

If the unit does not seem to operate properly, read the instructions again, then check the table below. Under no circumstances should you attempt to repair an amplifier yourself, as this could be dangerous and would void the warranty.

Symptom	Cause	Solution

No power	The mains power cord	Ensure the mains power cord is correctly connected to
	is disconnected.	the rear of the unit and then plug the power cord into
		the wall outlet securely.

No sound	Power is off	Ensure the MF350 is correctly connected to the mains
		supply and turn the ON/OFF button to the ON position.
		Wait 30 seconds for the valves to warm up.

	Volume control off	Make sure that all Gain, Volume and Master Volume
		controls are not on zero (also ensure that the guitar
		volume is up!)

	Guitar lead	Ensure your guitar lead is inserted fully at both ends
		and that the lead isn’t damaged. It is always good
		practice to have a spare guitar lead.

	MUTE Switch is on	First turn the MASTER VOLUME down and then turn the
	(amber light is on)	MUTE button off. Slowly increase the MASTER VOLUME.

	Direct signal in FX LOOP	Disconnect all cables from SEND and RETURN on
	is interrupted while the	the rear panel. If the sound comes back, check your
	FX LEVEL is on full	cables and outboard effects units.

	Speaker cable is	Ensure the speaker cable is in good condition and is
	disconnected	fully inserted into the MF350 and the speaker cabinet.

	LOAD PROTECTION	Switch the amplifier off and check the total minimum
	CIRCUIT active – the	impedance of your speaker cabinet(s) and that your
	red LED will be lit on	speaker cable is correctly connected. Turn the MF350
	the back of the unit	on, if the problem is solved the red LED will be off.

Low frequency feedback	Microphonic (i.e. loose)	Contact a qualified guitar technician for more
	pick-ups	information.

High frequency	Acoustic feedback	Increase the distance/orientation between the speakers
feedback and ‘squeals’		and the guitar pickup, or alternatively decrease the
		gain or volume of the amplifier.

No Digital Reverb even	Reverb Footswitch is	Ensure the red LED above the REVERB switch on
with the level control on	off	the supplied footcontroller is on.
full

LOAD PROTECTION	Minimum impedance	Ensure the minimum impedance of your speaker(s)
ACTIVE LED is on and	not respected	configuration is not below 8 Ohms; please refer to the
the sound stops while		Cabinet Options guide on page 10.
playing

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