Carvin MTS3212 manual Rear Panel, Help Section

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REAR PANEL

15. SPEAKER JACKS

Two 1/4” SPEAKER JACKS are featured to operate several speaker systems at the same time. Calculate the total speaker impedance based on parallel wiring as both speaker jacks are wired in parallel. Select the IMPEDANCE SWITCH for the correct impedance.

16. SPEAKER IMPEDANCE SWITCH

The IMPEDANCE SWITCH offers the selection of 4, 8 or 16 ohms to match your speak- er system. The correct setting for two 16Ω speakers or cabinets would be 8 ohms. Select the proper impedance. The impedance of the MTS3212 combo amp is 8 ohms. In the case of adding another 8 ohm extension cabinet, keep the switch at 4 ohms.

17. 4 TUBE 100 WATT OR 2 TUBE 50 WATT OPERATION

For maximum output power, be sure the power tube selector switch is selected for 4 TUBE operation. For lower overall levels and early power amp clipping, move this switch to the 2 TUBE operation. The volume reduction will only be 3 dB.

18. POWER TUBE BIAS SWITCH

If you desire to change from 5881 (6L6GC) to EL34 power tubes, you may do so by selecting the external BIAS switch to the EL34 position on the rear panel. Be sure that this switch is selected to the proper position or excessive heat will damage your tubes.

The internal P11 bias trim control can be set by a qualified technician. To set the bias, measure the current across the terminals of the STAND BY switch (set this switch to the off position when the amp is on). Set the idle current to 100 mA for all tube types.

19. VOICED LINE OUT

The LINE OUT 1/4” jack is “CABINET VOICED” to prevent excessive bass or highs going to your mixer. This greatly aids in sound quality because you do not have to move your mixer EQ setting to the extreme. The 1.5 VAC output (reference to 100 watts output at 8 ohms) is more than adequate to drive any professional mixer or power amp.

20. FS22 FOOTSWITCH

Most foot pedals with 2 switches, a stereo cord and plug will work. However, Carvin’s FS22 is recommended because of the correct identification label on the foot switch. First, the channel SELECT switch on the front panel must be selected to the “OUT” channel 1 position before the footswitch will work. Now that you are connected correctly, the chan- nels and reverb can be switched remotely. If a hum is heard in the speakers, the select switch is in the wrong position (this will not harm the amp).

21. EFFECTS LOOP

For the lowest possible noise from an effects processor, use the effects loop instead of plug- ging the guitar into the effects and then into the amp. To use the EFFECTS LOOP, plug the INPUT of your effects into the SEND jack and the OUTPUT of your effects into the RETURN jack. Use shielded cables, not speaker cables. It’s normal to have a slight gain reduction of several dB with some effects units. However, the amp has plenty of gain to overcome any loss.

22. AC POWER & FUSE

The detachable AC POWER CORD supplied is designed to operate with one type of volt- age (the European 230V export model uses a CEE-7 plug cord set). Check the rear power cord label for the proper voltage and fuse value. Make sure the cord is securely inserted into the back of the unit. Plug the cord into a grounded “3” prong” power source. No attempt should ever be made to defeat or use the amp without the ground connected.

The FUSE (some models have circuit breakers) is located within the AC power cord receptacle. To check or replace the fuse, remove the power cord, place a screwdriver under the “FUSE” cap and pull the fuse holder out. The fuse type is a 250V Slow Blow SB 5 x 20mm rated at 3A for 120V & 1.5A for 230V models. Do not use fast acting fuse, only a SLOW BLOW (SB) type fuse will work.

HELP SECTION

a) FEEDBACK FROM THE LEAD CHANNEL

The MTS3200 will feedback when the LEAD volume, DRIVE, TREBLE and PRESENCE are turned all the way up. Like other highly modified tube amps, this is normal. To help reduce feedback and noise, keep the DRIVE control set around 5 to 7 on the dial. Some of the best lead saturation will be at around 5—not 10. Sometimes replacing V1 (12AX7A) can help reduce feedback.

b) TUBE REPLACEMENT GUIDE

It is not uncommon for tubes to malfunction during shipping. If your amp is not work- ing properly, please call or refer to the following replacement guide.

1)The 12AX7A preamp tubes are located in the following order on your chassis: V1, V2, V3, V4, V5. To start with, V1 is located next to the outside of your chassis behind the output transformer. It is recommended to turn your amp upside down to replace tubes. Replacing V1 will help reduce feedback in channel 1. Replacing V2 and V3 can also help but V1 is the main tube to replace. Replacing V4 will correct problems with the reverb system unless there is a defective reverb tank or tank cables. If the power amp is not functioning, check or replace the 5881 power tubes and check V5 by inserting a signal into the Effects RETURN jack. All tubes are keyed in the same direc- tion.

2)The 5881 power tubes are located in the following order on your chassis: V6, V7, V8, V9. Normally you’ll want to replace these tubes as a set. Please call for our latest prices. Sometimes you can spot defective power tubes when they are glowing red- hot along with an audible hum in the speaker when the amp is idling. If this happens, shut the amp down immediately. After they have cooled down, remove by pushing the retainers on the base of the tubes down and rock the tubes in a circular motion while pulling them out. It is recommended to turn your amp upside down to replace tubes. All tubes are keyed in the same direction. Running defective power tubes could damage the amp. It is recommended that you have a spare set of power tubes along with several 12AX7A preamp tubes.

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22Press firmly until cord clicks in.

Guitarist Magazine, England

MTS3212 Combo Review—By Simon Bradley

“Actually, the MTS3212 is a more versatile beast than I at first assumed, because, in the process of turning the drive control all the way up, there are some excellent crunch tones along the way.

Maybe it’s the British Series (BR12) speakers, or the simple fact that the amp bristles with glow- ing tubes of loveliness, but these mid-driven sounds are of that responsive type that you just can’t beat. It’s warm, of course, but vibrant enough to cut through, and the tone’s dynamic qual- ities would seem to offer musical assistance to all but the most colourless of blues players.

However, I would argue that it’s at high gains that this Carvin comes into its own. In this situa- tion, it’s one of the most satisfying amps I have played in a long time. EVH was once quoted as saying that you know when you have a good sound when the guitar seems to play itself, and if Sir Edward of Van plugged into this combo, he would be more than happy with the brown-ness of the tone.

High octane rock sounds? No problem. Is mid-scooped thrash of angst-core your bag? Just step this way, Sir. The EQ is simple because it has no reason to be anything else, such is the efficiency of both the amp section and speakers to kick out a tone full of ballsy clout and high end shimmer. Putting it through a 2 x 12 extension cab merely enhances the tone further.

Just when you thought it was safe to think ‘so…it’s like a Peavey 5150’ (yes, the overdrives real- ly are that good), a flick to Clean 2 will see you reaching for a Strat and switching to position 4. An amp’s clean sound is, if anything, a more subjective affair than its dirty compadre, but I would say that the MTS3212 has the best clean sound I’ve ever heard from a 100w combo. Others might prefer a black-faced Fender Twin or even a Roland JC120, but the bass end available here is nothing short of incredible. It has the potential to turn the sound of a single coil solid into something akin to that of a monstrous f-hole jazz beast (should you so desire). Those in-betwee- ny Strat tones are well served, as is the neck position of a Gibson ES335, and the fact that the combo can handle such diverse sounds with equal aplomb is a major feat.

Conclusion

Whatever styles of music you play, I have a feeling that you may well be blown away by this Carvin. The price tag represents excellent value, and it could give other amplifiers costing twice as much a serious run for their money.”

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Contents High Impedance Guitar Input Clean and Overdrive ChannelsDynamic 5881 Power Tubes Technical Design of the MTS3200Master Section Clean ChannelFront Panel Lead ChannelHelp Section Rear PanelReplacement Parts List for circuit cards