Mesa Boogie Mark II B 2-Channel 60-Watt 1x12 EQ Guitar Combo amplifier 1980's

  

This amazing amplifier has been well cared for and comes with the heavy duty road case. I shouldn't sell it. It is literally the amp of a lifetime. Presence control in back, recording out, lead and rhythm channels, 5 band graphic EQ. Everything works as it should.

The lead channel is very creamy, and the main channel has a tone that makes every guitar sound brilliant. It is oh so loud.

There is a reason these are favored by the stars. This fifty year old amp is worth its weight in golden tone. I want it to go to a good home, and be heard. It is a player's dream.

One of the legendary amplifiers in the Mark series evolution, the IIB has one of the finest tones available and is a sought after piece. This particular model has many great features as listed below.

The IIB was the third in the evolutionary line, after the Mark I and the Mark II. There were several folios in the second generation Boogie. The Mark II introduced channel footswitching, so you could go from rhythm to lead. It also wasn't referred to as the "Mark IIA" until the Mark IIB was issued.

You could also get a separate head for this model, which could be hooked up to a number of different speaker combinations, although a 1x12 cabinet was typical. However, the reverb circuit is considered noisy and the footswitching made a popping sound when used; both of these features were later improved on in the IIB and IIC. The preamp gain on the Mark IIs occurs after the tone controls, unlike the Mark I.

A MESA/Boogie person has stated that the IIA has a "tighter, more focused sound" than the Mark I. The clean channel on this is very nice, but some argue that EQ is needed on the lead channel to be able to dial the midrange out in order to get something other than the "Santana" tone. A landmark review of this amp was posted in the German literature, namely the Fachblatt Test. It was the second folio of footswitch lead and rhythm modes between the huge warm clean tone and the famous Boogie lead tone that in the Mark I was obtained via separate channels.

Early problems in the Mark II were addressed in the IIB, namely less popping in the footswitch, less reverb noise and the Mark IIB introduced an effects loop and an expanded control panel, featuring both a lead drive and a lead master dial. More importantly, it marked the introduction of Mesa's "simul-class" system, where two of the power tubes (always 6L6s) run in class AB pentode while the other two tubes (either 6L6s or EL34s) run in class A triode.

If you have a simul-class amp, running all four tubes generates approximately 85 watts RMS of power, while running only the class A tubes produces about 15 watts. You could also get a non-simul-class Mark IIB in a 100 watt model, which allowed to shift down to 60 watts by turning off a pair of power tubes. No matter what the combination is the result is very loud. A well know "problem" is that they produce what seems ridiculous amounts of volume. So much so that in the Mark I re-issue, there is now a variac switch to produce a "brown-out" to obtain a lower output volume.

The two input jacks on the front panel are marked "Input" and Foot Switch. The front panels read Volume, Treble, Bass, Middle, Master, Lead Drive and Master.

It has "Pull Bright" on the Volume, "Pull Shift" on the Treble, and "Pull Bright" on the Master. " A Mesa/Boogie has stated that the Mark IIB lead sound is "bold and punchy. But it is the next model, the Mark IIC (see below), that is considered to have the best clean and lead tones of all the Boogies to date. The two input jacks on the front panel are marked Input" and "Foot Switch. The lead/rhythm footswitch plugs in and has a red LED to indicate function in the rhythm mode.

The front panels read Volume 1, Treble, Bass, Middle, Master 1, Lead Drive and Lead Master. It has "Pull-Bright" on Volume 1, "Pull-Shift" on the Treble, "Pull-Gain Boost" on the Master 1 and "Pull-Bright" on the Lead Master.

The Pull-Bright acts to make the amp brighter and hotter especially when combined with the Treble Pull-Shift. This has less effect as Volume 1 approaches 10 and is most apparent at low settings.

Also effects the amount of signal available for Lead Drive. RECOMMENDED SETTING: 7 - gives enough gain to both modes. The Pull-Shift acts to give an alternate, robust midrange which alters the lead tone to provide a more fat, powerful sound. Pushed in, the tone is similar to old Fender Amps. Pulled out, the frequency center point is shifted downward.

RECOMMENDED SETTING: 7-1/2 pulled out. Provide standard tone shaping but have less noticeable effect than the treble control. RECOMMENDED SETTING: Your choice - try 4 for mids and 2 for bass. Controls the over all volume in both modes. With the Pull Gain-Boost, the tone slope is altered to emphasize a fat, round bass and adds rich sustain in both modes.

Very helpful in fattening out single coil pickups. Footswichable via the output underneath the chassis via stereo cable and dual switch. Minute changes result in huge changes in volume.

A weakness in all Mark amps. RECOMMENDED SETTING: 1/2 to 2 pulled out. Pull function activates the Lead/Rhythm relay. Useful if foot switch is lost, or one chooses to use only one mode. The lead drive in conjunction with the Volume 1 regulates the amount of tube saturation and overdrive. The higher Volume 1, the more signal available for this control to shape. Pull-Bright affects only the lead mode and it causes a substantial boost in overdrive and brightness. The lead master controls the loudness of the lead mode but is limited by the Master 1 setting. RECOMMENDED SETTING: 4 pulled out. When on 60 watts, current is turned off to the two inner 6l6s but the filaments remain on so there is no warm-up time when switching to 100 watts. Useful feature to prevent speaker overload or produce more output distortion at lower volume levels. The Boogie can produce 200 watts RMS continuously when driven hard. This toggle turns off the high volatages in the Boogie, but keeps the tube filaments warm.

Used inthe powering up and cooling off period. This results in less strain on the tubes and electronics than shutting off the mains each time one takes a break. Controls the AC for the whole amplifier except for the AC utility outlet on the back, which remains unswitched. Proper power up involves having the amp in standby mode and turning on the AC.

After 30 seconds or so, turn the standby to on. This sequence prevents a high voltage surge from hitting the cold tubes, reduces strain on capcitors and electronics and prolongs tube life.

Overall tone warmth and volume is determined by Volume 1 and Master 1 and shaped by the controls as above. Its stage effects the Lead Mode. When in lead mode, these two controls remain functional.

With activation of the lead relay, the Lead Drive regulates the amount of tube saturation and its overall loudness is controlled by the Lead Master. With a little time, one can easily get the hang of this interaction. From right to left, standard features abound.

The 12 foot grounded cord is next to an un-swithced AC three pin utility outlet, Slo-Blow fuse and ground switch. Next is the Slave Out and Level Control, Effects Loop, Presence, Speaker Outputs 8, 4, & 16 Ohm, and Heat Sink.

Underneath on the chasis undersurface the Pre amp/Amp Junction outlet and the outlet for the Gain Boost/Reverb dual footswitch. Utility outlet that remains on despite position of AC switch.

This is very useful on stage. When linking Boogies, it is best to use isolated AC sources as one can run into the radio phenomonon where the amps act as radio receivers picking up FM! Make sure that you use high quality coaxial cables. All Boogies are clean of this, but if you combine them in certain configurations and use cheap cables, some RF will result. RF is staus quo in lesser amps, especially Fender, don't let someone sell you a line of crap that your Boogie is like all amps and needs "holy water" to cure it!

Generally never an issue unless there is a bad power tube. If it goes, replace the power tubes first and then fuse to prevent further blowouts. A three position switch with the center position being off, A to left, B to right. Useful in reducing buzzes that originate from AC power wiring outside the amp. Best to leave in center off position unless either A or B helps.

When in the center, the Boogie cannot be the source of ground shocks to micrphones. Provides a direct output feed the faithfully captures the preamp and amp sound. The level allows one to ensure the adequate signal strength. This output is useful when slaving to another Boogie's Preamp out/Power Amp in, or to a mixing board. Start with the level off and increase as needed.

Higher Slave settings with lower Master 1 result in less overall line noise. A useful feature to hook up external effects, or other Boogies. Modified from the Mark II, the new patch points offer a low noise connection without overloading of effects.

The output is desingned to have low impedance to ensure low signal noise and hum. The signal comes in before the Graphic EQ. So shaping of the effects is possible. Input will interupt signal so a loop must be completed.

Output however works alone and can be used to send a preamp signal to another Boogie. A know issue is when the internal switching jack fails and cuts the signal. To test this, place a cable from send to return. If this solves the problem, the jack should be repaired by bending the contacts or replacing it with a Switchcraft 12A.

Gil Ayan writes: A cool and little-known option with the effects loop of a Mark IIB (or original Mark II): one can run the output of a volume pedal (without your guitar being plugged into its input) into the'return' jack, and get on-the-fly preamp gain control. This is a feature that very few tube amps have ever had, even inadvertently - it uses the pot in the volume pedal as a passive limiting device, such that when the pedal is'wide open,' it allows the pre amp tubes' full voltage to pass into the power section. As the pedal is backed off, it decreases the amount of pre amp signal allowed through the'loop,' cleaning up the sound. To make use of this feature, setting the clean channel's pre amp to 9 and using an Ernie Ball pedal to vary the overall tone gives many different tone options.

In the Mark IIB mannual they describe this, but say that one should use the preamp/amp junction input underneath the chassis. The presence acts to affect the overall brightness of the amp. At low setting a very warm, mellow tone is obtained, at full, a more robust gain tone is heard. This control stes the overall reverb level. Use in conjuction with the optional dual footswitch to control the reverb effect.

Three outputs are available for different configurations and if so desired, speaker mismatches. No harm can come to the Boogie or the speaker, save that a mismatch in the wrong direction, (8 Ohm with 60 Watt or Class A) will cause the powertubes to run down faster. EVM and Altec speakers are able to handle the 100 Watts and 8 Ohm. For other speakers, MESA suggests 60 Watt and 4 Ohm.

Lower power setting with the 4 Ohm jack gives a mellow sound with distortion at a lower volume. 8 Ohm adds more clarity and crispness, and 100 Watt adds even more volume. Located on the undersurface of the chasis to the right, provides a juntion out of the preamp/Graphic EQ. Signal to slave other Boogies or a signal in to use the Boogie as a Power Amp only. When doing this, only the Master 1 functions and it is suggested all other pots are turned to zero. Best way to link the Slave Out or Effects Send of one Boogie to another for a Power Amp effect. Located to the left, this outlet works with a Stereo cable and footswitch to control the Gain Boost and the reverb. Very useful in adding a "third mode" to the rhythm with the significant boost and adds a "fourth mode" to the gain of the lead mode. This item is in the category "Musical Instruments & Gear\Guitars & Basses\Guitar Amplifiers".

The seller is "bifftar" and is located in this country: US. This item can be shipped to United States.

• Custom Bundle: Yes
• Modified Item: No
• Bundle Description: Heavy duty castered road case inc.
• Number of Speakers: 1
• Number of Channels: 2
• Suitable For: Acoustic Electric Guitar, Acoustic Guitar, Cigar Box Guitar, Electric Guitar, Lap & Pedal Steel Guitar, Resonator Guitar, Travel Guitar
• Venue Type: Performance
• Country/Region of Manufacture: United States
• Non-Domestic Product: No
• Model: Mark IIB
• Product Line: Boogie Mark IIB
• Amplifier Technology: Vacuum Tube
• Impedance: 8 Ohms
• Power: 85 W
• Amplifier Type: Combo
• Brand: Mesa