Mesa Boogie Mark Series
From Wikipedia, the free encyclopedia
The Mesa Boogie Mark Series of guitar amplifiers is a guitar amplifier series made by Mesa Engineering. It is one of the most influential series of amps ever made, and was its flagship product until the introduction of the Rectifier series.
Despite having a certain spec, Mesa Engineering has, can, and will customize and retrofit its amplifier for the customer. Therefore, the presence or absence of options, such as reverb, "simul-class," 60/100 watt capability, EQ, cabinets, and speakers etc. may not always be the best way to date an amplifier. the only way to get an accurate dating of the amp is through the serial number from back panel of the amp.
Contents |
[edit] Mark I
The very first Mark I was made in 1969, Smith, as a joke, modified Barry Melton's (Country Joe and the Fish) Fender Princeton amplifier. He removed the standard 10 inch speaker and modified the chassis to fit the larger transformers that were needed by the 4-10 tweed Fender Bassman, the circuit that he had added into the tiny 12 watt Princeton. Finally, Mounting a 12 inch JBL D-120, a popular speaker of the time, Smith had created what would be the first Boogie.
Randall Smith, needing to test his creation, took the "hot-rodded" Princeton into the front store. Coincidentally, Carlos Santana was present and "wailed through that little amp until people were blocking the sidewalk". Impressed, Santana exclaimed to Smith, "Man, that little amp really Boogies!" It was this statement that brought the Boogie name to fruition.[1]
The production Mark I refers to the first Boogies ever made - although they were not called "Mark I" until the Mark II came along. They were 100 or 60 watts combo amps with a 12-inch speaker, primarily Altec-Lansing or EVM. The Mark I had two channels: one clean, voiced somewhat similar to old Fender, called "Input 2," and one "high gain," called "Input 1," which produced the overdriven "Boogie lead" sound used most notably by Carlos Santana on the "Abraxas" album and after.
This amp in its original form is very collectable, but does not have footswitching capabilities - you plug in one or the other input for the two tones. Reverb was optional and a lot of early Boogies didn't have reverb. Later, you could get a Mark I with reverb and/or graphic EQ.
Early models have "slave out" and "reverb" labeled on the back with Dymo stick; they do not have any "pull lead" capabilities on the volume controls. Later Mark Is had "Pull Bright" and "Pull Boost" on the volume controls. The front panel controls were Volume 1, Volume 2, Treble, Middle, Bass and Master.
The early models are fairly inconsistent, since many of them were "custom" models, made-to-order for various buyers. Some sound cleaner, some don't. American guitarist Rivers Cuomo of Weezer used an early Mark I with an original double cutaway Gibson Les Paul Special to produce the guitar tone heard throughout 1994's Weezer.
Mesa has stated the original and the reissue have a "looser" lead sound since the first two preamp stages occurs before the tone controls. In the various later Mark II and III models, there is only one gain stage before the tone controls. This signal chain is an issue of some dispute among Boogie owners.
Original Mark Is are hard to find and expensive (and often modified), but very collectable. While the Mark I varies in sound quality, the Mark I reissue is very consistent from amp to amp.
[edit] Mark IIA
The Mark II introduced channel footswitching. It also wasn't referred to as the "Mark IIA" until the Mark IIB was issued. It was also available as a head, 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 the Mark IIC - see below. As noted above, the preamp gain on the Mark IIs occurs after the tone controls. Mesa Boogie has stated that the IIA has a "tighter, more focused sound" than the Mark I. 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.
The IIA and IIB, and some late-model Mark I amps used a silicon device called "fetron" in place of one of the 12AX7 preamp tubes, and included a switch for configuring the amp for either fetron or 12AX7 operation. The reason for using a fetron was to address some of the problems associated with microphonic 12AX7 tubes in a high-gain situation; somehow, Boogie users didn't care too much for the fetron, so its use was later discontinued.
[edit] Mark IIB
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. In a simul-class amp, running all four tubes generates approximately 75 watts RMS of power, while running only the class A tubes produces about 15 watts. Also available was 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.
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.
[edit] Mark IIC & IIC+
The Mark IIC and IIC+ are gaining reputations in vintage circles as the best Boogies, next to the classic Mark I, due to their much-praised rhythm channels, and to a lesser degree their lead channels.
The Mark IIC featured a quieter footswitching system and a new mod to the reverb circuit. According to Sacks, "The reverb was noise-ridden on the Mark II, a problem which persisted with some IIB models as well. The solution Mesa came up with involved resistor swaps and a change in ground lead placement. That mod is still on the books of 'official' mods, which they send to their authorized techs; it runs about $50." Mesa/Boogie no longer does this mod at its own factory.
The Mark IIC+ was the last of the Mark II series and featured a more sensitive (i.e. useful) lead channel and, more importantly, an improved circuitry in the effects loop. Unlike earlier Mark II models, pedals could be used without the amp's signal overloading their inputs. However, the volume pedal option on the Mark IIB discussed above by Sacks cannot be implemented on Mark IIC+s.
Some owners/dealers/sellers often say the "+" refers to an amp having an EQ, but they are mistaken. The mistake may have originated in the mid 1980s, when Mesa issued their Studio .22 model and then changed the name to Studio .22+, which featured improved wiring, etc. All the Mark II models could be made with EQ as an option, but not all of them did. A Mark IIC+ could, for example, refer to a 100 watt amp without EQ or reverb.
One can tell if a particular amp is a "+" by looking for a hand-written black "+" mark directly above where the power cord attaches to the back of the amp. Many dealers increase the price on a Mark IIC+ but often don't know anything about what the "+" means - they often don't even know where to find the "+" mark. Indeed, the mark itself can be forged. An owner can call Mesa/Boogie and ask them to check his or her serial number against their records. Mesa/Boogie only made about 1,400 Mark II amps before going to the Mark IIC+.
[edit] S.O.B. (Son of Boogie)
The S.O.B. was introduced sometime during the Mark II era. This was Mesa's first attempt at having a "reissue" of the Mark I. It had 2 inputs and its controls were Volume 1, Volume 2, Master, High, Middle, Low, Limit. The "Limit" seems to give distortion to the amp while maintaining the volume. It wasn't considered a true Mark I reissue, however.
[edit] Mark III
The Mark III introduced a third channel-a "crunch" rhythm sound right in between the rhythm and lead channels. This amp has a two-footswitch system; one footswitches between the current rhythm mode and the lead mode, and the other selects either the clean rhythm mode or the crunch rhythm mode. The two rhythm modes share all of their controls, while the lead mode only shares the rhythm modes' tone stack, featuring independent gain and master volume controls. There seems to be some dispute over the sound quality of this amp.
[edit] Mark IV
The Mark IV is the state-of-the-art Mesa/Boogie three-channel combo amp Most important is the independent controls for all three channels - except bass & mid, which are the same for both Rhythm 1 (clean) and Rhythm 2 (crunch). There were two versions of this amp. Start of production until about September 1993 Mark IV's are referred to as version A, late 1993 and on are version B which are the current model. Early B's have an attached power cord like the A version. Notable differences: Version A - No footswitch for reverb. Both normal and switchable effects loops. No satellite send for separate power amp. No stereo effects loop. Lead channel modeled more after the Mark IIC+ Version B - Switchable reverb, single switchable stereo effects loop, Satellite send to drive another power amp. Voicings altered slightly for a more modern tone. A tad more gain on Rhy 2 on tap.
Although there are 2 different versions, they are both highly regarded as equally impressive. The Rhy 1 channel is very clean and can be everything from twangy, to bluesy, to bell chime clean. Rhy 2 has more gain on tap, however falling short of a metal rhythm. More classic rock ACDC'esque. However with the addition of a boost pedal, this channel is often used for metal rhythm. Lead has most gain on tap. It is highly regarded as one of the best boogie lead channels to date.
