That MKII B has the very popular post phase inverter fx loop / reverb mod done by Mike B at boogie. Very cool amp and the mod fixes a few things that were done right in the MK II C's
Greg would benefit from keeping the presence knob down, that and the treble and gain can get out of hand if not balanced correctly. They have the best reverb out of all of the boogies to me and can sound so black face clean. I had one for a long time and wanted to get this mod done but couldn't find anyone local who knew what to do.
Thanks for the heads up on this. I don't give this back to Greg until Friday, so I might open her back up and draw out the mods on a schematic since I cannot find one online anywhere detailing this mod. I know it has to do with moving the effects loop from the current V2B position and changing that stage from a cathode follower to a normal gain stage, but I don't know much else. The only other place to put the effects loop would be one stage later, right before the EQ junction and post front panel Master Volume. I'll try to confirm that if I have time to get back in there. Factory mods would also explain some of the flying leads, the 1991 service RA#, and what appeared to be newer Mesa branded power caps already changed out. Probably will be a Part II.
@@TheGuitologist that would be awesome if you mapped that out, You'd be doing a lot of amp owners a huge favor, techs too!! I know this mod also increases the gain a little, tiny sacrifice on the clean channel but great for the lead channel. And gives it another master volume and better control over the volume and gain of the two modes. I bet if you needed Mike B would talk to you about any questions. Makes me want to buy my amp back and mod it. I see these mods on Mk ii's for sale and it's always nice if a buyer gets one that's already been done, I think it costs about $600 if they do it. They automatically charge about 2-300 to go through the amp first and bring it up to par then about that much more for the mod. I wish they would share their circuits and mods like we see on Fender and Marshall, I know they are pretty protective of their designs. ;-)
@@TheGuitologist Looking forward to part II, but yeah, they certainly stuff too much crap per square inch than any other brand that I have personally worked on. I've worked on a good number of Boogies over the years (Starting with a Mesa Studio 22 - that I scrimped and saved for in high school- that unwittingly turned into a veritable training camp of sorts for Boogie repairs) and the biggest pain in the ass, for me at least, was a tremoverb that hummed like the dickens. Talked to Mikey B at Boogie on more than a few occasions, and there seems to be a practice of them picking their pre-amp tubes for lowest hum. I finally solved the issue and it wasn't the pre-amp, but after soldering in an un-soldered heater wire that I discovered, the problem went away. I'd spent hours in that amp and it was weird that I hadn't noticed it sooner than I did.
@@scottjamable That was the annoying thing with 2 series, it was pain trying to balance clean and lead channel and still had o good sound on both channels.
I inherited a Mesa Blue Angel Dual Rectifier in great condition from my brother who passed two years ago, today, coincidentally. Thanks bro. And, I'm just an ol' country drummer with a few guitars sitting around that I should learn to play but I enjoy Brad's work, his easy going style and his playing. Thanks man!
I think its great that Brad gets to work on such a high profile guitarists amp. Especially a Boogie knowing what he will find inside. This was a great video. Thanks Brad......
My favorite quote came from Greg Martin. I was at a clinic with him and Andy Timmons. They asked Greg what his favorite effect was and he said my cord. Great answer.
Reverb vibrato, chorus, tremolo, and delay appear on more songs than they don't. Maybe not so much vibrato and trem these days. Find me a song not played on an acoustic that's 100% dry with no effects at all, I'll wait.
@@lordhotdawg9902 RIP English Language; it’s almost like you are trying to tell us something m’lord. I can fill it in me bones. Alas the nod I experienced from my last fix hath won me over. Fair the swell !
@@6nosis Here is a tough concept, perhaps people in non English speaking countries use the internet too? Maybe those non native speakers also enjoy this channel and Mesa?
Hey brad, love your opening. That HBO jingle brings back all kinds of happy memories of the early to mid 80s, from my friends and I sitting down to watch the feature presentation to cuddling under a blanket with my girlfriend with only the light from the tv screen.
TOURED 20 YEARS WITH MY EARLY 80'S CLASS 2C..........................AT LEAST 250 GIGS A YEAR ,STILL SOUND GREAT WHEN I RETIRED 4 YRS AGO....I REPLACED TUBES EVERY YEAR.....
@@TheGuitologist I have several older Mesa amps. They’re pretty damn robust. And when you do “have” to work on them, send them back to Mesa. Mike Bendenelli will make them as good as new. Done.
Interesting video. You always do really interesting videos. I used to own a Mesa Mark IIA (which they were originally just called a Mark II back in 1979 when I bought it). I really liked the amp and one mystery I have until this day is when I first got the amp (directly from Mesa...the only way to buy them back then) the amp had a very sweet clean channel. What it did was you could push it into to a sustaining overdrive sound and also there was a lot of note bloom in the clean channel blooming into sustaining harmonics. At some point (around 4-5 months after getting the amp) I deciding to take the Eminence speaker out and replace it with an Altec that I had handy, (I couldn't afford the upgraded EV speaker from Mesa at that time), well what ever happened along the way, I don't know, as I lost that over driven capable clean channel and lost the very pleasant note bloom it would exhibit. Even after returning the Eminence in the amp, it still never came back. I did eventually, put an EV12L in there, (like you could buy from Mesa) but never did get that really sweet over drive and sweet note bloom from the clean channel again. Just a mystery to me what happened. Most Mesa amps I was aware of just had a really clean first channel without the over drive and note bloom, so I guess mine was a model where the components just worked together perfectly. I really can't explain it... All The Best, Phil NYC Area
a great vid and restore, thanks for posting.... I recently had my 1984 MARK IIC+ gone over closely by my tech, with direct guidance from M.B. at MESA (he signed the amp originally) - the results are amazing... a gorgeous restoration was had!!
I left Port Arthur and moved to Austin in 87 with my best friend Devin Weber. We sold steaks and seafood door to to door for his gung-ho Zig Zeigler esque oldest brother Gerald. Gerald made millions pumping up sales guys to venture out to Belton and nowheresville to sell his wares. At night we jammed because Gerald played guitar and so did I and Devin is a bass player. Overnight he ended that career and started building amps under his wife's maiden name Kendrick. He did the same thing with amplification as he did with steak/seafood sales. Pioneered in an unorthodox manner that was always interesting. This vid took me back to those days. Thanks man.
I remember them well, he also serviced amps, etc. Those are the old school Austin days when Ray Hennig's shop was on South Lamar, and he had a wall of 50's Fenders and Gibsons...probably millions of dollars today.
@@daleyoung87 The way the components are arranged, crammed together and often over top of others appears to be done by someone with very little experience. Those who have worked on many amps can tell the difference at a glance, even from a distance, and it is considered very poor design.
@@daleyoung87 . If You ever worked on amps You would get it! Ergonomically Mesa's are impossible to work on, and so messily kluged together. What can be done in 5 minutes on a pre 1983 Fender takes about two days on a Mesa Mark II-II etc (unless it is just basic easy stuff). Please notice , the missing land and jumpered over wire @11:40 (upper left 1/3rd of view);,.. thats because when You try to replace a component the circuit trace delaminates.. God forbid you have to remove a board. You literally have to disassemble the whole thing, including taking out at least 50 parts that block access to whatever You have to get at. The remarkable thing is: You can mod a Fender Twin R or Super -R so that the input end is virtually the same as a Mark I-II or III (minus the 5 band graphic EQ), and get the Fenders, to do a nice Mesa sounding OD, with Master Vol, etc, and they can be just as easy to work on as the original Fender.
I absolutely LOVE Mesa amps! I have never had to do anything to the ones I have owned except change the tubes & clean the pots! Maybe a cap replaced, but nothing serious, EVER! Built like a tank, & tone for DAYS!! I have a late 80's Studio Caliber 20 watt combo. No slider EQ. Just a solid, loud, 20 watt 2 channel amp that sounds freaking killer. I also love old Marshall amps too. I have several of those that I would never sell. To each his own, I guess!! Rock on, man!
Mark Ii B 60/100 W probably an 1979_- 80 piggyback .This amp has been a pleasure to band with , all around beast with any guitar plugged into it . .Thanks for the most informative vid , enjoyed the demo as well ...
@@TheGuitologist yes you had a nice tone in the playing at the end, I’ve never been able to play one so I cannot personally testify on their tone in person. Would like one tho especially a lonestar. Also enjoyed your dummy load vid nice to see more of the amp tech vids from you. Speaking of which.. what happened to “when you don’t know what the fu@k your doing ask an amp tec??” 🤣😂
@@TheGuitologist You should take a crack at my Acoustic 165. All PCB with traces the width of a human hair millimeters from ground, etc. Like the Yamaha CS-80 of guitar amps.
Hello Brad. You reminded me of an amp (not a Mesa) that i had in for repair that had the same behavior with the noise going lower at higher volume settings. The damn thing broke into supersonic osc when the volume was high and that made the amp "sound" less noisy... Had to reroute some wiring and replace some resistors and 7025 that was in place of a 12ax and that fixed it
I have an ‘83 like this, but with cream tolex. It absolutely rips with a 5751 in the V1 position and a Celestine alnico cream in it. Those Mark IIs are killer amps!
Did I hear some good ole.....Black Betty riff in there?................awesome Boogie amp. Thank you Brad and also say thanks to Mr.s Martin for letting you video the encounter.
I love my Mesa amps. Mark 1 2003 reissue, a 1996 Heartbreaker and a 1989 Studio Calibre 22. The 22 is a much overlooked amp. Amazing little beautiful sounding amp. In terms of dependability and organized design, easier to work on layout, and amazing sound, Soldano takes the cake! I use a Reverbosonic along with my Mesa amps. All killer amps, but Soldano is built like a tank and never needs major repair.
I'm so glad I took my Boogie to an expert. It only took him a couple days to go through the whole thing and get it back to me RIGHT. He was the 2nd guy I took it to. The 1st Guy didn't have a clue. Took 2 wks and didn't fix a thing. My bad cause I was told who to take it to, but I started thinking, bad idea, he would be so busy it would take forever. When I got it back it went immediately to the right guy. Now that I know him everything will go to him. Always gotta find the right guy. 1 thing I never stated is mine is a 85 S O B. 60/100 watts, Reverb, 12L speaker. IMHO what makes mine easy is only 7 knobs on front 0 on back. No crazy stacked circuit boards.
I have a Mesa Boogie Rocket 44 that failed while being used - heavy smoke seeped out of it (not a lot) and it went silent. Maybe a cap went? Wondering if it's worth fixing. It had a great sound.
We’re did you get your knowledge I’m starting out on learning how to do tube amp repair what books and DVDs or classes should I be taking to get to we’re you are and be fixing all kinds of stuff I’ enjoy your videos thanks keep putting them on
The bane of High Voltage circuits are PC Boards. Nothin like Point to Point wiring! I worked on a .50 Caliber that just would not cooperate. Great video!! Thank you.
I bought a MkIV brand new, the year they released the model, and it gave me nothing but trouble to the extent that I had it replaced by another which promptly started doing the same thing. It was great with new power valves but it would gradually become increasingly thin and lost the punch, fatness, and eventually became extremely microphonic. There was literally no one in Ireland back then who was able to fix it and I sold it and swore off Boogies until I bought a Triaxis around 7 years ago
Between the beastly transformer and birch ply chassis, it adds up. But I think that’s part of the magic. I’ve had my Boogie combo 23 years and it’s worth the extra muscle. :-)
Yeah, I get you Brad. I had a customer bring in a SimulClass 2:90 recently, where they had broken off the 8 ohm output off one of the Amphenol jacks at the back. What a nightmare getting that two story Amphenol connector out. Would have been much nicer if they had used good old Switchjack plugs for sure. Customer was running that power amp with a TriAxis preamp that somebody had had fun "fixing" and as a result it was sending 230V up your arm if you happened to touch the chassis while it was running. And somehow the LDRs in that puppy had gone bad too. Unnecessarily complication for sure.
You're amazing, Rab. Thank you for your continued support over the years. Hope you and the wife are doing well. Here's hoping we don't have another full YEAR of lockdowns to deal with.
@@TheGuitologist Much appreciated, B. All fine, over here in Somerset, UK (although I will always remain a Scot, sans SNP ...). As for the 💉 farce/farse ... [insert text here]. All of it to you and your Darlings, Izzy (spl?) and Ivy! Maybe we'll meet soon enough, one of these old afternoons. Rab 🔊
I thought the point of PCB's in valve amps was to tidy up hand-wired mess. MB seem to have used it to make things considerably worse. Impressive. Always an education watching your amp videos Brad, many thanks!
To be fair, this one may have been worked on several times in the past. Looks like it was at least worked on in 1991, maybe even by the Mesa factory. But still...just messy as Nick Nolte's hair in a police photo.
Don't they (manufacturers in general mind you not just MB) also do this to compact things down a bit? With so much preamp level processing and tone shaping going on...??
Also those old amps still have nylon pcb supports that detoriate over time for stacking and securing purposes. When the shipment gets jarred like my mark iii no stripe did it dislodged the lead from the power board containing the caps and basically opened the standby circuit. It was the most quiet noise free amp I have ever owned. Since I resoldered it , it is super noisey especially with the lead drive turned up. What did I do wrong? Was it maybe a metal bands fault?
Played through a Studio .22 years ago. Was on the back line at a music festival in Mississippi. Great tone. Couldn’t afford one at the time and now they’re hard to find.
@@TheGuitologist well, no. I spell my name with one L. And I don’t build amps. Or repair them. And I didn’t stay at a Holiday Inn Express last night. But I do work for Gibson. Nice video, by the way. I can see why you don’t like to work on Mesa Boogies. And thanks for the reply.
Love my studio .22 bought it new in ‘ 87 had a .50 caliber head but it didn’t have the EQ it did crank with a Marshall 4x10 bottom...my Mk III BLEW TUBES and was sooooo heavy....peace...let’s see what Gibson does with them...
I’ve owned many amps in my 57 years. Fender, Hiwatt, Ampeg, Vox, the only ones that have given me problems are Marshall, and Mesa. Though I love Marshall’s.
Glad to see your dummy load is working good Brad. Things are best when are tools are functioning well. Yeah Mesas can be a royal pain in the ass to work on, but they do sound good. Good noodling there man.
I’ve got this exact same amp converted into a head. Run into a G65 Marshall 4x12, it’s probably one of the best sounding amps I’ve heard. My channel switch relay still makes an unearthly thump! 🤣 I just crank the lead channel and control it from the guitar. Once you understand the Boogie gain and tone structure, you can’t go wrong.
I’m getting a Mesa boogie mark 2a basically getting restored lol . Who ever put their fingers in it had no clue what they were doing. I’m so excited to get it back. In it’s 42 years has never had a proper cap job
Over the past 16 years I have owned a few older Mesa models, a 110 Subway Rocket, a 112 Nomad 55, a 410 Nomad 55, a 112 Mark IV and a 112 .50 Cal, the only one I really liked was the Subway Rocket, the Mark IV wasn't too bad but it was a beast! I'm not an amp guy but being proficient with a soldering iron I replaced all the control pots on the .50 Cal and it was a factory rats nest, it's really crazy how dependent the controls are on each other and how much one effects the other, I do regret selling the Subway Rocket, for such a small amp it had more balls gain and tone wise over the other ones except the Mark IV. The sad part is that Mesa has to keep coming out with new models and discontinued the older ones that were truly their best amps!
Mesa has done a lot of innovating over the years, I'll give them that. The Mark Series are great sounding amps when you dial them in. They take some getting used to if you're coming from the world of Fender and Marshall stuff. The later stuff I don't think I'd want to ever rely on if I was on a world tour. That's just me.
One of the bands I played drums in, the guitar player had that amp (with a speaker mod). It was an outstanding sounding amp but it's never worked reliably for more than a couple months at a time.
@@trillrifaxegrindor4411 It was new when he bought it. It was fine for a couple of years but the longer it was around, the more problems it had. I'm not even sure it's in use anymore. He bought another new one though. *shrugs*
When I saw that "new" pot that was added to the back of the chassis and how close it is to the power transformer I thought "HUM". It's easy for 60 or 120 cycle hum to get into a circuit from power transformers or rectifiers so be aware if you put a pot or and input jack to close to them. been there - done that.
I should get the bar out and leave it on this thing. I do like using it. It makes me play completely differently when it's there. I become almost a different player.
In my humble opinion, You are absolutely correct, except I hate working on Mesa's and I WON'T do it anymore. I have worked on 100's in the past but only a handful in the last 20 years. I think perhaps the hummy vol pot is a function of: maybe it was originally 1 meg and now has drifted up higher in value, plus it would help to shield the center lead of that pot on its way to the next signal grid. You could probably get by in there with a 500K pot and the consequently lower impedance would help it to be less susceptible to picking up noise. When i clean or lube pots, although its a major pain, i usually put the amp upright with the pot openings facing the floor over the edge of the desk so whatever drips off, ends up on the floor rather than back in the pot. A small mirror helps to accomplish that.
Great video! Please keep us updated on Greg's opinion when he gets it. Its one of my peeves when I get a customer's amp and cannot find anything wrong with it for the most part. Some customers may interpret normal noise as abnormal. Its great if there is a chance to test the amps on location if its possible to get rid of the possibilities of bad wiring on site or bad cables like you said Brad. The guts of this amp look like a novice tinkerer's mess. Not only is it poor construction service wise but it also seems there was no thought on how things were laid out in terms of noise and temperature. BTW what is that funky heatsink doing there? Great choice on the 12au7, it also seems the cleaning had a positive effect too. Awesome playing at the end!
Brad, have you considered widening the scope of your channel to include guitar playing tutorials? It would be instructive to hear how you taught yourself and maybe help others do the same.
