Mark III questions

[Marcus71]

Hello everyone, this is my first post.

Tonight I bought a Mark III, serial # 16546. I also test drove a Mark II, and I think it was a Mark II a. I could not find a serial number on it. The Mark II had a Black Shadow speaker and my Mark III has an Electro Voice. I sat the two amps next to each other and set the controls on Channel 1 the same for both. They sounded pretty darn close. The Mark III sounded clearer to my ears and I think is a bit louder when it's opened up.

Before today I couldn't have explained the difference between any of the old Boogie Mark series amps. I have owned a number of Boogie amps, but the only combo was a Mark IV I owned about 10 years ago when I lived in Austin.

I think, but am not for sure, my amp has no stripe. I see MB's initials, but there is no stripe above the cord. Here is a picture of that area. I know there is a shadow where the stripe would be, but trust me, there's nothing there.

Can you all tell me what is even the difference? I played a Mark III purple stripe but it was heavily used and too noisy. The amp I bought is as quiet as a brand new amp. I have a hard time believing this thing is about 25 years old. It's either been recovered or very well taken care of.

I have read the outer two tubes are supposed to be EL-34's. Is this correct? It currently has 4 6L6's. Also the reverb seems to be a little weak. It's there but I have to crank it past 5 or 6 to hear it. Is this normal? Is the reverb on these tube driven? Is this amp point to point wired (my guess it that it's not)? Also can anyone tell me what the stock speaker was on this model? How many watts is it? Is it 60/15 or 100/15?

Can anyone give me a link where I can read how the power tubes work in this amp. By the way, I used to own and run my own tube amp repair business in Austin. But I worked mostly on old Fenders. In fact, I have never dropped the chasis on a Mesa.

I just bought a brand new PRS and wanted a smaller amp with a great clean channel. I plugged right into this thing and it sounded amazing. In fact, better than anything I played that's being made today.

If there's anything else you all want to add it would be appreciated.

And FWIW, I paid just under $1,000. I simply love this amp. Tons of headroom and the break-up on the lead channel is quite a thing. To me, this amp doesn't sound like a Fender or a Marshall. It sounds like an old Mesa to me, which I why I bought it.

Thanks!

 

[MrMarkIII]

Hey, nice score, and welcome to the club!
Here's a link to the manual:
http://www.mesaboogie.com/manuals/Mark%20III.pdf
I'm betting the chassis was moved to a new cab.
EL-34s -or- 6L6s may be used in the outer sockets.
V1 is the 12AX7 nearest the input jack. V4 is the reverb tube. V5, the 12AX7 nearest the power tubes, is the phase inverter/driver.
(This is pretty much the extent of my tech expertise.)
The stock Mark III speaker was a Celestion-made 90 watter. The EVM 12L was an option, as was the Graphic EQ, Reverb, and Simul-Class. $150 each option.
Switch up (Simul-Class) is 75 watts. Switch down (Class A) is 15 watts.
Soon, someone will probably post the link to the site which supposedly explains the differences between the various stripes.
Yawn...
I have a blue stripe and a green stripe. There are far more similarities than differences. Any Mark III is better than no Mark III (IMHO)

 

[jpdennis]

I have read the outer two tubes are supposed to be EL-34's. Is this correct? It currently has 4 6L6's. Also the reverb seems to be a little weak. It's there but I have to crank it past 5 or 6 to hear it. Is this normal? Is the reverb on these tube driven? Is this amp point to point wired (my guess it that it's not)? Also can anyone tell me what the stock speaker was on this model? How many watts is it? Is it 60/15 or 100/15?

On the back of the amp chassis at the [facing the back] right side is there a switch and if so what does it have printed about it? This will give me a better idea as to what you can and cannot put in the power tube sockets. Also, I found out that the reverb really needs the foot switch. It is rather weak until the EQ/Reverb footswitch is inserted. Then you have the choice of rather weak (setting 1 - 4) to middling (setting 5 - 8 ) reverb with the switch in the "off" position [it is actually a misnomer] and extremely wet when the switch is "on". You have a no stripe [but check to see if there is a black dot above the power cord] and one of the early(?) 1,600 [check your serial number again] Mark IIIs since it does not say Mark III near the on/off switch as well as having the re-stamped IIC+ faceplate which is why your "Pull Rhythm 2" has a lighter and slightly smaller font then the other control nomenclature [another reason for no Mark III and your serial number is just under 900 higher then my no mark Mark III - see my note in my signature]

Let me know about the rear chassis switch and I hope this helps you on your beginning quest for Truth, Justice, and the American-Boogie way. 8) Welcome to the forum

Dennis

 

[Marcus71]

Thanks both of you.

My switch has Simul-Class on the top and Class A on the bottom.

Is that what you were referring to?

You mentioned the reverb switch. Looking at the user's manual (and reading the chasis), it's clear that jack for the reverb/EQ takes a two-button, two-way switch correct? Just want to make sure before I set out to find one.

As far as tubes, I was thinking RCA blackplates for the 6L6' and maybe Mullards for the EL-34's. Any other suggestions? The Mesa tubes have never impressed me. I was also thinking about Telefunken for the 12AX7's, well at least V1-V3.

Thanks again,

 

[jpdennis]

Thanks both of you.

My switch has Simul-Class on the top and Class A on the bottom.

Is that what you were referring to?

You mentioned the reverb switch. Looking at the user's manual (and reading the chasis), it's clear that jack for the reverb/EQ takes a two-button, two-way switch correct? Just want to make sure before I set out to find one.

As far as tubes, I was thinking RCA blackplates for the 6L6' and maybe Mullards for the EL-34's. Any other suggestions? The Mesa tubes have never impressed me. I was also thinking about Telefunken for the 12AX7's, well at least V1-V3.

Thanks again,

Thanks for the answers and I will apologize now if this gets too lengthy.

Your amp is a Simulclass so you can use 6L6 and EL34 for the power tubes. When you read the manual you can note that it states Mesa use to say either all 4 6L6 tubes can be used or 6L6 and EL34. Then Mesa go on to say that due to the life expectency, and all, the use of EL34 in the two outer power sockets (V6 & V9) and 6L6 in the inner two power sockets (V7 & V8) are the recommended way to tube your amp. As to the power wattage question I have read many slight alternates to whatever the true facts are. I can tell you that the reduction in power with the use of that switch in no way cuts you power in half. I have tried many ways to tell and for the most part it really just changes the tonality from the full girth American rock/crunch/Fendery sound in the Simulclass to the British Marshally sound of the EL34 in the Class A. You will find people like Monsta-Tone 8) and Boogiebabies 8) to be much better references for the technical side. I am assuming your serial number was correct. Did you have any mark like a small dot on the chassis above the power cord?

As to the EQ/Reverb pedal I bought the one direct from Mesa (for the warm fuzzy of having a Mesa branded pedal :mrgreen: ). That is what I am saying and I bought the Mesa Rythym 2 pedal as well. I forgot to check if you said you had any of the Mesa pedals. I made sure I got all 3.

Tubes are very subjective. It depends most importantly on your ear and then on a very specific playing style or a very overall playing style from what I have found. I like the ability to do mega-crunch rock and then slide into Bensonesque jazz. So my power tubes on all my amps are in the middle area for clean headroom and mid way breakup for the solo style - everything else for me drills down from there [Mesa Green, if you will]. I have tried many tubes which can be deceiving since they seem to be limited - there is the history of many suppliers using a select few production plants and just rebranding them. For preamp tubes I have tried JJ, TAD, Tung-Sol, EH, Mesa Russian, Mesa Chinese, and recently a RFT. When it comes to my Mark III, and probably all the Mark series I have read about, all of the V1 - V5 valves use 12AX7 [Mike B at Mesa was very specific about that in a conversation with me concerning my Mark III - NO 12AT7 is his mantra and I follow that (not being a tech I really didn't know that not every amp manufacture uses 12AT7 in the Phase invertor or the reverb ] and I have tried the Mesa SPAX7 (rubber sleeved Mesa 12AX7). For power tubes I have used JJs, Groove Tubes, RCA, Mesa, Winged C, and Mitchell. Now the answer which works for me and I will post a complete line up (valve position, power tube rating from the tube store DOT com and all) of position when I get home tonight. For now I use SED Winged C in the power side (EL34 rated at 35 and 6L6GC rated at 19). My preamp is a mixed bag of Tung-Sol, JJ, TAD, and RFT. I have noted that the Reverb socket on all the Mesas I have are really weird in that the wrong tube makes the Reverb suck and the right tube makes it sing. Like I have said I will be posting a complete "line up" in the tube section of this forum and will paste the Mesa Mark III selection I use and the why in this thread later tonight.

Hope this helps and does not confuse. More later. :wink:

Dennis

 

[Marcus71]

Dennis,

Thanks so much for the information. FYI, there is no black dot or strip on my chasis. I know the chasis is legit because it's got MB's writing all over it as well as the production month and year (Jan 86).

As far tubes go, you're right. It's a personal thing. From my experiences, nothing sounds better in Fenders than RCA black plate 6L6's. I remember the first time I did a tube job using RCA's. A guy in Austin brought me the tubes so I could drop the chasis and set the bias. He had a blackface Super Reverb. After I replaced the tubes, it was one of the best sounding amps I have ever heard. The guy brought his strat, plugged straight in, and it was something special. I didn't want him to stop playing. :shock:

Also I think I prefer Mullards in non master volume Marshalls. I have done side by side comparisons between Svetlanas and JJ's in a couple of different amps. My ears preferred Svetlanas but the JJ's were pretty good too. In fact, the difference was very small. If I remember it was a very slight clarity difference.

My thinking was to take the best of both that I have heard, i.e. RCA and Mullards, and put them in this amp. Honestly, I like to experiment with tubes. But the good NOS ones are not cheap.

Preamp tubes are really hit or miss. I don't have a lot of experience using NOS versions, but I did put some RCA 12AX7's into a Twin Reverb and it sounded good. I have read that Telefunkens are nice, but can't say for sure that I have ever heard one in person. I read on this board some people have used them in their Mark III in various positions with good results. But again, it's a preference issue.

I did get one pedal with this amp. It's the Lead/Rhythm. I need to contact Mesa about getting the other two.

Thanks!

 

[igfraso]

It is certainly a "no stripe/black stripe/black dot", for short a "black stripe".

The lower s/n I have seen on a purple stripe is 16657 while the highest I have seen of a black stripe is 16715.

 

[Marcus71]

It is certainly a "black stripe". Not only for the absence of stripes but also because of the serial number.

The lower s/n I have seen on a purple stripe is 16657 while the highest I have seen of a black stripe is 16715.

Thanks. That's what I figured.

 

[igfraso]

You can also check eBay for the other 2 pedals.

If you have some few dollars to spare, get the "Rhy2 Volume" pot mod and the Reverb mod.
Both mods are recommended by Mesa.

 

[jpdennis]

Preamp tubes are really hit or miss.

That statement is "so on the money". I normally use the ECC83-S JJ Gold in my reverb sockets with all my Mesas. Late last night, before the final change I made which I will be testing tonight, I noticed the reverb in the Mark III is no way near as warm as it was with the Mesa SPAX7 in V4 due to not having anything else I liked laying around until the TubeStore order arrived (like my previous post reverb for me is the weird socket anyway). TAD 7025-S work great in my Heartbreaker for gain, clarity, and low noises with no microphonics. It is just that the Tubestore was out of TAD and I had one balanced TAD available for the PI [I highly recommmend using a balanced tube in the PI but no where else]. Anyway, the next post will be tonight with the "final" line up. :lol: [if there is ever such a thing - God trying preamp tubes can be as bad as bleeding edge techno/computer envy :shock: ]

Dennis

 

[igfraso]

Also, cabinet is probably coming from some other Mesa amp.
If I am not wrong, the original cab has the "sus-4" suspension system.

 

[Marcus71]

Preamp tubes are really hit or miss.

God trying preamp tubes can be as bad as bleeding edge techno/computer envy :shock: ]

Dennis

I already bought tons of Apple stuff in the last 6 months. Don't get me started. :wink:

 

[jpdennis]

You can also check eBay for the other 2 pedals.

If you have some few dollars to spare, get the "Rhy2 Volume" pot mod and the Reverb mod.
Both mods are recommended by Mesa.

I would first advise to use the pedals and see how the amp responses. My Mark III gets an increase in volume as well as some real great crunch with the R1/R2 pedal switching to R2. My reverb is off the charts when the pedal is engaged as well [when I get the luck of the Irish on the darn proper 12AX7/ECC83] . I have noted that many Mark III users recommend the mods based specifically on the Mark III amps they own. My Mark has Randy's initials and it is serial number 15710. Maybe I just got lucky in that I have read that after the final assembly Randy and Mike would check the circuit and then change resistor values some times as their ears called for it. I can only wonder if this amp was made during the Mark IIC+ kinda-sorta sound alike solo side transition to the first Mark III series. The Doctor supporting the boogie files eludes to serial numbers being soft in some ways. Thus is my Mark III really the 710th made or is it lower on the Mark III numbering chain? I can only speculate since I have no knowledge of any of the truth behind the mystery. I do know how my Mark responses and "I Like It"..... :mrgreen: :lol: 8)

Three other things I realized are 1) I have the 4-Sus cab in Imbuya/Wicker, 2) the speaker is the EVL 12, and 3) the chassis and the speaker are sharpie marked matching serialized in another way by Randy - I noted a very similar style to three of the numbers with respect to his sig - similar to government serialization for matching and/or inventory control.

Dennis

 

[Marcus71]

One more thing.

I was in a local music store today trying out some pedals because I am on a tone-quest...what's new. Anyway, I was telling the guys about this amp and they said the EV speaker in this amp is probably rated at 200 watts and will be impossible to break up.

I checked when I got home. It's an EVM-12L. I looked it up and read they went into production in 1983 and they are rated for 200 watts. I guess this speaker could be the original. The back of it is huge.

 

[igfraso]

Both mods are recommended by Mike Bendinelli and are so easy to make that Mesa will do them only if you send your amp for clean-up/check-up purposes.

When you use the reverb pedal, be aware that you are not switching between off and on... but between weak and strong.

Also, when you engage the R2 and later you engage the Lead mode, you will realize that you get different sounds if you have a R1+Lead or a R2+Lead.
Actually, it is as if you have sort of 4 modes.

One last thing, the Mark III was designed around the EVM-12L.

 

[jpdennis]

One more thing.

I was in a local music store today trying out some pedals because I am on a tone-quest...what's new. Anyway, I was telling the guys about this amp and they said the EV speaker in this amp is probably rated at 200 watts and will be impossible to break up.

I checked when I got home. It's an EVM-12L. I looked it up and read they went into production in 1983 and they are rated for 200 watts. I guess this speaker could be the original. The back of it is huge.

Tone quest - the next generation [couldn't help it :lol: ]. Yep the speaker in my Mark III was the EVM-12L which I replaced with a brand new EVM-12L Classic [I was repairing everything and brought the wood cab back to life - all new caps, a few fried resisitors, two of the valve sockets, and a partridge in a pear tree - when I first got it] and then put the Mark III's in the .50 Caliber. I had an original EVM-12L professional in my Mitchell Pro 100 and an identical Mesa style EVM-12L in my Acoustic 165. Those speaker, for me, never broke up in the 30+ years I had the Mitchell and I played that loud and hard.

Dennis

 

[MrMarkIII]

Here's a source for replacement foot switches, he advertises on the board, he's a stand-up guy. The Reverb/EQ pedal needs a TRS (stereo) cable, by the by.

http://cgi.ebay.com/EQ-Reverb-Replacement-Footswitch-for-Mesa-Boogie_W0QQitemZ230450522510QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item35a7ebe98e#ht_500wt_684

 

[igfraso]

Yes, I also bought a Voodooman footswitch all-in-one to avoid the hassle of dealing with 3 different footswitches.

 

[Marcus71]

I saw an ad on the local Craigslist for Vacuum tubes so I replied. I found a repairman of sorts within a 10 minute drive. This afternoon I went to his shop and it looked like expected, i.e., **** everywhere.

I went through boxes of tubes, grabbed a bunch and tested them on his tube tester. None of these are brand new, but all of the ones I bought tested well into the good zone.

Here is a picture of them

There are 3 Telefunken 12AX7, 1 GE, 1 Sylvania, and a few RCA's.

There are a pair of Svetlana EL-34s. And a pair of Phillips 6L6's and they look identical to RCA black plates. He also had a pair of RCA black plate 5881's but I didn't buy those.

I am still monkeying around with these tubes. I had something really strange happen with the tube in V4. Whatever I put in there cut out a lot of the clean channel's headroom. Even with the coils split it was breaking up if I put the guitar on 10. When I backed off it cleaned up. This was with Volume 1 on about 7. As soon as I put the Mesa tube (Russian) back in, the channel went back to where it was.

 

[jpdennis]

Here is what I have landed on (for now :? ) concerning the tubes in my Mark III;
V1 – Tung-Sol 12AX7/ECC803-S (Gold)
V2 – Tung-Sol 12AX7
V3 – RFT ECC83/12AX7
V4 – JJ GOLD 12AX7
V5 – TAD 7025-S balanced
Power Tubes = SED Winged C - 6L6GC rated at 19 & SED Winged C EL34 rated at 35

I have been trying various tubes for the sound I want and after much TAE (trial and error) I really like the response and tonality across the spectrum of my style.

While I have used older tubes which have tested good, the literature I read about Mesa suggest to me to make sure they are very good and high gain for the V1. After many months of TAE I only feel in my gut that the balance 12AX7 for the PI is a great choice. I can't quantify it, just qualify it. Also, I may try other vendors but I have been extremely pleased with the TubeStore.com ... And that is all for now. :wink:
Dennis