Boogie MKIIB Rev Eq 60/100W head

[gitapik]

The clean sound of the Jubilee is pretty ok, also because the tone controls are more effective than on other Marshalls. Its a matter of taste anyway. But in IMHO nothing comes close to the cleans of a Boogie Mk II or a good Fender. Thats a Benchmark.
But: who plays a Marshall because of its clean sound... :mrgreen:

True, true, true...

 

[mark2boogie]

Hi gitapik & TiPiMods,

I read that you've converted a 15W BJ to a 30W one : that is to say that you've added 2 extra 6BQ5/EL84 in the power stage (among the other required modifications needed by this power change, indeed). Am I right ?

I had some stock BJ for service, and the only qualities I have found to them is their compactness, lightweight, and very nice custom colours Tolex... Side to side comparison with a VC-15 Laney and furthemore a SF Princeton Reverb demonstrated quickly that the sound wasn't worth, unfortunately. So using a BJ as a mod platform - yes - good idea, if doesn't sound too "boxy" due to the quite closed back.

Can you tell me more ? Maybe show some pictures of chassis / back of the amp to have an idea ?

A+!

 

[TiPiMods]

Hi Mark2boogie
as far as I know Billm (http://www.billmaudio.com) converts the BJ to oktal sockets, so you can use 6V6, 5881 or even 6L6. I never had the chance to try one of these converted amps. My own one is modded a lot, most important is the tone stack and the coupling caps. With different values it sounds a lot better than stock. The boxieness ist mostly due to the small coupling caps and the small cap value of the bass tone stack. I changed also the output transformer and the speaker (Celestion G12-65) and built a cathode follower with the one unused tube system to drive the tone stack. My power amp is the original 15W EL84 stage, biased a bit cooler for more clean headroom.

 

[gitapik]

Hi gitapik & TiPiMods,

I read that you've converted a 15W BJ to a 30W one : that is to say that you've added 2 extra 6BQ5/EL84 in the power stage (among the other required modifications needed by this power change, indeed). Am I right ?

I had some stock BJ for service, and the only qualities I have found to them is their compactness, lightweight, and very nice custom colours Tolex... Side to side comparison with a VC-15 Laney and furthemore a SF Princeton Reverb demonstrated quickly that the sound wasn't worth, unfortunately. So using a BJ as a mod platform - yes - good idea, if doesn't sound too "boxy" due to the quite closed back.

Can you tell me more ? Maybe show some pictures of chassis / back of the amp to have an idea ?

A+!

Sad to say that I know very little of the inner workings of an amp. So I can't say what should or should not work. But I do know that the sound of the amp that mine is being patterned after, in terms of mods done, was a very big, not boxy at all sound. Much easier to dial in volume and tone controls, and the Fat, Presence Control, and Clean Boost are all very effective. It's a serious, small amplifier. I was pretty blown away.

Keep in mind thar I wasn't going to send the amp to him unless I was happy with the one I heard. It's very impressive. I'll be returning from vacation on Thursday and getting the amp up shortly thereafter. Very much looking forward to it.

As to how it can eliminate that boxy sound while still retaining the almost closed back: ??? But it does. Maybe TiPi can chime in on that. I could have spent more than twice the money after selling the gear I sold...but this amp delivers. So now I've got my Boogie and a great lightweight grab and go with money to spare.

Here's a list of the mods that are being installed:

Basic mods, cream board (you can find these on the website. Many people just do this mod)
Presence control
Clean Boost
Audio-taper reverb control
Audio-taper master volume
Switchcraft input jack
Standby/Power switch
Line out jack
Cathode follower mod
Jewel pilot lens/LED conversion
Heyboer TO26 (includes aux)
TP24 power transformer
Octal conversion
JJ 6L6GC, burned in, matched
Bias Board 
2-button footswitch with lights

 

[TiPiMods]

On Billm's old site there is some explanations and diagramms about the tone stack and the values of the caps (http://home.comcast.net./~machrone/bjr/bjtone.htm) After I tried the modifications ( 0,1µ for the bass cap and 0,015µ for the middle) it proved right away what he wrote and showed on his site. boxiness is gone because the amp has a lot flatter response and with the "twinstack mod" you can dial out the mids completly. And they are more seperated from the bass.
the small cab of the BJ is a problem if you want really a lot of bass, because of acoustic shortcut you won't get as much bass as a Deluxe or a Vibrolux with their bigger cabinets.
But for my taste: I never go over "3-4" on a Silverface, Blackface Fender or my Boogie MkII in a band situation. And if I need the sound of a stack (very seldom live) I have to bring one of my 4x12s and a Marshall head :twisted:

@mark2boogie:
how's your MkIIB, did you finish all the work?

 

[mark2boogie]

OK guys - thanks for your input about the BJ. I will look further about it when I'll have another one for service, and in-between search more info.

No TiPiMods : the MKIIB is still awaiting. I have to send the transformer and wait for the new replacement one, probably on September... I have other amps to repair/restore before, notably a MKIIC export 60W Rev Eq hardwood.

A+!

 

[TiPiMods]

Great, a MkIIC! I hope you find enough time to compare it to your IIA and IIB and can give us some descriptions about the "holy grail" and if it is REALLY the "holy grail" of boogie amps

 

[gitapik]

Great, a MkIIC! I hope you find enough time to compare it to your IIA and IIB and can give us some descriptions about the "holy grail" and if it is REALLY the "holy grail" of boogie amps

The IIC+ is supposed to be the Holy Grail. I am the ugly duckling with my stock IIB.

But I, too, am definitely interested in your impressions.

 

[mark2boogie]

Yes, indeed : a fair comparison is compulsory here... Of course I will let you know the results of that side-by-side test. Probably in early-mid September.

Note that the amp is a stock MKIIC, not a C+, but it has the 2-stage overdrive circuit, like on the C+ and unlike on the IIA and IIB.

I will try to make samples if I can borrow the equipement and find the time to... At least, I will take pictures !

A+!

 

[gitapik]

Got the Blues Junior, complete with mods, this morning. Great amp, guys. I can set it like a Twin (Bass and Treble off and Mids up full) or so many other sounds. I've got a great grab and go, now. So happy.

It's got the Jensen C12n in there. With my G&L ASAT, the bridge pup tends more towards warm than thin, to begin with...so there's no ice pick there. And the neck pup and combination of the two are really fine. Same for my Les Paul with coil taps. It's all good there.

My Strat's got the ice pick, though. Bill mentioned putting a steel plate under the bridge pickup to soften that...though he also likes the Cannabis Rex better as an all around speaker for this amp.

Part of me feels like getting the Cannabis, but I often feel that people give up on gear too fast, sometimes. Especially speakers. I'm thinking of breaking this Jensen in and seeing what's what from that point.

Also looking at carry case/dust covers. First time I've even thought about clamshell cases. Anyone here use one? I've always used a straight slip cover on my combos. I like the idea of a clamshell, but, with the leather feet on it, I think it would just add more weight...

Bottom line, though: billM's mods deliver. Very, very impressive little soundbox, here.

8)

 

[gts]

Yes, indeed : a fair comparison is compulsory here... Of course I will let you know the results of that side-by-side test. Probably in early-mid September.

Note that the amp is a stock MKIIC, not a C+, but it has the 2-stage overdrive circuit, like on the C+ and unlike on the IIA and IIB.

I will try to make samples if I can borrow the equipement and find the time to... At least, I will take pictures !

A+!

I've compared a IIC 60/100 EQ Reverb with a similarly configured IIC modded to a IIC+.
They are very different amps.
So any comparison between a IIC with a IIA or IIB is NOT going to shed any light as if the comparison was done between a IIC+ with a IIA and IIB.

The above IIC was sold and the new owner Chip had it modded to a C+.
He posted his views of the "before" IIC to the "after" IIC+ in this thread:

http://forum.grailtone.com/viewtopic.php?f=27&t=40556&p=291948#p291948

I'm the guy who bought GTS's "other" Mark IIC. I liked with it for a few of months. Then, in early September I sent it off to Mesa to get upgraded to the IIC+. It just came back this week. It's been a good week.

My thoughts are this:

1) LEAD CHANNEL: I like the IIC+ lead channel better than on the IIC. I felt that the IIC was too harsh...both on rhythm work and on lead stuff and at all (low-medium-high) gain settings. Furthermore, if did choose to crank the gain on the lead channel, my IIC would never get that liquid feeling where the notes just ripple out smoothly like a rivulets of water in a stream. The IIC+ does. Mmmm. The change to the lead channel is (I believe) the main reason people get this mod.

2) EFFECTS LOOP: The effects loop on the IIC is fine as long as you never use the lead channel. But, in my opinion, you don't need an effects loop if you only play the clean channel...you can just put all your effects between the guitar and the amp. For the IIC, the trouble comes when you want to put some delay sound onto the lead channel. Because the IIC puts the effects loop BEFORE the lead circuit, all of your echos (or reverb, or chorus, or phase, or whatever) get all mashed up by the lead channel's distortion. Total crap. Like I said above, it's just like putting these pedals between your guitar and the amp and then turning on the lead. Ick. Totally useless. The IIC+ mod gives you a proper effects loop (ie, it comes after the lead circuit so that the distortion is first). If you like a little delay, you need the mod.

3) TREBLE SHIFT: I don't know if this is "official" or not, I think that he changed how my Treble Shift works. In the IIC in rhythm mode, you could push or pull the Treble Shift and hear the change in tone. Fine. When switching the IIC to Lead mode, the Treble Shift was automatically activated whether or not the pot was pulled. To my knowledge (perhaps wrong), the IIC+ should be the exactly same (switchable in rhythm, always on in Lead). But, when I got it back from Mesa after the IIC+ upgrade, it was totally opposite...in rhythm mode, the Treble Shift is always defeated (whether or not the pot is pulled) and in Lead mode, you can pull or push the pot to activate or deactivate the mode. In my opinion, this new way (whether it's standard IIC+ or not) is superior.

Here's some more of his comments/ insights:

The IIC and the IIC+ are totally different animals...well, they're still Mark-series amps, but the IIC is unique among all the Mark amps. It's not like the IIB and it's not like the IIC+...it's different.

I had a 2C that I had upgraded to a IIC+.

The lead channel is very different, IMHO. I like the IIC+ tone better. But, that's because I bought the IIC for the classic boogie lead tone and the IIC+ *is* the classic boogie lead tone.

So hopefully you can see that using a IIC to compare with a IIA and IIB is NOT going to give you any insight to the comparison as if a IIC+ was being used.

 

[gitapik]

Hey, gts. I didn't know that there was an upgrade for the Mark C to the C+. I'm going to keep an eye out for a Mark C in the future. That would be very cool. The C+ prices are out of my range. Wonder how much the upgrade costs.

I think there's a little confusion here, though: mark2boogie picked up a C model and is going to compare it to his A and B (sounds like grammar school here), knowing its a "C". TiPi mentioned it as being the holy grail and then I chimed in about how the C+ is the one that has that rep, now. Added a new step to the equation/discussion.

 

[TiPiMods]

Sure, a IIC+ is not a IIC etc...but any comparison is useful and useless at the same time: tone is a very personal and subjective matter, first of all made with your fingers, and second, there are a lot of great sounds out there, not only made by boogie amps. Every one of us loves boogie tones, often for quite different reasons, one for their great lead tones one for their georgeous clean sounds too and so on.
But anyway, not so often someone has the oportunity to compare amps side by side, so I'm always interested in opinions about that, if its a A,B, C or a C+

 

[gts]

Hey, gts. I didn't know that there was an upgrade for the Mark C to the C+. I'm going to keep an eye out for a Mark C in the future. That would be very cool. The C+ prices are out of my range. Wonder how much the upgrade costs.

I think there's a little confusion here, though: mark2boogie picked up a C model and is going to compare it to his A and B (sounds like grammar school here), knowing its a "C". TiPi mentioned it as being the holy grail and then I chimed in about how the C+ is the one that has that rep, now. Added a new step to the equation/discussion.

Last I knew the C to C+ Upgrade was $400 plus shipping to and from Mesa.

Sure, a IIC+ is not a IIC etc...but any comparison is useful and useless at the same time: tone is a very personal and subjective matter, first of all made with your fingers, and second, there are a lot of great sounds out there, not only made by boogie amps. Every one of us loves boogie tones, often for quite different reasons, one for their great lead tones one for their georgeous clean sounds too and so on.
But anyway, not so often someone has the oportunity to compare amps side by side, so I'm always interested in opinions about that, if its a A,B, C or a C+

Just trying to let you know (and be clear) that comparing a C to other amps will in no way be the same as comparing a C+ to other amps.
So if comparing a IIC to an IIA, no comparative conclusions should be made about the IIC+ to a IIA.

Yes agreed, Tone is very personal, very subjective.
And I agreed again, there are many great amps out there.
I have a small grab and go amp that I love (it's not a Boogie).

There is no one "be all and end all" amp out there. All are just different flavors on the tone palette.
But you can't compare Chocolate to Vanilla and say it'll give you and understanding of the differences between Strawberry to Vanilla.

 

[chipaudette]

Hi there,

I'm the "chipaudette" that GTS was talking about. To reinforce what George was saying, it's not tone-snobbery that is causing us to tell you that a IIC is not a IIC+, it's that the circuits are really very different. And I'm not talking simply about changes in resistor or capacitor values...nope...I'm talking about major differences in the circuitry. If you're a tech-head kind of person, you can check out the IIC schematic at the link below and compare it to your favorite IIC+ schematic from the web.

http://picasaweb.google.com/109244885492088240430/20090628MarkIICGuts

With a little study, you'll see the wackiness that is the IIC. It is completely unique in the Mark line-up. Frankly, I am stunned at what a weird step they took in going from the IIB to the IIC. To my eye, the IIC+ abandons some of the unique features of the IIC and returns more to the pattern of the IIB (though with other changes).

For one example of IIC uniqueness, note how early the effects loop and the reverb appear in the signal path....right after V1B. The IIB and the IIC+ deals with them much later in the circuit. This approach used in the IIC is totally wacky and results in the weird interactions with the lead channel that George quoted above.

As a second example, note that the signal from V1B is coming off the cathode of the tube. This is in contrast to the IIB and IIC+ (and Mark III and Mark IV and every classic Fender), where the signal comes off the anode at this point in the circuit. The cathode-coupled stage results in a very different signal level/impedance being fed to the gain stages that follow (and designing the interstage signal levels and impedances is crucial for the sound of a preamp-based distorted guitar sound). Why did Randall do this when going from the IIB to the IIC? I don't have a clue. None of the other Marks do it this way. This is unique in the Mark lineup.

So, from a circuit topology standpoint, the IIC is as different from the IIC+ as is the IIB. If we're looking just at the lead circuit (and not the power amp), and if we're looking just at the schematic (and not at the brand of components or at the type of printed circuit board or at the transformers), one might even say that the IIC is even more different from the IIC+ than the Mark III or Mark IV (of course, the III and IV have other changes that impress their own flavors on the sound). It's a bit heretical to say, but if you're a high-gain player, I think that Mark III gets closer to IIC+ than a stock IIC. If you're a mid or low gain player, well, each amp has its own flavor.

If you have or can get access to a straight IIC, you will be listening to one of the most unique circuits in the Mark family. For that fact alone, it's totally cool. But, its lead channel is not really like a IIC+ lead channel. You might like the IIC better, or you might not...that's totally up to you. All I'm saying is that it's a very different circuit.

Chip

 

[TiPiMods]

Hi guys
thanks for the schematics and explanations. It was not my intention to start a IIC and IIC+ discussion here (this "holy grail" thing was more meant as a joke, so forgive me beeing not accurate enough) . I know that the schematic is quite different and your explanations made me look again and indeed wonder, how much Mesa changed. With the C+ mesa tried to adress some problems with the reverb and the loop of the IIA,B and C. The C+is the first of the Mark amps where the loop is usable (at least what people say) and the reverb mirrors the actual sound of the channel. Plus the added gain made a different amp out of the IIC.

 

[gitapik]

I like how this thread evolves. It's cool learning things that I wasn't expecting to learn. It's so much like just hanging out and talking at a friend's place.

Wonder what Randall did have in mind?

Here's a question for ye tech gods: I haven't even bothered with the effects loop in my IIB since I got it, decades ago. It didn't work and I didn't understand how to get the lead tones at that time, so I mainly used pedals. So all my effects were up front.

I recently started playing without the reverb, though, and have found that the effects loop is much more useable when I cut out that feature. In both lead and rhythm mode. Is the "fix" that simple or is there more to be improved upon?

 

[TiPiMods]

:lol: In no way I am a "tech god", my guitar playing is a lot better than my tech abilities. mark2boogie is the man, look at his selfmade amps and his stompboxes.
But I'll try to answer: on the MKIIB the reverb signal comes in before the loop, so everything you patch in the loop gets the reverb signal too. Depending on which kind of effect you use, you get some kind of mess. Thats why it sounds probably much better to use either one.
The loop itself is quite clean with its cathode follower, which keeps the impedance low, so you dont loose treble with longer cables and its more likely you dont get any hum issues.
I am lazy, I dont want to carry around another piece of equipment so I mostly use the built in reverb, which in my opinion sounds good, maybe not as organic as the one from my Fender amps, more glassy, but ok.
The problem is always with the lead sound: the signal is taken before the lead circuit, so the reverb mirrors the clean sound and not the lead sound, which sounds not naturally at all. you get a distorted sound mixed with the reverb of a clean sound...and the balance changes, in lead mode there is less reverb. mark2boogie had a cure for that, but I didnt try it yet.
But the older I get, the more I try to use less reverb and be a "man" (like Eric Johnson said about using to much delay himself)

 

[gitapik]

Well...maybe not a god, but you said you've done some of Bill's mods, so that puts you a step above my neanderthal self.

Thanks for the info.

 

[mark2boogie]

Well, guys... What a debate... I like Vanilla, Chocolate, etc... :mrgreen:

I am not the owner of this MKIIC - which is there for (serious) maintenance (needs), and I unfortunately never had in hands a stock/factory MKIIC+ (I think that these are fairly rare in France). So indeed I can't tell the real difference between C and C+ through my ears.

I am pretty akeen to think that there is the MKI/IIA/IIB range of sounds at one side, and the MKIIC/C+/III range of sound at the other side, the second representing an improvement in the "rock agressivity" direction above the first, which was more aimed at a violin/horn-like "smoothness"...

I recently bought a Roland R-05 digital recorder, so i will be able to post (I hope) some samples for MKIIA/B/C side to side comparison. Nonetheless, a quick preliminary test of the MKIIC after maintenance for checking let me think that the statement that I wrote just above seems to be possible.

Wait and See...