Wizard MCII

[lovetone]

Has anyone any idea which Marshall amp the Wizard MCII amp is based on?

Has anyone had one across the bench? any images or schematic available?

[kdmay]

Check the thread you posted on at SLOclone. It has the schematic.

It’s a hot rodded Jubilee with some important tweaks.

[alfi27]

Could someone please repost the schematic in this thread? I've been looking for that schematic for months, and I tried to register over at the SLOclone forum, but I'm not receiving the activation email and I can't access the forum...

[kdmay]

Here is both the MC2 and MTL.

The MC2 schematic was done by a mate of mine along with my help. The clean isn't verbatim to the MC2 (in fact, I don't think anyone actually knows exactly what the clean MC2 is), it's just what I want to build. The Bright controls are a guess based on the MTL.

The PI and Power Section including filtering in the MC2 look to be the same as the MTL, so use that as a reference.

[kdmay]

I should also add that the MC and MC2 apparently bypasses both the 1st and 2nd stages for their boost. I have tried this in the past and didn’t like the unboosted mode and found the 1st stage bypassed permanently with he 2nd stage bypass as the boost a better option. Hence we drew it that way

[alfi27]

Thank you so very much! I wonder if it would be easier to modify a Marshall to that circuit, or get a kit and build it from scratch.... A very interesting cocktail of Marshalls, I have spent a bit of time with a Modern Classic (not II) but not enough to try out everything. How does the tone stack work, having standard Marshall values but being plate driven? I always thought it was some kind of Hiwatt and Marshal hybrid, although I'm no Hiwatt expert it doesn't seem to be much Hiwatt in there(?)

Also, a bit of a weird place to put the master volume, would it be possible to just replace it with a pre-PIMV or would you need to do other changes to the circuit?

[Roe]

these are hot rodded marshall style amps build with US parts. there is not hiwatt element here really

[kdmay]

People only describe them as Hiwatt Marshall hybrids because of the feel.

They are very big and open sounding amps, which I guess is like a Hiwatt in some ways. But it really shares nothing with a Hiwatt, as Roe says. It achieves this sound from a huge plate voltage (520vdc on the plates) and the plate driven stack, along with the clippers then feedback driven recovery stage.

This amp is essentially a hot rodded Jubilee (i.e. an extra stage). Trace out the Jubilee minus the clean channel, then add another gain stage and you'll see it.

When Rick designed this amp in the early 90s, he was addressing some of the short comings of the killer Jubilee amp (i.e. the Jubilee really only sounds great when really cranked). Adding the extra stage somewhat addresses this and the amp can sound great at lower volumes and the master volume has a great taper. But of course like anything it sounds better when cranked.

Here is an updated MC2 schematic with correct placement of the lead channel bright control and better channel switching.

In the last few days I converted my single channel Wizard MTL build (itself a Jubilee conversion) into an MC1 using the hand drawn schematic that's been floating around for ever (also attached). The MC1 is different as it only has a 2 gain stage clean with a single volume control, which I could only do as I was limited by pot holes. The amp is amazing. Much more me than an MTL, which is more saturated and a little more compressed, whereas the MC1 is open and gainy but not really compressed. I highly recommended this build.

[alfi27]

Again, thanks a bunch! Before I knew the circuit my mind went straight to Hiwatt because of the chassis/build style, and of course the tone and feel. Although I have never tried a real Hiwatt, I have tried Kemper profiles and models of DR103s. That was my assumption as well, that it gets that really tight and clear character from the high voltage and massive filtering. Rick also likes to use orange drops (does anyone which type exactly?) and metal film resistors, which I'm guessing adds to the clarity as well.

So the hand written schematic there is identical to the computer drawn one? It's pretty much the clean/rhythm channel that differentiates the MCI and MCII then? I really have to build an amp with this circuit, I have never wired up a relay but I don't think I need to either, might put the rhythm channel on a push pull pot just to have the option. I played an MC (Wolf Hoffmann's old studio amp) at a band rehearsal once, and it cleaned up so well that I almost couldn't believe it... With my Les Paul I could set the amp up for a quite distorted tone, dial back the neck volume, and achieve a genuinly good clean tone without too much volume drop. And when switching to the bridge pickup I got that really raw, big sound that just punched everyone in the room in the stomach!

Edit: sorry, I was in a bit of a hurry when I read it... The new computer drawn one is an updated MCII schematic and the hand drawn is MCI, got it.

[kdmay]

He just uses the standard SBE715P Orange Drops. No Mallory PVC mojo here! LOL

The Lead channel differences from the MC1 to the MC2 AFAIK are the bright control only. That's the difference between the hand written and computer drawn one. The Rhythm channel are very different in both amps. MC1 is 2 stage plate fed with no shared 1st stage and a single volume control. A little limiting but works really well as a one dimensional clean. The MC2, I speculate (because I don't know for sure), is 3 stage plate fed with a shared 1st stage and has a master volume. More flexible and can be used as a crunch.

Cool story about the MC. Wolf has been using Wizards for ever and still does. Gets a great tone.

Your "punch in the stomach" description is valid! The only other amp IMO that can hang with a Wizard is the SLO. I've built one also and side by side, they are a formidable pair!!

Good luck with your build, let us know how you go.

[alfi27]

Thanks dude! Regarding the bright controls; if you wired them up, did you find them useful? If they are fairly effective, it could make the amp a lot more usable with singlecoil guitars I reckon.

I am still very, very eager to get an amp with this circuit running, but I have to design my own turret board for Nik to be able to make me a kit... One question regarding V3, both triodes have a 1.5k cathode resistor. Should I use one resistor for each triode, or can they share the same one? And do you know if he uses electrolytic 1ufs? I scored a couple of NOS 1uf 160V Mustard caps in April, I believe that's the biggest value they were ever made in and they are massive...

Also, I think I would prefer the MCI clean/rhythm channel actually, if it can get crunchy as well as pristine clean. I really struggle to understand the hand written schematic in terms of the relay though... Can you actually change between the full lead channel, and two and three gain stages (including the tonestack driver stage) on the rhythm channel? So it will be selectable between two, three and five stages overall?

If I get the time to design the turret board I will definitely do it with the MCI in mind (once I fully understand it), should be much easier to eventually go back to MCII than the other way around...

Finally, Rick makes a fairly big deal about the output transformers and I believe he has three options right now. What I'll be using is a fairly standard Classictone 50w Marshall transformer, replicated from some Plexi OT if I'm not mistaken. Do you think that OT would yield different results from Rick's OTs, which should be compensated with using for example different capacitors? I suppose the only direction I could really change things by using different caps is to make it darker/fatter, as Orange drops are as bright as they come from what I understand...

EDIT: I read your post again, so I got the MCII and MCI schematics mixed up actually? The MCII is the one that can also do crunch? The part that really confuses me is that the rhythm master on the MCII receives signal from two places...

[kdmay]

Regarding the bright controls; if you wired them up, did you find them useful? If they are fairly effective, it could make the amp a lot more usable with singlecoil guitars I reckon.

The bright controls I find very useful (I only have the lead channel connected). I ended up actually putting in a bright control for both the lead and boost modes, because the boost mode with both bypass caps coming in at the same time can get a little hairy, so being able to tame the top end and control the runaway is useful.

That's one thing to mention. When my mate and I came up with the computer schematic, I had concluded the 1st bypass cap was essential. I've done a backflip on this now. Once I got the NFB correct @ 100k 4ohm (MTL was 39k), the unboosted mode with both 1st and 2nd stages unbypassed sounds amazing. That's the MC sound I was looking for.

But as I said above, when you kick in the boost and bring in both bypass caps, it gets a little more compressed with lots of top end. The individual bright controls helps to balance this.

One question regarding V3, both triodes have a 1.5k cathode resistor. Should I use one resistor for each triode, or can they share the same one?

Definitely not. It's not a shared cathode setup. Must use individual cathode resistors.

And do you know if he uses electrolytic 1ufs? I scored a couple of NOS 1uf 160V Mustard caps in April, I believe that's the biggest value they were ever made in and they are massive...

Yes, the 1uf bypass caps are electros. You can certainly use those NOS ones, but they aren't really necessary (standard axial 1uf 63v will be fine).

Also, I think I would prefer the MCI clean/rhythm channel actually, if it can get crunchy as well as pristine clean.

You'll want the MC2 clean though (computer schematic), as 2 gain stages still stays fairly clean.

I really struggle to understand the hand written schematic in terms of the relay though... Can you actually change between the full lead channel, and two and three gain stages (including the tonestack driver stage) on the rhythm channel? So it will be selectable between two, three and five stages overall?

EDIT: I read your post again, so I got the MCII and MCI schematics mixed up actually? The MCII is the one that can also do crunch? The part that really confuses me is that the rhythm master on the MCII receives signal from two places...

Correct, MC2 does crunch also. There are 2 sides to the relay: one side grounds the unused channels, the other side toggles the grid of the last stage between the desired channel. Have another look, it will make sense.

Finally, Rick makes a fairly big deal about the output transformers and I believe he has three options right now. What I'll be using is a fairly standard Classictone 50w Marshall transformer, replicated from some Plexi OT if I'm not mistaken. Do you think that OT would yield different results from Rick's OTs, which should be compensated with using for example different capacitors? I suppose the only direction I could really change things by using different caps is to make it darker/fatter, as Orange drops are as bright as they come from what I understand...

Transformers are key in this amp. A simple 50w Plexi set won't cut it IMO. You want big voltage (500+vdc even for a 2 holer) and a 1k7 Plexi OT won't sound right. You want 2k2, preferable M6 steel. I do believe the OT makes a big difference in this amp (like an SLO). M6 is a more "hi fi" steel, bigger bandwidth and frequency response. If you use a Marshall OT, it will loose a lot of this. Marshalls sound like Marshalls partly because of the steel used in their OTs. Just my opinion though.

[alfi27]

Wow... Again, I have a hard time expressing how grateful I am for you taking the time to responding to all of my (sometimes silly) questions! Thanks a million!

Transformers are key in this amp. A simple 50w Plexi set won't cut it IMO. You want big voltage (500+vdc even for a 2 holer) and a 1k7 Plexi OT won't sound right. You want 2k2, preferable M6 steel. I do believe the OT makes a big difference in this amp (like an SLO). M6 is a more "hi fi" steel, bigger bandwidth and frequency response. If you use a Marshall OT, it will loose a lot of this. Marshalls sound like Marshalls partly because of the steel used in their OTs. Just my opinion though.

You just saved me a lot of potential trouble, if I built the MC circuit with my Marshall OT and it didn't sound right, I would never have thought that the OT could have been the problem... The Classictone website states that the OT is 3.6k, but as that is about double of 1.7k I'm assuming that's just another method of measuring it. Transformer specs is something that I haven't educated myself too much about yet, turns out there's still a lot to learn.

Yes, the 1uf bypass caps are electros. You can certainly use those NOS ones, but they aren't really necessary (standard axial 1uf 63v will be fine).

The reason I asked about the capacitors is that I talked to a fellow who, somehow, knows the circuit of every Friedman amp, and he let me in on a few of them. He made a really big deal about the cathode bypass capacitors, which according to him have to be not just a certain type or have certain specs, but he sent me the exact parts number for a particular Nichicon 0.68uf electrolytic. Which I have ordered a 100 of now, as they were really cheap and I want to give the BE (or more specifically the SS100) circuit a final chance. Normally I would just blow off a claim like that and most probably do, but I did try the BE circuit in my JCM800 (with some Vishay polyester 0.68s) and it sounded quite bad, nowhere close to what I heard in the demos. Other circuits I tried in the amp like the Cameron Atomica, Ceriatone AFD and in particular the SE Lead mod that was the end station, sounded fantastic and close to what I expected, so I'm afraid he might be on to something...

That's one thing to mention. When my mate and I came up with the computer schematic, I had concluded the 1st bypass cap was essential. I've done a backflip on this now. Once I got the NFB correct @ 100k 4ohm (MTL was 39k), the unboosted mode with both 1st and 2nd stages unbypassed sounds amazing. That's the MC sound I was looking for.

But as I said above, when you kick in the boost and bring in both bypass caps, it gets a little more compressed with lots of top end. The individual bright controls helps to balance this.

So the first cathode is supposed to be the same as the second, with a 22k on a switch? Does that achieve that awesome AC/DC rock n' roll sound? I can't recall which knob I pulled on the Wolf Hoffmann MC, but the boost sounded really natural and organic even with a Tele. It has a push pull on the treble knob, and the other that I can't recall.

I thought I mentioned that in my previous post, but I didn't. After studying the hand drawn MCI schematic I also noticed the 100k NFB, and after experimenting with NFB in my 800 it is insane how much difference it actually makes... Started out with 47k/4ohm and a resonance knob, sounded pretty bad with resonance at zero but at about 2 the low end was right. Then I started working on my 72 Plexi, that has the 100k/4ohm setup stock, I realised how the low end was still really big and nice but the overall sound was much rawer and in your face. So I simply removed the cap on the resonance pot, which resulted in the NFB to be about 100k for all frequencies with the pot at 2, and that was "it". No resonance knob needed at all.


Like I mentioned I spoke to Nik at Ceriatone about getting a turret board made, and it turns out he just needs a schematic of the entire circuit, with the correct values. Not sure how he got in touch with him, but he emailed me about a guy with a MCII that was willing to open up the amp and take pictures, for a price (not sure how much yet). He has no amplifier knowledge though, so I am not sure how much information can be gained if he struggles to understand what to photograph and how... And even if he can, I don't have the tools to make a schematic, so not sure how to solve that. Is that something you could be interested in helping me out with?

[martin manning]

Transformers are key in this amp. A simple 50w Plexi set won't cut it IMO. You want big voltage (500+vdc even for a 2 holer) and a 1k7 Plexi OT won't sound right. You want 2k2, preferable M6 steel. I do believe the OT makes a big difference in this amp (like an SLO). M6 is a more "hi fi" steel, bigger bandwidth and frequency response. If you use a Marshall OT, it will loose a lot of this. Marshalls sound like Marshalls partly because of the steel used in their OTs. Just my opinion though.

1k7/2k2 are 100W Plexi specs. This is a 2x EL34 power section, wherein 3k6 is nominal for 50W Marshalls. If you want something a bit higher, which seems like a good idea at 500V, there are some 4k2 Fender options.

[alfi27]

Ah, that makes sense. So that's the difference between the transformers Rick offers, the impedance? Apparently the options are A, C and V where the A is smoother and darker, C has more highs and lows (more aggressive) and the V is in between. Could it be that the A is more like a Plexi OT?

This should be a good one for C or V performance, shouldn't it?: http://www.classictone.net/40-18092.html