Mark IIC+ Mod Idea

[Restless Rocks]

Okay Boogiebabies and all you Mod Hounds out there! I was wondering if anyone has tried this. How about a MarkIII R2 Mod on a IIC+. It would be real easy and has the potential to sound great in the gain structure of the IIC+. What dya think?

 

[Boogiebabies]

It can be done, but I prefer a pedal boosted channel 1 or 2 over a modded R2 anyday. If I want crunch, I just roll the volume pot back.
If you don't use the relays and LDR's, the mod would effect the clean and Lead channels. On the MK III, if you leave the R2 in, it effects the lead tone and makes it thin and buzzy.

 

[Restless Rocks]

Hey man! Of course the relay and LDR would be necessary to switch it in and out just like on the MkIII. Perhaps I'll focus on possible mods for the MkIII R2 for starters. I was thinking of a tweak that would involve only a couple cap changes and could make the MkIII R2 more like a MIIC+R1 fully cranked. (you know that nice touch sensitive, use yer guitar vol type thing) That way you could keep your R1 gain at about 6 for a good clean clean and R2 might be found a little more useful at lower output levels. I'll try and draw up something and see what kind of mayhem we can get going here :wink:

 

[Buddy]

Sounds cool . And what about a triode /pentode switch mod ?Time to slash and burn some warrantee's !
Boogiebabies , hows biz on the Miramax lot?

 

[Boogiebabies]

Miramax, ****, they account for 75% of my business.

Hey? Do you guys have medical?

A triode pentode switch is possible, but I personally would not want to change the impedance the irreplaceable SC-152019B tranformer sees. The pentode wiring on the MK III Green Stripe and MK IV are safe because of the 562004 OT.

 

[Boogiebabies]

I would be careful with this mod. The MK III R2 basically adds another 3.3M resistor and a 180pf cap in parallel with the existing 3.3M/20pf lead bridge circuit. In effect, you get 0 resistance an 200pf of capacitance. The output is buffered much less by a 6.8K resisitor instead of the 330K/47pf that the R1 and Lead circuit passes through. I personally would not bother with this effort. I have already modded the IIC+ in different ways to get a better effect on the clean and lead channels as well as a mid scoop switch. The two gain mods add a pedal like jump in gain and the second adds so much gain it's crazy. Without altering the switching, which is in the works, you have to live with boost 1, boost 2 or the off position. Adding an R2 would also need a pot to be effective in the mix.
The mid scoop is the nicest of the mods because it allows for an SRV on crack tone for single coils and a Master of Puppets tone on Humbuckers. Also, I think the way Petrucci has the second Volume 1 is the best way to balance a great clean and alternate lead Volume 1 setting. I already did the mod and have to work out the switching circuit. All the mods are great, but the biggest concern is that you are working on a nearly irreplacable circuit board and a layout that is not very condusive to work on. You have to be a solder gymnast to make one simple joint without burning a crucial signal wire. If you burn through the underside of a wire or loosten a component, it could take a week to figure out where the short is. I took about six months of careful study and seriously slow steps to ensure that I would not make a tonal error or ruin a rare amplifier. A very slow and painful ordeal.

 

[Elpelotero]

you should work for Mesa.

 

[Boogiebabies]

I would not mind, but I would have to make some serious money. The cost of living is enormous. The same house I live in now would cost $ 1.2 Million in Santa Rosa. I don't mind the occasional earthquake, but I would have to live in a tent making $ 40K.

If I get in, I would reissue the IIC+.

 

[Bullen]

If I get in, I would reissue the IIC+.

Now we have get you working for Mesa.

 

[Boogiebabies]

If I get in, I would reissue the IIC+.

Now we have get you working for Mesa.

While your petitioning for my employment,
clean the connections on your reverb cables and tank. Shoot them with some contact cleaner and try to shine them up with some 0000 steel wool if possible. If the contacts get hinky, they hold the reverb circuit above ground and can make all kinds of weird noises and tones.

 

[Restless Rocks]

I would be careful with this mod. The MK III R2 basically adds another 3.3M resistor and a 180pf cap in parallel with the existing 3.3M/20pf lead bridge circuit. In effect, you get 0 resistance an 200pf of capacitance. The output is buffered much less by a 6.8K resisitor instead of the 330K/47pf that the R1 and Lead circuit passes through. I personally would not bother with this effort.


Hey BB, Actually I have built several of these R2 circuits on a small 2"x2" board and installed them into some older Fenders to get a pretty good functioning boost circuit. One could easily be added into a IIC+ with out any permanent alterations. What I've found is that in Mark III's later than the black dot (which is shown on the only known MkIII schematic) LDR3 has an additional B side which is used to add in a 15uf cap in parallel with the V2a cathode resistor. This really darkens up the R2 voice. I've made some variances on the 180pf cap with mixed results. You're absolutely correct that persons with out experienced soldering skills should not be messing around on a boogie PC board. I buy nice new sharp needle tips for my 15watt soldering pencil every couple weeks. I had a Nomad 55 in here a few months ago where the guy had the switching matrix go out and I had to replace the LM-3914 bar driver. That was a pain in the neck! Apparently nobody thought that chip would ever fail!!!!

 

[Boogiebabies]

I feel your pain. I had a Road King 1 with a bad LM3914. Talk about harsh.

I have a freinds Fender Blues Deluxe that I added a gain stage to. I went with a .022 coupling cap, 1.5K cathode resistor and a .22 cathode bypass. It now does sweep arpeggio's with ease. I used a 680K grid resistor and this thing is also an awesome Boogie clone.

Sorry about the disclaimer, I don't want some hooplehead to claim my words as gospel. I get scanned by Google a lot and I'm not in the mood to have some kid kill himself trying to turn his Subway Rocket into a C+.

Do you have a C+?

 

[joepopp]

It can be done, but I prefer a pedal boosted channel 1 or 2 over a modded R2 anyday. If I want crunch, I just roll the volume pot back.
If you don't use the relays and LDR's, the mod would effect the clean and Lead channels. On the MK III, if you leave the R2 in, it effects the lead tone and makes it thin and buzzy.

BB:

What pedal booster are you using? I am building an MXR Microamp but the MXR/Dunlop/Custom Audio Electronics Pedal looks cool. It appears to have a detented pot?

http://www.jimdunlop.com/index.php?page=products/pip&id=265&pmh=products/p_and_e_detail

 

[Boogiebabies]

I got sick of my 1997 Klon and sold it for a lot of money. I ended up with and Xotic BB ( No pun intended) preamp. It is the most transparent, audiophile grade boost I have ever heard. It's true bypass and does not drop your level when you engage it. It does a clean boost and then an overdrive that can turn a clean MK series into a fat singer or a shredding beast. It also tightens up the RK II and turns Channel 2 Brit into a Stiletto.

 

[Shep]

i made a dual mosfet 30 db booster with a master knob so it goes from true bypass to 30db...it's so clean and nosie free..

 

[Reeko81]

Although i have a mark IIIc+ i sometimes use a booster crunch on my clean channel too instead of R2 channel.
I've built a fulldrive 2 clone...pretty close, or better....identical to that original FULLCLONE pedal....
Nowadays excellent overdrive pedals exist so....who need a third crunch channel when you can get good crunch overdrive from a pedal?( Mr FULLCLONE you're warned...i'll clone your OCD too!!!!)
Thanks Restless Rocks for that info about that 15uF cap on V2....so if it darkens the sound on R2 I'll try a different value there...although I really like this sound with my strat...heavy bodied sound!
I've also R2 mod on my mark III so i removed that buffered 6,8k output in place of a 250k linear pot ( as for mesa specification).

I'm planning about building or modifing reverb on my mark III to make it closer to that sweet tremoverb's....
I have all reverb mods on my mark III (glitch and boost mode) but reverb is always a kind of thin...want to try to mimick that full and spacial tremoverb's.
What do you think about?