AmpClones.com Mesa Boogie Mark IIC+ Help total newb

[WesPalladini]

Are you absolute sure you'll pull this off..? I'm not a pro builder, more like average, this scheme seems kind of gnarly.

This forum has more than a "few dedicated people" eager to help. So if you think you can land this jumbo jet by instructions. Go for it dude! My first build was a Twin Reverb and I loved every bit of it. Eh now I love playing/listening to it.

Keep us nerds updated. :-)

I am I sure I can pull this off? Yes, alone will take a long time. But yes I think I can land it with instructions from home base.

[WesPalladini]

Safety... Well I guess the best thing to do are some google searches.
In short

• Always one hand on the back while you're got the amp fired up.
• Make sure you know how to drain the filter caps on your amp and why you need to do it. (They hold juice even if the amp is turned of or un plugged.))
• Measure from ground to point. A simple subtraction is safer than point to point measurements.
• Always triple check every thing. (Might save other things than your life.) ;-)

Edit, no point in reanswering questions answered by g-one.

Yea so they said no BOM and no picture/video diary. They felt it was quite easy to build based on the schematics. I guess they didn't plan on making this easy for the average DIYer. They said I could ask them 1 question at a time.....

[WesPalladini]

This is correct. But there is more. The original switch for the EQ was a 3 position switch that was setup this way:

UP = EQ on

MID: IF channel = "Rhythm" THEN off. ELSE, on.

Down = EQ off

So the lead channel switch also closed the circuit for the EQ when the EQ switch was in the MID position. This is where I leave mine most of the time, although with some guitars, I will switch the Graphic out completely.

As if that wasn't enough, there was also an auxiliary footswitch box available to switch the reverb or the graphic in or out. On the originals, there was a stereo phone jack up under the chassis pan, just to the right of the speaker (looking from the back). It's a pain in the butt to reach around all the tubes to plug it in, but it is great to be able to control these features with the footswitch.

Mine is a December of 1983 Mk II C Simul (Reverb, EV12L, hardwood combo) that was upgraded to a C+ a few months later by the Mesa techs. I ordered and picked it up directly from the factory as I lived in the SF Bay Area at that time.

I agree with what Big_Tee says... it's a huge undertaking to build one of these for a first amp build. Finding transformers that will operate and sound like the originals will be very challenging as well. The OT's on these amps were designed to run specifically around the performance parameters of the Sylvania STR-415 power tubes. You can use other tubes, and some will sound pretty good. But the unique character of these amps was, in my experience, largely found in that combination of the OT and the 415's. I pass that along just as anecdotal info.

There must be other builders who have built this kit before. What kind of information are you getting from them about things like proper trannies and inductors?

Interesting I didn't know the EQ worked that way. Also didn't know the originals had the jack on the back, this one has the jack mounted on the front .

I havn't found any other builders of this kit, I have been looking and was hoping one would happen to see my post and help out but no luck yet.

[tedmich]

Just wanted to say thank you to everyone who has posted so far. I am going to post the schematics they gave me so you can all see. And respond to all your comments later today just had a lot of school due for university in the past few weeks.

Gr8! Most of the online Mesa schematics are famously "nonfunctional" to keep down the clones and are only useful for repairs. The only "deal breaker" on the BOM would be the spacing on the pots IMO at least there are only a few sources for linears...

I don't know why so many are freaked by how "complex" this is, if its a correct schematic with a correct PCB you can build it up no problemo; its NOT rocket science! The only "problemo" is if a mistake was made on their end or your end! "Troubleshooting" is MUCH more of an art than assembly IMHO...


Hell scan the boards and I'll build up a BOM at Mouser...maybe!

[WesPalladini]

Gr8! Most of the online Mesa schematics are famously "nonfunctional" to keep down the clones and are only useful for repairs. The only "deal breaker" on the BOM would be the spacing on the pots IMO at least there are only a few sources for linears...

I don't know why so many are freaked by how "complex" this is, if its a correct schematic with a correct PCB you can build it up no problemo; its NOT rocket science! The only "problemo" is if a mistake was made on their end or your end! "Troubleshooting" is MUCH more of an art than assembly IMHO...


Hell scan the boards and I'll build up a BOM at Mouser...maybe!

Schematics!

[soundguruman]

Gr8! Most of the online Mesa schematics are famously "nonfunctional" to keep down the clones and are only useful for repairs. The only "deal breaker" on the BOM would be the spacing on the pots IMO at least there are only a few sources for linears...

I don't know why so many are freaked by how "complex" this is, if its a correct schematic with a correct PCB you can build it up no problemo; its NOT rocket science! The only "problemo" is if a mistake was made on their end or your end! "Troubleshooting" is MUCH more of an art than assembly IMHO...


Hell scan the boards and I'll build up a BOM at Mouser...maybe!

They are complex because too many parts, crammed in too small a space, with much too little space between the circuit tracks, inaccessible maintenance because of a poorly thought out hardware and double sided board design. It's pretty much as if they wanted to discourage people from maintaining it, and that's a success.
The amp can be copied, but the schematic does not show a great deal of the circuit, or the layout, which at some points is rather critical. There are a number of capacitors, to stop the oscillation and ringing, which are not shown on the schematic. Also the circuit tracks are laid out to act as capacitors and shielding, which is not shown on the schematic.
So you can build it, but it would take a more experienced person to get the bugs out of it.
If you do not have a scope and other test equipment, you can pretty much forget about it.

[WesPalladini]

They are complex because too many parts, crammed in too small a space, with much too little space between the circuit tracks, inaccessible maintenance because of a poorly thought out hardware and double sided board design. It's pretty much as if they wanted to discourage people from maintaining it, and that's a success.
The amp can be copied, but the schematic does not show a great deal of the circuit, or the layout, which at some points is rather critical. There are a number of capacitors, to stop the oscillation and ringing, which are not shown on the schematic. Also the circuit tracks are laid out to act as capacitors and shielding, which is not shown on the schematic.
So you can build it, but it would take a more experienced person to get the bugs out of it.
If you do not have a scope and other test equipment, you can pretty much forget about it.

I have a multi meter... they have an electrical engineering class at my university so I am sure I can get access to a oscope when needed.

[tedmich]

popped the schematics into a smallish pdf file
https://docs.google.com/open?id=0Bx4...JhMTNjMWEwYzUy

[WesPalladini]

Picked up a transformer

Dmitry at ampclones (where I got the board and PCBs from) I guess happened to be on this forum and saw my post. He gave me a lot of encouragement and actually helped me find a transformer that was meant for this build but the guy never got around starting the project (hope I don't turn out like him). New it cost around $125 I picked it up for $80, just wanted to mention his help on the forum. It is an #HTS-10121 (Heyboer). I will also scan the boards in soon times and upload my BOM so far.

-Wes

[überfuzz]

Off topic, slightly...

Dude, there are some questions that you might consider before you set sail. First of all, what sound are you looking for? There might be some wiz-techs here able to point out a simpler way. Secondly, you're mentioning the BOM list every now and then, but you've already started to order stuff. I'm not sure but I guess the first one mentioning the BOM list did it because it's most likely you'll figure, holy Moly thats even more than the amps going on ebay. (Cheaper builds often gets the hardware from retired amps and such.) Finally, have you seen anyone posting builds on this on the net. Check the tube, it might give you an idea what you're in for.

I don't want to be discouraging, just thought you might give it a thought,... or two. :-)

[soundguruman]

Sellers often mislead customers into believing they can build their own amplifiers.
They tell you that all you need is basic soldering skills.
Don't believe it. More than often these kits wind up in the hands of professional techs, who finish them the right way.
If you do not have soldering station, O scope, load bank, sine wave generator, multimeter, and the training and ability to use them all, you are probably fooling yourself.
Also, the amp you are copying is not what I would call the greatest design. You can bank on spending much more to maintain it than an ordinary amplifier.

[tedmich]

All true but these things go for +$3k, so an initial ~$300 investment and learning/buying on the installment plan can provide tons of "hobby time" and it may sound great in the end.
Had a friend who rebuilt a '67 Firebird in his garage over the course of 10 years; too bad he couldn't hire a pro but he had a ton of FUN doing it and it cost pennies on the dollar (as his time was "free")

[WesPalladini]

Exactly!

[big_teee]

Dmitry at ampclones (where I got the board and PCBs from) I guess happened to be on this forum and saw my post. He gave me a lot of encouragement and actually helped me find a transformer that was meant for this build but the guy never got around starting the project (hope I don't turn out like him). New it cost around $125 I picked it up for $80, just wanted to mention his help on the forum. It is an #HTS-10121 (Heyboer). I will also scan the boards in soon times and upload my BOM so far.

-Wes

Don't Mean to be the 1/2 Glass Empty Guy.
However If Dmitry is reading these Posts, Why doesn't he jump in here and help out.
Sounds like He's just lurking in the Bushes to continue to sell you stuff?
B_T

[WesPalladini]

Don't Mean to be the 1/2 Glass Empty Guy.
However If Dmitry is reading these Posts, Why doesn't he jump in here and help out.
Sounds like He's just lurking in the Bushes to continue to sell you stuff?
B_T

He didn't sell me the transformer he just found somebody with a used one in the states for me.