Grateful Dead Music Forum

Hey all. I got my SMS and MC2105 last week. now to hook it all up.

So here are the questions:

1. SMS to Mac: if i am using one side of the Mac it looks like i should have a 1/4" to single RCA jack. is that right?

2. MAC to Speakers: If i am using a cab with 2 8ohm E120's, should i be hooking up the cap to the 4 ohm section? Also what are people using to hook up the speakers? The MAC has screw type jacks.

3. How have you guys mounted your Mac's? I think it should go in its own road case, but would like to hear how you all mount them.

1960strat wrote:Hey all. I got my SMS and MC2105 last week. now to hook it all up.

So here are the questions:

1. SMS to Mac: if i am using one side of the Mac it looks like i should have a 1/4" to single RCA jack. is that right?

2. MAC to Speakers: If i am using a cab with 2 8ohm E120's, should i be hooking up the cap to the 4 ohm section? Also what are people using to hook up the speakers? The MAC has screw type jacks.

3. How have you guys mounted your Mac's? I think it should go in its own road case, but would like to hear how you all mount them.

1. Yes. You can use a simple Y connector to get both channels going (I have been doing this since I got my 2105 back in 1979).
2. If you are using 2 8 ohm speakers in parallel, then you want the 4 ohm section. If you are using them in series, then you should use the 16 ohm section. I prefer parallel because if one speaker blows, the other won't cut out. I got some of these http://tinyurl.com/26ca3cv and some banana plugs. I found that if you are using 8 ohm taps (which I would do in your case: drive each speaker with its own amp channel. It might require adding a jack to the cabinet, but it's well worth it) then a standard dual banana jack fits perfectly. Coincidence? Maybe. Otherwise single banana plugs are easily available, just not as convenient.
3. I never really got this aspect nailed down. It's one of the reasons my 2105 looks like hell. Mine has feet on it with serious screw mounts (think T-nut style in huge metal feet) so it could be screwed down to a shelf, but finally instead of coping with this, I got a Crest CA9. Being a bass player, I wanted the extra power anyway, but I think you could take the bottom plate off, mount some kind of nuts to it so that you could screw it to a shelf that you then rack mount. Shouldn't be too hard. I would probably do it in a shock rack with wheels, though! The sucker is heavy.

Let us know how it comes out!
Edwin

I am looking at a Mac 2300 and was wondereing how many rack spaces it is? Looks like 6 anybody have one racked up? thanks!

1960strat wrote: 2. MAC to Speakers: If i am using a cab with 2 8ohm E120's, should i be hooking up the cap to the 4 ohm section? Also what are people using to hook up the speakers? The MAC has screw type jacks.

For the Mac to Cab section... The guy I bought mine from made a jack-terminal with two 1/4" jacks. It's made out of a piece of wood about the size of a playing card and like an 1/8" or 1/4" thick maybe.
This wood block connects to the MC250 terminals with like 6" of wire that he did nice job of using the those U-shape screw down connectores on.
I'm currently using one side of the Mac with a 4ohm speaker and using the 4ohm tap.
I have 1/4" to RCA for the PreAmp to Mac. I split that with a Y-cord if needed.

I thought about mounting it, but god it is too heavy to go in my rack. it needs its own case for that imo, then it also needs to breathe and get air. After all those considerations, I figured I would carry it by itself from the car to the wheel dolly my cab sits on. The cab uses about half of the 4 wheel dolly's surface, so it slides behind the cab quite nicely. I also thought of screwing it down there, but the " what if this" and "what if that" started going through my mind. So I am back to the old carry it alone to and from the car idea again. Also, I know this way it will get a good spot in transport and be babied to and from the gigs. They are tough, but they can break.

I have yet to turn my 250 into 1/4" plugs for the speakers, but it is as easy as connecting the pos to neg on the 1/4" jack to some wires if needed. I went to radio shack and bought a pack of 50 solder on "U" ends for $2 to go over the speaker wire to make screwing down easy enough. I would consider having the power section caps redone and all the electrolytics replaced, it sure makes the amp perk up.