Hooking up speakers to a MC

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Hooking up speakers to a MC

Postby JonnyBoy » Tue Jun 29, 2010 3:03 pm

when you hook up say a 4 ohm and a 16 ohm speaker to a Mcintosh amp do they have to be connected in series/parallel first then one connection to the amp, or can you hook up the 4 ohm to the tap and the 16 ohm to its tap then both to the negative; both speakers with separate wires going to the amp?
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Re: Hooking up speakers to a MC

Postby nabco » Wed Jun 30, 2010 12:57 am

I have a MC2100 that I use with my Fender Twin Preamp and that model has a left and right channel to tap your speakers to. The right side is for mono, I think, so you can just connect each speaker to each side of the amp. Each channel has its own volume knob too, so to be more clear in trying to answer your question there is two separate sets of speaker taps (one for each channel left and right ) very much like your stereo receiver at home. So yes you would hook up one 4 ohm speaker to the left side and one 16 ohm speaker to the right side. I would not hesitate on buying one if you have the chance, they are heavy but the sound quality is worth it. I will not sell mine, that's fo sho!!!
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Re: Hooking up speakers to a MC

Postby mijknahs » Wed Jun 30, 2010 1:59 am

JonnyBoy should have mentioned that his amp is a monoblock MC50 (one channel only).

Personally, I would hook up the speakers, calculate the ohm load and then connect to the appropriated tap (equal or lower than the combined speaker load).

Also, hooking the speakers up directly at the amp terminals is the same as hooking them up before the amp (in parallel). In other words you can hook up 2x 8ohm speakers directly to the amp's 4 ohm terminal rather than hooking up one speaker to the other then to the amp. Then if one blows, the other is still hooked up directly to the amp. I think this is how Jerry's 3x12" cab is hooked up. Each speaker goes directly to the amp (rather than the speakers all connected together with only one set of cables going to the amp).
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Re: Hooking up speakers to a MC

Postby JonnyBoy » Wed Jun 30, 2010 11:09 am

thanks, that's what I needed to know. I should calculate the ohms and pull off that tap as a combined load. It isn't against the law to tap more than one wire off the same terminal? Thanks Nab & jim, I failed to mention its an MC50 mono. With the twin pre and a pair of -K110's or a single 12" its way louder than I expected. I hope it doesn't get or seem softer when I use it to play.
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Re: Hooking up speakers to a MC

Postby SarnoMusicSolutions » Wed Jun 30, 2010 2:01 pm

I'm a bit confused,

but I'd never want to connect to more than one output terminal at a time. Ground and whatever ohm tap you want to use, but NOT multiple taps. With a 16 ohm and a 4 ohm speaker you're pretty much screwed out of using them together. You could tie the speakers in parallel and connect to the 4-ohm tap and be reasonably safe, but the 16-ohm speaker will hardly make any noise compared to the 4-ohm speaker. Only with a stereo Mac could you properly match the speakers. In that case one channel could be appropriately tied to the correct impedance, and so could the other. But both speakers (a 16 ohm and a 4 ohm on a monoblock, I wouldn't attempt it.

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Re: Hooking up speakers to a MC

Postby SarnoMusicSolutions » Wed Jun 30, 2010 2:05 pm

mijknahs wrote:
Also, hooking the speakers up directly at the amp terminals is the same as hooking them up before the amp (in parallel). In other words you can hook up 2x 8ohm speakers directly to the amp's 4 ohm terminal rather than hooking up one speaker to the other then to the amp. Then if one blows, the other is still hooked up directly to the amp. I think this is how Jerry's 3x12" cab is hooked up. Each speaker goes directly to the amp (rather than the speakers all connected together with only one set of cables going to the amp).


Agreed.

Jerry's Mac was modded a bit to have banana jacks on back so that each of the 3 JBL's had its own wire all the way from the speaker to the amp. The 2-ohm tap was hard wired to all three red banana terminals. This way, like mijknahs said, one speaker could blow, be disconnected, removed, replaced, and reconnected all while the other 2 speakers continued to run and completely uninterrupted. Definitely a live, quick fix mentality, and without the show needing to stop. The only trick was if the speaker with the mic on it was the one that blew, they'd have to figure that out and move the mic to one of the other speakers real quick.

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Re: Hooking up speakers to a MC

Postby JonnyBoy » Wed Jun 30, 2010 7:02 pm

That was very helpful thanks. I plan on either running a 1x12 or a 2x10" on it, but not a the same time. I was wondering if the amp had separate power to each tap independent from the other taps, meaning each tap was getting a hot signal not depending on any other speaker hooked up to the machine.

Anyway, I love it, and you were right brad and Jim, with the preamp this is more than enough power to get loud, especially if you mic at your gigs. Even if you don't its loud and clear as a bell even cranked. The LPB1 helps push the clipping a bit, it is much different than any other amp I have used or played trough. it actually sounds more like a tube amp than a SS amp. Thanks for all y'alls help... I have finally reached my gear plateau, You guys have helped me a bunch to get a tone I really love. Thanks again. JB
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Re: Hooking up speakers to a MC

Postby Kennay » Thu Jul 01, 2010 6:13 pm

I`m still not all that clear on this. I`m planning on hooking up a mc 50 pretty soon, I hope.
1 I want to hook up the preamp to the mac with a 22 guage (would that be a good gauge?) 1/4 to 1/4 cable. I bought a 1/4 to rca adapter for that. I think I`m on the right track there.
2 From mac to cab I want to use a 12 gauge 1/4 to 1/4 cable. I have to cut off one of the 1/4`s to connect it to the mac. How many wires are in a cable? 3? What color are the positive, negative and ground. Do I have to be super paranoid about letting the + touch the -? Connect ground to Com and positive to 4ohm tap. Is it soup yet? Thanks in advance for your help and for putting up with the remedial reading class.
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Re: Hooking up speakers to a MC

Postby SarnoMusicSolutions » Thu Jul 01, 2010 6:57 pm

JonnyBoy wrote:I was wondering if the amp had separate power to each tap independent from the other taps, meaning each tap was getting a hot signal not depending on any other speaker hooked up to the machine. ..... JB


No. That's why you can't hook them up like that. The output taps are all tied along the same output coil of the "autoformer" which is essentially half of a transformer. They all share the same amplifier output and are NOT independent.

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Re: Hooking up speakers to a MC

Postby SarnoMusicSolutions » Thu Jul 01, 2010 7:05 pm

Kennay wrote:I`m still not all that clear on this. I`m planning on hooking up a mc 50 pretty soon, I hope.
1 I want to hook up the preamp to the mac with a 22 guage (would that be a good gauge?) 1/4 to 1/4 cable. I bought a 1/4 to rca adapter for that. I think I`m on the right track there.
2 From mac to cab I want to use a 12 gauge 1/4 to 1/4 cable. I have to cut off one of the 1/4`s to connect it to the mac. How many wires are in a cable? 3? What color are the positive, negative and ground. Do I have to be super paranoid about letting the + touch the -? Connect ground to Com and positive to 4ohm tap. Is it soup yet? Thanks in advance for your help and for putting up with the remedial reading class.


Kennay.

The cord from the preamp to the mac should be normal shielded audio cable, guitar cord, stereo rca type connector wire, whatever, just be sure it's good and it's shielded audio cable. It will have 2 conductors, a center "hot" conductor and an outer shield (ground) conductor just like any guitar cord would have.

The wire from the Mac to the Speaker cab should be decent quality speaker wire. Not shielded audio wire, but speaker wire. 2 conductors. One wire will go to the "com" or "common" (aka: ground) on the Mac. The other will tie to the terminal screw on the Mac that corresponds to the impedance load of your cabinet. It's best to solder on eyelets or lugs at the mac end, so they safely and securely fasten to the Mac's screws and can't short out or touch anything else. And of course, at the speaker cab end, never let those contact short out. To be sure this never happens, always have the speaker cord plugged into the speaker cab jack before powering up the amp. So yes, always be super paranoid about letting the speaker leads at the cabinet end short out (or touch eachother). Never let that happen. This can hurt an amp in a very short period of time. Shorted speaker wires is one of the more common and easy ways to fry a power amplifier.

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Re: Hooking up speakers to a MC

Postby Kennay » Thu Jul 01, 2010 7:28 pm

Brad,
I can`t even tell you how much you`ve helped me out over this past year. I`ve got 5 pages of notes front and back and most of them came from you. I hope to eventually purchase your preamp and wish you huge success in creating a power amp up to your very high standards.
Thanks Again!
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Re: Hooking up speakers to a MC

Postby JonnyBoy » Fri Jul 02, 2010 12:29 am

Yhea, Brad is cool. And so are a few more people around here willing to answer a question twice, not ignore basic questions, set straight the ignorance. He especially is always friendly and willing to help people no matter if they are superior gear heads, elitist gear heads, or beginner gear heads. You can tell he has a real love for this stuff and people too. Thanks Brad!

KEN- you will love the MC50 especially if you have a preamp too. When you get the Mac, top it off with a SMS Classic or twin preamp to drive it right. With both preamp and amp you'll have plenty of power and sweet sound! I was worried I wouldn't have enough, its PLENTY for a small gigs.
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Re: Hooking up speakers to a MC

Postby Kennay » Sun Jul 04, 2010 9:52 am

Thanks JonnyBoy. If I ever get my hands on one, I`m gonna run my Vibrolux reissue thru it. It seems like everytime I see one on ebay, it dissappears before the bidding deadline is up. What`s up with that?
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Re: Hooking up speakers to a MC

Postby James-T » Sun Aug 07, 2016 6:38 pm

These posts are awesome. Got my MC50 up and running as the power amp for my Axe FX. Definitely in the right sonic territory to make me happy. Great affordable purchase. It's small compact light and gives that unique to Garcia time even when fed by a cheesy digital modeller like the Ultra. I've got a tube boost in front to give it a touch more life. :smile:

Thanks Jim for your post. Scored what I needed at an electronics store nearby.
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