MARANTZ 140 power amps and MARANTZ 3200 preamp

[Joseph5151]

I have 2 marantz 140 amps with a 3200 marantz pre amp. Im going to be running McIntosh ML-2 speakers. I have read so many different things about using both amps that I have no idea what to do. I have read I can use one amp for each channel, or I can use RCA splitters to use both amps. What is best. Or should I just use 1 amp and keep the other as a backup. Any help is much apprcted. Im knew to this stuff. Guess I need to stop buying things and figure out what Im doing first.

 

[Oerets]

Welcome to AK first off.

I don't know for sure. But the 140's IIRC are not able to run in bridged so are for stereo only.

Get another pair of speaker?
Or save for backup.....

 

[Lavane]

You could use splitters on the pre out jacks. I have a 3200 and I had two 140's at one point. The preamp drove both fine. You may or may not need to adjust the gain controls on the 140's a bit. As Oerets posted they can't be bridged to mono.

 

[Joseph5151]

You could use splitters on the pre out jacks. I have a 3200 and I had two 140's at one point. The preamp drove both fine. You may or may not need to adjust the gain controls on the 140's a bit. As Oerets posted they can't be bridged to mono.

So all I need is a set of RCA splitter cables and run from my 3200 pre-amp to both amps. My 3200 only has one set of outputs. Do I run my speaker wires to the speakers from the preamp? Will this give me more power the McIntosh ml-2's are big speakers. I Cannot thank you enough for the info.

 

[Lavane]

Yes use the splitters on the preamp output jacks. I guess you could run one set of speaker wires from one amp through the speaker switching connections on the preamp if you want to retain the use of the headphone jack. I use the short rca splitter jacks. Something like these.
https://www.amazon.com/FolioGadgets...=2025&creative=165953&creativeASIN=B01LRXI14K

 

[Lavane]

Also when using these splitters remember your adding extra weight of the cables along with a bit of leverage on the jacks. Try to arrange them so the jack and cables aren't pulling down on the output jacks.

 

[avionic]

Welcome to AK..

 

[spark1]

So all I need is a set of RCA splitter cables and run from my 3200 pre-amp to both amps. My 3200 only has one set of outputs. Do I run my speaker wires to the speakers from the preamp? Will this give me more power the McIntosh ml-2's are big speakers. I Cannot thank you enough for the info.

Unless there's something I'm missing, the speakers would be connected to the power amps...right speaker to right channel of one, left speakers to left channel of the other.

This still gives you only 75 watts per channel, same as using just one 140. Two other things to consider;: first, I think you need the Mcintosh equalizer for your speakers to perform correctly. Second, these speakers are a 4 ohm load, while the 140s are rated for an 8 ohm minimum load. I have no experience with these amps, so they may handle 4 ohms ok...or not.

Oh, one other thought...those speakers are not very efficient (I did a major restoration on a set several years ago). Not sure if 75W is enough if you want to play them cleanly at even moderately higher volumes.

EDIT: OK, I figured out what I was missing...the 3200 has a speaker selector function. Nice if you have two pairs of speakers, I guess?

EDIT - I apparently read the wrong specs for your speakers. They are 8 ohm, not 4 ohm.

 

[Dingman]

Biamping would be the ticket then, with the two amps.

 

[Joseph5151]

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Also when using these splitters remember your adding extra weight of the cables along with a bit of leverage on the jacks. Try to arrange them so the jack and cables aren't pulling down on the output jacks.

You have been super helpful. I was getting all kind of crazy information. I guess Ill just run the speakers of the pre-amp and make sure the RCA jacks are supported. As far as the amps will the gain knobs need to be used for adjustment. Or just play with them for the sound I like. Thank You again.

Unless there's something I'm missing, the speakers would be connected to the power amps...right speaker to right channel of one, left speakers to left channel of the other.

This still gives you only 75 watts per channel, same as using just one 140. Two other things to consider;: first, I think you need the Mcintosh equalizer for your speakers to perform correctly. Second, these speakers are a 4 ohm load, while the 140s are rated for an 8 ohm minimum load. I have no experience with these amps, so they may handle 4 ohms ok...or not.

Oh, one other thought...those speakers are not very efficient (I did a major restoration on a set several years ago). Not sure if 75W is enough if you want to play them cleanly at higher volumes.

EDIT: OK, I figured out what I was missing...the 3200 has a speaker selector function. Nice if you have two pairs of speakers, I guess?

You are right I have the 140 EQ for them.

 

[Joseph5151]

View attachment 1330570 View attachment 1330571 View attachment 1330572 View attachment 1330573 View attachment 1330570 View attachment 1330571 View attachment 1330572 View attachment 1330573

You have been super helpful. I was getting all kind of crazy information. I guess Ill just run the speakers of the pre-amp and make sure the RCA jacks are supported. As far as the amps will the gain knobs need to be used for adjustment. Or just play with them for the sound I like. Thank You again.



You are right I have the 140 EQ for them.

I have 4 of them but live in a small condo about 1200sqr feet. Spend a lot of my time on my boat a 51 exspress cruiser. Im sure will not be able to turn them up to loud anyway.

 

[Joseph5151]

Also when using these splitters remember your adding extra weight of the cables along with a bit of leverage on the jacks. Try to arrange them so the jack and cables aren't pulling down on the output jacks.

So I'm reading I need to connect one side to one amp and another side to the other amp. Is that the case? This is what I do not get. Why use RCA jacks for that. Might as well just use one amp. I was reading like you said with the RCA splitters its like piggybacking both amps with speakers being hooked to pre-amp.

 

[Joseph5151]

So I guess I am getting to use both amps for the speakers I'll run one amp for speaker left and one for speaker right without using the other channel of each amp? Does that do anything positive for me over just running one amp.

 

[spark1]

Not really. Perhaps less demand on the common power supply, but nothing significant I am aware of.

I don't see any reason to use this configuration. I was only clarifying HOW it would be done, since it was suggested by another member in a previous post.

 

[spark1]

Not really. Perhaps less demand on the common power supply, but nothing significant I am aware of.

In your situation, I would think about procuring a single, more powerful amp. Your speakers cannot be truly bi-amped without modification, and you would need two new amps to do it, and an active crossover.

For speakers such as yours - not as detailed or revealing as modern high-end speakers - I might think about something like a Crown XLS1002 or 1502. The power would be good for your speakers, and the slight edginess of these very well made amps will not be an issue with them (in fact, it might even be a virtue). Additionally, they will have absolutely no issues with low impedance loads.

I obtained an XLS1000 some time ago, and have been very impressed with it, especially given its very low cost. It is not my best amp by any means, but it is not embarrassed to be in the same room with them!

I know that suggesting different equipment is often not a helpful or appreciated response, but I suspect you may find that your 140's are not a good match for your Mcintosh speakers.

Of course, the first step is to just try the 140s (running just one, or both...no real difference). Who knows, you may find that they make the ML2s sing! But I would still be concerned about running them into a low impedance load.

EDIT - those speakers are 8 ohm, not 4 ohm, so impedance should not be an issue (unless you try to power both pairs with one amp).

 

[winters860]

WHOA!

FULL STOP, PARTNER!

The McIntosh ML-2 is 4 ohm speaker with only one set of positive and negative terminals feeding the crossover. That means, absent modification, you are only going to be able to use two channels of amplification to power a pair of them.

You have two 140 amps, and each has two channels of amplification. These stereo amps cannot be bridged to mono. Also, each channel is only rated down to an 8 ohm load.

The 3200 preamp has speaker-level inputs and outputs, yes. But these are strictly to enable switching in a system for those who would like to switch between multiple pairs of speakers. If you're using only one pair of speakers, the higher-fidelity option would be to run speaker wires directly from your amplifier to the speakers.

ANY configuration of the above gear that includes all four channels of amplification is likely to damage your amplifier, your preamp, your speakers, or all three. Further, the use of an 8 ohm-rated Marantz 140 on 4 ohm speakers is not recommended and will likely either cook it slowly or cook it quick. Repeat - any method of hooking both of your amps up to these speakers is going to make something go boom right away, and hooking only one of your amps up to these speakers probably isn't that great an idea either.

 

[winters860]

Biamping would be the ticket then, with the two amps.

These speakers aren't bi-ampable.

They could be, by modifying the crossover to separate the woofer part of the crossover from the mids/highs and adding a second set of positive and negative terminals. That would be passive bi-amping. It's of contentious benefit, and shouldn't probably be considered by a novice, particularly one without any amps capable of running his speakers safely.

The other option for bi-amping isn't really bi-amping at all. It would entirely do away with the passive crossover and each amp channel would power a different driver or set of drivers, with frequency division being done line-level by an electronic crossover or modern speaker management system. Since these are 4-way speakers with 6 drivers in each cabinet, true multi-amping would require at least 8 channels of amplification and accompanying processors, along with a measurement mic and a whole lot of know-how. This is also not a great idea for a beginner.

 

[Dingman]

Ya, I didn't look up the speakers at all - I sorta assumed they would be bi-amp-able.

With that out of the picture, you're down to using just one amp - and ya, impedance is of concern. Winter860 is right on what he says.

 

[spark1]

WHOA!

FULL STOP, PARTNER!

The McIntosh ML-2 is 4 ohm speaker with only one set of positive and negative terminals feeding the crossover. That means, absent modification, you are only going to be able to use two channels of amplification to power a pair of them.

You have two 140 amps, and each has two channels of amplification. These stereo amps cannot be bridged to mono. Also, each channel is only rated down to an 8 ohm load.

The 3200 preamp has speaker-level inputs and outputs, yes. But these are strictly to enable switching in a system for those who would like to switch between multiple pairs of speakers. If you're using only one pair of speakers, the higher-fidelity option would be to run speaker wires directly from your amplifier to the speakers.

ANY configuration of the above gear that includes all four channels of amplification is likely to damage your amplifier, your preamp, your speakers, or all three. Further, the use of an 8 ohm-rated Marantz 140 on 4 ohm speakers is not recommended and will likely either cook it slowly or cook it quick. Repeat - any method of hooking both of your amps up to these speakers is going to make something go boom right away, and hooking only one of your amps up to these speakers probably isn't that great an idea either.

Did you read the response I posted before yours? If so, can please tell me what was addressed in your post that I failed to cover? Thanks.

BTW, there is a configuration in which the OP could use both channels of both amps. Specifically, he could connect both to his preamp with splitters, and run one pair of his four speakers to each amp.

Obviously this would not address the impedance issue that I raised in my posts (and you reiterated), and I am not recommending it.

EDIT - speakers are apparently 8 ohm, not 4 ohm. So this is a viable approach, if the OP wants to run both pairs of speakers.

 

[wlhd1610]

So I guess I am getting to use both amps for the speakers I'll run one amp for speaker left and one for speaker right without using the other channel of each amp? Does that do anything positive for me over just running one amp.

The others have all given good advice.

I'll add that the 140 is basically the amp section of a Marantz 2270 and while considered a high powered receiver in it's day it quickly lost that designation when 125 wpc amps/receivers arrived a year later.
The 140/2270's are not rated for nor do they like 4 ohm loads.

My recommendation would be to trade your two 140 amps for a Marantz 250M which is almost twice the power output of a single 140 ,will run 4 ohm speakers ,would allow you to properly utilize the front panel speaker switching capabilities of your 3200 all the while keeping those nice blue meters.


Bob