Is it better to get dedicated monoblocks instead of bridging stereo paired amps?

Dedicated monoblocks over bridged amps.

In your case, the Mac's are a definite upgrade over the SimAudio bridged amps. I had a pair of amps bridged a while ago, and the sound wasn't particularly smooth.

Bob

I can't imagine making this decision based on the theoretical pro and cons of stereo vs. bridged alone.  If I was buying amps for a touring system maybe... but this?
 

If your hearing is as sensitive as you say it is you should 100% listen for yourself.  I personally could not listen to one of those brands for more than 5 minutes, and bridge vs. stereo won't have anything to do with it.

My suggestion is if you love the Moon's you have stick with them until you actually hear something you like better and ignore everyone elses opinion. 

In general I would choose (and did), dedicated mono blocks, never truly been happy with bridged...

I recommend you get Sim Moon monoblocks. If you like the Moon sound... well the Mac sound is very different. If you want monoblocks... get monoblocks... not a bridged compromise. In high end audio every tiny detail matters. Monoblocks are designed to be monoblocks... not duplicate circuits. If I was dealing with consumer products... then bridging would be an option. 

I've know a number of folks that have compared bridging with monoblocks and concluded they are a compromise. I have experience with monoblocks vs the same designed stereo amps. I prefer monoblocks... not everyone may. 

Always monoblocks and especially those McIntosh MC611s? that is a no brainer. @dman777 

@dman777  - 

You don't mention what speakers you are using. 

I'm suprised no one has mentioned it yet, There is one thing that happens when you bridge a stereo amp.  The amp will see the speaker impedience load to be one half of the rating.  I.e. 8 ohm speakers are seen as 4 ohm,  4 ohm as 2 ohm, etc.  This can be a real problem if the impedience drops to 2 ohms or less.  It is not an ideal situtation when that happens.

So that alone may make your choice for you.

- Jeff

Wow, thank you all for this valuable information and saving me from making a expensive mistake. 

It seems if I want that Moon Audio North collection sound, I will have to settle on a 861 stereo amp. They have the 888 monoblock but it is to expensive for me. They have the 400 mono amp which is not in the Northbound collection and from the price of it, I don’t think it would have same level of Moon Audio quality that I enjoy so much in the North collection.  

I need a lot headroom... I really pick up on it when a amp has a lot of headroom. When I compared the Moon 761 stereo amp (200/400 watts) to the McIntosh 462 stereo amp, I could tell the McIntosh was more powerful because it just sounded more open and more there. I still preferer the Moon Audio 761 sound overall, but I know eventually there would be times when I wish I had more headroom when I ether have a low recording, feel like jamming out super loud, or upgrade to speakers that could be more demanding (like Dynaudios).

but I know eventually there would be times when I wish I had more headroom when I ether have a low recording, feel like jamming out super loud, or upgrade to speakers that could be more demanding (like Dynaudios).

This, combined with the @jeffbij comment makes your decision for you, bridged amps at high volumes and demanding speakers will melt down. I would stick with the Sim sound that you know that you like, but consider going with a higher quality two channel amp vs the mono blocks. 

And you can always go with two stereo amps and bi-amp the speakers if you want the "monoblock" aesthetic (and I use that word very loosely).  It isn't always about power or wattage.  Amp design and their inherent "sound" usually more important, which you have already determined.  You like the Sim Audio's sound and the 761's are a dual mono design.  So technically they are monoblocks stuffed into the same chasis. 

And in the end, if you were to buy the McIntosh, which have a much different sound, would you be content or still wanting or yearning for the SimAudio's?

- Jeff

Bridging two SS stereo amplifiers to mono is usually NOT a good trade-off for the massive power gained - up to 4x power for amps that "double down" i.e. high current. Why 4x power and not 2x? Because bridging doubles the output voltage which also draws (or attempts to) 2x current since the speaker load is the same. Or put another way, each L/R side of an amp "sees" half the speaker load and thus is dumping 2x the current at the same voltage as before - but both sides are now working in tandem (opposite phase) so these stack and 2x (current) * 2x (L/R sides) = 4x. Net result: amp is working harder (as if the speaker load were halved), and it often sounds worse. There’s also often extra circuitry to invert the input signal for opposing phases. I’ve experienced this myself - don’t like the bridged mono sound. Dedicated monos are the much, much better way to go.

Tube amps with a switch to stereo/mono mode are different - they typically parallel the output of L/R sides through their output transformers. The taps effectively become half the labeled value  in "mono" mode (e.g. 8 ohm taps become 4 ohms), so you just move down to the next tap as needed - that’s how 2 ohm taps (or even 1 ohms) can come in handy! In my experience, the extra power here (2x) is a benefit with none of the downsides of bridging - in fact, often these tube amps sound drastically better in mono!

Yes it is. Separate power supplies.

@dman777 

+1, absolutely yes, “dedicated mono blocks instead of bridging stereo paired amps”.  

Sorry for not reading your post more fully, OP.

I still think you should NOT compare one brand which you know to another which you haven't heard based on whether they are true monoblocks or bridged stereo amps.

Having made that part clear, a dedicated bridged mono amplifier is superior only because they tend to have a lower minimum impedance.  Usually when you bridge a stereo amp they also raise the minimum speaker impedance.  So if the minimum was 4, it becomes 8 after bridging.  This has to do with the current carrying capabilities of each output stage involved.   There are, of course, exceptions.

Having said all of that I might prefer the sound of a single stereo amp of one brand to any size monoblocks from another.  Depends and I'd not make a switch without a personal audition.

Thank you for the valuable information again, it is quite a interesting learning experience. 

Unfortunately, there are no stores where I can compare the MC611 monoblocks to the Moon Audio 861. 

Hard decision.... if I went with the Moon Audio 861 stereo amp, I would loose the black levels and separation/soundstage that the MC611 monoblocks would have from being monoblocks?

Seems you answered your own question with "I love the Moon audio 761 sound".

I have bridged two ARC amps to run the bass channel in a tri-amped system. it worked very well, but I'll admit that as long as any distortion is low I certainly can't hear it as well as other persons ears I trust.  They have since been replaced by Pass Labs X260.8 monos.

dman777, go with the sound that you love.  They'll make you smile every day.

Regards,

barts

If amps are really designed to be bridged they can be wonderful. Some amps are already bridged such as Pass lab amps and they ain't too bad.

I bought a used Moon 700i. The single chassis is 2 mono amps and a pre, all separate power supplies, short connection paths internally. Only analog.

Look used if you like the sound of certain brands. Patience, and you will find your gear.

I bought 2 pieces from The Music Room. They inspect the gear, take good pictures, 30 days to return, 90 days warranty on used. 

My Tambaqui, Grimm MU1 and Treo CTs were all used.

I bought new cables: Sablon and Fidelium cables over multiple years.

As much as I loved the 761 Moon sound, I could never do just a single Moon 761. When I compared the Moon 761 to the McIntosh 462, I could tell the difference in the McIntosh having more headroom and just sounding more open from it. The Moon had way more detail, richer body, incredible tight bass than the McIntosh. But because of the wattage, the McIntosh had more presence and was felt like it opened the speakers (dynaudio towers that were $15k) more to breath. 

The major audiophile battles are both:

1. Finding components that subjectively/personally resonates with you
2. Finding affordable components

Go for the Simaudio 2x 761 if you can afford it- Try to get a dealer discount.