Are Mono Blocks worth the effort ?

[rtate]

So I'm gonna build a "high end" amplifier for 2 channel listening.
Solid state with the best components I can get. Most likely a "dual mono "configuration with 2 transformers if it is to be in a single chassis. So the cost difference is in the chassis.
Currently listening to a Pass F5 single chassis that I built a couple of years ago and looking for a "covid" project

When it comes to the chassis, is it worth the effort and extra cost to build Mono Blocks verses a Single channel chassis ?
Even if it's not about the cost are there big advantages to mono's ?

I hear that there is less cross talk and some other small differences but is there some real world gains to be had ?

 

[rayma]

Better channel separation, less hum, cooler running, each lighter in weight than a stereo amp.
And the amplifier can be close to the speaker. But make them identical, not in mirror images.
Give it a try, you won't go back.

 

[WntrMute2]

Interested in why you recommend not doing them mirror imaged? I did not mirror mine as I am a novice and felt that I didn't need the added complexity but I'm interested in your reasoning.

 

[JeffYoung]

I went with monoblocks primarily to get rid of the heat. (I'm looking for about 4x the output of my F5.)

But now that one is about 80% constructed it's clear I wouldn't be able to lift a stereo version.

 

[chromenuts]

Monoblocks are for sissies!

I’ve built two pair so far...the original ACA monos and my F2J monos.

It was an easier decision for me as I build almost all of my equipment cases by hand myself...my ACAs were an exception.

I did it for all the reasons rayma mentioned...but I did mirror them as I try to keep symmetry with cables on the backside so they can be as short as possible and avoid crossing when I can.

I have a strange current situation that forces me to offset them on top of a cabinet to the right of my turntable. I’m working on a new space and hope to have them placed near the speakers symmetrically.

 

[schiirrn]

No. Build a separate power supply and locally decouple everything by putting individual regulators as close to the loads as possible.

 

[billshurv]

Personally I think it's worth it to get speaker cable lengths down. Unless you are a lifestyle audiophile who wants his amplifiers in front of the speakers to show off. In that case you are a lost soul...

 

[Mark Tillotson]

Better channel separation, less hum, cooler running, each lighter in weight than a stereo amp.
And the amplifier can be close to the speaker. But make them identical, not in mirror images.
Give it a try, you won't go back.

The channel separation argument has no legs, people can't detect even 30dB separation or so! Being able to common supply and protection components strongly suggests stereo is the way to go, economy of scale still works at a
scale of 2...


There is one advantage of monoblocks though, if one malfunctions you can still listen to the other while repairing it!

 

[rayma]

Interested in why you recommend not doing them mirror imaged? I did not mirror mine as I am
a novice and felt that I didn't need the added complexity but I'm interested in your reasoning.

The two channels should be as closely the same as possible.
Layout, wiring, construction, and pcb design all can have effects on
the measured and audible performance. Some confuse things like
acoustical performance in speakers (which should be mirror imaged)
with electrical performance in amplifiers (which should not be).

 

[rayma]

The channel separation argument has no legs, people can't detect even 30dB separation or so!
Being able to common supply and protection components strongly suggests stereo is the way to go

Separate power supplies is in fact a strong reason in favor of monoblocks.
Even my HK-430 receiver has separate power supplies for each channel, including
the two identical power transformers.

 

[SRMcGee]

rtate:

I disagree with Rayma on the issue of mirroring monoblocks (do it) but agree with everything else said here. If you don't need the power or heat sinking, dual mono in a single chassis is marginally better than stereo. On the other hand, monoblocks look cool. I don't mind admitting I have an ego and like the look of my projects. We're audiophiles so we're supposed to focus on sonics and performance, not cosmetics, but the truth is the amp will most likely be visible while you're listening to it and will be a source of pride. For that, two is better than one.

Regards,
Scott

 

[DDzStereo]

No. Build a separate power supply and locally decouple everything by putting individual regulators as close to the loads as possible.

Go all in, mono blocks with separate chassis' (4 total) for power supplies.

 

[duncan2]

I agree with Ryma & DDzStereo ,if you are going to do mono-blocks do it "right " --all the way , yes its more work and time but any problems relating to same chassis use are removed and more stable amplifiers are achieved with less compensatory factors needed.

 

[knotscott]

If your speakers have separate inputs (a big "if"), you can use two stereo amps vertically bi-amped as monoblocks....one amp on each side. This still offers the improved separation of monoblocks, plus it allows you to dedicate one channel for the tougher task of driving the woofers, freeing up the other channel for the easier task of driving the mids/highs, which theoretically should give cleaner sound.

 

[Bones13]

The M2x boards came in a mirrored pair, so, my monoblocks are mirrored. Double chassis, and PSU costs. I managed to position the power switches nearer to each other, while putting the speaker termination posts further apart (closer to the speakers)

I am thrilled with the sound vs my big standard DIJ Aleph J stereo amp. Although I guess a true comparison would involve a monoblock set up Aleph Js, with similar PSU.

 

[Andersonix]

If the idea of monoblocks isn't appealing, just hang around a lot longer.

If it's real gains you're looking for, you could separate the transformer, rectifiers, and first bank of caps from the main amp by an umbilical cord of some distance.

 

[Bigun]

for some amplifiers a mono block is needed simply because the weight for a stereo would be prohibitive

 

[rayma]

I disagree with Rayma on the issue of mirroring monoblocks (do it)

Don't do it.

 

[Ozark HiFi Doctor]

I am only building mono amps...

I had to design and build mono blocks, in that I could not fit *everything* in one chassis I am tired of working in terribly confined chassis's ~and~ they would be over 50lbs., unfortunately too heavy (for me to safely carry) with shoulder issues... an injury would not be worth it...

Also for me... placement is a hassle for floor space, interconnect and wiring... I want to get my amps as close as possible to the speakers. not stress my interconnects and speaker wiring... every time I swap gear out or test newer builds...

I do believe that the mono chassis perform and sound better even using the exact same parts and circuits.

 

[pinholer]

I like building class A amplifiers and stereo amps often run into problems with cooling and weight. If it has enough power supply and heatsinking, then it becomes too heavy for me to lift. Not getting any younger, but weaker.