45 th Parallel ~ correct .. this is because an 8 ohm load looks like a 4 ohm load .. to keep within the SOAR curves of the output transistors ideally the power supply rails should be reduced . Mono blocks will always image better .. they are fully independent.

Agreed. Their may be a lost of detail, which is important for imaging, by running a stereo amp in bridged. For example, damping factor may take a hit.

Consider that the primary difference between the topologies on the circuit side is the power supply. I wouldn't worry of traditional crosstalk which will be dwarfed by the crosstalk in the phono cartridge for that use. In the case of the monoblocks the power supplies are typically oversized from my limited experience and by virtue of the separate units, not interactive which I think is the key. With soft passages there should be no difference at all but when you experience dynamic events at high volume, you ask the supply to give everything that it's capable of giving and that is where the performance will diverge. I've designed both mono and stereo amps from a common base and my tendency is to arrive at a slightly oversized power supply for a stereo design which then becomes a 2x oversized supply for a mono design but I don't know what approach other take past the schematics I've reviewed. Think of crosstalk not from the standpoint of signals contaminating each other directly, but from the standpoint of the demands being made on the power supply at the same time from each channel and how those demands interact. With a mono source of course there is no difference, but with modern stereo music born of synthesizers it's possible for each channel to demand considerable peak currents with asynchronous phase and frequency relationships, however few are probably using PS Audio gear for hip-hop. lol.

@Larry Niles recruiting people again? can't you take a stand for yourself?

@Larry Niles kettle black.😂

Yes, I would agree, crosstalk's pretty low down the list. The biggest differences are in dual power supplies.

@Larry Niles Is that a royal we.

A bridged stereo amp is not the same as a monoblock. Bridging take the opposite amp channel and runs it inverted. Think of it as two push-pull amps working as one larger push-pull amp. Yes, the power goes up but so does the distortion and noise floor, as much as double. Bridging it not necessary or desirable for HiFi use other than perhaps a sub woofer. It's used in large concert venues where very high power is needed. It was also popular in the 1980s for higher end car stereos as you have a limit on the audio power with a 12 volt electrical source. By bridging they could at least double the available audio power at 12 volts. Today they just use a switch mode inverter which is actually much cheaper and can provide even more audio power.

I wonder why Paul didn't pick up on this. It was glairing obvious it me too. Of course the term 'imaging' is a little ambiguous as it dosen't really identify the real problem here.

I’m running 5 Crown D75s into Linn Sara loudspeakers from a DBX electronic crossover. One D75 in stereo mode feeds the left & right treble the other 4 are bridged into the 4 woofers (2 woofers per bookshelf speaker cabinet in an Isobarik configuration). Are you saying I’d be better off using 3 of the amplifiers in stereo mode rather than 5 in bridged mono? The speakers are configured so each driver is connected directly to its own pair of 4mm input sockets so I need 6 channels of amplification to power them. The Crown D75 can be used in 3 distinct modes of operation: stereo mode (feed two signals in, connect two outputs red & black to two speakers @40 watts each) - bridged mono mode (feed one signal in connect one output across the red outputs @90 watts) - dual mono mode (one input to two outputs, connect two speakers @40 watts each but reverse polarity of channel 2). If the amps do sound worse when bridged maybe I should try just using 3 of them to get the 6channels required but at a lower output of 40watts per channel rather than what I assumed was going to be better & using separate D75s for each woofer to get a greater power output into the woofers.

@@tomeasterbrook9486 While the distortion can double in bridged mode, the question is doubled from what? Say 0.4% in bridged versus 0.2% in stereo? That difference isn't worth the effort. And not all bridged amps double in distortion, it always a bit more not could also be less than double. Another thing you need to consider is the total audio power needs. If you have six speakers and three stereo amps, you still have the same power just divided up differently with bridging versus stereo or dual mono connections. In your specific situation I would just leave it alone if it has served you well over a year or more.

I prefer a vertical biamp rather than bridged. My Martin Logans had the panels and the woofers tied together with a strap across the lo/hi terminals, like a lot of speaker do. I ran one channel of a stereo amp to the panels and one channel to the woofers, and did the same with another identical amp for the other speaker. It sounded better than bridged or a single stereo amp.

Consider though that with monoblocks it's possible to eliminate the majority of the cable going to the speakers. I would much rather put the cable extensions in a run with 10KΩ impedance than one with 4Ω impedance.

@@Peter_S_ You can shorten the length of the speaker cables but you then need the interconnects to be longer. I know that they say that's better but the difference is small and depends greatly on cable quality and design. Mono blocks do sound better but they cost twice the price. I'm not sure if the small improvement justifies the large extra cost. It would be of more interest to compare the stereo amp if it cost the same as both monoblocks together. Better components and design in one box versus two cheaper and more simple design amps

@@stephens2r338 I agree with you that it depends greatly on cable quality and design, but in this price bracket the majority of players have the funding to explore things like frightfully expensive speaker cables which will always present their effect in the result, however small. The rather large cables connecting the amps and the Infinity IRS-Vs in music room number 2 at PS Audio are a sight to behold and demonstrate the bulk of cable necessary to make that part of the equation disappear as much as possible. They're big, beautiful cables with a ton of copper and I'll wager they're not inexpensive. Most things in life have a point of diminishing return and cables are no exception. For the majority of us there will be a profound difference between a speaker cable of 26 gauge and one of 12 gauge even if that 12 gauge is made from a coat hanger. That difference is then multiplied by the cable length and it adds up. The complex physics of all the EMF interactions in that speaker cable which is carrying considerable current can then influence the sound and that's where the best policy in my humble opinion is to minimize the length of the cable. The signal level interconnects are far more forgiving because they're barely transmitting any current at all and obtaining or building a longer high quality interconnect is far easier than trying to overcome the physics inherent in the high current output circuit.

@@Peter_S_ Thanks Peter, you are totally correct. I have owned too many types of cables over the years, from solid silver to some l believe being breathed on by a fairy. They all sounded different and some were just amazing. However dropping 10,000$ on nterconnects will not give you the same improvement as on the amp or source. AQ said it best that good cables only do less harm than poor one's. I agree that cables are very important but the question was about stereo amps vs monoblocks and which offers the best value what do you think?

Peter S Yes, I cant disagree with that point but it’s mostly a valid point for fairly large rooms and still, you might get more audio fidelity for your money by going for a stereo amp.

dennis walsh I was thinking the same yes mono blocks are two separate channels but the preamp is a stereo preamp so Your going to get cross over and so you will still have cross over well that’s how it seems to me

@@ianyates7742 There are many differences between amps but the switching for strapping usually effects the preamp too. One channel is inverted and the input defaults to a mono input. The outputs are "series-ud up" and a crude explaination is one channel is now push and the other is pull. Speaker output no longer uses the normal negative terminals (usually grounded) and speakers are usually connected between the two positive terminals of both L & R amps. A bit confusing, speaker polarity issues sometimes crop up because now the (pos. & neg.) speaker connections are now defined by physical position, not color. Just make sure they are the same. Example, if you pick the "left red terminal" for neg on one amp, then the same position for the other amp.

dennis walsh Thank you for the explanation Dennis it’s sort of made sense to me not being electronics engineer but I’ve grasped the basics of what you were saying thank you very much

I think you're taking the statement out of context. He obviously meant that he's heard some cool things from them. Like when someone sends an email with bad news and you reply, "Sorry to hear that," rather than the more correct "Sorry to read that."

Too many gimmicks in this business. The only engineer i really trust is Andrew Jones...brutally honest guy who doesn't give a crap about sales numbers.

@@wa2368 I agree that there are too many gimmicks in high end audio, but Andrew Jones? He's a talented dude, but if you work for Pioneer, TAD, and Elac you are clearly in touch with sales numbers. Maybe you mean he's not as interested in the snobbery and gimmicks of high end? I think that's a fair conclusion.

@@terrywho22 yeah, he'll give you a pair of speakers that costs a 100 bucks, 200 bucks or 60,000 bucks, tell you exactly what you're getting, tell you exactly where the production costs went into ( no bullsht) and let you make a informed decision. He gives a rat's ass about all this audio snobbery and puts his best effort into everything he does at any price point. Stupid sales guys spin it however, but everything coming out of Andrew's mouth is truthful.

And the source lol unless you want to run 2 cd players or whatever your source is 😂

Channel balance? Probably find this with a high end pre amp designed to be used with mono blocks.

that is not how it works, you have to have both to appreciate and enjoy the most out of music. someone who ha no technical details cant enjoy those aspect of music and music reproduction. hence cant enjoy that part. its like forgetting those who built the speakers and amp that you are actually listening to.

Scott R Smith doesn’t electricity move at the speed of light?

That was my exact thought as well..... No idea if it is a valid thought in practise, but still a logical one I think. Could there possibly be phase differences between the two as well ?

he's gonna say that because he want's to sell you the sprout

I agree with you, especially the M10 they released recently and has fenomenal sound and features for the modern audiophile.

@Fat Rat Not being fair ! The nad is $2700, the sprout is $ 500