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I'm familiar with the design advantages of monoblocks for 2 channel/stereo recordings, however, how does that translate to someone who listens to say 50% mono recordings.  Is channel separation irrelevant then?  The larger question is: Is there value in monoblocks for someone who listens to recordings circa <1959 ?   wondering if there's something i don't understand....or is it obvious....

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If two separate channels process identical information then it stands to reason that cross talk through a shared power supply won't cause the same issues compared to two separate channels processing two different sets of information. The cross-talk pollutes one set of information from the other; each output no longer contains only the pure information that was at it's inputs.

 

So if the two separate channels both contain identical information then cross talk won't matter and there is no benefit to two mono amps.

 

 

 

 

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11 minutes ago, captainbeefheart said:

If two separate channels process identical information then it stands to reason that cross talk through a shared power supply won't cause the same issues compared to two separate channels processing two different sets of information. The cross-talk pollutes one set of information from the other; each output no longer contains only the pure information that was at it's inputs.

 

So if the two separate channels both contain identical information then cross talk won't matter and there is no benefit to two mono amps.

 

 

 

No

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50 minutes ago, heresyForthe1sttime said:

Is channel separation irrelevant then? 

 

It's not irrelevant when you are listening to stereo recordings the other 50% of the time. Of course that is only if you have a source capable of excellent channel separation for stereo recording playback. Vinyl stereo playback systems have awful channel separation.

 

51 minutes ago, heresyForthe1sttime said:

The larger question is: Is there value in monoblocks for someone who listens to recordings circa <1959 ? 

 

Not really, no.

 

 

 

 

If you are on the fence about whether to get mono amps or a stereo unit ask yourself what source do you use most? If you say vinyl then the cross-talk is horrendous with vinyl playback and mono amplifiers aren't going to matter since the pollution has already taken place at the source. If you listen to digital sources then mono amps will be technically beneficial the other 50% of the time when you listening to stereo recordings. Digital sources have excellent channel separation compared to vinyl playback.

 

 

There are other benefits to running mono power amps other than channel separation. It's the lesser of two evils to have longer interconnects, especially balanced ones while keeping the mono amplifier directly next to the speaker with a very short speaker cable length.

 

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Thank you for your generous reply.  You make light of something interesting:  How a good (jazz) mono record vs. a stereo record is more desirable objectively..... but then, you listen to a sample such as early columbia / teo macero produced stereo recordings - possibly 1st 200 recordings that were released.   They sound pretty amazing - example dave brubeck: Time out 1959.  I agree with you for certain, but some of these early ones are impressive to my ears despite the limitation of a record vs. digital.  

 

 

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16 hours ago, heresyForthe1sttime said:

Thank you for your generous reply.  You make light of something interesting:  How a good (jazz) mono record vs. a stereo record is more desirable objectively..... but then, you listen to a sample such as early columbia / teo macero produced stereo recordings - possibly 1st 200 recordings that were released.   They sound pretty amazing - example dave brubeck: Time out 1959.  I agree with you for certain, but some of these early ones are impressive to my ears despite the limitation of a record vs. digital.  

 

 

 

I have tons of records and enjoy them immensely, I'm not a perfectionist digital snob by any means.

 

I read an article written by one of the big recording engineers, the name escapes me but he claims that some high frequency cross talk between channels  improves the sound and is one of the reasons people love to listen to vinyl. So he actually mixes this high frequency cross talk into near perfect digital recordings to emulate vinyl on CD or streaming formats. I found that very interesting.

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On 12/3/2022 at 5:49 PM, heresyForthe1sttime said:

I'm familiar with the design advantages of monoblocks for 2 channel/stereo recordings, however, how does that translate to someone who listens to say 50% mono recordings.  Is channel separation irrelevant then?  The larger question is: Is there value in monoblocks for someone who listens to recordings circa <1959 ?   wondering if there's something i don't understand....or is it obvious....

The advantage is true mono, whether you are listening to tube or solid state.

BTW, using 1 speaker.

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Dual Mono Block Integrated Amps have a following

They are typically in the 50 WPC range

and are snapped up quickly.

 

Looking at the performance specs

nothing jumped out at me when I took a quick look them

 

How does any AC flow backwards through the DC power supply and filter caps

and the higher energy AC is happening on the Amp rails or circuits and far from the DC supply

The line level voltage from the pre amp is tiny and away from the other channel

how can it induce cross talk especially if using multi layer boards with ground planes.

Yeah the vintage stuff, some barely qualifies as a PCB with traces dribbled onto the board.

 

Kenwood KA-9100 Dual Mono

Specifications:
Power output: 90 watts per channel into 8ohm (stereo)
Frequency response: 7Hz to 50kHz
Total harmonic distortion: 0.03%
Input sensitivity: 2.5mV (MM), 150mV (line)
Signal to noise ratio: 83dB (MM), 100dB (line)
Output: 1V (Pre out)
Speaker load impedance: 4ohm to 16ohm
Dimensions: 430 x 149 x 384mm
Weight: 16.7kg
Year: 1977

https://www.stereonet.com/forums/topic/340186-kenwood-ka-9100-dual-mono-vintage-integrated-amplifier/

 

1668501326_Kenwood13.thumb.jpg.527a21218

 

 

It is a beauty, design matters

1547005934_Kenwood2.thumb.jpg.c30e2a6323

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Good discussion with some facts and measurement on the AVS Forum

 

Quote

No. Also it is exceedingly unlikely that in any real world scenario the improved channel separation would be audible because, as with most stereo power amps, the channel separation is already quite good.

Edit to add: I looked up a technical review to confirm, but it's for their multi-ch. E-500 amp, from some years ago:

"Crosstalk at 1 kHz driving 2.83 volts into an 8-ohm load was –80.97 dB left to right and –83.17 dB right to left. "

Emotiva BasX System Review Test Bench

Test Bench Emotiva BasX Speaker System L/C/R Sensitivity: 88 dB from 500 Hz to 2 kHz
www.soundandvision.com www.soundandvision.com

https://www.avsforum.com/threads/benefits-of-dual-monoblocks-vs-stereo-power-amp.3248840/

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35 minutes ago, Bubo said:

Dual Mono Block Integrated Amps have a following

They are typically in the 50 WPC range

and are snapped up quickly.

 

Looking at the performance specs

nothing jumped out at me when I took a quick look them

 

How does any AC flow backwards through the DC power supply and filter caps

and the higher energy AC is happening on the Amp rails or circuits and far from the DC supply

The line level voltage from the pre amp is tiny and away from the other channel

how can it induce cross talk especially if using multi layer boards with ground planes.

Yeah the vintage stuff, some barely qualifies as a PCB with traces dribbled onto the board.

 

Kenwood KA-9100 Dual Mono

Specifications:
Power output: 90 watts per channel into 8ohm (stereo)
Frequency response: 7Hz to 50kHz
Total harmonic distortion: 0.03%
Input sensitivity: 2.5mV (MM), 150mV (line)
Signal to noise ratio: 83dB (MM), 100dB (line)
Output: 1V (Pre out)
Speaker load impedance: 4ohm to 16ohm
Dimensions: 430 x 149 x 384mm
Weight: 16.7kg
Year: 1977

https://www.stereonet.com/forums/topic/340186-kenwood-ka-9100-dual-mono-vintage-integrated-amplifier/

 

1668501326_Kenwood13.thumb.jpg.527a21218

 

 

It is a beauty, design matters

1547005934_Kenwood2.thumb.jpg.c30e2a6323

Has one 1980

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According to Paul McGowan of P&S Audio, when listening to a stereo source, a dual-mono amplifier does sound better than a stereo amp with a shared power supply.  Monoblocks are slightly better than dual-mono.  The big jump in sound improvement is from stereo to dual-mono, and the jump (step?) to monoblocks is also there, but it's much smaller.  He knows a lot more about this than me, so I'll go with that.

 

As for listening in mono, there should be no difference, since as the real Duke Spinner and captainbeefheart posted, both channels are carrying identical program material.  It's tempting to put "identical data" these days.  The only difference could be that mono blocks are generally fairly high-performing units, benefitting in other ways than channel separation.  With some companies, there are directly comparable dual-mono and monoblock units, but much of the time this is not the case, making apples-to-apples comparisons difficult or impossible.

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