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Single vs Dual Power Transformers

Fellow members

I have a question I hope you clarify. I've noticed some excellent stereo amplifiers and integrated amplifiers have a single transformer with dual windings for each channel (Hegel and others) and some have 2 separate transformers, one for each channel. (Gamut and others). Is there true benefit to having two separate power transformers given excellent design elsewhere? Can an amplifier be defined as truly dual mono without separate power transformers? I do realize that the totality of the design is the most important issue, but I would like to know the real benefits if any.
Thank you for your responses in advance.
audiobrian
jdub39
495 posts
 

@watchdog005  That may very well be true but if the transformers are large enough (oversized for the application) to begin with, then problem solved.

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cleeds
5,943 posts
 

watchdog005

... one negative to dual mono transformers is if there happens to be a time when the recording requires an unbalanced surge of power to the left or right channel in which one of the two smaller transformers might not be able to provide all the power to that channel that a single larger transformer can provide.

That doesn't really make sense. Any amplifier should be able to provide its rated power output to both channels driven simultaneously.

watchdog005
10 posts
 

They were referring to the rare time when one of the channels have twice the output due to the recording being much louder in either channel for a short duration. In most cases the two smaller transformers should not have a problem but in the rare case where the recording is much louder in one channel or the other a single much more powerful transformer can handle the spike much easier than one smaller of two transformers can. It’s possible for a short duration the smaller of two transformers might not be able to handle the extra power on demand. I suspect this might happen in a single dual transformer chassis in which space is limited and two smaller transformers are needed to fit and not in a dual mono amplifier in which each channel has its own chassis and each amplifier can have a transformer the size of a single transformer used in a single chassis. Hope this makes more sense now...Lol. 

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cleeds
5,943 posts
 
 

watchdog005

... in the rare case where the recording is much louder in one channel or the other a single much more powerful transformer can handle the spike much easier than one smaller of two transformers can.

Sorry, but that doesn’t make sense. Amplifiers are specified using a specific frequency range (typically, at least 20 Hz to 20kHz), at a specific maximum distortion level, with both channels driven. If in your example the amp cannot deliver rated power to the one channel, then it is not meeting spec. One channel doesn’t magically acquire more headroom simply because the other channel is loafing along - maximum output is determined not only by the amplifier’s power supply, but also by its output devices.

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