2. amps-preamps
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What do you hear with a better/bigger power supply and output capacitors in same amp?

Start by assuming a good stereo power amp with a proper-sized toroidal transformer and a good supply of output storage (good capacitors).  One option might be to merely enlarge both toroidal transformer and cap supply. What do you hear?

Another option is taking that amp and bridging to mono (I’m not knowledgeable; but I have ears) and using two as mono power amps. For all practical purposes each channel has twice the toroidal watt capacity and output cap capacity as before. (Another question, unrelated; what improvements can be claimed from using both L&R sides of the signal path board together?)

Typically more watts claim more headroom on transients and long loud passages. But what else do you get from this? I changed amps and my ‘new to me’ amp (avoiding names) sounds audibly better in at least five distinct ways from my prior (and decent) power amplifier (admittedly on rather good speakers).  I hear more bloom/air, tonal texture, detail, micro-dynamics, and low bass ‘growl’ than before. If I move to mono-blocks will I get something more, or not? How audible?

musicaddict
erik_squires
16,041 posts
 

Hey OP,

Well, maybe nothing. We can talk some theory though.

When we imagine how things change from say, an undersized power supply to an oversized power supply the practical difference would be described as reduced output impedance.

The output impedance of an amp is a combination of many factors, including the number of output stages, amp topology (zero feedback vs. feedback) and the power supply sizing relative to the load.

With a purely resistive 8 Ohm load it is relatively easy to design an adequate power supply that ensures the amplifier performs up to it’s specified output, with a flat frequency response.

When impedances drop, and reactances rises is where things get more interesting and, generally speaking, a larger power supply will support the output stage and keep it "stiffer." That is, the amplifier performs equally well at all frequencies up to rated output.

In other words, along with the right amplifier circuitry, a low impedance power supply makes sure you get consistent performance regardless of load.  As your power supply gets smaller, the amp becomes more sensitive to the speaker load and the output will stop being flat and will start to track the speaker impedance.

So, all kind of depends on your speaker load, volume, speaker efficiency, etc. as to whether or not you’d hear any difference at all.

erik_squires
16,041 posts
 

, including the number of output stages

 

Sorry, I meant to write: "... number of output devices" not stages.

erik_squires
16,041 posts
 

It may help a little to understand that the power supply has to provide DC voltages.  Say + and - 50 VDC.

That voltage will drop, or sag, as the current needed by the amp stages increases.

The larger the power supply, the less sag in the voltage.  That is, the voltage will remain + and - 50 Volts, allowing the amplifier circuits to perform optimally.  this is what we call a "stiff" supply, because the power supply's output is constant despite the demand on it. 

musicaddict OP
370 posts
 

No throwing components in DIY; certainly not qualified to. I'm talking upgrading to the mfr's mono version of a good stereo amp.

E.G. a 'Mark L' 200wpc stereo w/one large toroid and lots of capacitance.  Say you converted that to bridged mono (and added one more amp). Would that new additional output capacitance (double the caps from before) and the same transformer to power only one channel, would one hear anything?  I'd hope on extended dynamic passages it would help?  Might there be more air/bloom/body/detail, etc?

If the stereo version is all you're (me) gonna get, why monos? My speakers are small inefficient (85?) D2 towers (raidho) and seem to like power...

 

erik_squires
16,041 posts
 

See the very first sentence in my first reply.

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