Class A/B Pre Into Class D Amp


Both SS, integrated class A/B as Pre into Class D amp. Yes, no, overkill?
Dbfff427 fddc 4041 ac5e a790f21552a1mental
Why not? Most audiophile pre's are usually class A though. The voltage is so low they can waste a few watts.

Best,
E
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Ain't no preamp on the planet driving 5 watts. 
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@Mental
SS preamps are high impedance, low voltage therefore relatively low power.

There may be some waste heat since the buffer stages are class A, but the whole preamp operating power is usually under 30 watts.

The power spent on the load (the amp's inputs) is certain to be in the milliwatts.


The 5 watts is the Class A portion of the 100 watts A/B, but that's the power amp section. If you're using the pre-outs, the power amp is out of the circuit. The preamp output is usually measured in volts, not watts.
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Yeah, it is, but it contributes no power of its own to the power amp output. 

And very few class AB amps have a 5 watt bias. They're usually like a tenth of a watt. Insignificant for all intents and purposes. 
@mental
High quality SS preamplifers with discrete stages are almost always class A. However, because they are low voltage/low current the total power spent is relatively low.

Amplifier inputs are around 15kOhms, though in the past pro amps had very low 600-ish ohm inputs. Max voltage ever seen is usually 3-5 V.

So, yes, preamplifiers can be class-A, but the power is still a fraction of a power amplifier.

And there's no problem using a SS or tube preamp into a class D amp.

In fact, I don't know of any other choice. :)

Best,
E
I should point out that most preamp makers don't even discuss the "class" of amplifier they use, we all just assume it is class A for solid state, and single ended for tube.
Thanks to all for the info. I'll put the i3 somewhere else stand alone. Heh, why I like this place, knowledgeable folks.
@eric_squires -- How can one find out the class of their preamp?  I have a Parasound 2100, and the literature says nothing about the class, although it does say the input power is 10 watts when not in standby. 
cheeg,

Just assume it is class A IF it is 100% discrete. If it uses op-amps it probably is not.

The only reason all linear amps are not class A is due to power and heat.

However preamps are very low power even when class A.


Best,
E
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A manufacturer will likely mention their preamp is a class A design—mostly for marketing purposes. Audible Illusions does this (no slight, as I own their preamps). 

http://www.audibleillusions.com/products/modulus-3b-full-function-stereo-preamplifier/

Reading my original post this mornin and started chuckling. Think it was a combination of rum and love for the i3 I've grown accustomed to.
Anyways, it was time for a change. That B-135 and 704 S2's have settled in and I'm quite happy with the results. The i3 ended up with the SCM1's in my lil work area.