I am looking for a power amp that would sit in a doorless small cabinet under TV, so it needs to stay cool. My class A amps that are fine on a rack really overheat inside that space
Something like 15-25W into 8 ohms will be enough. Voltage gain not important, can be down to unity
I have a few of Nelson Pass designs and I really would like something that sounds as close as possible, given all the limitations
I don't like forced cooling I have to say
Appreciate any recommendations!
Something like 15-25W into 8 ohms will be enough. Voltage gain not important, can be down to unity
I have a few of Nelson Pass designs and I really would like something that sounds as close as possible, given all the limitations
I don't like forced cooling I have to say
Appreciate any recommendations!
For lowest heat you'll be wanting classD. A TDA8932 with appropriate mods should sound excellent, see this thread : Fasten seat belts. TDA8932 pessimistic review.
Most any class AB amp with a decent OLG and reasonable slew rate will perform well with the output bias current turned right down. Also choose an appropriate supply voltage - 20W into 8Ω is 18V peak, and can be done with +/-22 to 24V supplies easily. Quiescent dissipation under 2W with <0.001% 10KHz THD and 5-10V/μs slew rate is perfectly doable.
Don't think you can even come close to a Pass topolgies' sound quality.. Without! going to a pass circuit.
Learn to adapt to forced cooling,? Find a better location for your amps ?
Real Life.. has it's complications.. adapt?
Although Some Firstwatts barely get past Warm.
A chip amp is a Poor imitation .. by any honest yardstick.
Learn to adapt to forced cooling,? Find a better location for your amps ?
Real Life.. has it's complications.. adapt?
Although Some Firstwatts barely get past Warm.
A chip amp is a Poor imitation .. by any honest yardstick.
That depends entirely on what sound quality means to you. With Pass DIY class A topologies at least, we are talking of prodigious amounts of mainly 2nd harmonic distortion which chipamps or regular AB designs don't have and that will be a problem if, like the OP says, it's what he wants.
So, once again, we're asked for sweetened class A without the heat. Wouldn't that be nice if it was so simple
So, once again, we're asked for sweetened class A without the heat. Wouldn't that be nice if it was so simple
Ah yes, digital innovation but not a kosher way to extract ear-thrilling quality sound You see, audio designers here, are expected to do their audio the hard wired analog way, concealed in masses of iron, copper and aluminium with only a little PVC sleeving to pretty it up. It's a matter of audiophile and high end audio lore which extends to brass and glass tech. too.
Well, that's my view but others will have their own and some will embrace anything digitally derived or processed as inherently superior so let's see how far the interest in that direction goes.
If it wasn't for the stellar price tags, we might dismiss high-end analog gear as antique or retro but there are still some respected techs and industry names associated with the products. I'm sure they don't mind the income from the sale of just a few products either.
You see, audio designers here, are expected to do their audio the hard wired analog way, concealed in masses of iron, copper and aluminium with only a little PVC sleeving to pretty it up. It's a matter of audiophile and high end audio lore which extends to brass and glass tech. too. Well, that's my view but others will have their own and some will embrace anything digitally derived or processed as inherently superior so let's see how far the interest in that direction goes.
If it wasn't for the stellar price tags, we might dismiss high-end analog gear as antique or retro but there are still some respected techs and industry names associated with the products. I'm sure they don't mind the income from the sale of just a few products either.
I have scaled the 50w VSQ Class AB design by Ranchu/Aksa, which has a harmonic profile with dominant H2 and monotonically descending higher orders down to a 1.5W into 30ohm headphone amp by use of smaller outputs and lower voltage rails and revised DC setpoints. It still sounds very nice and has same harmonic distortion profile similar to a SE Class A amp. It would seem that scaling it to a 20w amp would be easy. It has only 7 actives and no DSP needed.
Here is schematic of 50w version:
http://www.diyaudio.com/forums/atta...tary-mosfet-amplifier-ranchu-hybrid-quasi-pdf
Many PCB layouts are available for this amp, with the Dacz layout being verified and tried and true. It’s quite compact and simply de-rating the rails to +/-19v (let’s you use two cheap laptop amps in series), drop the bias current a bit, and adjust a few resistors that set the input stage and VAS stage bias, will probably get you a nice sounding circa 20w amp.
Here is my 1.5w HPA build:
http://www.diyaudio.com/forums/soli...mentary-mosfet-amplifier-186.html#post5138640
Here is schematic of 50w version:
http://www.diyaudio.com/forums/atta...tary-mosfet-amplifier-ranchu-hybrid-quasi-pdf
Many PCB layouts are available for this amp, with the Dacz layout being verified and tried and true. It’s quite compact and simply de-rating the rails to +/-19v (let’s you use two cheap laptop amps in series), drop the bias current a bit, and adjust a few resistors that set the input stage and VAS stage bias, will probably get you a nice sounding circa 20w amp.
Here is my 1.5w HPA build:
http://www.diyaudio.com/forums/soli...mentary-mosfet-amplifier-186.html#post5138640
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