The First Watt is The Sweetest!
Here you can post your 1-2 Watt amplifier. Maybe 3.
Because often there is no need for more power.
Especially if your have speakers with high sensitivity.
Here I will post a couple of my own low power amps.
Here you can post your 1-2 Watt amplifier. Maybe 3.
Because often there is no need for more power.
Especially if your have speakers with high sensitivity.
Here I will post a couple of my own low power amps.
That doesn't have to be a low power design.
I have a Hafler 9290 amp, 145Wpc. The output stage is 3 pairs of lateral mosfet, biased at 100mA each.
Thus, anything below 1W is in pure class A, which means very low distortion at that level.
The same principle can be applied to BJT EF2/EF3 output stage, too. With Re 0.22 Ohm, the optimal bias is around 100mA per pair. If you parallel 3 pairs output transistors, it can stay class A upto 1W.
I have a Hafler 9290 amp, 145Wpc. The output stage is 3 pairs of lateral mosfet, biased at 100mA each.
Thus, anything below 1W is in pure class A, which means very low distortion at that level.
The same principle can be applied to BJT EF2/EF3 output stage, too. With Re 0.22 Ohm, the optimal bias is around 100mA per pair. If you parallel 3 pairs output transistors, it can stay class A upto 1W.
Why would anyone listen to only a few watts when affordable class-D power in the range of 100-200W is readily available for around $200-$ 500?
When the listening level is 70 dB on my desktop. Doesn’t even tax that 14 watt amp. When I want it louder there are bigger amplifiers and speakers.
The best solid state really low power one was a TA7205 chip with a 1.5A current sink hanging off the output before the cap. It was the old LM324-op-amp-trick on steroids. Nice, but only 2 and a half watts at 8 ohm. Don’t have it anymore, though.
Small amplifiers are fun to play around with. Most of the ones I’ve had over the years don’t do the first watt especially well and aren’t the last word in fidelity even within their limits.
The best solid state really low power one was a TA7205 chip with a 1.5A current sink hanging off the output before the cap. It was the old LM324-op-amp-trick on steroids. Nice, but only 2 and a half watts at 8 ohm. Don’t have it anymore, though.
Small amplifiers are fun to play around with. Most of the ones I’ve had over the years don’t do the first watt especially well and aren’t the last word in fidelity even within their limits.
Bah Humbug.
Those of us who drive Magnepans know the First TEN Watts are the sweetest.
😉😉
That said, if the noise floor of your system is good enough, even a Zenductor or 10w SIT will make the Maggies sing - not lots of bass sure...
My two low wattage amps in one picture. (Only one is solid state.)
Top: Elekit TU-8200R (6L6GC tubes, set to triode mode)
Bottom: Burning Amp 2024 Zenductor 2 (IRFP048 MOSFETs)
Both plenty loud enough driving KEF R3's.
Top: Elekit TU-8200R (6L6GC tubes, set to triode mode)
Bottom: Burning Amp 2024 Zenductor 2 (IRFP048 MOSFETs)
Both plenty loud enough driving KEF R3's.
Currently listening to Grand Canyon Suite on the living room system. Subwoofers are some pro 18 inch woofers vented into the attic. They really do not need alot of power in the bass range. They are driven by some old AV receiver. Midwoofers are EV 15Ws from 100 hz to 800 hz. Currently they are driven by some old junky JVC reciever. 16 ohm loading. Horns higher loading the amplifier even less. I have measured the peak power at times and rarely hit near a watt. Have to say it sounds great.
Looking to come up with a MOFO style amp for the top with 1W standby and maybe 10 Watts when the kids want to really push it. Will likely use microwave transformers.
Looking to come up with a MOFO style amp for the top with 1W standby and maybe 10 Watts when the kids want to really push it. Will likely use microwave transformers.
The first HUNDRED watts are the sweetest. That’s about where my big class H amps stay on the lowest tier. And no sign of power compression at all in the speakers.
Ay... that is NICE.
EL38? 40 wpc? That's a really nice amp.... nice cooling slots in the front panel. DB15, DB28s? What's that in the back? A huge tube? Rectifier? Something driving the grids?
I need to pull out the ARC D70-II from the shelf and use it... I had the factory go over it last year.
60 watts of 6550 Svetlana Russky thermionic bliss.
One of these days I'm gonna buy myself an ARC VT100, or a CJ Premier One and hide from DIYAudio and everybody () forever. Lost in thermionic bliss, no need for solid state anymore, as I was from '90 to '14 when I bought the Rawson A5s and asked on a fateful Friday night about the schematics. (*)
Although, if I won the Lotto... a pair of push-pull KT150 amps.... hmm....
In the meantime... would a comparison between the Semisouth F6 and the ARC D70-II be useful? It might lead to a Big Sale of amps....
(*) Yeah, you'll be happy.... won't ya? 😉
(**) Gawd, I got my butt fried... but eventually I found the cold solder joint - thanks to those of you, including Nelson, who actually tried to help, after sort of lecturing me.... oh well.. 😳
EL38? 40 wpc? That's a really nice amp.... nice cooling slots in the front panel. DB15, DB28s? What's that in the back? A huge tube? Rectifier? Something driving the grids?
I need to pull out the ARC D70-II from the shelf and use it... I had the factory go over it last year.
60 watts of 6550 Svetlana Russky thermionic bliss.
One of these days I'm gonna buy myself an ARC VT100, or a CJ Premier One and hide from DIYAudio and everybody () forever. Lost in thermionic bliss, no need for solid state anymore, as I was from '90 to '14 when I bought the Rawson A5s and asked on a fateful Friday night about the schematics. (*)
Although, if I won the Lotto... a pair of push-pull KT150 amps.... hmm....
In the meantime... would a comparison between the Semisouth F6 and the ARC D70-II be useful? It might lead to a Big Sale of amps....
(*) Yeah, you'll be happy.... won't ya? 😉
(**) Gawd, I got my butt fried... but eventually I found the cold solder joint - thanks to those of you, including Nelson, who actually tried to help, after sort of lecturing me.... oh well.. 😳
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I built this Papas design with added push pull current buffer and some modifications to get first sweetest 200W 🤣 🤣 🤣 . This original Papas diagram is I think the best sounding amp that falls in your category, when not considering tubes.
My iteration is still my best amp and reference with not so good THD at all:
"post-7672602"]https://www.diyaudio.com/community/...ttle-fb-160watt-amplifier.412261/post-7672602
Maybe an amp based on a small power-JFET such as LU1014 which I recall has a triodic gain characteristic, maybe can be used as a single in a circuit similar to the one below designed for 2SK1058 (also a sweet amp), but the supply voltage must be lowered and some component values recalculated. 🙂
Scalable with 1…4 LME49600 for 1…8 Watt.
I use opa1611 for U1 on adapter.
For high sensitive loudspeakers(>110db), no noise.
Easy to build, see link for PCB gerber.
https://www.diyaudio.com/community/...ny-recommendations.342387/page-4#post-7136313
I use opa1611 for U1 on adapter.
For high sensitive loudspeakers(>110db), no noise.
Easy to build, see link for PCB gerber.
https://www.diyaudio.com/community/...ny-recommendations.342387/page-4#post-7136313
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