You might like the Ranchu/Aksa Quasi (50w into 8ohms), or if you want to buy one pre-made, that is commercial amp, try one of Hugh's ASPEN amps. I think Hugh designs all of his amps with a similar harmonic profile.
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I commented:
Virtual Audition of Very Simple Quasi MOSFET Amp
Australian amps + shipping to Spain (EU) + 21% + 4% is too money to me to buy it without having heard it. And without measures and graphs.
A DIY class AB amp with H2 predominance is better and cheap idea.
Virtual Audition of Very Simple Quasi MOSFET Amp
Australian amps + shipping to Spain (EU) + 21% + 4% is too money to me to buy it without having heard it. And without measures and graphs.
A DIY class AB amp with H2 predominance is better and cheap idea.
Have you tried Fetzilla?
Swordfishy/ASPEN FETZILLA power amp
One thing about the Alpha 20 is that it drives even my 82.4dB speakers perfectly loud for most music. Even orchestral pieces sound good now with my new Baltic birch cabinets with sound dampening sheets and eggcrate foam. They play much louder without distorting. But perhaps you might like the 52w Big Boy?
Swordfishy/ASPEN FETZILLA power amp
One thing about the Alpha 20 is that it drives even my 82.4dB speakers perfectly loud for most music. Even orchestral pieces sound good now with my new Baltic birch cabinets with sound dampening sheets and eggcrate foam. They play much louder without distorting. But perhaps you might like the 52w Big Boy?
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It looks like above is FFT near clipping which typically will be 3rd order. Is there FFT of Fetzilla at 1w or 8w rms?
Maty Tinman,
Although appreciate your efforts to show all the different profiles of other amps, it looks like you are searching for another amp, and the Alpha is not in your search window. If you wouldn’t mind starting a new thread called, “Looking for a muscular 2nd order harmonic distortion Class AB amp”. Otherwise it’s getting too far OT.
Thanks,
X
Maty Tinman,
Although appreciate your efforts to show all the different profiles of other amps, it looks like you are searching for another amp, and the Alpha is not in your search window. If you wouldn’t mind starting a new thread called, “Looking for a muscular 2nd order harmonic distortion Class AB amp”. Otherwise it’s getting too far OT.
Thanks,
X
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Streacom DB4
It could be a slight challenge as the chassis is intended fanless but they offer an interesting folded heatpipe-LEGO to get the processor or GPU cooled against the side walls. Flexible system of clamps inside could simplify the build. Upper deck has on perimeter four narrow slots and the bottom a big one for the cables so a slow silent fan surely could be mounted inside. The walls are 260x260mm of 13mm alu IIRC so for ALPHA 20 cooling must be viable. I actually wanted my current ICEPower 125ASX2 be my final amp but the ALPHA and this case make me uncertain...;-)
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With so many graphics of commercial amplifiers of well-known and expensive brands I wanted to make clear that the ALPHA has a harmonic profile much better than them, costing much less.
You only need high sensitivity or high impedance speakers that require little watts.
For me, this amplifier and the preamplifier mark a point apart from any other commercial/DIY system (class A or class AB, tubes or state).
In short, with them Hugh and his collaborators have achieved stardom.
You only need high sensitivity or high impedance speakers that require little watts.
For me, this amplifier and the preamplifier mark a point apart from any other commercial/DIY system (class A or class AB, tubes or state).
In short, with them Hugh and his collaborators have achieved stardom.
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Exactly what I was thinking. Would be great if you could DIY the heatpipes to large external heatsinks. That could make for some very clever layout designs, possibly allowing very efficient use of space and short wiring paths to power, input and output.
There might be a COTS solution but I am afraid it won't be cheap as using CPU coolers.
Flexible avionics and aerospace high-temperature heat pipes, Thermacore Inc.
Thanks for your kind words Mati Tinman! It is a true team effort with Hugh's brilliant topologies and JPS64's superb mastery of professional PCB layout and design. I am lucky enough to get to build prototypes with them.
So, I probably want my coolers to be placed between roof holes and sinks, so that they will suck air through the heatsinks and blow hot air out from the roof? Theres lots of holes in the bottom where to suck replacement air and legs to give some clearance from floor. What are best availeble coolers nowdays and where is the most convient place to get some power for them? 2 coolers are enough?
Edit: it seems that Be quiet! silent wings 3's are quiet and you can have them voltage controlled, so no pwm needed.
Edit: it seems that Be quiet! silent wings 3's are quiet and you can have them voltage controlled, so no pwm needed.
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JPS64 will hopefully, have some links to the CPU coolers he had in mind when he placed all the mounting holes. As for power, the fan controller JPS64 is designing as part of the BB project will supply the PWM controlled power to the fans. A temp sensor and fault indicator will be provided. Finally, a mechanical bimetallic 75C fail-safe thermal switch (like in coffee makers) can be installed in worst case scenario.
I just ran across this massive all copper Intel Xeon cooler with coaxial fan. The problem with compact cooler slike this is high fans speed noise.
Intel Xeon Heatsink CPU Cooler Fan for Xeon X5472-X5482-X5492- Socket LGA771 New | eBay
You want want of the newer heat pipe spreader to large sink woth large diameter fan for quiet operation.
Like this:
Dual Fan CPU Cooler Heatsink Silent for Intel LGA775/1156/1155 AMD AM2/AM2+/AM3 | eBay
Qnty 4 is $60 - seems a fair price for 400W+ of cooling?
I just ran across this massive all copper Intel Xeon cooler with coaxial fan. The problem with compact cooler slike this is high fans speed noise.
Intel Xeon Heatsink CPU Cooler Fan for Xeon X5472-X5482-X5492- Socket LGA771 New | eBay
You want want of the newer heat pipe spreader to large sink woth large diameter fan for quiet operation.
Like this:
Dual Fan CPU Cooler Heatsink Silent for Intel LGA775/1156/1155 AMD AM2/AM2+/AM3 | eBay
Qnty 4 is $60 - seems a fair price for 400W+ of cooling?
This option looks very cost effective at $50 for qnty 4.
DEEPCOOL GAMMAXX 300 CPU Cooler, 3 Direct Contact Heat Pipes and 120mm PWM Fan | eBay
DEEPCOOL GAMMAXX 300 CPU Cooler, 3 Direct Contact Heat Pipes and 120mm PWM Fan | eBay
X, this one is for Alpha20, bigboy monos will get those huge sinks with backup coolers..probs useless, but just in case for hot summer days. (Yeh..those are so common in Finland.....)
For Alpha 20, I would just use passive metal standard heatsink with UMS bolt holes (as designed). Or something like the Dell CPU coolers that Vunce has. I have same one and it works great with a fan - temp is below 35C with fan barely on. About 300mm x 175mm x 40mm sink seems to be 41C. So could be smaller and push 55C.
Note that easiest thing to do is use R131=0.47R and R132=0.22R for 1.35amp bias vs 1.93 amp bias with 0.33R and 0.15R. That really cuts down on the heat (30% less) and seems to be sonically, just fine sounding.
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My building might be little confusing..that big proto-frame that I have been showing, it's one channel for BigBoy, there will be two identical of those.
So i'm already doing those side by side with Alpha20.
For Alpha20, I will try those Dell server heatsinks with fans, I'm missing toroid, fans and couple of components from pcb. That black case is Alpha20
Edit: so question is; is it better to suck air through the heatsinks and out from the case? Or blow cold air below and through the sinks? I guess sucking is more efficient?
So i'm already doing those side by side with Alpha20.
For Alpha20, I will try those Dell server heatsinks with fans, I'm missing toroid, fans and couple of components from pcb. That black case is Alpha20
Edit: so question is; is it better to suck air through the heatsinks and out from the case? Or blow cold air below and through the sinks? I guess sucking is more efficient?
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On CPU heatsinks with thin spacing between heat exchanger fins, I believe the standard is to push air through the fins. Once through the fins it probably makes more sense for the hot air to exit the top or side of the case. Perhaps a sketch of your case and how you want to route air would be useful. But you current layout looks like it would be easier with fan on top sucking air through fins. Try it and if temps are reasonable, keep it. No set rule here in DIY.
This one is going for basic modushop case atleast at first (I have hands full for 2 BigBoy cases now)
Pesante 04P400N 4U 10mm NERO
Sorry for bad photo from previous post, but as seen there, heatsinks lay horizontally in backside of case and I built them much like Vunce did his. Cover is moved a little aside in the photo, so you can see a little insides also
Pesante 04P400N 4U 10mm NERO
Sorry for bad photo from previous post, but as seen there, heatsinks lay horizontally in backside of case and I built them much like Vunce did his. Cover is moved a little aside in the photo, so you can see a little insides also
I will not dispute the notion that this looks like a golden recipe for an amplifier, and if i didn't already have an F6 built fairly recently (and no money at the moment), i would be on that GB list asap!
I will however dispute, like Xrk, the idea that you need high sensitivity speakers to enjoy amps with this wattage. I run speakers of 86db/w sensitivity with my F6 (12db gain), and also thought the amp was limited in its ability to drive them, but i recently added a BA-3 FE preamp (30 db gain or something in that ballpark) and have discovered grunt i had not expected in the combination. I have yet to turn the volume more than 2/3 up, and that is very loud (and sounds fantastic). This is not an advert for the Alpha per se, but an argument that you can definitely enjoy this amp (26-28db gain, right?) even with mid-lowish efficiency speakers. If you need more grunt, most likely you can just add a pre with gain.