As the title suggests, I'm looking for something relatively inexpensive with a focus on high fidelity and absolutely low noise at idle. I'm using a minidsp 2x4 as crossover and EQ for a pair of two way speakers I built and I was thinking it would be nice to build a little enclosure with all four channels of amplification, power supply and minidsp in one.
I'm very open to suggestions and have a reasonable set of skills and tools so bare PCBs to populate are fine as are prebuilt boards, also in Canada so ideally things easily acquired here.
The HF drivers are 111db and the LF is in the 105 ballpark so power isn't really that important, thinking like 30 clean watts would be plenty but it never hurts to have more.
Looking forward to suggestions, I have no biases or expectations, just looking for good ideas.
I'm very open to suggestions and have a reasonable set of skills and tools so bare PCBs to populate are fine as are prebuilt boards, also in Canada so ideally things easily acquired here.
The HF drivers are 111db and the LF is in the 105 ballpark so power isn't really that important, thinking like 30 clean watts would be plenty but it never hurts to have more.
Looking forward to suggestions, I have no biases or expectations, just looking for good ideas.
I have looked at this a bit because I have similar mid horns.
A lot (all?) of the DIY class D seems a little noisy.
The Hypex Ncore and PuriFi modules are quiet but probably not quite noiseless in this application.
For the mids, especially, is there much point in Class D?
A 30 W Class B+ linear amp can be very quiet indeed and would have all the power you need without too much waste.
My current project is a Class H, powered by Class D style variable rails, for the best of both worlds.
No one else seems much interested so development is slow while I do all the work from scratch.
But it should be nice when it's all finished, sorry I can't help with boards at this point.
Your 105 dB ballpark seems a lot, is this with room boundaries included?
Best wishes
David
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I ran compression drivers for a long time with Tripath amps, the little 12V ones. No real noise problems unless I stuck my ear in the horn. Using an L-Pad on the driver resulted in no noise at the horn.
But I wasn't trying to drive 110dB drivers with 30 watts in a domestic setting. 😱 Just no need. For PA, that's a different story.
But I wasn't trying to drive 110dB drivers with 30 watts in a domestic setting. 😱 Just no need. For PA, that's a different story.
I'm a total greenhand when it comes to compression drivers but with 111dB sensitivity would you likely need more than 10W? If so you could use a step-down transformer on your amp's output to reduce the noise. A suitable transformer can be built from cheap ferrite cores as the minimum working frequency is at least a few hundred Hz.
30 watts is probably overkill but just like the idea of having a bit of headroom as my only other digital amp I find distorts pretty badly when it gets nearer to its limits. I'll check the tripath ones out though thanks for the tip.
A decent headphone amp or even DAC will suffice. I tried powering through JBS labs Atom and it was very quiet. A friend of mine powers horns directly from a Chord Mojo dac. Plays well and no noise.
TPA3255 4 channel, very quiet and cool running.
Otherwise Class A <25w amps, with very quite power supply (Smooth Like Buttah?). Depends how much space and heat you are prepared to deal with.
Or as mentioned above, run direct from Preamp or DAC.
Otherwise Class A <25w amps, with very quite power supply (Smooth Like Buttah?). Depends how much space and heat you are prepared to deal with.
Or as mentioned above, run direct from Preamp or DAC.
The perfect solution for very low noise that is about the Watts you need is the MoFo amp by Mike Rothacher, a member here. Look for the thread called "build that MoFo" for info. Not class D, though.
Honestly, ditch the 2x4, it's very noisy. No amp will fix that.
Honestly, ditch the 2x4, it's very noisy. No amp will fix that.
If you want to stick with class D, then 3e audio TPA3251 is 4 channels and also low noise... It comes ready to play, just add power supply
The MoFo looks very very cool but the idea here is a simple one box solution that is a bit less real estate. Although now I've got images of four very cool monoblocks....
It's looking like 3e might be the way to go for this project, also you say the 2x4 is inherently noisy, is there anything else around its price point that can do active crossover and dsp that would be quieter that I'm not aware of?
It's dead quiet the TPA3251 four channel with very good dynamic.
Have mine as desktop 1 meters from ears.
Have mine as desktop 1 meters from ears.
I have one LRS-350-24 since before so thats what I use and trimmed it up a little to about
28V.
They recommend I think 31-32V for this amp so an LRS-350-36 also works and turn the voltage down with the inside potentiometer.
Many say you dont need so powerfull SMPS but I like to have the headroom as I read on a forum don't push it.
And next generation amp or the next buy you do need more power so put in that 10-20 extra dollars.
28V.
They recommend I think 31-32V for this amp so an LRS-350-36 also works and turn the voltage down with the inside potentiometer.
Many say you dont need so powerfull SMPS but I like to have the headroom as I read on a forum don't push it.
And next generation amp or the next buy you do need more power so put in that 10-20 extra dollars.
I will second the Meanwell LRS-350-24 or LRS-350-36 for a power supply. The former for 4 or 8 Ohm loads and the latter for 8 Ohm loads only, when turned down to the min voltage (32V?).
The PS is rated for 350W continuous output, and note 7 in the datasheet indicates that it will provide 50% more than rated current for up to 1 second before protection kicks in. That's 3dB of headroom for 1 second - pretty good!
The PS is rated for 350W continuous output, and note 7 in the datasheet indicates that it will provide 50% more than rated current for up to 1 second before protection kicks in. That's 3dB of headroom for 1 second - pretty good!