Lm1875 amp with 6ak5 buffer. Horrible wiring etc. but no issues with hum or noise. Sounds much more alive than non-buffered amp. Tempted to build another valve buffered chip amp with neater wiring. Transformer cover to be added for safety
Lodda loose wire.
What the H### is a BLAT ?
Here is a link to a fun project combining PC liquid cooling techniques and a small footprint power amp build. A bit of overkill for the LM3886 family but could easily be applied to high-temp situations.
Here is a link to a fun project combining PC liquid cooling techniques and a small footprint power amp build. A bit of overkill for the LM3886 family but could easily be applied to high-temp situations.
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No - Not actually, the idea crossed my mind several months ago when I was testing several standard convection heat sinks. Thought it would be good to introduce a control element. When the LM3886 gets close to the temperature protection trigger point the sound can deteriorate and intermittent drop outs occur.
In general the available SPL from the MyRef family is in the usable range with only an attenuation pot. As a big band fan/player, I push the amps (using 200 & 300 VA toriods in some builds) with a JC-2 pre and they stay in the upper range of the power scale when driving my fairly inefficient speakers. No doubt a larger heat sink could be sufficient, but that wouldn't be any fun.
I have said in several posts that this may well be overkill for a chipamp, but there is a possibility it might be a prety good fit for something like hotter transistor builds. I've seen some F5s and such the size of a small freezer
There is also the possibility of hearing/measuring the performance of the LM3886 across it's working temp range. Not a super high priority but potentially interesting. I'll post anything of significance if I stumble across it.
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Don't know if you have any experience with the liquid cooling for PC world, but they have developed some fantastically quiet pumps and fans. Once all the air has worked completely out of the system the pumps are dead silent. You have to touch them to make sure they are working. Fans are almost as good and any trace of noise beyond ~ 12" can be eliminated by slowing them down a bit.
The major cooling is not from fan air flow. All that is needed is a steady light breeze across the fins of the radiator. A little adjustment for efficient air and liquid flow rate (less is better) does the trick. There are also some good additives that both protect any metal components and increase heat transfer.
I guarantee you can build a liquid system all the way up to the 120mm format that you can't hear past 1 foot.
The major cooling is not from fan air flow. All that is needed is a steady light breeze across the fins of the radiator. A little adjustment for efficient air and liquid flow rate (less is better) does the trick. There are also some good additives that both protect any metal components and increase heat transfer.
I guarantee you can build a liquid system all the way up to the 120mm format that you can't hear past 1 foot.
My second LM3857 Non inverting amplifier ( 200VA 2x24V transformer; standard small bridge rectifiers with small heat-sinks ;4x4700uf filter capacitors + 4x2200uf bypass caps + 4x 1uf, snubbers caps under PSU board ; p2p installation; compact enclosure from e-bay; salvaged stepped attenuator
No hum no noise , small DC offset. I will try to measure amp later :
No hum no noise , small DC offset. I will try to measure amp later :
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I agree. I have an overclocked, 6-core AMD that is water-cooled (Corsair H70 all-in-one solution), and when the fan is dialed back, I can't hear it. Not sure I'd adopt water-cooling for an amp, but it's an interesting proposition and one that you've successfully tackled. Good stuff.
Nice looking amp and construction. Do you have a link for the enclosure. It looks familiar, but I haven't seen that switch assembly before, and was wondering if it came with the case?My second LM3857 Non inverting amplifier ( 200VA 2x24V transformer; standard small bridge rectifiers with small heat-sinks ;4x4700uf filter capacitors + 4x2200uf bypass caps + 4x 1uf, snubbers caps under PSU board ; p2p installation; compact enclosure from e-bay; salvaged stepped attenuator
No hum no noise , small DC offset. I will try to measure amp later :
I've used several of those style enclosures from China and very happy with them. The one in question just looked a little 'dresser' hence the question. I was particularly intrigued by the push-button switch with the flange ring on the front. Looks fancier than what I use.
My second LM3857 Non inverting amplifier ( 200VA 2x24V transformer; standard small bridge rectifiers with small heat-sinks ;4x4700uf filter capacitors + 4x2200uf bypass caps + 4x 1uf, snubbers caps under PSU board ; p2p installation; compact enclosure from e-bay; salvaged stepped attenuator
No hum no noise , small DC offset. I will try to measure amp later :
Congratulations osscar! That is a very nice integrated amplifier! Very neat and compact