It's amazing how good this LM3886 sounds with a good RCA cable to it now. No longer getting hum and popping from household switches. Also the signal sounds more clear. Oh my goodness this amp sounds so good! I love it!
Thanks guys for all the help/tips! 🙂
Can't wait to hear how it will sound with the B1 Buffer vs 10k ALPS passive pre (Y split to powered sub). Guessing I'll hear a difference?
Thanks guys for all the help/tips! 🙂
Can't wait to hear how it will sound with the B1 Buffer vs 10k ALPS passive pre (Y split to powered sub). Guessing I'll hear a difference?
the 8 wires.Here is a photo of it powered up:
Note: the dc supply to amp board wiring will be replaced with stranded 18 guage, well insulated with hi temp jacketing if possible (recommendations?). I agree solid core puts way too much mechanical stress on the pads.. I tried to be as careful as possible though but I am not comfortable with it.
AndrewT, now you can see what I am talking about regarding the 8 wires? By the way the matching colored wires on the dc supply board are connected together on the PCB with a 1/2 inch wide (or so) trace.. so I wanted to run both wires for extra current capability.
EDIT: leaving the speaker wire solid core because I want it to stay suspended over the heatsink without touching it.
It looks like you have two outputs from the dual rectifiers.
treat each output separately.
From each output you have two +wires and two -ve wires. these feed two separate loads (amplifier)
Split a yellow and a purple and twist them as a pair to one amplifier. Repeat for the second amplifier.
From the second output yopu have red and green. One red and one green going to one amplifier. Twist these as a pair.
Repeat fro the other amplifier.
You now have four twisted pairs. Each twisted pair has a flow and return in close contact. That minimises interference.
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Could I see some photos of them both? It'd be awesome to see 🙂 Internals too if possible 🙂
More or less the same construction as early NAIM amplifiers (ie the NAP160 i used to own)
dave
I will dust them off and get a photo, the B1 is still on a wood test chassis, and has been for several years. It is a nightmare of dangling wires and hot glue, it is also completely hum free even in that state.
Now I just need to find out how to attach photos.
John
Now I just need to find out how to attach photos.
John
Jennifer G: Great project! Very inspiring. I have a collection of "metal boxes that could become cases" And "old components that could be gutted and reused" Thanks for reminding us how effective this can be to overcome one of the most expensive issues of DIY, and recycle lonely pieces.
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Here is one to be going on with (if it attaches) that started with a piece of wood rescued from a drunken party firewood pile
John
John
Here is one to be going on with (if it attaches) that started with a piece of wood rescued from a drunken party firewood pile
John
Gorgeous 🙂 Nice job with the finishing! 🙂
What is the best 18 guage stranded copper wire I can get? I want something with a thick high temperature jacket no? That way if it gets hot it won't melt and short?
melt from what, bad soldering😀
Teflon wire ( mil spec) from Apex Jr.
Silicone Wire ('premium' grade for high copper ) from 'HobbyKing' this super flexible high strand wire is useful for test leads too.
Silicone jacketed fine copper strand RC helicopter battery to motor controller wire is the best. That Teflon stuff is a pain to strip and is so stiff.
$2 for 3ft is a deal actually.
PRC Silicone Wire - 18 AWG - ProgressiveRC
$2 for 3ft is a deal actually.
PRC Silicone Wire - 18 AWG - ProgressiveRC
nah I have NOT found any good sources of Silicone wire from any web sites ( ebay is worse), interestingly it measures close to aluminum for the AWG, ive yet to measure the "premium" grade tho. I'm thinking Chinese vendors have decided hobby stuff needs the lighter weights 1st. sadly "pure" means something else in translation, try pure "premium" or "authentic" in the product descriptions!
I recommend wire from Apex Jr cheaper and better for wire harnesses.
I recommend wire from Apex Jr cheaper and better for wire harnesses.
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High temperature (Heat resistant) wire for speaker terminals pushed at the top corner of the back panel instead of exactly above the IC and kept firmly attached with heat resistant tape would be good in the long run. Isn't it ?
Regards.
Regards.
Probably 🙂 I might change it to that thanks.
As is now, the wire is sitting above the IC about an inch since I'm using solid core I can bend it so it won't touch the heatsink.
I think I am going to keep it solid core and move it away from the IC as you suggest. Just need to cut some new lengths after I get the wire.
The noise is pretty good on this amp. Cranked to 100% (with nothing playing) I have to put my ear within two inches of the tweeter before I hear any noise. Does this sound good? I'm new to this all. This was my first amp I've built and best sounding one I've had so far.
That's good - but even better is ear touching the tweeter and no audible hiss. It takes a good amp design with careful layout and a clean power supply with sub just a few mV ripple. Chip amps are very good for what they are but they can't beat a discrete stage amp for authority and overall dynamics.
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