I'll maybe make the case with a copper or aluminum sheet top and bottom. That would be sorta cool with the wood. I like this (I know, I only have one pot, sigh):
Whoa $0.01!
I won't be needing to be 100% portable. Semi portable is nice though. I can always switch later right? Don't the audiophiles say batteries are better? Is a wall wart a clean source?
Whoa $0.01!
I won't be needing to be 100% portable. Semi portable is nice though. I can always switch later right? Don't the audiophiles say batteries are better? Is a wall wart a clean source?
BAtteries are cleaner generally, but I've honestly never had an issue using cheap/found wall warts. The caps and resistors help filter out noise.
Lets say this; I just finished building a low noise mic preamp for recording. Basic INA217 chip and layout. PSU is 9V AC wallwart, 2 1n4007 diodes and 2 1000uF panasonic FM caps. The noise floor of the amp is about 110dB down with a 40dB gain. Any potential noise from the PSU is so much lower than the noise from even a high-quality mic that it is irrelevant.
In my experience anyway.
Lets say this; I just finished building a low noise mic preamp for recording. Basic INA217 chip and layout. PSU is 9V AC wallwart, 2 1n4007 diodes and 2 1000uF panasonic FM caps. The noise floor of the amp is about 110dB down with a 40dB gain. Any potential noise from the PSU is so much lower than the noise from even a high-quality mic that it is irrelevant.
In my experience anyway.
Ok, where should the LED go then?
I have to say I'm not a huge fan of this tight layout. I don't like cramming multiple wires/leads into one hole or soldering wires directly to pads on the bottom. If I knew how to design a layout, I'd have probably done this all differently.
Thanks for all the help by the way. This is great.
You can keep the led in the same place. I was talking about the first single pad holes to the left and right of the three pad groups at the top.
As for the tight layout, I was actually going to say you could make it a lot tighter. Soldering directly to pads or other leads is a really handy skill. Sometimes, having a component right on the lead of something is important, as in the case of the decoupling 0.1uF caps on power pins 4 and 8. I personally find the board used for these cmoy layouts to be annoyingly confining. They are nice in some ways, but more challenging in others. You can also cut traces with a razor blade. I like prototyping or one-off the best using regular perfboard, connecting parts with bare wire traces on the bottom.
I also prefer mounting pots and jacks directly on the board whenever possible, to minimize interconnect wire length and as a convenient way of mounting the board later.
As for the tight layout, I was actually going to say you could make it a lot tighter. Soldering directly to pads or other leads is a really handy skill. Sometimes, having a component right on the lead of something is important, as in the case of the decoupling 0.1uF caps on power pins 4 and 8. I personally find the board used for these cmoy layouts to be annoyingly confining. They are nice in some ways, but more challenging in others. You can also cut traces with a razor blade. I like prototyping or one-off the best using regular perfboard, connecting parts with bare wire traces on the bottom.
I also prefer mounting pots and jacks directly on the board whenever possible, to minimize interconnect wire length and as a convenient way of mounting the board later.
Here is a good example of why its nice to have practice soldering bits together.
http://www.diyaudio.com/forums/chip-amps/79303-chip-amp-photo-gallery-35.html#post2532356
and another
Mick Feuerbacher Audio Projects
http://www.diyaudio.com/forums/chip-amps/79303-chip-amp-photo-gallery-35.html#post2532356
and another
Mick Feuerbacher Audio Projects
But how is it sounding?
Have you tried other sources yet? Even open and with the longer wires you should have very good sound currently, something noticeably different from the source alone. If not, or if you have really bad noise of any kind, now is the time to figure out why and fix the issue.
I also remember you asking about the position of the volume pot. Keep in mind the pot does not really affect the sound or performance of the amp. All it does is limit the amount of source voltage getting into the amp. The ideal position depends on you. Having it maxed out means you wasted money on the pot
have it almost down all the time suggests to much gain in the amp, and might be an issue if the extra gain causes noise or distortion. You don't need a pot at all if you are willing to adjust the volume at the source. As for the source, digital sources like mp3 players should be at 90-100% volume. Analog source may need to be lower, say 50-75% but that depends on the device.
Have you tried other sources yet? Even open and with the longer wires you should have very good sound currently, something noticeably different from the source alone. If not, or if you have really bad noise of any kind, now is the time to figure out why and fix the issue.
I also remember you asking about the position of the volume pot. Keep in mind the pot does not really affect the sound or performance of the amp. All it does is limit the amount of source voltage getting into the amp. The ideal position depends on you. Having it maxed out means you wasted money on the pot
have it almost down all the time suggests to much gain in the amp, and might be an issue if the extra gain causes noise or distortion. You don't need a pot at all if you are willing to adjust the volume at the source. As for the source, digital sources like mp3 players should be at 90-100% volume. Analog source may need to be lower, say 50-75% but that depends on the device.No bad noises, I do get some hiss with the pot all the way up, but any music is unlistenable at that level. Halfway up on the pot is still too loud for comfort.
It sounds quite good. I'm listening now through my airport express. I don't have a proper dac yet. I'll try the TT next. I'm not sure it's really any better than the Grados alone. It could be my sub par sources, or my ears.
Grados alone is thinner, but clearer. With the amp, the sound is fuller, rounder, but with less clarity and a higher noise floor. I think my power routing should definitely move because I am noticing a change in the noise floor as I touch components and wires. Especially the Wimas, I get a loud hum when anything comes close.
It sounds quite good. I'm listening now through my airport express. I don't have a proper dac yet. I'll try the TT next. I'm not sure it's really any better than the Grados alone. It could be my sub par sources, or my ears.
Grados alone is thinner, but clearer. With the amp, the sound is fuller, rounder, but with less clarity and a higher noise floor. I think my power routing should definitely move because I am noticing a change in the noise floor as I touch components and wires. Especially the Wimas, I get a loud hum when anything comes close.
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