This is one of the best amplifier ICs I've used -
there is no noise (well barely any)
it has a built in digital volume control so you can just use a single gang pot to control the volume (or a microcontroller if you want)
it has an on/off switch that fades the audio in and out so you don't damage your speakers/headphones with pops and it is also very low voltage 3volts - 6volts
the only downside is the max rating is 6 volts so you can't just whack a 9v battery in it -
but 2 - 3 AAs and you're laughing.
I built this to use with my iPod but I strongly advise that you don't turn it on with your headphones on because this goes VERY loud. easily loud enough to damage your hearing instantly!
NB: there is now a hifi preamp with bass/treble/balance controls that works well with this project LM1036-hifi-preamp-and-tone-control
I can't wait to try this out. I just made an offer on a couple of TPA6021A4N chips (I'm a cheap bastard). Unfortunately my purchase options are pretty slim for this chip :/ I'll comment back when I've built it. Thanks for the great circuits, Paul!
ReplyDeleteto be honest dude - I came up with this one after I got free samples of a load of random parts from Texas Instruments so I think we can all be accused of being a bit cheap.
DeleteWell, there's a coincidence... Some turd wanted $4.95 each on Ebay, or best offer, so I offered $3.00 each for openers (see? I'm cheap!) and he responded with a counter offer of $4.75 to which I replied "you're an asshole" an declined. A few days later I just happened to be on ti.com to request some samples and, and rambling story less rambling, I remembered wanting to build this, they had it, and I ended up with them for free. Yay, Texas Instruments! Eat shit, greedy Ebayers! :D
DeleteUnfortunately the jacks I ordered are wrong and I had to order more, so still waiting to try this out.
Oh, almost forgot, one question, do you recommend Log taper of Linear taper for the 100k pot?
you can almost guarantee they got them as a free samples too - that happens a lot unfortunately . my policy is that if I've gotten something for free and I end up not needing it
DeleteI give it away for free - unless I have put time/money into fixing it in which case I'll charge whatever it cost to fix it. I get so sick of people trying to make money off people who don't realise that things are cheaper direct from source.
just a linear pot - the audio signal doesn't go near it - the post controls the voltage of an internet digital pot which you'll notice if you turn the pot very slowly - you might catch the step
or if you turn it very fast there's a tiny delay while the internal digital pot catches up. so much more reliable - no crackly pots ever!
Hi Paul, I get the chip in tomorrow and I've got the vero all ready to go. I was wondering, since i'll be using it for guitar, would I just jumper left and right ins, and have my guitar out going to one of those? I'm going to put the "rub-a-dub" reverb into the same box, and it has a 5V regulator, I was just going to run the amp off that 5V. Thanks man!
ReplyDeleteAlso, are the outs 220u or 220n?
ReplyDelete220u but if you're using it solely for guitar you'll be okay using 100u
Deletethe amp is 2 watts per channel so you can just plug your guitar into 1 channel unless you're going to have stereo cabs on the output - I imagine it will be fine if you just jumper the 2 inputs but I've not tried it.
I used my stereo chorus on the 2 inputs going into a stereo marshall cab - it was beautiful
That sounds perfect! It's sole use will be as a headphone amp so I can play without waking anyone up.
ReplyDeleteWhere should I connect the ground from the headphone jack? About to fire it up! Thanks :)
ReplyDeleteto the GND on the board
DeleteThanks Paul, it works great! After some troubleshooting I got it working with my guitar, after I realized that I needed to turn it on, lol
ReplyDeletePaul, I built this a put it after your HiFI preamp. I have it connected to bookshelf type speakers. Using an iPOD it does not seem to be very loud. With the vol maxed out has a good listing volume but barely so. How loud does your sound?
ReplyDeletethank you for the grear layout.
Coi2001
I didn't see this comment for some reason. how loud this goes depends on a lot of factors - 1 main factor is the speaker impedance - it's all ohms law stuff. another of course the size of the speakers.
DeleteHey Paul, thanks for posting this :) I have a question for you though, what type of capacitors did you use? Thanks
ReplyDeletePolyester Film capacitors because they looked nice.
Deleteyou can use ceramics if you want
i dont think my last comment posted, or i just cant see it. i set up this chip on a breadboard without any resistors/diodes/capacitors and it kinda works only there is alot of distortion. im not very good at reading schematics, so do you happen to have a simpler schematic using just right in and right out? i have all the resistors and diodes and the 100k pot but i dont think i have the caps. could you at least tell me what is the bare minimum for capacitors i need, because i read somewhere someone made this chip work with just two .47uf caps. thanks -your neighborhood noob
ReplyDeletethe circuit as presented is the bare minimum - someone may have made it work with just 2 capacitors but it will have burned out by now - the external components basically keep the internals of the IC stable. if you don't have the money to buy parts - ask around for old electronic junk, capacitors are abundant in a lot of things; that's what I used to do as a kid - I don't think I ever bought anything other than solder and veroboard for the first 5 years of making electronic stuff
DeleteThis comment has been removed by the author.
ReplyDeletethanks, i already looted two cable boxes, a broken power strip, dvd player, and a computer speaker amp and i still dont have the right caps lol, what are the purpose of the 1uf caps connected to pins 4-8? and the 470nf cap connecting 1 and 3?
ReplyDelete