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Tuesday, February 13, 2018

1 Watt Mini Amp

Here's a nice little solid state amp for headphone use or a small 4Ω speaker. Good candidate for a bench top amp for testing purposes. You can board mount the pot and it will fit in a 1590A just fine.

36 comments:

  1. This is rad. I don’t have any TDA7052A’s. And they are a little obsolete, or I didn’t find them easily from my favorite sources. I did find a number of them on eBay. I was also unable to find a direct replacement. So, it’s to eBay if anyone needs IC’s.

    I think I’ll add this to a Wampler Tweed 57 and try and make a little solid state tweed headphone amp.

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    1. I was wondering just the same but I want to do a amp with a a medium speaker like 8 inches, and put another preamp for switch between clean signal and tweed (od) signal before the amp, what do you think? This would be sound cool or just to quiet? You think I need another layout of amp like 10 watt?

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  2. What do you think is this better than the ROG Ruby?

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    Replies
    1. Not better, just a different option.

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    2. How many inches is the speaker size, and how many watts is the maximum

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  3. Replies
    1. You can use it with 8 ohm load, since it's a typical working condition, according to 7052A datasheet.
      I'm not quite sure why author says output is rated for 4 ohm load.

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    2. Cuz it's what the schematic said. I didn't look at the chip's datasheet :D lol

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    3. Oh, I'm not blaming you, kind sir. I was talking about schematics' author.
      :-)

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  4. Hi! Simple and nice sounding! But it works without power connection to the D of the transistor. Its normall?

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    1. That's weird... The JFET is an input buffer, so it would work (just not as well) without it.

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  5. i put a jumper instead of G and S of the transistor and it works too. :O

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  6. Which component do I have to change to use a larger speaker?

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  7. Verified!
    I used a 8 ohm 2w speaker, and a stereo jack with a switch to use the headphones and cut the speaker.
    The sound is very transparent and defined, when using other mini amps like the ruby or the MXR could not notice great difference in the sound of the guitar when using the pot of the tone, with this, it is noticed all the variations of tone, and the selection of the pickups with great detail.
    I will abandon the MXR and start using this.
    Thanks for your dedication and talent to this site, I hope you continue for a long time!

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  8. Hey. Built it acc. to layout. Got two things happenening.
    1- the signal is getting distorted but like two signals together, one clean signal and the other is the fuzz added signal.
    2- the ic is heating like a barbeque... is that smth to be expected ?

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  9. How would this work with a celestion greenback, 25w speaker?

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    1. This comment has been removed by the author.

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    2. It's better to use a tiny giant amp output 20 watt tagboard effect

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  10. Is out + the tip of outputjack and out - ground on outputjack??

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  11. Replies
    1. No. You'll be using a regular mono jack. Positive to the tip, and negative to the ring. You'll use that to connect to a speaker, which should have it's positive lead wired to the tip and negative lead to the sleeve of a similar mono jack.

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    2. I've just built The amp with a tda7052b and a 2n5458. Works awesome!! As i am a newby, i am struglling to make The output stereo for headphones using. I am not shure what to do in terms of impedance. Anyone has a clue??
      And thanks so much for the schematic!!!

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    3. I did it!! I just had to assemble The + on tip and - out on The second part of the tip! Done!!

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  12. thank you very much for sharing your hard work, time and knowledge. this is the best site i've ever seen in my life, definitely.

    I built this amplifier, and it works very well, except that the 47k resistor should be changed to 4.7k. It sounds much louder and better after this change.

    tested transistors:
    BF247a - very clean, small gain.
    J112 - much more gain and definition than BF247

    I wish you all the best in the upcoming new year. Take care man!

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  13. How many inches is the speaker size, and how many watts is the maximum

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  14. It's better to use a tiny giant amp output 20 watt tagboard effect

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  15. Can i use tda2030 instead of tda7052a ?? I cannot find this any alterntives??

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  16. Can I combine it with an amp emulator in the prev? for have equalization and gain control. Like input jack to a in of amp emulator (like super lot, angry charlie or other) out amp emulator to in of amp. Sorry for the bad english.

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  17. it's my first time buildling a pedal from your schematics, wanted to ask if the 3-volume-1 means 3-2-1 for the b100k? also, there is in, out +, out -, ground and 9v. how do i connect it to a 3pdt?

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    1. Yes, the pads directly above "3 - Volume - 1" are the pads for the pot with middle pad being lug 2. As for 3PDT wiring, this is an amp with the in pad going directly to a jack and with the out +/- pads going to a speaker or output jack to connect to a speaker. You can wire an on/off (SPST) switch that connects/breaks the +9v connection to the board.

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    2. thank you so much for the answer

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  18. just a buzzing sound, what could it be that is not obvious? thanks.

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  19. I build it without buffer and ommit 100K pot replacing with 100K resistor soldering on pin 4 from IC direct to ground. Keep 470n capacitor soldering on pin 2 (input), ommiting this caps make this circuit not work. You can pair with any preamp pedal without oscillation. I suggest to attach small cooler plate on IC because in some case IC's becoming too hot. Nice sounding mini amplifier beside LM386.

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