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TDA2003 Suggestions

Started by RubberSalt, November 01, 2011, 04:04:30 PM

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RubberSalt

I'm new to amp building, made a couple of LM386 set ups running on batteries, a muff pi, and a simple crappy tone killing fuzz effect.  I recently got 10 TDA2003 chips for fun ($8)

I built the simple amplifier circuit from the datasheet and had it sounded like garbage.  Would hum really bad with nothing hooked up, wasn't very loud.  If i cranked my guitar to max volume, it would cut out all together.

This was powered off the 12v lines of a computer power supply.  I also(for giggles) hooked a 9 volt to it. <-- same results with the 9volt just not as loud.

My intended use is to build a battery powered amp.  I've got me a nice little 12v 7amp security battery with a regulator/charger that will push a steady 12v at 3 amps max.



my lm386 builds are louder than this thing is currently, they also have more clean head room than this does (NONE)... So I'm doing something wrong.

Where should i start?

joecool85

Quote from: RubberSalt on November 01, 2011, 04:04:30 PM
I'm new to amp building, made a couple of LM386 set ups running on batteries, a muff pi, and a simple crappy tone killing fuzz effect.  I recently got 10 TDA2003 chips for fun ($8)

I built the simple amplifier circuit from the datasheet and had it sounded like garbage.  Would hum really bad with nothing hooked up, wasn't very loud.  If i cranked my guitar to max volume, it would cut out all together.

This was powered off the 12v lines of a computer power supply.  I also(for giggles) hooked a 9 volt to it. <-- same results with the 9volt just not as loud.

My intended use is to build a battery powered amp.  I've got me a nice little 12v 7amp security battery with a regulator/charger that will push a steady 12v at 3 amps max.



my lm386 builds are louder than this thing is currently, they also have more clean head room than this does (NONE)... So I'm doing something wrong.

Where should i start?

You will need a preamp in front of that chip.  The LM386 is pretty much the only poweramp chip that doesn't.
Life is what you make it.
Still rockin' the Dean Markley K-20X
thatraymond.com

RubberSalt

So.. i need to turn an lm386 into a pre amp...? :)

I've got 90+ 2n5088 transistors left.  Pre amp possible? 

I can also order what ever i need.  What type of output should i get from a pre amp?  at what point will the TDA2003 be over drivin?

joecool85

Quote from: RubberSalt on November 01, 2011, 04:11:22 PM
So.. i need to turn an lm386 into a pre amp...? :)

I've got 90+ 2n5088 transistors left.  Pre amp possible? 

I can also order what ever i need.  What type of output should i get from a pre amp?  at what point will the TDA2003 be over drivin?

You can use an LM386 as a preamp as long as you like it "gritty".  I've done it.  Not sure how many volts before the TDA2003 overdrives, you'd have to look up the datasheet.

I will note that I built a TDA2003 and wasn't very happy with it for the same reasons, I stopped fussing with it though because I built a larger amp and never went back to put a preamp in front of the TDA2003.  From what I understand that will fix all your issues...I should dig that little guy out and play with it at some point.
Life is what you make it.
Still rockin' the Dean Markley K-20X
thatraymond.com

RubberSalt

Im mostly just looking into portable amps, the more versatile the tone the better.  Like to start clean then get dirty if need be.

I figured if a TDA2003 can sound good in car radios, why not an amp?.. so hear I am woundering if that is still true lol

I've also got a TDA2005.

But im thinking maybe lm386 pushing bridge tda2003/or that tda2005 in bridge.

Unless some one has a clean way to do it.

darwindeathcat

#5
The AMZ "Muff Boost" (halfway down the page here: http://www.muzique.com/schem/projects.htm) uses 2n5088's, and should give you enough boost to at least get the volume up on the tda2003. You can make it clean by omitting a couple of components (as directed in the build instructions). I've built a clean one for similar purposes, and had good success. Good luck!
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RubberSalt

I like it, i actualy thought about doing that but was unsure if it would provide enough power.  Im new to alot of this stuff, but i understand it.

My goal is to build a portable battery powered set up with good clean sound and a muff pi built in lol

darwindeathcat

If the Muff Boost doesn't give you enough volume on it's own, I've developed a second stage using an MPF102 (I had some lying around) to go after it. It pumps the volume up even more, but the sound still remains clean. I powered it at 9v, so you may have to adjust some of the bias resistor values if you are running it at 12v. I'll attach the schemo to this post.
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RubberSalt

#8
Awesome.  Looks like i need to buy a supply of MPF102.  I enjoy buying 100 of something opposed to 1 or 2.. little more price - crap ton more stuff to build! :-D

So far im looking at building a set up like so;

For my electricity I have 1 of these http://www.amazon.com/Belkin-Battery-Backup-Power-Supply/dp/B004RRX1CG.  The juice is not directly off the battery, it's off the 12v regulated supply.

2N5088 pre amp->Wah(just a knob)/w bypass -> muff pi/w bypass -> Fender style tone stack->MPF102/volume->TDA2003(bridge maybe) -> speaker/line out/Phones.

I figure that a Wah would allow for some odd sounds, even as a set it and forget it style knob.
  I like this idea  - probably do something like that for a little more control.

Muff pi will have an extra switch to cut the diodes for a good crunch.

Tone stack will be based on the fender 3 tone knob set up.

Before i start drawing up my schematic, any suggestions or effects I should add to the list?

RubberSalt

http://www.newark.com/electroswitch/c4d0406n-a/switch-rotary-4p6t-500ma-125v/dp/06M4597


This make me happy -think of the possibilities!! be 1 knob and like 6 differnt versions of a pi/whatever all in 1.

I like knobs.

polo16mi

Hi RubberSalt:

May i suggest that use your TDA2005, and go straight forward to its datasheet and make the bridged suggested circuit. It work very well with 12V, even without any preamp. Plus, very low component count needed.

Besides, you can (i do it too) use your ruby as a preamp and work fine too  :tu: . I dont know what version of ruby are you using, but if you use this (http://www.runoffgroove.com/ruby.html), you´ll have a nice 12V amp.


Alexius II

Interesting read. I've built a TDA2003 a while back and it was absolutely noiseless and did not distort with just guitar at the input. Maybe your pickups have much more output... or maybe my 18V supply helped with the headroom.

It's a really nice chipamp for bedroom-practice (with some nice preamp/pedals) :tu:

polo16mi

#12
Quote from: Alexius II on November 13, 2011, 05:04:39 AM
Interesting read. I've built a TDA2003 a while back and it was absolutely noiseless and did not distort with just guitar at the input. Maybe your pickups have much more output... or maybe my 18V supply helped with the headroom.

It's a really nice chipamp for bedroom-practice (with some nice preamp/pedals) :tu:

I remember that i made a tda2003 circuit like datasheet, at secondary school, a lot of years ago.... Just plugging guitar at the input, and it has very low (VERY) volume at the speaker. So i put the higher resistor that i found then. (1M5) in parallel with the input (raising up input impedance), more guitar signal get into amplifier. Worked better like that. Anyway, our friend should use his lm386 as a preamp for better result.

RubberSalt

I built the tda2003 according to the bug eye schematic. First I used 3 2n5088s for a preamp. This worked decently, but I feel it wasn't Lou d enough. 4 transistors made it clip and cut out real bad.

I then built the pre amp with a singe mpf102, volume was about the same but less feedback.

It seems my lm386 builds might actually be louder. Both are equally clean I'd say.

Now I have switched my power supply to a lithium ion setup pushing 12v at 4.8amp peak.

Now from what I'm reading, I need to use my lm386 set up to power this thing. I currently have them bridged on 12v also. This chip is maybe 5 degrees more than room temp.

I'm thinking(no idea) that the lm386 set up would drive this thing to the point of failure. 4 transistors made the sound go from clean to popping inexistance.

Alexius II

Quote from: RubberSalt on November 28, 2011, 11:41:24 AMIt seems my lm386 builds might actually be louder. Both are equally clean I'd say.
Maybe you set your LM to have more gain than the TDA, or maybe the early clipping of the LM is percieved to be louder. I've A/B tested them, and TDA was about twice as loud, which is not surprising as it had about 10 times the output power (LM386@12v into 8ohm and TDA2003@18V into 4ohm). I used overdrive/distortion preamp as it was hard for me to determine the loudness of cleaner sounds.