PUNCH - 1W amplifier

[tca]

Hi,
I would like to share with you my latest build. A 1W amplifier  using the TDA7052. In my opinion it sounds much better than any LM386 it has a much better frequency response (only one capacitor on the signal path). It works with batteries but preferable with 1.5V AA in series.  I usually power it with a 9V power source.



Comments, suggestions?

Cheers.

[deadastronaut]

cool, is it very clean?

[tca]

Yes, very clean, wonderful to plug in any effect!

[deadastronaut]

cool, might have to knock this up as part of my grandsons xmas prezzie... (he wants a guitar)
i'm making him a spitfire distortion, so he'll be stoked with a liittle amp too..cool.

might have to whack an headphone on it too though...to keep his mum happy..

[B Tremblay]

I just looked through my chip amp notes and found a schematic using the 7052. It appears that I found that the chip had less pleasing overdrive tones than the 386, but I was feeding it with a FET gain stage rather than a buffer. I may have been clipping the FET and the chip was innocent. I did put in a low pass filter ahead of the chip, so it must have been a little bright to my ears.

Thanks for sharing your work.

[J0K3RX]

Here's another nice one and really loud 3W runs anywhere from 6v to 15v and very small...(TDA7267) I run it from 9v and it drives a 4x12 @ 8ohms and loudly!

http://www.velleman.eu/downloads/0/illustrated/illustrated_assembly_manual_k8066.pdf

Sounds great with guitar!

[deadastronaut]

^ 3watts...nice!

my little roland cube is 2watts and is loud enough to annoy people....so 3 is even better!...nice one.

[Mark Hammer]

I gather these chips are typically found in small plastic add-on speakers for computers or MP3 players?

[John Lyons]

Have to try the punch amp, thanks for posting.

Can someone please email me the TDA7267 (Velleman kit) schematic please?
I keep getting errors trying to download it. And the one on line is tiny...
Thanks

John

[garcho]

sent it to ya John.

[haveyouseenhim]

this it what i made with the velleman kit. (they sell the kit at radioshack for about $20)

[tca]

Just made a PCB. Going to test it tomorrow.



Cheers.

[tubelectron]

cool, is it very clean?

Yes, very clean, wonderful to plug in any effect!

That's a good point, indeed. I made some trials with the LM386 and none of them were satisfactory for a reasonably audible clean power on guitar, even if I noticed that the speaker had an important influence on the result - I speak about small/miniature speakers, not guitar speakers, indeed !

Here's what I tried for guitar. it wasn't interesting... nor in power, nor in tone... I also tried the Smokey amp : it was the less bad, but not worth...



Conversely, I could derive from it an excellent battery-powered stereo monitor for my PC, very good sounding and powerful, with a volume and a tone control, using 2xLM386 (= 1 per channel) :



But connecting a guitar on that monitor gives inexplicably bad results : saturation, low power output...

A+!

[deadastronaut]

^ nice builds though bruno/mike..

@tca:  might be worth adding a tone control, and headphone on it too..

[tca]

might be worth adding a tone control, and headphone on it too..

I just wanted an plug-in-and-play amp with a small part number and I usually don't play with headphones (it makes me dizzy). But a tone control could be a nice thing. I didn't also put a volume control because I use a L-Pad (8Ohm attenuater) between the amp and the speaker and this works fine as a master volume.

BTW, the LM386 does not like this L-Pad, it reacts strangely  to it, but it works great with the TDA7052.

Cheers.

[tca]

@tubelectron I've made also stereo monitor for my PC but using two class A mosfet (IRF610) amplifier.



It works fine with a booster but due to the power source (9V/100mA) it is some what muddy when used with a guitar. These class A configurations works better with higher currents and higher voltages, but nevertheless it is the amp that I use to listen to music from my PC.

Cheers.

P.S.
The bulbs are  the drain load for each of the mosfet.

[tca]

@tubelectron I've build a few Rubys and usually the speaker that I use is something like this double cone speaker:



Freq. range: 50 - 12.000 Hz,
Sensitivity: 90 dB, 1 W/1 m
Size: 5.25''

It is this speaker that I plug in the punch amp.

You can buy them in Portugal for about 15 eurs.

Cheers.

[bancika]

that sounds expensive, you can almost get a "real" guitar speaker, like jensen mod 6 or mod 8

[tca]

that sounds expensive, you can almost get a "real" guitar speaker, like jensen mod 6 or mod 8

You are quite right, but I can't find them with that price in Portugal (or online + mail), and I do like the sound of these speakers that I just mention.

Cheers.

[Jaicen_solo]

I'm going to pick up one or more of these to knock up a cheap bass amp. I'll be running the output of a Bass Pod through it, so I don't need tone controls etc. Looks perfect, but any suggestions what speaker I should use?
This is very much 'bedroom' use so I don't want it to be loud, but I want to hear the lows a little more than my current ValveJnr with the 8" speaker