TDA 2050 amp photo's & mp3

[MartyMart]

http://aronnelson.com/gallery/albums/Martys-layouts-and-photos/tda_demo.mp3
sound file recorded with a mic - rough but sounds pretty cool !!

No enclosure yet - need to think of something "funky" for it.
Really sounds amazing - not valve but a damm fine SS attempt !!
Well worth picking up a TDA2050 for one of these, it'll take just an hour or two
get a BIG heatsink for it though !!!

The colours just keep me "safe" at the wire up point !!   
enjoy, MM

[snoof]

interesting.  did you use one of the appnote schems??

[slacker]

Looks cool, what are you powering it with?

[MartyMart]

Looks cool, what are you powering it with?

A psu from an old answering machine !
It's 18v DC 300ma - regulated, seems quite hum free !
MM

[Victor]

Marty, are you using some limiting output device on the amp? Like a resistor after vol. pot.........

TDA2050 can suck a lot current, I burned a 2040 a year ago using a 15V@500mA ps ..... 

[puretube]

I`d increase the heatsink, on the long run... 

[MartyMart]

Marty, are you using some limiting output device on the amp? Like a resistor after vol. pot.........

TDA2050 can suck a lot current, I burned a 2040 a year ago using a 15V@500mA ps ..... 

No, all I've done is add a volume pot, strapped across pins 2 & 4.
I used a "lower limit" 390ohm so, as my vol pot is reversed  it means that once
the amp is at a low bedroom level, it does'nt turn totally off.
I'll fix that, but the chip has that huge heatsink - which is keeping it so it's "just" warm and the
PSU hardly got warm after 1 hr.
It gets LOUD but doesn't seem like 30 watts to me .... more like 10/15 watts .. but I'm much
more used to valve amps  !!
From my schem that I found, output from pin 4 had a 2.2ohm with a 680n cap to ground, then
1000uf cap and out to speaker, I got close by using 3 x 10ohm paralleled resistors here.
Speaker is 8 ohm, perhaps this is helping ? I'm not SO sure with amp/spkr impedances !
Bias to pin 1 (+ input) is 22k from V+ with 22k to a 100uf/22k node to ground, I replaced a further 22k
which DID go between 2&4 with a 22k pot for volume control.
MM

[slacker]

It gets LOUD but doesn't seem like 30 watts to me .... more like 10/15 watts .. but I'm much
more used to valve amps  !!

according to the datasheet to get 30 watts you need to run it at 36volts at least and that's with a 4ohm speaker. Running it off 18volts gets about 10 watts, so your ears are spot on

[RLBJR65]

That sound pretty darn good Marty! Is that straight into the power amp no pre amp?

[Mark Hammer]

Well that gives me hope!  Got a couple of ampless, speaker-loaded practice-amp cabs sitting around and some TDA2030s, LM1875s and a TDA2050 or two.  I would have though that a 500ma supply would be on the weak side, but clearly I can still get some oomph from them, and obviously more from a 12VAC/1A supply, especially if double-ended.

Thanks for that morale booster!

[Steben]

That sound pretty darn good Marty! Is that straight into the power amp no pre amp?

I wondered about that too.. It sounds impossible 

[sfx1999]

I'm guessing that's the Thor.

[John Lyons]

I would imagine this is marty's mosfet/mu thingy no?
Sound nice marty!
Gotta love the simplicity with that amp!

John

[MartyMart]

That sound pretty darn good Marty! Is that straight into the power amp no pre amp?

I wondered about that too.. It sounds impossible 

I'm guessing that's the Thor.

It has my new little "Mos-Mu" circuit up front on that sample
I've also tried it with :
Thor
English Channel
Bassman '59
Dr Boogie  .... and they all sound  FABULOUS  !!!  
I wanted to put a preamp on the board but can't decide which !!
I hope my little 18v PSU holds up, if not i do have a large 24v DC 10 amp "Brick" that weighs about 4 kilos !!

Mark - Go for it , I'm SO impressed with this, I'll post the schem tomorrow, as it's a little different from the
standard app note  

MM.

[RLBJR65]

Ah yes, you posted that in the other thread.

Maybe I will gut that old Peavey now and rebuild it! It's got a good transformer already. Rectified voltage is + / - 17 vdc according to the schematic.

Thanks Marty! Looking forward to seeing your schematic.

[jrc4558]

Cool! I built me a couple of this chip-based amps for a near-field monitoring on my hoome computer. The Pentawatt line is awesome!

[MartyMart]

Schematic - use a Jfet amp sim or similar up front .

[dschwartz]

I did a stereo version some weeks ago..it really sounds amazing as the cheap it is, and is so frickin´easy to do too!!

Anyway, youre not using the capabilities of the chip with such a small power source..
I use a 4 amp, 17vdc source simmetrical.. and man, i have to put something heavy over the speaker cabs cause they jump around playing loud with the tight strong bass response!
an with the dr boogie.. great combo!

[petemoore]

Maybe I will gut that old Peavey now and rebuild it! It's got a good transformer already. Rectified voltage is + / - 17 vdc according to the schematic.
 I would measure that with a DMM for goodness, then figure most of the hard stuff is already done [chassis, box, speaker mount, power supply]
   I built a few LM3886TF [TF = insulated body], GGG amp projects using split ~17vdc supplies [IIRC they were seeing > +/- 18Vdc]. They work great, top bang for bukk with these little chip amps, especially when you have the PS iron already!
  The only thing I may have overkilled on was running all separate ground wires back to the CT, I even ran the input jack and volume control separately, not sure if that's necessary.
 I smoked a chip, then decided everafter to debug a few times before applying power.

[MartyMart]

I did a stereo version some weeks ago..it really sounds amazing as the cheap it is, and is so frickin´easy to do too!!

Anyway, youre not using the capabilities of the chip with such a small power source..
I use a 4 amp, 17vdc source simmetrical.. and man, i have to put something heavy over the speaker cabs cause they jump around playing loud with the tight strong bass response!
an with the dr boogie.. great combo!

.... possibly, but it's still really "kickin" with that 18v single supply
I have a 3.2 amp traffo, with 230v primary and +/- 15v DC taps, so perhaps I'll try another that way and
see how THAT sounds ! 
Seems like a superb chip for a few bucks !
MM.