I had problems with my LM4780

[destroyer X]

I have used boards from Peter Daniel, but parts and Integrated circuit did not came from Peter.

I have assembled and no error, received double check, no shorts or wrong parts.... transistor insulated, and even side screws have no metal to touch into the Integrated circuit.

Was powered using 35 plus 35 volts supply, 3300uf each rail for condensers, speakers impedance 8 ohms.

Since the first moment i had full positive rail voltage into the "B" channel...the other channel operated normally but the temperature was too much big.... sometimes reached 80 degrées celsius into the plastic cover..the black cover (gray)... i suppose heatsink had a bigger temperature, was not measured... thermal protection have not entered into operation.

Them i decide to reduce voltage, and the unit goes operating using 17.5 volts plus 17.5 volts (datasheet said more than 10 plus 10 volts)... operated warm and sound was great...much better than 35 plus 35 volts.

Well...the rigth channel damage was creating problems, i could not switch off positive and negative supply from the rigth channel to let the unit work in peace.

Finally, what was obvious happens, the integrated circuit started to have off set floatings.... sometimes speaker jumped forward and then jumped backwards... fuse was 5 amperes and the unit was sending less than that... my speakers (2 units, 4 ohms each, 150 watts each) can hold the DC power on them without problems if less than 30 seconds.

I have made a video showing you what happened..... the chip is dead...buried and will not produce problems to me anymore.... there's another youtube video into "Dx Amplifier" that shows the unit operating yesterday...of course..when already alive.

Visit youtube to understand what happened:

http://www.youtube.com/watch?v=PtlR7qGu3xk

regards,

Carlos

 

[destroyer X]

Here is the chip.... was installed inside the supply case

The heatsink was between the transformer and the chip board.... the integrated circuit was insulated...no electrical contact with the heatsink or other chassis part.

regards,

Carlos

 

[destroyer X]

What do you think... was bad luck?....

Are there fake units alike this one? (LM4780)

regards,

Carlos

 

[destroyer X]

Here... the sound when operating

http://www.youtube.com/watch?v=e6gZljMEazg

regards,

Carlos

 

[destroyer X]

I have built the LM4701T amplifier too

Dislike the over current and over voltage protection...produces noises.

Here you have one video about this chip... there are others, type Dx Amplifier and others will appear, also this chip playing music.

http://www.youtube.com/watch?v=pLNCR2X57bw

regards,

Carlos

 

[destroyer X]

I have assembled the fouth LM4701T

The second one burned with i was fliping a switch.

http://www.youtube.com/watch?v=F5tr4gHsNkU

regards,

Carlos

 

[Juergen Knoop]

 

[destroyer X]

hehehe.... i usually do not understand those smilies

...what they mean.... but seems may be something good.

Thanks

regards,

Carlos

 

[MJL21193]

Great stuff!
I approve of your taste in tunes - Stevie Ray's Tin Pan Alley on your sonic voyage

 

[destroyer X]

Your kindness is what deserves approval my dear friend

Be happy into beautifull Canadá

regards,

Carlos

 

[destroyer X]

4701T is sounding fine today.

But seems it is overheating....using 20 plus 20 volts and 4 ohms speaker.

http://www.youtube.com/watch?v=pgBtIabHuwg

regards,

Carlos

 

[destroyer X]

Cannot say good things or commend this chip

Observe what is happening...the noise shows what i think about this unit.

http://www.youtube.com/watch?v=eF1_dg3tUDE

hehehe.


Carlos

 

[Juergen Knoop]

hero

do not understand those smilies

I'm simply worshipping you, because you are my true DIY hero. 😎
I wish, I had a little bit of your passion and energy! 🙂
regards

 

[destroyer X]

Oh! thanks... i am not hero... i am a simple guy...with a lot of defects

And i wish to have a so pretty name as yours... i know the German pronunciation of Jurgen.... and sounds great... sounds wonderfull.

Another name i love is Panzer.

My mail adress is panzertoo@yahoo.com .... means i use to be kind almost all the time but i can be hard as a Panzer tank if needed.

This name, Panzer....has a meaning?... is it Panther?

No more Integrated Circuits for a while...my old and good Dx Standard is playing once again and i giving to myself a break to build amplifiers.

I will have 2 days off!

regards,

Carlos

 

[destroyer X]

Thank you by the attention Juegen, also the the chip forum folks

I will return to my place.

For a while no more Chips.

Enjoy them folks.... i wish you more luck than i had...or at least more knowledge, because it seems i have made some ship...because i have lost a
lot of units.

Well...... "Cest la vie!"

C'a marche!

I will be into Solid State.... bye folks!

regards,

Carlos

 

[Juergen Knoop]

This name, Panzer....has a meaning?

Panzer is a word, which is used for armour. Knights wear Panzer, a turtles shell is called a Panzer and so on.
The dictionary says it comes from italian panciera or mediaval latin pancierum and refers to the part of amarment that protects the belly.
But it is widely used for all kinds of protective bracings, mostly in millitary context.
regards

 

[destroyer X]

Ya!... danke shoen..... thank you.

Ich bin ein Panzer.

aufwiederlehsen,

Carlos

 

[destroyer X]

Never give up!..... always figthing!

I have tried my sixth integrated circuit...now playing.... obbeying schematic..i have just included an input condenser, because afraid of some Dc from the computer audio board... we never know....just in case.

Condensers are not so small as people like.... into the supply i am using 25 thousand plus 25 thousand.... into the board only 220uf only to avoid oscilations..... i have filtered the computer audio board including small condenser into the input...just in case.

Short connections made... the unit is too much sensitive (i do not like that, this captures noises from the source).

Voltage is 18 plus 18 volts (18.1 and 18.2)..... i am glad no big offset have appeared into the output.

The unit is sounding fine....nothing special in my point of view but also has not that deserves criticisms or commends.

regards,

Carlos

 

[destroyer X]

I have played Mozzart very loud and the man working into my second

bathroom ceiling felt the sound lovely.

Well...he use to listen portable radio receivers... and this one, for sure is hundred times better.

regards,

Carlos