Power amp under development

Hahah Quasi, I think the card I got for my birthday, yesterday, from my wife says it best...

IMG_0698_1.jpg
 
Thanks Hugh, May is obviously a special month :)

Thanks Whoandcar. 30-19, I like the sound of that. Anyway I'm closer to 40 than 60.

Thanks Dudaindc, Zeonrider, Taj....you're all catching up - in percentage terms anyway.

Cheers AndrewT...reminds me of a song...

But Quasi cant read
Summer is over and hes gone to seed
Quasi cant read
He never learned nothin that amps ever need....


Haah Nordic....funny card. Happy birthday for yesterday.


Anyway today's the day....where's my $#@!*& present????!!!

Cheers
Quasius fiftius almostus
 
Once, in my jonger days, I met an elderly lady; I supposed she whas around 60.
She complained about here age to the jonger girl helping here with a newspaper etc.

I had to mingle in their conversation and tried to make here day.
"Helo" I said, "I do not believe you must complain about your age."
"Look at me; I'm 23 and I assume you're 53." (That last number alone made her grow 5 cm.

"When I whas 1, you were 30; that's 30 times my age.
At 10, you were 40, that's only 4 times.
Now I'm 23 and you 53 that's hardly double my age.
One of these days I'll be cathing you up."

She kept on listening as all other customers in the newspaper shop did.

"So," I went on, "I'm the one who's getting older and a bit faster then you.
Try to enjoy the rest of the day thinking that youth is getting older much faster then those who are."

She then left the shop; If I didn't know who she whas, I wold say she whas 35, the way she walked...

Cheers,
Tarzan
 
Hi Quasi,

I have tried the TIP121 on your soft-start curcuit and seems working fine.

Then I tried to use a 9VAC (for 12V relays) and I tried 2k2 and 3k for R2. the 2k2 doesn't work but the 3k is OK. As far as my ears can tell, it seems that the delay time has lengthened. Which of the 2 Rs is affecting the delay time (or both?)

I think R1 = 11k(/12k), R2 = 1k5 should also work but I haven't tried it yet. In fact I think any conbination within these 2 should be fine as far as firing the relay is concerned, but for the timing...
 
Quote : " Once, in my younger days..................I would say she was 35, the way she walked... "

Surelly off topic but should fit in 'anywhere'. It's getting closer to the core of what we really are !

Tarzan ,
a GREAT observation and WONDERFULLY applied !'
Nothing like lifting up other people's spirits especially when they feel 'down'. It's priceless. GREAT job !

Cheers,
Ashok
 
1.1C/W is OK for a mono Nmos on +-60V
But it will run pretty warm trying to cool a stereo amp.

If you listen to your music at the -20dB (ref max power) level then the occasional peaks will not raise the temperature much above the quiescent temperature.
But if you like to draw significant power from the amp, then the sink will run much hotter and severely reduce the SOAR of the output and driver devices just when they need capacity for the high output currents.
 
AndrewT said:
1.1C/W is OK for a mono Nmos on +-60V
But it will run pretty warm trying to cool a stereo amp.

If you listen to your music at the -20dB (ref max power) level then the occasional peaks will not raise the temperature much above the quiescent temperature.
But if you like to draw significant power from the amp, then the sink will run much hotter and severely reduce the SOAR of the output and driver devices just when they need capacity for the high output currents.


Andrew, thanks for the observation. I'm planning on using one for each channel, so I assume it must be ok even for higher power settings.
Hari