something like this.
An externally hosted image should be here but it was not working when we last tested it.
yes, that is right.
excuse me, maybe i need more practice
of the english language.
And about my own build, Mr Andrew,
i made it with LM3886, doyou recomend
using local PS caps?, I mean close to the chip,
if so how small can they be? in capacity.
At the moment i am using only the caps at
the bridge rectifier,and sound is OK, low freqs
are good down to the kick and bass region,
would it improve with some extra uF´s?
thanks in advance for your attention.
I´ll try to be more clear when posting
thanks again.
martin martinnez
uruapan michoacan.
excuse me, maybe i need more practice
of the english language.
And about my own build, Mr Andrew,
i made it with LM3886, doyou recomend
using local PS caps?, I mean close to the chip,
if so how small can they be? in capacity.
At the moment i am using only the caps at
the bridge rectifier,and sound is OK, low freqs
are good down to the kick and bass region,
would it improve with some extra uF´s?
thanks in advance for your attention.
I´ll try to be more clear when posting
thanks again.
martin martinnez
uruapan michoacan.
You want at least 470 uF very close to each of the LM3886 chip's power pins. (It would be better if you used several smaller caps instead of one 470 or larger uF, for each power pin.) Having their current available without the rail inductances in the way should help the transient response accuracy (maybe improving imaging) and the high-frequency response accuracy, as well as providing better support for the feedback's HF activity. You want low inductance (i.e. caps with small lead-spacing, and very short connections to pins and ground).
You also need a physically-very-small cap to ground directly at each power pin (within 2 mm), for high-frequency stability. Without a scope, it would probably be safest to use an X7R-type ceramic, there (such as 0.1 uF), since they have some internal resistance (ESR) to help damp any LC resonance that might be formed with the inductance of the nearby electrolytics. But you could maybe try a very (physically-)small film cap and see if the chip gets warmer (and change the cap if it does get warmer).
National specify quite precisely what the two sets of Cs should be.
Cs is the MF & HF decoupling.
You should never build an amplifier without properly sized and properly located decoupling.
That is not my recommendation. That comes from Designers and Manufacturers.
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What if transistors have power supply of their own and also the LM3886/3875 has its own (lower voltage) supply
So, we could have higher output power and higher ohms...
So, we could have higher output power and higher ohms...
Mihkus - i would use a power supply that supply's -/+5V or more (DC) over what the the audio chip can take and use Volt regulators from that to the chip, this way you should have MAXIMUM power that could be achieved, you do need to KILL on testing chip to get the max voltage it can take, and could be a little over ABSOLUTE MAXIMUM RATINGS, my TDA7294 (the one in the picture) is running 51V+/- even thou it should only take MAX 50V+/-, this is not due to experimenting but the Ring Trafo i had that worked, and in about 5 years it has not blown yet, and it has been ON on average 12 hours pr day in that time.
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Completely unrelated but was digging in my old qbasic programs since i just found QB64 which works in linux and all other platforms, what do you guys think about my OLD (approx 10 years ago) program to fast "calculate" crossover networks?
if it can be used i would take advice on what to add and such 🙂
NOTE: this is an .exe that works in windows and wine.
Run or Choose "save as"
https://dl.dropboxusercontent.com/u/29047266/Qbasic/TONE36DB.exe
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Completely unrelated but was digging in my old qbasic programs since i just found QB64 which works in linux and all other platforms, what do you guys think about my OLD (approx 10 years ago) program to fast "calculate" crossover networks?
if it can be used i would take advice on what to add and such 🙂
NOTE: this is an .exe that works in windows and wine.
Run or Choose "save as"
https://dl.dropboxusercontent.com/u/29047266/Qbasic/TONE36DB.exe
Hello,
I had the same idea to the TDA7293 with transistors BD911 BD912.
For the resistor you keep the same value?
I had the same idea to the TDA7293 with transistors BD911 BD912.
For the resistor you keep the same value?
they will help but not much of an upgrade, unless you use 2-5 sets pr 7293, this i why i use 5200/1943 as the are some of the most powerfull transistors in the size.
Most will disagree with you.
I certainly disagree.
Look at the SOA in the datasheet. It is terrible above 50Vce.
well in the 7294/93 we only need about 60V 🙂, but always open for suggestions, have use many different power transistors over the years.
EDIT: and i said some of the most powerfull, not THE most powerfull, also they are cheap from where i buy
EDIT: and i said some of the most powerfull, not THE most powerfull, also they are cheap from where i buy
Hi Martin,
Sound interesting using 3886, can you share schematic or drawing if available.
I'm getting excited to give a try...
Thanks