Thanks
Thanks Dan, A LOT!
My rails are +/- 63vdc not quite 70v. Will this value differ in setting the bias current using 10mv?
Thanks
Thanks Dan, A LOT!
My rails are +/- 63vdc not quite 70v. Will this value differ in setting the bias current using 10mv?
Thanks
Rail voltage and load
+/-63 volts. The 250 lbs ea, 3 way Line Arrays can dip down to 2ohm. Had them at concert level, clean sound and amp does not get very hot at all.
I was wondering if my heat transfer needed improving. No smoke or problems.
What about your boards? Modifications, PICs would be nice also.
I did smoke a resistor on one board when I powered it up (need the light bulb then) and found the trimmer pot turned completely in one direction. Thats why I am concerned about the trimmer. If you have any info on these, please send, in english if possible, lol.
Thanks
Paul
+/-63 volts. The 250 lbs ea, 3 way Line Arrays can dip down to 2ohm. Had them at concert level, clean sound and amp does not get very hot at all.
I was wondering if my heat transfer needed improving. No smoke or problems.
What about your boards? Modifications, PICs would be nice also.
I did smoke a resistor on one board when I powered it up (need the light bulb then) and found the trimmer pot turned completely in one direction. Thats why I am concerned about the trimmer. If you have any info on these, please send, in english if possible, lol.
Thanks
Paul
that pic was sama board pcb from Bgr, but I modified dual supply with Stepper class h.
I am not see compound/silicon gearse, transfer heat will be better, and why using 1n2 in input ? ﹑ not same like schematic.
I am not see compound/silicon gearse, transfer heat will be better, and why using 1n2 in input ? ﹑ not same like schematic.
Heat transfer compound
Yes, I used the heat compound. The 6063 grade is what I should have used for the angled Aluminum. The 6063 is architectual, flatter and mates better. I think I will change that.
This schmatic, however flawed, is all I have, sorry. BLZ 400w-500w is what it has on the actual PCB. You have a good eye! It will take me some time to correct it. And I don't have a CAD program whic slowes things down considerably.
Yes, I used the heat compound. The 6063 grade is what I should have used for the angled Aluminum. The 6063 is architectual, flatter and mates better. I think I will change that.
This schmatic, however flawed, is all I have, sorry. BLZ 400w-500w is what it has on the actual PCB. You have a good eye! It will take me some time to correct it. And I don't have a CAD program whic slowes things down considerably.
Glad To Help A Polite Newby...
Lower voltage power rails should not change the bias current spec.
Once your bias current value has stabilised and is set, it is wise to check for same or similar value (10mV) on each of the other 5W emitter resistors....expect some minor variation.....+/- 10%.
The 45mA value I gave is an arbitrary one...some output stages give lowest distortion with less bias current (20-25mA = 5mV), some require higher, like 100mA (22mV).
V/R = I....0.010 V/0.22 R = 0.045 A....you can work out the mV values for other current settings.
Exceeding 100mA may be problematic, and also ups your quiescent power dissipation....be wary of this, high power, high bias current amps can bump up your power bill substantially 😱...keep in mind that you are running multiple modules.
There are plug in power meters available for $20.00 or so...I think these are a good investment.
You could try 5mV (22.5mA) setting or less, if you don't hear a difference, save the electric cost and spend it on beer
.
Dan.
Paul, you are most welcome, it's my pleasure to help you through this 😉.
Lower voltage power rails should not change the bias current spec.
Once your bias current value has stabilised and is set, it is wise to check for same or similar value (10mV) on each of the other 5W emitter resistors....expect some minor variation.....+/- 10%.
The 45mA value I gave is an arbitrary one...some output stages give lowest distortion with less bias current (20-25mA = 5mV), some require higher, like 100mA (22mV).
V/R = I....0.010 V/0.22 R = 0.045 A....you can work out the mV values for other current settings.
Exceeding 100mA may be problematic, and also ups your quiescent power dissipation....be wary of this, high power, high bias current amps can bump up your power bill substantially 😱...keep in mind that you are running multiple modules.
There are plug in power meters available for $20.00 or so...I think these are a good investment.
You could try 5mV (22.5mA) setting or less, if you don't hear a difference, save the electric cost and spend it on beer
.Dan.
Beer, stuff and more PICs
Thanks for the advice.
Trying to educate myself on the various transistors and how to use the equations to keep within the operating parameters. The wife (a Kiwi) is great, loves the sound, and loud like me. She said get a book. I remember seeing one on amplifier design here that may be good if it is not too far over my head. She also said San Miguel, won’t argue with that, HA!!!
Cheers
Paul
The MTM, Lace wood and truck bed liner paint with poly over the paint, is 2 Focal paper drivers, $20 ea, with a K-1 tweeter, $12 ea. Sound is very good for a budjet set up, excellent bass. The other was all Focal drivers using the older TC120 tweeter. Nice bright sound, hard dome tweeter, done in Mahogany
Thanks for the advice.
Trying to educate myself on the various transistors and how to use the equations to keep within the operating parameters. The wife (a Kiwi) is great, loves the sound, and loud like me. She said get a book. I remember seeing one on amplifier design here that may be good if it is not too far over my head. She also said San Miguel, won’t argue with that, HA!!!
Cheers
Paul
The MTM, Lace wood and truck bed liner paint with poly over the paint, is 2 Focal paper drivers, $20 ea, with a K-1 tweeter, $12 ea. Sound is very good for a budjet set up, excellent bass. The other was all Focal drivers using the older TC120 tweeter. Nice bright sound, hard dome tweeter, done in Mahogany
Attachments
The different is in pin trimpot and caps 100nf position, you can check pin from layout dan pin in schematic. You can redrawing it if not sure...
Finally , this "bombastic wattage" amp thread ............
I've replace driver with C5200 & A1943 , and some "minor" adjustment , like +/- 56 VAC supply , 12 Final transistor / channel .... etc
The last problem encountered "unsolved" was too little gain , this amp must have a high output preamp ....., for a little while , a "little OpAMP" kit stays there .....
I've replace driver with C5200 & A1943 , and some "minor" adjustment , like +/- 56 VAC supply , 12 Final transistor / channel .... etc
The last problem encountered "unsolved" was too little gain , this amp must have a high output preamp ....., for a little while , a "little OpAMP" kit stays there .....
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Why?
Other than the loss at idle it could be a quieter product (and less expensive in large quantity).
Small quantity, below 500VA, toroid.
Other than the loss at idle it could be a quieter product (and less expensive in large quantity).
Small quantity, below 500VA, toroid.
Coz the final transistor, I don't know why it uses so much.... ??
more expensive than less expensive too...
To keep in SOA safety range, this amp borrowed for "outdoor use" , with many speakers conected in series & pararel, output impendance sometimes reach 2 ohms ....
The most expensive parts is power supply transformer , with 15Amp each channel , it takes almost half of total money at that stuff .....
In fact , after 5 years use , this amp never make me down , it never broken , even just one screw .....
up to 4 pair of 15" cheap speakers , for "17 August" events , "mariage events" etc ....
At a little space , the speakers joined pararelled and series ...., at a larger spaces ,it conected all pararelled ...
ouput sound was loud enough , with "fair" quality at all freq , especially "low" heavy & Deep bass .
A few friends has asking if I want to sold this , but I've said to them if I could find the "bigger" ones .
FYI, i've already sold more than 10 items of power amps ....
4 speakers all conecte parareled = 2 ohm , series+ pararel = 8 ohm for each channel
sometimes only take 2 pair ,3 pair or just one pair , depends on area coverage ....
2 x +/- 56VAC = 2 x +/- 80VDC , 15" - 8 Ohm , 4 Pair pararel into 2 ohm , how much "theoritical" output wattage expectation ?
Various speaker , cheap ones .....
As you know , here in indonesia , many informations about specification always "misleading" , and now we talk about speaker max wattage rating ....
it says 300W, 200W at back of the speakers ....., who cares ?
As long sound as loud as we need , no smoke comin' out , audience satisfied ....
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