planning to build car sub amp, help needed

[clipto333]

hi guys,

thanks a lot for the replies. im not gonna build a car amp as of now as i don't have the required experience. ill go for home amp.
i already have 2 lm3886 chips but im confused as there are too many schematics. DIY Chip Amplifier Kits, PCB's, Components and Information. has a kit based on 3886. should i replicate that? and how much watts will it put out? i want to be realistic. when i have the experiance ill go for bigger amps. guys you know what it is, the excitement is there so much that you think you can diy anything.

Navin,

the drivers i was reffering to were 6 ohms(im confused now if they are 6 or 8 ohms.) they were 6 ohm definitely. lol
i think you mistook it for 6". they are from my old sony stereo system. they are floor standers with a 6 incher midbass i guess and edge drived dome tweeter( i dont know if im correct can any one explain edge driven? the coil is on the edge of the dome and the dome itself is removable. i think ts-20s are the same kind) theres also a xo which is mounted inside of the terminals and are glued there so couldn't check.
i love the sound quality of the speakers. are the drivers made by sony ?

will let you guys know what i decide. yaar if anyone has a schematic with parts lits please post it yaar.

thanks
rishabh

[clipto333]

hi,

the elec shop guy in jalandhar has a 48v smps ps. can i use it with these chips or is it too much.

can anyone tell me how to wind a toroidal core. eg. what do you mean by no. of turns, 4+4, what wire size to use etc.

how do i convert a schematic into actual board design?

thanks

rishabh

[low_bass_makker]

Originally Posted by clipto333

hi,

the elec shop guy in jalandhar has a 48v smps ps. can i use it with these chips or is it too much.

can anyone tell me how to wind a toroidal core. eg. what do you mean by no. of turns, 4+4, what wire size to use etc.

how do i convert a schematic into actual board design?

sir the 48v smps he must be giving would be a 0-48 volts one...but you would be requiring a +24 , 0 , -24 one to get the required to power the amp only the 0-48 is no good till you split it you up to +24 , 0 -24 again using a power circuit.....




dont go for number of turn or such details....for ordering a simple transformer or a torodial you require first the input and the output voltages and second the current requirement or how much power would you require which that transformer can deliver......and the tapping you require...thats all.....

hmmm like this one....



here you can see the pri or the input voltage is 230 volts and the secondary is having 4 taping which are 71-0-71 , 71-0-71 , 12-0-12,
15-0-15 which are used in different circuits of the amp....

here is a full pic of that same amp....




in the above amp he is using simple bridge rectifiers to supply the DC and two capacitor on each side for filtering it....the main power supply to the amp section is of 71 volts wala...for the pre-amp section and the fans and other stuff the 15 and 12 volts supply is used.....

the above amp is capable of 800 watts rms x 2 at 4 ohms.....and it is full range amp...

which circuit have you decided to make....there are many software which can help you to make the PCB design

[navin]

Originally Posted by low_bass_makker

the above amp is capable of 800 watts rms x 2 at 4 ohms.....

and the tranny is a 3000 VA job. The amp uses dual rectifiers (but a single tranny) hence the dual 71-0-71 secondaries.

LBM are those fans always on or do they trigger if the heatsink gets too warm? I dont see a thermistor on that photo but some amps use current triggers as well.

clip the V on your tranny should be atleast twice the output wattage. so if you are looking at a 50W x 2 amp I would suggest a 300 VA tranny.

[navin]

Originally Posted by clipto333

i already have 2 lm3886 chips

There is nothing wrong with the ChipAmp kit. Apex Jr. and Vikash both sell nice kits too. The 3886 and 3875 can put out about 50-60W rms /ch.

[low_bass_makker]

Originally Posted by navin

and the tranny is a 3000 VA job. The amp uses dual rectifiers (but a single tranny) hence the dual 71-0-71 secondaries.

LBM are those fans always on or do they trigger if the heatsink gets too warm? I dont see a thermistor on that photo but some amps use current triggers as well.

clip the V on your tranny should be atleast twice the output wattage. so if you are looking at a 50W x 2 amp I would suggest a 300 VA tranny.

yes the fans are heat controllered they have two speeds one is normal and the other when the amp gets hot....it is made like if one channel is used the only one fan of that channel will get fast not the other one....

and i can see the thermistor at the bottom end of the heat sink .....white grey in colour.....Navin Ji I think you must get some close eyesight glass.......just joking.....

[navin]

Originally Posted by low_bass_makker

yes
and i can see the thermistor at the bottom end of the heat sink .....white grey in colour.....Navin Ji I think you must get some close eyesight glass.......just joking.....

I do need glasses. You point them out and I still cant see them! :-(

[clipto333]

Originally Posted by navin

There is nothing wrong with the ChipAmp kit. Apex Jr. and Vikash both sell nice kits too. The 3886 and 3875 can put out about 50-60W rms /ch.

hi navin,

im planing on using the chipamp schematic for my amp. can i use short forms? i fractured my finger last night so cannot write properly.

and is there any substitute for the mur860 diode? do i need it? where can i get it in india

thanks

[low_bass_makker]

Originally Posted by navin

I do need glasses. You point them out and I still cant see them! :-(

here they are marked....

[navin]

oh boy my fault. i did not scroll down on my 12" screen.

[low_bass_makker]

Originally Posted by navin

oh boy my fault. i did not scroll down on my 12" screen.

no problem sir.........

[clipto333]

hi navin,

well i asked something sir. can i use short hand because i fractured my finger lastnight? it is a special request to the mods. never mind if not possible.

i have 15 days now before i can solder again. so will look for the diode and psu.

thanks

please let me know from where i can source this mur860 fast diode? or is there an alt diode which i can use without creating problem in the amp?

[clipto333]

hi guys,

i have a diode which says fmgg2c. i googled and it says fast rect diode dont know if i can use it. please search for this diode and let me know. also i have a pc smps. is it possible that this psu uses ultra fast diodes?

please bhai logon let me know asap

thanks

rishabh

if im really asking for too much then upto you guys i you wanna help or not.
i not getting the required help here. i have to look elsewhere

[low_bass_makker]

hmmm....where and how you are planning to use these diode.......

[navin]

Originally Posted by clipto333

hi navin,

well i asked something sir. can i use short hand

the problem is that

a) I am too old to follow that SMS stuff kids use nowadays
b) can imagine if everyone starts using SMS claiming some injury or handicap?

The amp can wait. I will be here for more than the next 15 days.

You can PM me SMS if you like but given my understanding of SMS I wonder if it will lead to more questions than answers! :-)