planning to build car sub amp, help needed

[navin]

A tranny is a Transformer not a Transvestite.
A Torroid is one type of Transformer, and EI is another.

clip to, I thought you were going to use the chip amp you posted earlier. there are dozens of schematics on the intenet. 50-100W is not that rare.

[clipto333]

Originally Posted by navin

A tranny is a Transformer not a Transvestite.
A Torroid is one type of Transformer, and EI is another.

clip to, I thought you were going to use the chip amp you posted earlier. there are dozens of schematics on the intenet. 50-100W is not that rare.

hi navin,

yes now ive decided to build the chipamp design. never mind it copying just wanna get a hang of it for further projects.

how do i convert a pdf to eagle file. i wanna etch my own board. also there are hundered types of resistors and caps in the library. dont know which ones are used on the chipamp. alos how do i substitute mur860 for mur 1560?
now my hand is hurting...:-(

cheers

clip

[clipto333]

hi navin,

i have some questions.

1) where do we need a transformer with centre tap? inverting amp?

2) can i use 2 lm3886 per channel? i have a schematic. here it is.



3) this amp has a psu with mur1560s. and i dont think it uses ct tranny. can i use a tranny with centre tap with a non centre tap power supply design? here are the schematics. 2 of them.





4) can you help me source a toroidal transformer? can i use a bigger tranny so that i can make it more powerful when i want? How much do you pay for the toroid? can i have the specification with price so that i have a rough idea?

i hope im not asking for too much and im clear with my questions.

cheers

clip

[clipto333]

hi,

navinji still waiting for yor reply. i wanna start my project today itself so please help.

cheers
clip

[Sam Kapasi]

Clip, are you building an amplifier for 12VDC use or 230Vac???

Navin is maddeningly proficient at transformers that connect to 230V AC. I believe even he might have to do some thinking and research when it comes to building a 12V DC power supply. And you dont use those large toroidal (*cringe*) trannies in car amplifiers.

[clipto333]

Originally Posted by Sam Kapasi

Clip, are you building an amplifier for 12VDC use or 230Vac???

Navin is maddeningly proficient at transformers that connect to 230V AC. I believe even he might have to do some thinking and research when it comes to building a 12V DC power supply. And you dont use those large toroidal (*cringe*) trannies in car amplifiers.

hi sam,

im building a home amp. what tranny do you use in car amps? just asking for knowladge.

now im making a schematic in eagle. i might use two parrellel 3886s. how do i build a two channel? i.e. 4 ICs 2 per channel. should i build two seperate amps and use it as a 2 channel or is there a way to connect 2 ICs so that they have the exact same output? if i use 2 seperate amps im sure there will be a difference in the output. so please suggest how to.

bolo tararara,
clip

[Sam Kapasi]

Originally Posted by clipto333

bolo tararara,
clip

You said the magic words clip, so here's what you want, to increase your knowladge

[clipto333]

Originally Posted by Sam Kapasi

You said the magic words clip, so here's what you want, to increase your knowladge

Hi sam,

well people do make mistakes once in a while sam and it was because of my hand. if you are going to behave like a professor( guru ) rest assured im going to make your life a living hell in here.
thanku unkilji phor thee chematic(peronaoonsed ch - chimp).

i hope you participate more and help me build a really good sounding amp. i know you have a lot of knowledge on audio systems.

dhik chik

clip

no offense meant dude

[navin]

sorry i was busy. I think you got your info from here.

PA100 2x LM3886 in parallel

if so just do it. it is tried and tested. as you can see there is a 300W versio using 6 LMs on the same website.

BTW have you got the 3886? if you are using 2 why not use a 4780? it makes for a cleaer circuit like done here http://www.unisonus.com/pdf/lm4780_sch.pdf

with regarding parallel 3886s this is one ckt that I have seen around a lot.
App Note - Bridging Power Audio Amplifiers
DC Electronics - Kits

I assume you have already read Brian's PDF on the LM3886 PSU. Brian is a regular at diyaudio (uses the handle BrianGT). I would also look at Pavel's posts on Diyaudio. I think his last name is Dudek or something like that.
http://www.chipamp.com/docs/lm3886-manual.pdf

Speaking of Diyaudio there was a "indian" thread on dual 3886s I think I have it here...diyAudio Forums - PCB design of parallel of two inverted LM3886 with buffer and dc-servo.

You can contact Miracle Electronics for your torroid transformer (I am never gonna use the word tranny on this forum again). Miracle will make you a transformer with dual taps.

and lastly this tutouial with pics will show you how your amp can turn out.
LM3886 Stereo Amplifier
http://www.parttimeprojects.com/audi...newebpage.html
Single Chip 50W Stereo Amplifier (Elliot was one of the earlier "gain cloners").

[clipto333]

Originally Posted by navin

sorry i was busy. I think you got your info from here.

PA100 2x LM3886 in parallel

if so just do it. it is tried and tested. as you can see there is a 300W versio using 6 LMs on the same website.

BTW have you got the 3886? if you are using 2 why not use a 4780? it makes for a cleaer circuit like done here http://www.unisonus.com/pdf/lm4780_sch.pdf

with regarding parallel 3886s this is one ckt that I have seen around a lot.
App Note - Bridging Power Audio Amplifiers
DC Electronics - Kits

I assume you have already read Brian's PDF on the LM3886 PSU. Brian is a regular at diyaudio (uses the handle BrianGT). I would also look at Pavel's posts on Diyaudio. I think his last name is Dudek or something like that.
http://www.chipamp.com/docs/lm3886-manual.pdf

Speaking of Diyaudio there was a "indian" thread on dual 3886s I think I have it here...diyAudio Forums - PCB design of parallel of two inverted LM3886 with buffer and dc-servo.

You can contact Miracle Electronics for your torroid transformer (I am never gonna use the word tranny on this forum again). Miracle will make you a transformer with dual taps.

and lastly this tutouial with pics will show you how your amp can turn out.
LM3886 Stereo Amplifier
http://www.parttimeprojects.com/audi...newebpage.html
Single Chip 50W Stereo Amplifier (Elliot was one of the earlier "gain cloners").

hi navin,

yes the pa100 is taken from that website. sorry forgot to mention.

i already got 2 lm3886s, but i dont have a problem buying another 2 pairs of lm4780s. the design is quite simple to build.

i have read almost all the threads on lm3886 on diyaudio...lol

what my problem is rightnow is using the library in eagle.

thanks for the transformer.

clip

[navin]

Originally Posted by clipto333

what my problem is rightnow is using the library in eagle.

which lib and what is eagle? are you talking about gerber files?

[clipto333]

hi navin,

eagle is a program to design pcb and schematics.

can i convert a pdf inta a schematic?

navinji, what program do you use?


well actually im poor at using a pcb program. if anyone can help, please make me a schematic and pcb in eagle please please. people who are familiar with the software can do it realy quick IMO. please please do it for me. http://www.unisonus.com/pdf/lm4780_sch.pdf

Thanks alot.
expecting the sch and pcb design soon

cheers
clip

[navin]

Originally Posted by clipto333

hi
navinji, what program do you use?

http://www.unisonus.com/pdf/lm4780_sch.pdf

I used Spice. Now (last 15 years or so) I have others do this for me (for a fee). BTW that PDF has a PCB layout on the top righthand corner.

[clipto333]

hi,

just searched the market for a transformer, the guy is askig for aroud 1500 rs for a 24-0-25 300va el trans. i think its quite expensive. can anyone give an estimate for the above transformer?

i need to power 4 lm3886s(navinji im using the 3886 as i have 2 of them)

i have a few questions which ill post later.

cheers

clip

[low_bass_makker]

the 300 VA 24-0-24 or 25-0-25 or 24-0-25 step down would cost around 1200/- .........for 1500/- it is a bit on the higher side....is there any brand related to the transformer or just it is a local brand....I used to get GURU....they were quite good.....