LM3886/Vox SS Amp Thread(w/ Samples!)

[Joecool85]

Chipamp.com has that kit too.  Now, if I was to build that, wouldn't it give me 2 x 120w?  Is there anyway to get it bridged to get 1 x 240w?

[RDV]

Chipamp.com has that kit too.

Out Of Stock.

Now, if I was to build that, wouldn't it give me 2 x 120w? 

I suppose, or two separate 120w amps.

Is there anyway to get it bridged to get 1 x 240w?

You got me. Ask here.

RDV

[Joecool85]

Cool, you the man RDV.

The reason for all this isn't for me, but for my brother.  I'm planning on doing the lm3886 stereo kit for my guitar head, but my brother plays bass, and wants a beefy bass head.  He was kinda ok with 2 x 120, but would rather have it as 1 x 240 so that he could just play one big 4x10 or something.

Well, I put a message on diyaudio.com and I'll let you guys know what I figure out.  So far it seems really possible.  If I do construct this monstrous beast this summer, trust me, there will be plenty of pics on here for you guys to oogle at.

[RDV]

Cool, you the man RDV.

The reason for all this isn't for me, but for my brother.  I'm planning on doing the lm3886 stereo kit for my guitar head, but my brother plays bass, and wants a beefy bass head.  He was kinda ok with 2 x 120, but would rather have it as 1 x 240 so that he could just play one big 4x10 or something.

Well, I put a message on diyaudio.com and I'll let you guys know what I figure out.  So far it seems really possible.  If I do construct this monstrous beast this summer, trust me, there will be plenty of pics on here for you guys to oogle at.

Check this guys projects with chipamps, UNREAL!!

RDV

[RDV]

Welcome back!

I've ordered some LM4780s and a PCB to make a parallel version which with enough transformer should make at least 100 watts into 8 ohms. Maybe 120.

I'm sick. Somebody stop me.

I'll be making a sub amp with it to run one of my Peavey Black Widow 12"s. I'm afraid I'll have to find another toroid transformer cause my stereo amp I used one in sounds so good. I listen to recorded music again. I also drink again. Oh well.

I'm thinking eBay for the tranny this time cause $40.00 is a lot to drop at a time. I mean that'll buy at least 2 half gallons of good vodka.

I'm running the guitar amp one as a sub amp right now with a smaller Eminence 12" and it sounds pretty good, but I want to make the earth move with something else besides my footsteps.

Cheers.

RDV

[Joecool85]

It will yield 80 watts at 8 ohms and 100w at 4 ohms.  I talked to brian about it    I was going to buy a dual mono kit so that its the lm4780 chip running in parallel and then I was going to bridge both chips for a total of 200w!  It looks like I have no need for this anymore though since my brother is buying a bass head instead.  If you want more info, check this thread out: http://www.diyaudio.com/forums/showthread.php?s=&threadid=71502&perpage=10&highlight=&pagenumber=1

It should be easy enough and yield tons of power 

[RDV]

II talked to brian about it 

It's cool he returned your email. He returned one of mine and ignored the next. I guess he gets a lot of them.

RDV

[Joecool85]

Yeah, not only did he return the email, but then he got me on aim also, just to make sure if I had more questions I could ask!  What a guy!  I tell you, with all of my hobby endeavours as of late (pedals and amps), I've met a bunch of nice people online.

Did you check out about bridging both the lm4780 via DRV 134?

[RDV]

Did you check out about bridging both the lm4780 via DRV 134?

Yeah, but you gotta have a lot of transformer to make that happen the right way. Something that'll dim the lights when you turn it on, like 300va or over. Did you check that one link where the guy wired a 4780 up with just the pins. I LIKE that. I may do one like that just to see if I can.

RDV

[Joecool85]

Yeah haha.  I don't know if I'm that sure of myself to try that one.  Pretty neat though.  And 300va shouldn't dim the lights, I mean, thats pulling like 350watts or something, no biggie.  But yeah, it would be a little pricey...and huge.

[RDV]

More OT than ever!

I've taken a couple of crappy little 6.5" monitors that were given to me and bought nice replacement woofers and dome tweeters from Parts Express and now have a killer little pair of monitors! For less than $40.00 USD! The x-overs were already there and looked pretty decent. I just made sure and used the same impedance drivers so the response would be the same.

My next project will be a DIY 12" sub cabinet to go with the LM4780 amp I'll soon be building. Since I retired(semi) from every week gigging I actually enjoy listening to music now. I need to research how to make a good x-over for the sub.

I haven't been building pedals lately but at least this is electronics.

Computer sounding good!

RDV

[Joecool85]

Cool, thanks for the update.  And keep us posted on the lm4780 project.

[RDV]

I don't ask for much around here, but I'm asking now.

I need a simple 200Hz or so active crossover design that I can easily perf up with one dual op amp(I hope).
I've been reading a lot at the audiophile forums and at ESP and haven't really laid eyes on what I need.
I know I could go passive easily enough but I don't want to waste that much power.

I know I could(should?) post this at Diyaudio but I don't feel real comfy there.
I know there are some filtering experts here who won't BS me with audiophoolery.

Help! ...please.

RDV

[R.G.]

http://sound.westhost.com/project08.htm

[RDV]

http://sound.westhost.com/project08.htm

Thanks R.G.
I remember seeing that one. I just have seen so many the last few weeks it's been confusing.
I can just use the bottom half for a sub out, right? 300Hz would probably be a decent freq for this setup.
I'm using my near field monitors at full range which they seem to be fine with. They don't seem to distort so I was just going to use a one channel low pass x-over for the sub I'm building. I can use the 18vct or 30vct from one of those big transformers(The other being in the guitar amp of course) I bought. I'm going to be taking a bit of a chance hoping the 48vct @ 2A tap will run a paralleled LM4780. I'm not looking for a ton of power anyway.

Thanks again.

RDV

[Joecool85]

300hz is pretty high for most subs (to me).  Any regular 5" speaker can go that low, so I normally set my low passes to about 150hz or so.  Of course, thats for automotive subs, but I don't see as there would be much difference.

[RDV]

300hz is pretty high for most subs (to me).  Any regular 5" speaker can go that low, so I normally set my low passes to about 150hz or so.  Of course, thats for automotive subs, but I don't see as there would be much difference.

You're right but my little monitors aren't too efficient in that range. They produce it, but they're specialty is from about 500 on up(I bought cheap woofers). I'm going to socket the appropriate parts and the project tells you how to raise or lower the range, so I'm sure I'll experiment.

RDV

[RDV]

Based on the info in the project, will this work for 150Hz?


RDV

[Joecool85]

Looks good to me, but I would wait for a second opinion seeing as I haven't built anything like that yet.  Also, if your main speakers suck below 500hz (which is really bad lol, but cheap is good), depending on the sub, it should be fine around 250hz or so.  A lot of subs are rated for as high as a couple thousand hz, they just sound like garbage up there, and plus its a waste of power if your other speakers are already handling that.  If I was you, I would try 150, 250 and 500 or so and see what works best with your setup.  Afterall, its all about the overall sound, not just one piece.  So many car audio guys don't get that.  In one car I set up, the guy had 5 1/4" stock speakers in the back, so to get a nice even sound we had to set his 10" sub to around 225-250hz or so.  If you have some nice 6x9s you can normally turn your sub down between 80 and 100hz and get great overall sound.  Afterall, the purpose of a sub is to fill in the low end.  If the low end of your speakers is 200hz, you'll want to set your sub a little above that to get a good overlap, probably 250hz or so.

[RDV]

Right now I'm using a graphic EQ as my crossover(actually it's the graphic in my ancient Peavey Monitor head) with everything dumped except the 50 & 100Hz sliders and that works pretty well actually, so I'm thinking 150Hz might just be the ticket. I'll be using a pretty decent woofer for the sub, but not one of those 50lb. monsters. The one I'm using right now is overkill(a 12" Peavey Black Widow in my stage monitor), and it easily overblows the rest of the system.

RDV