any use for velodyne plate amps?

cowanrg · 2004-12-16 4:43 am

hey all. i have about 4 velodyne plate amps from their SPL series II subs. they are 1250 watts, 3000 peak. they do pretty well. however, they use accelerometers on the cones. without the accelerometer, they dont quite function correctly. is there a way to fake the input from the accelerometer, OR, where can i get a suitable accelerometer to attach to a cone.

with four of these things, im thinking of some rear-channel sub reinforcement maybe, or who knows... so, has anyone messed with these to know how to get them to work on their own?

troystg · 2004-12-16 7:11 pm

Hi cowanrg-

Most likely the accelerometer circuitry is not part of the actual amplifier circuitry. Try to find the tie point and separate them.

Also take a good, detailed picture of the PCB and I'm sure someone here can assist in finding that point.

cowanrg · 2004-12-16 11:31 pm

sounds good. ill get some pictures when i get home.

actually, iirc, the accelerometer is attached via a 6-pin cable to the main circuit board... i dont think there is any additional circuitry.

Stocker · 2004-12-17 12:23 am

The accelerometer plugs in somehow to the feedback loop of the amplifier, otherwise it wouldn't work. It *should* be possible to work around / otherwise remove the related circuitry while keeping the rest of the "normal" amplifier part.

cowanrg · 2004-12-17 6:42 am

ok, that makes enough sense.

ill just take some high-res pictures tomorrow and post them, and hopefully someone will have an idea.

we also got a driver in from velodyne, and it has an accelerometer attached. i will see if i can get pictures of that too.

cowanrg · 2004-12-19 9:20 pm

ive got some nice high res pics of both the driver and the plate amp, but my site is all messed up, so i can upload to it

ill have to fix that monday and get them uploaded.

thomas997 · 2004-12-19 11:44 pm

You can upload to www.imageshack.us too.

I have a velodyne sub with the same 6 pin cable going to the sub, really small wires too. But its no where near as powerful as yours.

mjarve · 2004-12-19 11:45 pm

If you want, I can put them on my site for the time being.

cowanrg · 2004-12-20 1:47 am

thanks, but ill see if i can get my site fixed tomorrow, then we'll see...

the pictures will be big, becuase there are a lot, dont want to clutter up anyone's website.

cowanrg · 2004-12-20 11:42 pm

got it all working (website). here are some pictures of the driver. pretty darn substantial, this is only a 10" driver. very very heavy.

http://www.cowanrg.mesanetworks.net/projects/images/velodyne/DSC00047.jpg

http://www.cowanrg.mesanetworks.net/projects/images/velodyne/DSC00048.jpg

http://www.cowanrg.mesanetworks.net/projects/images/velodyne/DSC00049.jpg

http://www.cowanrg.mesanetworks.net/projects/images/velodyne/DSC00052.jpg

http://www.cowanrg.mesanetworks.net/projects/images/velodyne/DSC00053.jpg

im going to take the amp apart and take some nice detailed pics of it. ill post those when im done.

johnnyx · 2004-12-21 12:10 am

Some guys have all the luck. You will be able to bypass the accelerometer feedback point, but if you can, it is probably better to try to draw the schematic from the PCB layout. I'd love to have a play with those!

thomas997 · 2004-12-21 12:12 am

Yeah those drivers weight about 5 tons..

I took the 15" out of the box once, damn surprised that the screws holding it in have even held up.

thanks for the pictures.

Stocker · 2004-12-21 12:41 am

If you have a Velodyne amp
And a Velodyne woofer...

Why not try to mate them, before modifying either?

cowanrg · 2004-12-21 1:13 am

Stocker,

the woofer isnt mine. its a defective one (i think) from our store. i cant use it

Stocker · 2004-12-21 3:37 am

hoo boy! looks like you have a project on your hands there!

I reverse-engineered a Klipsh plate amp and it took several weeks of spare time (note: YMMV, I have a wife, 2 kids and job! )

If I were you, I would go for what look to be the highest power transistors and go backwards from there, as it's probably the output stage of the amplifier. This means making a drawing of the PCB, with component layouts, and then drawing the connections. Find the datasheets of the components and make a schematic. Then do the same for the what-looks-to-be-the-preamp board if you want those features. I am guessing you will find a straightforward amplifier with a crazy preamp, but when you have made your own schematic, it will make sense what to do with it (if you understand the shcematic! )
Note: this is not what I advise you to do, for legality's sake, but it's what I would do, probably. I would advise against posting the schematic here, but there may be less chance of trouble if you emailed it to a select few experts...

Did you try just hooking it up to a regular speaker and seeing what happens?

cowanrg · 2004-12-21 4:24 am

ugh, i dont really want a project... an accelerometer would be the best thing... if that driver is a dud, ill bring it home, take it apart and see what the accelerometer looks like, maybe i can buy one somewhere else.

the amps all act pretty funny with just a regular driver. if i put just a meter on the amp with a signal, it LOOKS like its working. i have a little graph meter on my meter, and its going with the bass, like its responding to the signal. but with the driver, its really just noise.

they COULD be all broken, im not 100% sure either. they do power on though, so i have that at least going for me. the best way would be to just get an accelerometer and attach it to see if they work first...

Stocker,

i wish i had the knowledge to do what you "arent" proposing i do

im just not that good with this stuff yet. its not that i want someone to do all the work for me, i was just hoping someone maybe already DID the work, or someone has some simple ideas.

it appears like the smaller board with switches and such is the pre-amp board. however, it does have a transformer, some sort of rectifier, a regulator and some other stuff. not sure if that is just for itself or if it powers the amp in some way. the amp board is what actually connects to power though. so it may pass power to the preamp board, and it has its own power supply for the preamp functions.

however, the input goes into the pre-amp board, and the traces are so complicated, and it travels though IC's and such, its too hard to tell how it eventually comes out to the amp. if there was a way to just send an input straight to the amp without all the fancy xover stuff, that would be very cool. could be a simple amplifier for a sub (if you were using it with line-level xover, or active xover), and you could just use a simple pot for volume... BUT, that would be too simple.

if anyone has any ideas, let me know. i would also be willing to send one to someone if they think they could do something with it and share the wealth...

Stocker · 2004-12-21 5:14 am

Uh, hello? :bigeyes:

I would be happy to share the wealth with you by email if the wealth were a schematic on *MY* new Velodyne plate amp!

The possibility of getting the sensor to work with another (normal) driver seems remote, but making the amplifier work that I would be willing to try!

Note: I knew NOTHING about amplifiers before I started my poking around in this Klipsch over a year ago... and I am in process of designing one from scratch now!

How much is shipping to Austin for one of those amps?

Stocker · 2004-12-21 5:52 am

Hang on a second! I realized that the preamp looks pretty complex...Better not make promises I can't 100% guarantee to keep! How about some 98.5% promises:

I can almost certainly get a block diagram
If I can get datasheets on those ICs I can probably get you a schematic
I would be shocked :bigeyes:

and

disappointed with myself if I couldn't get you a workaround for the servo feedback!

cowanrg · 2004-12-21 7:20 am

well, there is no gaurentee that any of these work though... they all power on, but beyond that, im not sure how well they function.

yeah, to me that preamp looks very complex. looks like it even has a firmware chip on it? cant really tell. ill see if i can get that driver though to strip out the accelerometer.

just keep in mind i dont have much electronics knowledge at all, so it really wouldnt be "sharing" per se... more like giving of information

ill see what the deal is with that driver. shipping should only be like $10 to austin. if you can figure it out, i have a near unlimited supply of these things

Stocker · 2004-12-21 7:42 am

Uh, hehe, uhm....hehe, uh,

If you have a near unlimited supply, then it may take several examples to figure out how they work... teehee!

I guess I could swap knowledge for a few thousand watts of amplification... that's a trade to me! Or if you wanted some 2n4918s, 2n6039s, TL074s, LM324s or some small 12 and 30 turn potentiometers... prolly just want to know how to hook it up though eh? I was thinking it looks like a programmed chip there too but you never know till you (I? ) see one (or two! )

any use for velodyne plate amps?

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