Converting Carver Sunfire True Sub..

[Sm88]

I have a Sunfire True Sub Super Junior which unfortunately has a blown amplifier, the internal fuse blew but it looks as if there is significant burn damage to the components (one resistor is essentially melted, big char area as well).

Contacted Carver about repair and it would run upwards of $400 if even possible, which is roughly what the thing is worth in working condition. What I would like to do instead of reattach the amp panel (to create a seal) but convert it to passive.

I'm not entirely sure, but would this be correct:
Disconnect everything in the amp
Wire the driver leads to one of the sets of binding posts directly
Obtain a crossover with volume control (Paradigm X30 perhaps) and connect between preamp and external amplifier. (Or do I need this if my processor can crossover?)

Any ideas would be appreciated, i'm mostly playing around with the idea for right now. Thanks!

 

[richie00boy]

Worth a shot, but I wouldn't be surprised if the sub uses some tailored EQ to get the response down a bit.

Maybe you can use the line level stuff by disconnecting the amp parts. A bit clunky but you could route the signal back out to an external amp.

 

[Sm88]

An externally hosted image should be here but it was not working when we last tested it.

This is the board

 

[east electronics]

another drawback could be the woofer's resistance ....since the carver amp is almost class Ddont be surprized if you find it 1 or 2 ohms or so ...

that can be a serious complication since normal class AB cannot drive that low load

kind regards sakis

 

[Sm88]

Thanks, didn't consider that. I'm not going to risk my McIntosh on it. But I just so happen to have a broken Nakamichi PA5 which is a Nelson Pass Stasis amp, only one channel is working, which might be perfect. I know it is a very well built amp, but would you happen to know if it is stable to low impedances?

 

[Trevor White]

I believe it uses Carvers tracking down converter to improve amplifier efficiency. You'll need about 1000 watts to get the same volume out of it.

You'd be better off trying to fix it if you can. I don't believe that the amplifier is isolated from the mains connection either so be careful.

 

[454Casull]

I believe it uses Carvers tracking down converter to improve amplifier efficiency. You'll need about 1000 watts to get the same volume out of it.

Are you talking about output power or wall draw?

 

[Sm88]

As far as I am aware the tracking down converter is essentially Carver's term for Class D (or close enough). From what I understand, the amp in the Sunfire is 100w RMS, peaks don't count. Also the person at the carver shop I wrote mentioned the driver should measure between 3.6 and 4.3 ohms impedance or something along those lines. The lack of isolation might be worry-some.

 

[richie00boy]

I'd be willing to bet a fair sum of money that far more than 100W is used in that sub.

 

[djk]

It has 2.4KW peak on tap, and a very fancy circuit.

http://www.google.com/patents?id=XoYfAAAAEBAJ&printsec=abstract&zoom=4#v=onepage&q&f=false

http://www.google.com/patents?id=uXMOAAAAEBAJ&printsec=abstract&zoom=4#v=onepage&q&f=false

They offer a flat rate repair for most of their gear that is quite reasonable.

 

[tb46]

Hi djk,

Neat links, now all we need is a service manual. 🙂

http://www.thecarversite.com/manuals/files-manuals/Sunfire Downconverter.pdf

Regards.

 

[east electronics]

It has 2.4KW peak on tap, and a very fancy circuit.

High power audio subwoofer - Google Patent Search

High back-EMF high pressure ... - Google Patent Search

They offer a flat rate repair for most of their gear that is quite reasonable.

i will agree with djk since most of this equipment is smd and smt and means that beyond a certain damage i might require that all pcb replaced ...of course that will be costy ...

 

[Trevor White]

Are you talking about output power or wall draw?

output power.