Chip amp for 58vdc

srinath

Member
2010-02-12 4:09 pm
I have a dead power amp that I am thinking of re purposing to be a chip amp housing.

The cool thing is it has controls and power meters all run out of separate boards etc.

The thing has a 57-58 vdc supply. Is there a chip amp that would use that sort of voltage ?

Thanks.
Srinath.
 
Is that 58 V measured from + to - rail, or from each rail to ground? No chipamp that I know of can handle +/-58 V.

National (TI) makes a driver IC, which requires separate output transistors plus a handful of other components, lme49810. That may be as close to a chipamp as you will get on +/- 58 V rails.

There are several Sanyo STK series chip amps that can handle +/-58V DC rails...

If you design requirement is for 100+ Watts but don't need ultra low distortion those would fit the bill nicely. Some even have pretty low distortion figures, like the STK4048XI:
http://www.pablin.com.ar/electron/circuito/audio/amp205/stk4048XI.pdf

-Charlie
 
I don't know if the STK series should really be rated that highly. They are after all discontinued, a bit bulky, and they predate the still not complete acceptance of chip amps within hi fi. They are also near impossible to re-source if something goes wrong.

How about unwinding one of your transformers a touch and bringing it down to a more reasonable voltage? Or using them as an original power supply for a regulator (though even then that's a fair voltage drop). You will of course end up with an even lower impedance transformer and something that probably has a higher Va rating than you could normally purchase.
 

Mihkus

Member
2012-07-22 8:01 pm
Arguing about output voltage and builing amplifier that suits the power supply...

WTF you can rewind it cant you?
Even if transformer is welded you can grind the welds down and still take it appart and put i together as the small transformers are.

Then you find the chipamp you would like to hear.
 
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srinath

Member
2010-02-12 4:09 pm
Rewind the transformer ...

Arguing about output voltage and builing amplifier that suits the power supply...

WTF you can rewind it cant you?
Even if transformer is welded you can grind the welds down and still take it appart and put i together as the small transformers are.

Then you find the chipamp you would like to hear.

I really cant rewind the trafo. However - I have dead amps in many voltage ranges.
I also have a +/-38vdc - which I know is an easier fit. This amp and chassis etc are beautiful, power meters etc etc ... I want to use that if I can.

Cool.
Srinath.
 

srinath

Member
2010-02-12 4:09 pm
That is 60v and it needs 500 watt, my power supply can barely consume that, 400 max IMHO.
Now I think I can do a mono - cos I could use a big subwoofer amp, but then I'll kill the power meters etc. maybe mine is 500 watts - not 500va - let me look.
Thanks.
Srinath.
 
That is 60v and it needs 500 watt, my power supply can barely consume that, 400 max IMHO.
Now I think I can do a mono - cos I could use a big subwoofer amp, but then I'll kill the power meters etc. maybe mine is 500 watts - not 500va - let me look.
Thanks.
Srinath.

I think I would focus on finding an amplifier that can handle the rail voltages that your transformer will generate. You are correct to think about the load, however, I assume you will be using the amp for music. In that case, the average current draw will be much less than the "full power" current, at least 10 times less probably. You can therefore use a smaller VA rated transformer, if you keep in mind that the peak power can not be sustained for more than short bursts (because the PS voltage will quickly sag).

I suggest that you take another look at the class-D amplifiers.

-Charlie
 
Build this one.
Feed it your +/-58V and in that case you can use just 2 pairs per side, 3 if you want to play it real safe.
http://www.diyaudio.com/forums/solid-state/164208-500w-pa-amplifier-limiter.html

Or this one.
Read the thread on how to adapt the basic circuit to different PSU and output power
http://www.diyaudio.com/forums/solid-state/167394-quasi-amplifier-beginners.html

Both projects have successfully been built by many, offer PCB layout and the Forums are there for you to clear your doubts.