Any chip amp to run on +/- 50V into 6 ohms?

jcx

Member
2003-02-17 7:38 pm
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TDA7293 is a possibility

the supply needs good regulation not the exceed the chip's 120 Vmax no load spec

and 6 Ohm, +/-50 Vs is so close to the power limit curve that I would parallel 2 chips - don't know if the master/slave is better/worse than paralleling 2x complete amp circuits with output current sharing R
 
A little mathematics would have told you how impractical this is.

There are chip drivers that require a discrete output buffer designed to work off this voltage.

Maybe this would be a solution for you. Yuan-Jing L12 TTA1943/TTC5200 Mono Power Amplifier Module 120 Watts I have a whole chassis, power supply, and heat sinks waiting for a couple of these boards. I can't build something like this that cheap. I can't vouch for quality or authenticity of the parts. I'm intrigued enough to roll the dice myself.
 
TDA7293 is a possibility

the supply needs good regulation not the exceed the chip's 120 Vmax no load spec

and 6 Ohm, +/-50 Vs is so close to the power limit curve that I would parallel 2 chips - don't know if the master/slave is better/worse than paralleling 2x complete amp circuits with output current sharing R

That is cutting it very close.

Isn't there a chip designed for paralleling? The chips can be tied together at a certain pin, if I remember.
 

wolf-audio

Member
2009-04-09 5:27 pm
The reason it needs to be a chip amp is for speaker protection, I'm living on $100-$150 dollars a month income and probably will be for the rest of my life, and can't risk blowing $800 dollar speakers that I'll never be able to replace. I know that there are discrete designs that are more suitable, but then theres no protection...
 
TDA7293 is a possibility

Um, no.

There are some Sanyo STK chips that could do this easily. For example:
http://www.bucek.name/pdf/stk4191v.pdf

In fact, if you want for the cost of shipping to you from CA a populated board for this chip, drop me a line. I have several. You will need to unsolder a lower power but identical footprint IC and replace it with this one. You may also need to change out some caps for a 63V rated version. A little bit of work (which I have done myself) but its free if you have the time to do it. For info, see:
http://www.diyaudio.com/forums/chip-amps/210482-using-hta-2000-2-ch-amp-diy.html?highlight=HTA-2000
 
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The reason it needs to be a chip amp is for speaker protection, I'm living on $100-$150 dollars a month income and probably will be for the rest of my life, and can't risk blowing $800 dollar speakers that I'll never be able to replace. I know that there are discrete designs that are more suitable, but then theres no protection...
It's not so.
If a chipamp blows, it will place 40/50V DC into your cherised speakers *destroying* them, period.
Exact same as a discrete amp.

What you need is a speaker DC protector, which may be included in the (discrete) amp board or added externally, search the Forum for examples.

In fact, you are trying to stretch the chipamps so much that you are *guaranteeing* failure , which will carry speaker destruction as a bonus.
 
The TDA7293 is a monolithic MOS power amplifier
which can be operated at 100V supply voltage
(120V with no signal applied) while delivering output
currents up to ±6.5 A.

Can be operated does not equate to should be operated...

If into 8 ohms or lower, you may require a very, very large heatsink with no insulating washer. You are operating extremely close to the power dissipation limit of the device at this voltage/load combination.

Even though the datasheet says it's possible doesn't mean it's practical. That is what I was implying in my "Um, no". For 8 ohms, operating from +/-40V rails is more realistic for this device IMHO.
 
The chipamps themselves run out of ability to dissipate heat. The amount of energy you have to move is related to the square of the absolute supply voltage.

Figure 11 of the TDA7293 datasheet seems to be operating a la "Class-H".

There are quite a few driver chip boards for HV, particularly for the LME49830 using IRFP240/9240 Hexfets on EBay. You could also use the Toshibas (2SK1530/2SJ201) but these are getting hard to find. If using Hitachi/Renesas (2SK1058/J162) note that the pin assignment differs from the others.
 

jcx

Member
2003-02-17 7:38 pm
..
I believe I did mention paralleling the TDA7293


but the general problem of good audio on a budget really doesn't include home built amps when working or easily repaired few year old mass market stuff can be had 2nd hand at fleas, even free at recycling centers

Geddes used a CostCo Pioneer Home Theater Amp for his multi $k each OS Loudspeaker demos

http://www.diyaudio.com/forums/soli...mplifier-studio-monitoring-2.html#post4483583
 
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After reading everyones input on the matter and finding out that there isn't dc speaker protection on the chip amps I think I'm going to just go with discrete amp and protection circuit, opens up more oportunities for power supplies, I have several, the +/- 50v was just the lowest voltage one and closest to chip amp range.
 
After reading everyones input on the matter and finding out that there isn't dc speaker protection on the chip amps I think I'm going to just go with discrete amp and protection circuit, opens up more oportunities for power supplies, I have several, the +/- 50v was just the lowest voltage one and closest to chip amp range.

I already lost one speaker to one of those STK modules. It didn't take long to cook the speaker.

With a 50 volt supply, you'll cook the speaker real good.

There are protection circuits that work with chip amp and discrete circuit alike. Many ebay offerings have the amp and protection circuit on one board. I can't vouch for quality, though.
 
I already lost one speaker to one of those STK modules. It didn't take long to cook the speaker.

With a 50 volt supply, you'll cook the speaker real good.

There are protection circuits that work with chip amp and discrete circuit alike. Many ebay offerings have the amp and protection circuit on one board. I can't vouch for quality, though.

Not so fast, Eddie! I've used STK chipamps in active speakers for years without a problem. They work pretty much exactly as described. I find the STK4191v (a dual amp package) very convenient for your basic 2-way active speaker. I run these from +/-40V rails into 8 ohm speakers.

There are many, many different "STK modules" by Sanyo with disparate performance capabilities so I find your comment overly-general. Must have had some bad luck there, or something.
 
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