This idea came to my mind, what if National create a new chipamp, with golden leads, internal feedback resistor and larger heatsink surface contact.
Even less external components.
Even less external components.
Peter Daniel said:
it doesn't matter as long as one can chose the other feedback resistor, 🙂
The "foundamental flow" in this design, from the "resistors sound different" crowd, is that a silicon based feedback resistor would be terrible.
Seriously, it is certainly doable, AD for example makes a high precision instrument amplifier with four laser-trimmed resistors embedded on the chip. It probably will make the chip more expensive and given the intended market for the chip (mass produced consumer audio?), I suspect it isn't economical to embed the resistor.
They could make a new family with various gains, or one with a fixed gain... maybe 220k ; 22k internal resistors.
It is just an idea, I think many diy´s here would love to play with them.
It is just an idea, I think many diy´s here would love to play with them.
From national's point of view, they have to be concerned about making money off this thing. How many of us would be willing to pay for such specialty chips? Aside from the fact that they are likely expensive.
Some TDA power op-amps have fixed gain, you have no way to chage it.
It's done internally.
More specifically, those that are made for car-audio, they work with single 12v supply.
It's done internally.
More specifically, those that are made for car-audio, they work with single 12v supply.
future said:
Inverted or non-inverted?
Serious power op-amps allow you to change the gain, and it's how it should always be.
But OFC copper or silver pins wold be nice.😉
it would suffer from terrible thermal induced gain distortion when the temperature of the die changes with load and frequency material=> affecting resistor value.
How much will of course depend on time constants, but I feel that for low frequency material it would be useless.
the A/D chips have ALL resistors on die , and power dissipation is much less also, giving a near constant temperature.
/rickard
How much will of course depend on time constants, but I feel that for low frequency material it would be useless.
the A/D chips have ALL resistors on die , and power dissipation is much less also, giving a near constant temperature.
/rickard
cm961 said:Carlosfm,
Which TDA chips are you talking about? I would like to do some experimenting....
Pete
This one, for instance:
http://www.semiconductors.philips.com/pip/TDA1554.html
My car amp, which I made some years ago, has two of these in bridge mode, for a total of 4x22w.
It has fixed gain.
It sounds very good, and it works with single 12v supply.
There are more powerful ones, but for me this is more than enough in my car.
I wouldn't bother to compare tese to the high-end LM chips, though.
But for car audio, TDAs are good.
Philips makes one that has 70w (single channel), and this from the 12v supply in your car!
- Status
- Not open for further replies.