I am currently undecided on which power op amp to use in my amp. I am looking at lm3886, lm3875, OPA 549, I have a couple of opa541's but I have seen no info regarding its use in audio. From a purely construction point of view I would like to use the TO-3 packs. I would appreciate any comments on the which power op amp is most suitable, and any specific info on the opa541 and its use in audio. I have +-35v unloaded supply @6A and a 2u rack case.
Hi!
2U case can held a good heatsink.
Why don´t you try the LM12?
You can bridge two of them and have about 160W with your PSU. Be carefull with the high temperature they can go!!
Don't be afraid, it turns off automaticaly if it gets very hot!
I like the LM3886, it has a good sound quality.
About the opa541, the TO3 - OPA541SM is better. It can go to more than 100ºC without blow up.
In audio applications, it has some THD. If you are using it as a subwoofer amplifier, it's ok.
Pedro Martins
2U case can held a good heatsink.
Why don´t you try the LM12?
You can bridge two of them and have about 160W with your PSU. Be carefull with the high temperature they can go!!
Don't be afraid, it turns off automaticaly if it gets very hot!
I like the LM3886, it has a good sound quality.
About the opa541, the TO3 - OPA541SM is better. It can go to more than 100ºC without blow up.
In audio applications, it has some THD. If you are using it as a subwoofer amplifier, it's ok.
Pedro Martins
You could also check Apex but I think they are a little bit expensive.
http://www.apexmicrotech.com/
http://www.apexmicrotech.com/
audioPT said:
I have considered LM12 but I cannot affoard it and its pretty hard to come by in ireland. Unless NSC has started doing samples on it again. I am leaning towards the lm3886. Unless there is something better out there. I would also like to hear from someone who has build a working opa541.
pundip said:
Yes, you are right.
In portugal a LM12 costs about 50€ 🙁 🙁
So, try the LM3886. it's cheaper and have goos results.
Anyone compared the ST’s TDA7293 and it's sister TDA7294 with a LM3875 by listening? I am considering the TDA7293 for a sub because it looks it can supply more current into a complex load.
😎
😎
Power OpAmps in Class A???
Just though about this...
I have heard of forcing regular opamps into Class A output by tieing a resistor or CCS to + or -.
Can this be done with a power opamp output stage?
Of course limited by internal heat dissapation....
TXS!
Just though about this...
I have heard of forcing regular opamps into Class A output by tieing a resistor or CCS to + or -.
Can this be done with a power opamp output stage?
Of course limited by internal heat dissapation....
TXS!
Pjotr said:
For sub - go with either TDA
For an example Hypex http://www.hypex.nl/ HS80 sub amp uses single TDA7294
Well, the lm3886 is popular right now but I sure see a lot of blown up ones. I fix pro audio and so much junk uses them. I wonder about their usage and dependability.
My opinion is that they are crap. I prefer STK packs but only use 8 Ohms or they will blow!!!!!
Either that or go descrete.
Chris
My opinion is that they are crap. I prefer STK packs but only use 8 Ohms or they will blow!!!!!
Either that or go descrete.
Chris
Diode said:
Or so I used to believe. I run a pair of STK 4191 in bridge mode, at 42 volt rails, into 4 ohm speakers at party levels (I didn't know better when I built them, about 7 years back) - and now I don't play them that loud, but still into 4 ohm loads (which for each half is 2 ohm, effectively).
But the whole thing has a thermo-fan (not from ESP, my own design using BD139 which is easier to secure onto heatsink, but I digress) and HUGE heatsinks, so I guess that I might be 'overclocking' the chips but they work, so what the heck.
Edit: BTW this is my experience only. YMMV and don't blame me for blown chips.
pundip said:
I'm currently working on a subwoofer amplifier using OPA541 in TO-3 package because of the same reason as yours. 🙂 So far, I have built active crossovers for both right and left channel using TL072 op-amps, and connected low-pass signal (below ~100 Hz) to OPA541. I used the schematic on Amp Chips DIY forum.
I don't have a subwoofer right now. But, I'm going to drive an 8" DVC subwoofer. All the parts are on the way. So, I should be able to describe how it sounds in a week or so.
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