So my amp has very low input sensitivity, and I need an op amp to amplify the line level signal to the amp by at least 10dB.
I don't really know anything about op amps, so I'd like to keep things simple.
Can anyone make a recommendation based on these requirements? Note, this is for an active setup, and it is only used for the woofer that is covering from 400Hz and below. I'm guessing things like noise isn't really a concern for the woofer band?
1. Stereo (yes, stereo, there are 2 woofers in each speaker and each woofer is filtered differently and needs a separate amp channel, and therefore a separate op amp)
2. At least 10dB of gain.
3. Can work with 17V DC power
4. No volume or tone controls
5. Preassembled PCB, uses raw wire instead of RCA jacks
6. Small, say under 60mm x 60mm. I can do long and thin too, such as 100mm x 30mm.
7. No mod needed
Cost is not a concern, so I'd like to buy a very high quality one without needing any mods. However, the performance of the preamp is actually the LOWEST priority on my requirements. The requirements 1-7 are musts, and they take priority over performance. I rather have something that has lesser performance than something I can't use at all. Something that misses any one of the 7 requirements means I can't use it at all. So, only when those 7 requirements are met, then performance is considered.
Thanks
I don't really know anything about op amps, so I'd like to keep things simple.
Can anyone make a recommendation based on these requirements? Note, this is for an active setup, and it is only used for the woofer that is covering from 400Hz and below. I'm guessing things like noise isn't really a concern for the woofer band?
1. Stereo (yes, stereo, there are 2 woofers in each speaker and each woofer is filtered differently and needs a separate amp channel, and therefore a separate op amp)
2. At least 10dB of gain.
3. Can work with 17V DC power
4. No volume or tone controls
5. Preassembled PCB, uses raw wire instead of RCA jacks
6. Small, say under 60mm x 60mm. I can do long and thin too, such as 100mm x 30mm.
7. No mod needed
Cost is not a concern, so I'd like to buy a very high quality one without needing any mods. However, the performance of the preamp is actually the LOWEST priority on my requirements. The requirements 1-7 are musts, and they take priority over performance. I rather have something that has lesser performance than something I can't use at all. Something that misses any one of the 7 requirements means I can't use it at all. So, only when those 7 requirements are met, then performance is considered.
Thanks
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I have some PCBs for what you need. The PCB size is around 3x4 cm. Just look in my signature. I can easily assemble one for you since it is really simple. All my PCBs are designed for dual polarity power supply which may be a problem since you seems to require a single polarity operation which implies coupling capacitors on the gain stage input and output. As for the op-amps to use, it is usually a matter of personal preference when it comes to advice for a particular type/brand/model. The top pic does not always correspond to the best datasheet performance.
Regards,
Oleg
Regards,
Oleg
Yes it will be placed inside a very small speaker, and the amplifier is inside the speaker too.
17V because that's the voltage output on the aux power on the amp. I want to avoid adding a power supply just for the op amp and just use the one on my amp to reduce complexity.
I don't know what you mean by symmetrical signals. Can you explain?
Best possible because the parts are just a few dollars, compared to the cost of drivers this is nothing. I don't mind spending more when the cost is so small to ensure I get optimal performance. I don't want to buy some cheap board then needing to mod it. I don't have the time to do that or to learn this stuff well because it is just an unexpected problem that came up, so I have no problem spending even $100 for the 4 channels of op amp I need if it means getting excellent performance for little effort. And yes, the chain is very good.
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Has/needs it xlr or chinch(rca) connectors?
I read it is icepower, do you know model nummer or output power?
Icepower has + and - Voltage at the aux connector as i know.
Most icepower amps need preamp as you ask for. Simple lm4562 will work very good.
Ronny
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The amp takes a balanced input, but I am using RCA connectors. I looked at the manual for the amp, and there are specs for position and negative analog auxiliary supply output voltage. This must mean it has + and - voltage.
Oh also I need to mention, even though I'm looking for a high quality op amp and cost is not a concern, the quality of the preamp is actually the LOWEST priority on my requirements. The requirements 1-7 are musts, and they take priority over performance. I rather have something that has lesser performance than something I can't use at all. Something that misses any one of the 7 basic requirements means I can't use it at all. So, only when the basic requirements are met, then performance is considered.
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Also forgot to mention, this is for an active setup, and it is only used for the woofer that is covering from 400Hz and below. 16W per channel is enough drive the midrange and tweeter to their limits without a preamp. I'm guessing things like noise isn't really a concern for the woofer band?
Even though it is for the woofer band, I need a stereo op amp. There are 2 woofers, and each woofer needs its own op amp because each woofer is filtered differently on the DSP, so 2 channels of amplification is needed, one for each woofer.
Even though it is for the woofer band, I need a stereo op amp. There are 2 woofers, and each woofer needs its own op amp because each woofer is filtered differently on the DSP, so 2 channels of amplification is needed, one for each woofer.
Before I ask Olegsh for a board, would something like this NE5532 work for my purposes?
NE5532 Dynamic Microphone Stereo Preamp Amplifier Board DIY DC9-24V AC8-16V New
NE5532 Dynamic Microphone Stereo Preamp Amplifier Board DIY DC9-24V AC8-16V New
It need a little modification, the gain will be around 200 times.
You need to change 1 resistor a channel for 3 times gain.
That mic preamp is two channels. So one PCB does both of the woofer channels in your active speaker.
The gain needs to be reduced from 200times to between 3times and 4times.
The gain setting resistors are SMD. You may need help to change the SMDs.
The power input is AC, but you can connect DC to this and the on board rectifier bridge will route the DC to the correct power pins.
Being a mic input stage it will probably be low enough noise to suit your duty after lowering the gain.
It has the option to swap to a different DUAL opamp in DIP8 package.
The gain needs to be reduced from 200times to between 3times and 4times.
The gain setting resistors are SMD. You may need help to change the SMDs.
The power input is AC, but you can connect DC to this and the on board rectifier bridge will route the DC to the correct power pins.
Being a mic input stage it will probably be low enough noise to suit your duty after lowering the gain.
It has the option to swap to a different DUAL opamp in DIP8 package.
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