Pardon the new thread, all I could find were posts dated 2012. That's an eternity based on Moore's Law.
Building an audio widget that will be powered by a single 9V battery supply. Obviously want to reduce battery drain as much as reasonably possible.
Have been looking at the TI, Linear, Signetics web sites... too many choices! Probably any of the low-power rail-rail choices would work fine in an audio application.
Question: has anybody had any recent experience with a low-power op-amp for audio? Say 1mA or less, per amp?
Building an audio widget that will be powered by a single 9V battery supply. Obviously want to reduce battery drain as much as reasonably possible.
Have been looking at the TI, Linear, Signetics web sites... too many choices! Probably any of the low-power rail-rail choices would work fine in an audio application.
Question: has anybody had any recent experience with a low-power op-amp for audio? Say 1mA or less, per amp?
It's not immediately coming to mind, but (IIRC) there's a family of low-power, single rail OnSemi opamps that Zap'n'Spark has used in his mic preamp designs. If not on DiyAudio, check the micbuilders yahoo forum.
Sorry that's vague, but I hope it helps somewhat!
Sorry that's vague, but I hope it helps somewhat!
MC34182. Its not rail-to-rail though and don't ask it to drive much current. Hard to beat just 210uA though.
The TI TLV2370/1/4 is very good, 2.7to 16V, rail to rail in and out, 3MHz GBW, 500uA per amplifier and it drives 600 Ohms
ADA4805 may be worth a look, possibly OP262 but it's not the best for linearity.
TI's OPA parts offer excellent performance and a number have Iq of 2mA or below if there's some flexibility on the 1mA requirement. OPA1662 in particular; 1.5mA typ.
low power audio opamp (rail-to-rail) : the best choice is probably
OPA1662 (BJT) - 1.5mA
OPA1642 (JFET) - 1,8mA
OPA1662 (BJT) - 1.5mA
OPA1642 (JFET) - 1,8mA
Muse 8832 , design for low power < 7V.
But I have not try it yet.
MUSES8832,MUSES8832E,MUSES8832VA3 ( Rail-to-Rail Output, High Quality Audio,Dual Operational Amplifier ) | MUSES Official Website
But I have not try it yet.
MUSES8832,MUSES8832E,MUSES8832VA3 ( Rail-to-Rail Output, High Quality Audio,Dual Operational Amplifier ) | MUSES Official Website
The 7-9mA typ of NJR's Muse series (7.5 for the 8832) is some ways from low power. The ±7V supply limit of the 8832 doesn't meet the OP's requirements either.
I think current is important for audio. But when low current is a must (e.g. for portable audio), the MUSES mentioned previously is known to be used in expensive sound cards.
Certainly adding MUSES silicon is a highly effective way to increase the BOM cost. But soundcards really don't need to be particularly expensive for engineering reasons, only for marketing ones.
Many sound cards or computer devices only provide the common 5V supply used by the digital circuitry. If they want to use NE5532, they have to provide dedicated higher voltage power supply. If they have to stick with 5V supply, they either have to use the bloody 4558 or use expensive opamps.
That's why many soundcards use high quality DAC chips but degrade the overall performance with 4558
My Asus Essence ST card uses a 12V feed from the ATX PSU, no limitation of 5V there. Whilst I would agree that the 4558 is probably the cheapest opamp known to man, there's a huge choice of parts available before the extremes of MUSES. Providing a dedicated -5V rail also is far from expensive with the likes of ICL7660.
Yes, my point was that the common voltage (5V and 12V) is below the +/-7 volt many opamps are limited to as its minimum supply voltage. And we are talking about PCI slot (where the cards are designed to work with) here.
There are most probably many low voltage opamps out there, but I'm not sure if the spec is suitable, or better than 4558. Usually I just use 4562, which is also expensive, but very common so I can have them without online purchasing.
I have a stalled project to transform the power supply of my audio server into analog (at least for the analog circuitry).
My advice to the OP, which has access to online purchase, is to browse the vendor database for the low power opamps and specify/filter the key specifications needed for good sound. May be he needs help regarding what specification to look into (e.g. minimum slew rate of 6V/uS, etc.)
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