Cimarron has the 1641 in SOIC-8
OPA1641AIDR Texas Instruments - Cimarron Technology
They can also mount SOIC-8 on a DIP-8 adapter. 1641 is one of their many options.
SOIC-8 to 8-pin DIP Adapter - 970601 - Cimarron Technology
Cimarron Technology customer list:
Customer List - Cimarron Technology
CAGE Code is 8BVA0 DUNS number is 012113139
I usually pad my Mouser orders with a couple of OPA1656's and/or OPA1641. They are always in stock, and I always have a buffer.
I don't understand all the panic.
Jan
I don't understand all the panic.
Jan
No stock at Mouser for the 1641 in SOIC-8.
The OP's requirement is single in SOIC-8 or DIP-8.
Duals won't work. Existing PCBs - one or the other.
The OP's requirement is single in SOIC-8 or DIP-8.
Duals won't work. Existing PCBs - one or the other.
You guys must have a different Mouser then we. I just ordered some today.
Edit - I see, you want the SOIC. Ok yes that's in short supply.
Jan
Edit - I see, you want the SOIC. Ok yes that's in short supply.
Jan
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Jan,
Some of us need a bit larger quantity. This week of assorted ICs I use to make my microphones I bought 35,000 pieces. I could use another 25,000 of just the OPA1692. One source lists more than that as stock, but they don’t respond to an inquiry.
Some folks are selling small quantities at wee bit high prices.
In quantity some of the op amps I might substitute are $.057 and others $.09. But for the first stages of my gizmo it is around $.74 per unit.
I did offer free parts to others a while back from my extra junk lying around. Didn’t get many takers who actually have little access to parts.
Some of us need a bit larger quantity. This week of assorted ICs I use to make my microphones I bought 35,000 pieces. I could use another 25,000 of just the OPA1692. One source lists more than that as stock, but they don’t respond to an inquiry.
Some folks are selling small quantities at wee bit high prices.
In quantity some of the op amps I might substitute are $.057 and others $.09. But for the first stages of my gizmo it is around $.74 per unit.
I did offer free parts to others a while back from my extra junk lying around. Didn’t get many takers who actually have little access to parts.
Hi Ed, yes I realize you're a mass buyer. Still, the prospect to build - and sell! - 35,000 mikes is, well, interesting.
But I guess the average audiophile here building a phone amp, a dozen opamps will carry the project trough a couple of prototypes.
I saw your offer of free parts, but they were not specified. Most of us have been in the experience that a 'friend' comes over with stuff they don't need and put you in the awkward position to show gratitude while racking our brain how to get rid of it ;-)
Not that your stuff would not be valuable, I think you and Nelson are some of the very few here that give away really good stuff, just because you can and because you're nice guys!
Jan
But I guess the average audiophile here building a phone amp, a dozen opamps will carry the project trough a couple of prototypes.
I saw your offer of free parts, but they were not specified. Most of us have been in the experience that a 'friend' comes over with stuff they don't need and put you in the awkward position to show gratitude while racking our brain how to get rid of it ;-)
Not that your stuff would not be valuable, I think you and Nelson are some of the very few here that give away really good stuff, just because you can and because you're nice guys!
Jan
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Jan,
Five ICs per microphone for 80% of the units sold. The rest are simpler and only use two.
As for free parts I tried to give folks the stuff they asked for, but didn’t always have what they wanted. Some got PCBs and most of the parts and a schematic. Some did ask for stuff I have never used.
Five ICs per microphone for 80% of the units sold. The rest are simpler and only use two.
As for free parts I tried to give folks the stuff they asked for, but didn’t always have what they wanted. Some got PCBs and most of the parts and a schematic. Some did ask for stuff I have never used.
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Hi all !
As the open loop output impedance shows, OPA1656 appears to have an output stage similar to OPA1611 (2) which is involved with partial driving current.
He is interested in how such an operational, with 150db open loop amplification, has a small ringing at an amplification of (-) 1. This OPA uses multiple compensations to control the unit amplification.
However, as shown in figure 6 closed-loop gain vs frequency (see amplification at 20db) this operational seems to "like" large amplifications, over 30db! Under these conditions, in many of the usual applications that require a 1x ... 2x amplification, the so-called noise gain artifice must be used. And the noise of this op am is to be taken into account, being higher than operational such as OPA828 (see in the range 0.1hz to 10hz)
I'm sorry for ... google english! 🙂
As the open loop output impedance shows, OPA1656 appears to have an output stage similar to OPA1611 (2) which is involved with partial driving current.
He is interested in how such an operational, with 150db open loop amplification, has a small ringing at an amplification of (-) 1. This OPA uses multiple compensations to control the unit amplification.
However, as shown in figure 6 closed-loop gain vs frequency (see amplification at 20db) this operational seems to "like" large amplifications, over 30db! Under these conditions, in many of the usual applications that require a 1x ... 2x amplification, the so-called noise gain artifice must be used. And the noise of this op am is to be taken into account, being higher than operational such as OPA828 (see in the range 0.1hz to 10hz)
I'm sorry for ... google english! 🙂
... and on top of good specs, it does sound very good in all audio applications I used it for.
That is mainly RIAA (output stage), preamp, portable HP amp, DAC output stage, all in various units with various (audio = lowish, from 1 to 20 or so) gains and with various in and output impedances... next try will be unitary gain inverting stage between a pot and B1K
Amazing little AOP for many uses, even withstanding my abuses...
Claude
That is mainly RIAA (output stage), preamp, portable HP amp, DAC output stage, all in various units with various (audio = lowish, from 1 to 20 or so) gains and with various in and output impedances... next try will be unitary gain inverting stage between a pot and B1K
Amazing little AOP for many uses, even withstanding my abuses...
Claude
Dear Johnc124,
Thank You very much for really impressive OPA1656 and useful information presented here. Can You tell us how is THD measured? For instance Fig.12. 1 kHz FFT from data sheet shows harmonics below -160 dB. Such measurement requires a signal source with better than 170 dB purity and an AD converter with similar distortion. I think direct measurement is impossible, is there any clever trick?
Vojtech
Thank You very much for really impressive OPA1656 and useful information presented here. Can You tell us how is THD measured? For instance Fig.12. 1 kHz FFT from data sheet shows harmonics below -160 dB. Such measurement requires a signal source with better than 170 dB purity and an AD converter with similar distortion. I think direct measurement is impossible, is there any clever trick?
Vojtech
I know the above mentioned trick, but Fig. 12 shows the whole spectrum with SFDR higher than 160 dB and noise floor around -170 dBc and I am not sure that it can be obtained by this approach.
A couple of things:
1. The OPA1655 (single channel version) released yesterday: https://www.ti.com/product/OPA1655 , units should be in-stock on ti.com in the next couple of days. The datasheet is now updated with the single channel as well.
2. THD was measured using an APx555, the distortion gain configuration mentioned, and some custom software from our validation team as well.
1. The OPA1655 (single channel version) released yesterday: https://www.ti.com/product/OPA1655 , units should be in-stock on ti.com in the next couple of days. The datasheet is now updated with the single channel as well.
2. THD was measured using an APx555, the distortion gain configuration mentioned, and some custom software from our validation team as well.
Hi John,
Many thanks for your kind post and... for being still present here on the forum despite the very busy schedule you surely have.
2 short questions:
1- Is there any change regarding sonic signatures between OPA1655 and OPA1656? I mean, while sticking well within the capabilities of each chip, would one notice any difference soundwise replacing an OPA1656 with 2 OPA1655?
2- Should point 1 not really be easy to answer or say not yet have been addressed, will there be as in the past the possibility for us to get a reasonably small number of samples... to try to address point 1 by ourselves?
Many thanks again for all what you are doing
Claude
Many thanks for your kind post and... for being still present here on the forum despite the very busy schedule you surely have.
2 short questions:
1- Is there any change regarding sonic signatures between OPA1655 and OPA1656? I mean, while sticking well within the capabilities of each chip, would one notice any difference soundwise replacing an OPA1656 with 2 OPA1655?
2- Should point 1 not really be easy to answer or say not yet have been addressed, will there be as in the past the possibility for us to get a reasonably small number of samples... to try to address point 1 by ourselves?
Many thanks again for all what you are doing
Claude
Claude,
No changes have been made to the amplifier. For consistency sake we always try to make the different channel variants of an amplifier as identical to each other as possible. When there are (measurable) differences between the variants we add information to the electrical characterization table in the datasheet. The only difference between the 1655 and 1656 is that the second amplifier has been removed from the die of the OPA1655. Whether that results in auditory differences, I'll leave to the listener to decide 🙂 And yes, samples should be available here in a day or two once the stock becomes visible on ti.com.
No changes have been made to the amplifier. For consistency sake we always try to make the different channel variants of an amplifier as identical to each other as possible. When there are (measurable) differences between the variants we add information to the electrical characterization table in the datasheet. The only difference between the 1655 and 1656 is that the second amplifier has been removed from the die of the OPA1655. Whether that results in auditory differences, I'll leave to the listener to decide 🙂 And yes, samples should be available here in a day or two once the stock becomes visible on ti.com.
Thank you very much Johnc124!!! It was a long wait, but well worth!!! Just ordered some samples to play with them on a Condenser Mic Project 🙂