I'm working on an AMB headphone amplifier.
Pretty sure the opa627 opamps have failed.
These opamps are nla, at least in the quantities I need.
Can anyone suggest a drop in replacement ?
8 pin DIP package.
Ta.
Pretty sure the opa627 opamps have failed.
These opamps are nla, at least in the quantities I need.
Can anyone suggest a drop in replacement ?
8 pin DIP package.
Ta.
Mouser offers it as a SMD device. You'd have to build or buy adaptor boards. Or you buy the even more $$$ TO metal can version.
Best regards!
Best regards!
The OPA627 Product Details page on Texas Instruments' website suggests a compatible replacement, see below. T.I. also provide a side-by-side comparison table (here) . If you prefer to use an actual OPA627 in SMD package, but are unwilling or unable to solder an SOIC-to-DIP adapter yourself, I would be happy to solder it for you, free of charge. You only pay the round trip shipping fees. Send me the ICs, the SOIC-to-DIP adapter PCBs, and the thru-hole "legs" which fit your adapter boards. I'll solder them together and test them to verify they work, then send back to you. Send PM when you've got everything together and ready to ship.
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Did not check the datasheet but it's likely the smd version has lower max dissipation. If the opamp drives the headphone directly that can be a problem so better check this.
Rochester Electronics claims to have 41K of the PDIP in stock. Min order of 7 pcs. I've used them before and they are legit. I would pretty much guarantee that anything from eBay, ali, etc. would be a fake.
The SOIC8 from Mouser, etc. would be your best bet. I would recommend the Aries SOIC8-PDIP8 adapters (LCTQ-SOIC8) unless you can work out a deal with stellavox.
The SOIC8 from Mouser, etc. would be your best bet. I would recommend the Aries SOIC8-PDIP8 adapters (LCTQ-SOIC8) unless you can work out a deal with stellavox.
For the OPA627 Junction to ambient for the DIL8 package is 46.2C/W and for the SOIC is 107.9C/W
But you can parallel them up with commoning resistors of a few ohms. With the NE5532 you can parallel dozens and drive speakers with them.
But you can parallel them up with commoning resistors of a few ohms. With the NE5532 you can parallel dozens and drive speakers with them.
Thank you to all for the suggestions and major offers of help.
I've seen all the options of 'bulk' buys through partner stores etc. Rather more $$ than I believe the owner will pay. Possibly more than what this thing is worth.
ebay, ohhhh no, I prefer proper channels for all my parts 🙂
This device has mosfets driving the output so I'm thinking the load on the opamps will be very low. irf9z34 / irfz24. 55v 17amp devices.
Doing the smd adaptor boards with smd versions isn't an issue for me at all.
I was just hoping for a plug in option.
I'm not too concerned about how it will sound compared to the correct opamps. A slightly lower quality device would be ok for me.
Gent got it second hand and it never worked, so we have no idea how it 'should' sound to start with.
There's no markings on the case at all. but the pcb has amb m3 screened on it. I haven't looked it up so no idea if it's good or not 🙂
Guess I'll price up a smd adaptor with opa828 and see what the owner wants to do..
Edit.
Ahhhhhhhhh always look for the obvious = me lazy.
Just did something I should've started with.
Voltage to the board is 24vdc.
Voltage supply at the opamps is 3vdc. Yes across pins 4 and 7.
Stated range is 9-36vdc.
Somehow I think I need to look into the power supply to the opamps 😛
I've seen all the options of 'bulk' buys through partner stores etc. Rather more $$ than I believe the owner will pay. Possibly more than what this thing is worth.
ebay, ohhhh no, I prefer proper channels for all my parts 🙂
This device has mosfets driving the output so I'm thinking the load on the opamps will be very low. irf9z34 / irfz24. 55v 17amp devices.
Doing the smd adaptor boards with smd versions isn't an issue for me at all.
I was just hoping for a plug in option.
I'm not too concerned about how it will sound compared to the correct opamps. A slightly lower quality device would be ok for me.
Gent got it second hand and it never worked, so we have no idea how it 'should' sound to start with.
There's no markings on the case at all. but the pcb has amb m3 screened on it. I haven't looked it up so no idea if it's good or not 🙂
Guess I'll price up a smd adaptor with opa828 and see what the owner wants to do..
Edit.
Ahhhhhhhhh always look for the obvious = me lazy.
Just did something I should've started with.
Voltage to the board is 24vdc.
Voltage supply at the opamps is 3vdc. Yes across pins 4 and 7.
Stated range is 9-36vdc.
Somehow I think I need to look into the power supply to the opamps 😛
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Amb has lots of other opamps that are recommended, and Amb's stuff is generally pretty good.
https://www.amb.org/audio/mmm/
https://www.amb.org/audio/mmm/
digikey has NE5534AP https://www.digikey.com/en/products/detail/texas-instruments/NE5534P/378265
same pinout, May take a little more rail current. Surely dinking with the regulator diode & resistor would be easier than a soic adapter.
same pinout, May take a little more rail current. Surely dinking with the regulator diode & resistor would be easier than a soic adapter.
I may be stupid here , but TI states that the OPA827 has rail to rail output ?
https://www.ti.com/compare-products...ernate-gpn&partList=OPA627,OPA828&sticky=true
Figure 6-18 & 6-19 , says no. But I maybe wrong .
https://www.ti.com/lit/ds/symlink/o...l=https%3A%2F%2Fwww.ti.com%2Fproduct%2FOPA828
Feel free to make your own substitutions if you don't like the ones suggested by Texas Instruments.
OPA627 doesn't have rail to rail either. It is not about liking it, TI's suggestion is valid , but I just wonder about them writing rail output.
I have used both opamps .
I have used both opamps .
Hi RickTH
There was an error in the model number in your post, and at first I thought you were claiming that "OPA627 is not rail-to-rail, but TI says it is."
I was a little confused, but I guess you meant to say that OPA828 isn't actually rail-to-rail.
I have posted the confirmation results here.
Thanks for letting me know.
There was an error in the model number in your post, and at first I thought you were claiming that "OPA627 is not rail-to-rail, but TI says it is."
I was a little confused, but I guess you meant to say that OPA828 isn't actually rail-to-rail.
I have posted the confirmation results here.
Thanks for letting me know.
Yes sorry , I meant the OPA828 of course . With 627 and 828 and there is an 827 too , an easy error. Now I kinda understand Mark J's post.
But in the TI comparison is an error too . OPA 828 is not rail to rail . That is why I kept it on 2 x 15 V instead of 2 x 12V to keep the chip cooler.
Thanks for the correction and confirmation.
But in the TI comparison is an error too . OPA 828 is not rail to rail . That is why I kept it on 2 x 15 V instead of 2 x 12V to keep the chip cooler.
Thanks for the correction and confirmation.
An opamp cannot possibly do rail to rail. There are at least voltage drops in the drivers, Vce(sat) in the output pair, and a further drop in the emitter resistors of the output pair. So you ultimately be limited to at least 2V between voltage rails and peak output voltage. So for example if the rails are +/-15V the maximum output swing will be +/-13V or very close.