TPA3251d2

[kevinr]

OPA627AU

I just received the OPA 627AU IC's and installed them in my Aiyima 04 place of the stock 5332.
Volume level dropped by quite a bit , almost half .
Is this typical for this IC swap ?

 

[ClaudeG]

Nope!

Often in that case one of the pins is not making a good contact

If the adapter board isn't rock stable in the socket, try to rock it slightly or push it further down if not inserted properly.

They should be NO volume loss at all, gain structure is elsewhere around the op amp (resistors, fixed gain per definition)

Good luck

Claude

 

[kevinr]

Thanks for your reply Claude , the 627AU chip on adaptor went right in to the mount easily and securely .

Here is the link to the one I bought , maybe it is the wrong IC ?

1PCS BB OPA627 OPA627AU on DIP8 adapter | eBay

I removed the 627AU IC's and reinserted the 5532 IC's and typical operating volume returned .

 

[phase]

The opa627 is a single opamp while the ne5532 is a dual.
You will need one that has two of the opa627 on a board to actually replace the one in your application.

Also the ebay opa627 are all ad744, not bad at all for the price, but are not what are advertised.

 

[Rob43]

Thanks for your reply Claude , the 627AU chip on adaptor went right in to the mount easily and securely .

Here is the link to the one I bought , maybe it is the wrong IC ?

1PCS BB OPA627 OPA627AU on DIP8 adapter | eBay

I removed the 627AU IC's and reinserted the 5532 IC's and typical operating volume returned .

Do they both have the second chip on the bottom of the adapter like this picture ?



Rob43

 

[ClaudeG]

Phase is absolutely right: you bought the wrong ones, you need to have 2 OPA627 per adapter.

 

[phase]

Again, the ad744 are great sounding fet input opamps, but that particular vendor has been known to sell total garbage, fyi.

You can’t use a single opamp in place of a dual part.

 

[kevinr]

Thanks , the 627 is only a single chip , there isn't another one on the bottom .

Is the single chip unusable ? Or just result in half the power ?

I have been enjoying listening to this little Aiyima amp the last couple of weeks.

 

[Rob43]

Thanks , the 627 is only a single chip , there isn't another one on the bottom .

Is the single chip unusable ? Or just result in half the power ?

I have been enjoying listening to this little Aiyima amp the last couple of weeks.

Unless you're able to solder in an identical bottom chip on both adapters, I'd call them unusable.


Rob43

 

[kevinr]

Thanks , can you recommend a reliable vendor to source from ?

 

[phase]

I would look at this one, is likely what I would go with if I needed more.

1x Dual to Mono AD744KR SOIC TO DIP8 Precision, BiFET Op Amp AD744 | eBay

 

[Toku]

Thanks , can you recommend a reliable vendor to source from ?

OPA627 is very expensive. The price of the IC chip is over $15. A DIP8 conversion module with two of them costs over $30. The distribution of new IC chips is small, and most of them use used IC chips.
Most of the cheap OPA627s sold in China are fake. We cut the name of the cheap OP amplifier and sell it with the OPA627 name stamped again.

 

[Rob43]

Thanks , can you recommend a reliable vendor to source from ?

Sure, Mouser or Digikey. Both sell the real parts, not fakes.

Let's face it, a ~$4 dollar OPA627 from china is a fake. The same real Ti OPA627 from Mouser or Digikey is about ~$28 each.

OPA627AUG4 Texas Instruments | Mouser



Rob43

 

[phase]

EBay electronics 101 regarding the fakes. Try searching for “fake opa627 ad744”.

There are many great sounding opamps out there, and for the price of 4 legit opa627, I would rather have something else. I do use the ad744 however.

 

[Rob43]

Fake OPA627 vs Real OPA627.



Rob43

 

[daniboun]

Thanks , the 627 is only a single chip , there isn't another one on the bottom .

Is the single chip unusable ? Or just result in half the power ?

I have been enjoying listening to this little Aiyima amp the last couple of weeks.

Get the Dual version here, ready to use :
You can trust Audiophonics = solid reputation

BURR BROWN OPA627 Dual OPA with Support (Unit) - Audiophonics

 

[daniboun]

OPA627 is very expensive. The price of the IC chip is over $15. A DIP8 conversion module with two of them costs over $30. The distribution of new IC chips is small, and most of them use used IC chips.
Most of the cheap OPA627s sold in China are fake. We cut the name of the cheap OP amplifier and sell it with the OPA627 name stamped again.

Guys, if you are looking for a reliable vendor, you can get genuine dual OPA627 @ Audiophonics. This is one of the best Audiophile Vendor in Europe. They ship anywhere and their prices are really great

BURR BROWN OPA627 Dual OPA with Support (Unit) - Audiophonics

 

[kevinr]

Thanks for the information everyone .
I appreciate the education and links you posted .
I think since the Aiyima 04 was a $49 electronic I am going to order a handful of the authentic new NE5532 IC's from Mouser and install them in case the ones marked in the Aiyima are fakes . It seems a low cost potential improvement.
I don't know how many times the Aiyima power jack can be used before failure .
Maybe I will save money for a TI 3251 board before investing in opamp rolling

 

[daniboun]

Thanks for the information everyone .
I appreciate the education and links you posted .
I think since the Aiyima 04 was a $49 electronic I am going to order a handful of the authentic new NE5532 IC's from Mouser and install them in case the ones marked in the Aiyima are fakes . It seems a low cost potential improvement.
I don't know how many times the Aiyima power jack can be used before failure .
Maybe I will save money for a TI 3251 board before investing in opamp rolling

Great alternative is OPA1656, as far as I know, you won't find any fake and they perform better than OPA627 : see spec.

 

[phase]

Thanks for the information everyone .
I appreciate the education and links you posted .
I think since the Aiyima 04 was a $49 electronic I am going to order a handful of the authentic new NE5532 IC's from Mouser and install them in case the ones marked in the Aiyima are fakes . It seems a low cost potential improvement.
I don't know how many times the Aiyima power jack can be used before failure .
Maybe I will save money for a TI 3251 board before investing in opamp rolling

A more modern, common replacement for the ne5532 is the njm068, are 60 cents each, are good sounding. The shipping from Mouser will be much more than the parts...
Another inexpensive one to try is the ad827, but I think those are getting hard to find in dip 8 package.