Good Alternative to OPA627?

[mrdon]

I am getting ready to replace all the opamps in my Denon 2900. BTW, there are 28 opamps to replace for 5.1!

Therefore...any good and cheaper alternatives to the legendary opa627?

 

[Jazper]

Quote:

Originally Posted by mrdon I am getting ready to replace all the opamps in my Denon 2900. BTW, there are 28 opamps to replace for 5.1! Therefore...any good and cheaper alternatives to the legendary opa627?

Depends on the sound you want!

The AD8610 is a good chip - supposedly the first port of call aside the 627 (not my cup of tea- a bit bright, but it's good)

then there's the AD843, AD845
the AD8065/8066,
the opa604


plenty around..

 

[1UP]

What does it use currently? How comes there are 28?!

What's the voltage going to the opamps? Most of the newer Analog Devices opamps can't take more than 12v.

I guess a safe bet would be the OPA2132.

 

[mrdon]

Quote:

Originally Posted by 1UP What does it use currently? How comes there are 28?! What's the voltage going to the opamps? Most of the newer Analog Devices opamps can't take more than 12v. I guess a safe bet would be the OPA2132.

This is the message I received from a modder who alread did the 2900. Quote:

You will need at least 2 opa627 per channel (Each channel has 2 opamps, except the front 2 channels, they have 3 opamps per channel.) The opa627 is a single opamp, so it takes 2 of them to replace each of the dual opamps in the dvd 2900. {total 28 opa627 to change all opamps in the audio stream of the 2900}

 

[Jazper]

you could go duals or singles - the opa 2132 is a dual.

and most analog devices opamps can handle high voltages (36ish like the opa627) with the exception of the AD8610 (27.3v rail to rail) and the 8065/8066 (26.5 rail to rail)

 

[mono]

What are the stock opamps? What kind of change do you hope to make to the sound/etc?

Are they all surface-mount dual-channel, SO8? Have you pulled the board and checked clearance to ensure that if you're replacing SO8 with dual-opamp adapters, that they're all going to fit in the space available, possibly including clearance from any adjacent boards?

Random suggestions- AD843, AD8620, OPA2107. The latter is most like OPA627. If you really want OPA627 they can sometimes be found on ebay for le$$. I leave it to you to distinguish between legitimate sellers and samples-resellers.

 

[Jazper]

Quote:

Originally Posted by mono What are the stock opamps? What kind of change do you hope to make to the sound/etc? Are they all surface-mount dual-channel, SO8? Have you pulled the board and checked clearance to ensure that if you're replacing SO8 with dual-opamp adapters, that they're all going to fit in the space available, possibly including clearance from any adjacent boards? Random suggestions- AD843, AD8620, OPA2107. The latter is most like OPA627. If you really want OPA627 they can sometimes be found on ebay for le$$. I leave it to you to distinguish between legitimate sellers and samples-resellers.

the 8620 would remove the necessity to use single chips in some channels (as it's a dual)

should also be noted that you can't get samples of the 627 from Ti anymore

 

[peranders]

Quote:

Originally Posted by mrdon I am getting ready to replace all the opamps in my Denon 2900. BTW, there are 28 opamps to replace for 5.1! Therefore...any good and cheaper alternatives to the legendary opa627?

Before you do anything, I'll suggest that you get a service manual or at least the schematic so you actually know what you are doing. 28 OPA627 seems to be totally insane if you are going to buy all those and even more insane to get so many free samples.

Change opamps with taste. I'll suspect that you have only a few interesting locations where it may be an idea to change parts.

 

[mrdon]

Quote:

Originally Posted by mono What are the stock opamps?

The stock opamps on the audio board are Analog Devices OP275.
Quote:

Originally Posted by mono What kind of change do you hope to make to the sound/etc?

I would like to improve the 2900's lackluster redbook performance. I would like to fatten it up, smooth it out, provide more air, etc...and while I am at it also squeeze some more audio juice out of SACD and DVD-A.

My reasons for focusing on opamp upgrade is so I don't have to replace caps, diodes, etc... I've already replaced the power cord with 12AWG braided teflon coated copper wire terminated with cryo'd plugs and that made a vast improvement.

 

[Jazper]

after looking at the datasheet, the obvious choice would be the AD8620, provided you checked the voltage supply to the chip and it was in spec (afaik 27v MAX )

 

[bg4533]

I suggest you figure out why there are 28 opamps. Eliminating some of them might give a nice gain in performane.

 

[Emon]

I think the AD843 is half the price of the OPA627, but I could be mistaken. I know Tangent holds it in very high reguards, he said it contended for the "best op-amp I've ever heard".

Edit: Just remembered the voltage and current requirements of the AD843 are way different. Probably won't work then.