[Jeff Guidry]

I am a non-DIYer, so please forgive such a simple minded question.

I have a Firestone Audio Cute Beyond amp with Supplier power supply which uses the OPA2227. I use Sony V6's and will soon use the Grado 225's, and I am looking to tone down the aggressiveness of the highs of these headphones.

From what I have read, the OPA2107 would be a good choice.

First, am I correct? Second, is this an easy drop-in replacement for the OPA2227? Third, where do I buy, and what precisely must I order?

Thanks for all your help.

 

[n_maher]

First, I have no idea, never heard that chip. The 2227 ain't bad though.

Second, no, it's not a drop in replacement. It's a SMD chip package only type opamp so you'll need an adapter. Someone around here can mount it for you if you ask nicely. Adapaters are made by BrownDog. And what's more I don't know if the chip in your Cute is socketed or not which could really complicate things.

Third, the only name you need to know, DigiKey.

 

[dhp]

Quote:

Originally Posted by n_maher The only name you need to know, DigiKey.

atm, digikey only has the DIP version in sets of 50

 

[Jeff Guidry]

Firestone says of this amp "OP amplifiers exchangeable! You can tune the tone by yourself" and the unit came with a key to open up the amp, so I am guessing it can't be all that hard. There is a picture of the inside of the amp, but it doesn't appear to be big enough to determine details about what's inside. Here it is though.....

UPDATE: This is not the same circuit, but I have found a picture of the OPA2227 that is in what appears to be an identical mount as the chip on my amp. Here it is:

 

[gtp]

You can find them on that auction site that starts with an "E" and ends with "bay". They have SOIC perpetually and sometimes DIP.

Otherwise, try emailing a few of the HeadFi builders, and/or starting a "WTB" thread.

I love that chip!

 

[dhp]

im positive that they are compatible/interchangable

 

[n_maher]

Jeff,

Yes, the 2107 and 2227 are pin compatible and would be plug and play if you could find it in a DIP8 package. The link that I posted to Digikey is to the surface-mount version of the chip as that's generally all that is available. However, as I also noted all you have to do is mount the chip to an adapter and it will turn it into a DIP8 compatible setup.

HTH,

Nate

 

[Gorthon]

Go to Texas Instruments and order a free sample. I just did this and recieved (4)-2107 and (4)-2134 to play with in my Go-Vibe.

 

[n_maher]

Quote:

Originally Posted by Gorthon Go to Texas Instruments and order a free sample. I just did this and recieved (4)-2107 and (4)-2134 to play with in my Go-Vibe.

I have no desire to debate this type of behavior in this thread but it's actions like this that cause sample programs to be canceled. What the crap do you need with 4 of each?

 

[Jeff Guidry]

Thanks, I did in fact request the 2107 from TI (though I only asked for one). It appears from the PDF to be identical looking to the 2227 that is currently in my amp, so I believe I will be able to just drop it in.

Crossing fingers.....

Thanks for the advice everyone, and I won't dirty up your forum anymore.

 

[Xakepa]

Just keep in mind, free samples are usually of a lower quality than stock chips.

 

[dhp]

Quote:

Originally Posted by Xakepa Just keep in mind, free samples are usually of a lower quality than stock chips.

mmm... are you sure about that?

 

[Xakepa]

Well, that's my expirience with AD free samples: out of 4 843s, 2 were having (slightly) excessive input offset voltage, one was "maxed" (1.7/2) and only one was "typical"
I don't expect TI to be much different...

 

[skyskraper]

did you compare this to non samples?

 

[bigcat39]

Samples IMHO are hand picked perfect examples. That way, real engineers who need them to do our jobs get working chips.
And I WILL get into the debate. Taking samples to just save a couple of bucks is immoral @ best. And it ruins it for those that need it to do their jobs.