The Opamp thread

[ROBSCIX]

I will see what I can do about information on the discrete. I will send you info if I can.

I have a bunch of units I need to solder up, including the OPA827's.. I really enjoyed those when I initially tested them but they were for an associate. These new ones are built for my collection. If you have too many 827's you can send me a few if you want

 

[SpudHarris]

On that note......

I have spent the weekend with the OPA827's in L/R of my P3+. I had to mess about with buffers and ground/V.ground to begin with but settled with Buf634's (Hi-C) and LME49710's (not the HA's). All I can say at this stage is that they are really, really beautiful Opamps. It's weird because warmer sounding opamps to my ears seem to miss certain details which is why I personally would describe an opamp as warm or tube like, these however seem warm but still have clarity and resolution in spades. In my set up they are not a nuetral sounding opamp but they are the best I've heard for a long while.

I've given up on the LT1363's as the scratching of the volume pot (poss DC offset) was really bugging me, it was noticeable even with music playing and I feared for my earphones. So my top choices are OPA827's / AD797's biased to class A and OPA132UA's. I haven't tried the 827's in class A yet and didn't like the 132's in class A at all.

 

[igor0203]

Can you tell me how to push opamp in class A? I put 10k resistor between V- and which out? A or B? I have LT1364

 

[Slash47]

Both.

10k from V- to out A and 10k from V- to out B

 

[igor0203]

Thanks!

 

[ROBSCIX]

Quote:

Originally Posted by SpudHarris /img/forum/go_quote.gif On that note...... I have spent the weekend with the OPA827's in L/R of my P3+. I had to mess about with buffers and ground/V.ground to begin with but settled with Buf634's (Hi-C) and LME49710's (not the HA's). All I can say at this stage is that they are really, really beautiful Opamps. It's weird because warmer sounding opamps to my ears seem to miss certain details which is why I personally would describe an opamp as warm or tube like, these however seem warm but still have clarity and resolution in spades. In my set up they are not a nuetral sounding opamp but they are the best I've heard for a long while. I've given up on the LT1363's as the scratching of the volume pot (poss DC offset) was really bugging me, it was noticeable even with music playing and I feared for my earphones. So my top choices are OPA827's / AD797's biased to class A and OPA132UA's. I haven't tried the 827's in class A yet and didn't like the 132's in class A at all.

What about Class A bias on the OPA827?

 

[igor0203]

F'cking amazing!

 

[ROBSCIX]

Quote:

Originally Posted by igor0203 /img/forum/go_quote.gif F'cking amazing!

You like the sound of the Class A biasing?

 

[LuciferX]

I need help with linear technology samples, they never send me anything buy now in my email inbox i have this message:

Code:

[left]We have received your sample request as below. The approval is not automatic for countries in South América. In order to approve your request the following information must be fullfilled. Pls note that information not received in 2 days, the sample request will be canceled. SAMPLE APPROVAL ORDER FORM Request ID:2101752 Customer Information Customer name: Address: Purchase contact: E-mail/Phone number: Engineering contact: E-mail/Phone number: [b]Fedex number: Pls note that the international freight as well as all import and other taxes applied by local governments will be customer responsibility.[/b] Project Information Project Name: Prototype date: Production date: Application: Estimated Annual Volume 1st year: Estimated Annual Volume 2nd year: P/N: Qty per board: Target US$:[/left]

So .... I have to pay for free samples !?!?!?

 

[SpudHarris]

Quote:

Originally Posted by ROBSCIX /img/forum/go_quote.gif What about Class A bias on the OPA827?

Like I said I've not tried that yet. Maybe when I've completely got used to the sound as they are I'll give it a go so I've got something to compare.

 

[igor0203]

Quote:

Originally Posted by ROBSCIX /img/forum/go_quote.gif You like the sound of the Class A biasing?

Yup, it's awesome. It's whole new sound dimension.

What do you use for opamp cooling?

 

[leeperry]

Quote:

Originally Posted by LuciferX /img/forum/go_quote.gif So .... I have to pay for free samples !?!?!?

they pack them very poorly anyway, try your luck on ebay maybe? LT1364CN (LT1364) Dual and Quad 70MHz Op Amp IC - eBay (item 110333253654 end time Oct-29-09 19:25:27 PDT)

 

[ROBSCIX]

Quote:

Originally Posted by SpudHarris /img/forum/go_quote.gif Like I said I've not tried that yet. Maybe when I've completely got used to the sound as they are I'll give it a go so I've got something to compare.

Just curious as I know you like to test with biased opamps. I like the OPA827's also. Have a bunch more here to solder up soon. Might do it here today...always soldering. I have ot get more Cardas Quad also running low.

 

[ROBSCIX]

Quote:

Originally Posted by igor0203 /img/forum/go_quote.gif Yup, it's awesome. It's whole new sound dimension. What do you use for opamp cooling?

You notice a big difference from the unmodded unit?

 

[igor0203]

Well not really a BIG difference but it's noticeable. I found that bass is little more refined and controlled, vocals are little bit more "liquid" if you know what I mean. Generally, sound is more musical.