[Moonwalker]

Hello, Alex!

You are very kind and I thank you very much!
Please, could you post some graphs (graphic measurements)?

I'm happy you answered so quickly.

PS: And I thought it was output #2 having lower output impedance, not the output #1!

Your
Moonwalker

 

[Alex Nikitin]

To Moonwalker:

I am sorry - probably too much work

. You are correct - output 1 is the one with the higher output impedance, output 2 is lower impedance. Please reverse the numbers. I can see that I probably created even more confusion with that post

. I just did re-measure bare boards and didn't check the front panel - oops... . What kind of graphs would you like to see?

Alex

Creek Audio Limited

 

[Moonwalker]

Well, man, you make my life even happier!!

Alex, I'd like to see graph of freq. response, 2nd harmonic included, and some graph of freq. dropoff at extremes using real phones, especially hi-imp. Senns and lo-imp Grados/Koss, if that's possible.

Nice day!

Moonwalker

 

[daycart1]

It really is VERY interesting and helpful when the folks from our sponsors, from ASL, Ety, etc., and now Creek drop in.

Just to repeat some stuff I've read: The SE version seems to offer a very substantial upgrade for those who have RFI problems--otherwise, some report only a slight diffrerence.

 

[Duncan]

Alex, Welcome to Head-Fi from a fellow Brit

I've just sent you a PM about your website... hopefully it should flash up that you have a message automatically

No... I'm not allowed to be tempted... I'm walking straight back out of this thread...

 

[tangent]

This thread piqued my curiosity, so I went and opened my OBH-11 (no -SE). There are four things on the board that could be linear regulators -- they're tiny little things without heat sinks, but they stand vertical and they have three pins, so....

There is indeed an op-amp in there: the infamous NE5532. Now that I've technically voided my warranty, I'm tempted to multillate, spindle and bend the warranty, too -- mmmmm, Creek OBH-843?

By the way, class A doesn't require regulation, it requires more current. That's why the OBH-2 is necessary. The all-discrete design might also have a lower PSRR value, which means power supply noise is a bigger problem. Op-amps tend to have excellent PSRR numbers, so you can get away with some really bad power with them. There may also be an issue with power supply "quickness": the big 2200uF cap in the OBH-2 should help it react better to instantaneous current loads than the OBH-1.

Oh, and kwkarth: I'm glad to see that I'm not the only one who can't hear an improvement in the OBH-11 with the OBH-2 vs. the OBH-1. I suppose it might matter with low-impedance headphones, but I'm Sennheiser/AKG guy.

 

[kwkarth]

Well Tangent, I have to agree, I really couldn't put my finger on any quantifiable audible improvement in the OBH-11 between the std wall wart and the OBH-2 supply. OP amps also typically exhibit better CMRR than diecrete designs as well, making them more immune to marginal power supplies than a good discrete design.