Quote:   No, I bought a long straight bar. I used my bare hands and a couple of strokes with a small sledgehammer and bent it against a toroid transformer (a smaller one than in the picture above). It would've been better to use a cylinder with a smoother surface. I used countersunk...

Yes, they're very comfortable. Except for the weight there's no difference. I think I was lucky to get the bend and pressure to the head to fit my head perfectly.   The weight is 350 grams so it's + 90 grams.  

After thousands and thousands of hours my HD650's headband snapped. A complete headband is the equivalent of 160 USD + shipping costs in Sweden. The phones are so worn down it's just not worth it. I've tried to convince myself that the Denon AH-D2000 I just bought second hand sounds just as good...

THD has almost nothing to do with perceived sound quality. If it were so tube amps would totally be out of the question. When designing discrete amps a lower THD can be achieved by higher open loop gain and increased feedback. Does it make the amp sound any better, well I don't think so. Some...

Quote: Originally Posted by Slash47 Why you would end up with a noisy amp I do not quite see. The resistors are way too resistant, but other then that you'll end up with a nice opamp rollable cmoy. Johnson–Nyquist noise - Wikipedia, the free encyclopedia I've tried that...

Quote: Originally Posted by Koyaan I. Sqatsi But it doesn't entirely work as advertised. It's advertised as bypassing ground. It doesn't. That's a myth. I've never seen it advertised as "bypassing ground". I don't even know what that means. Quote: A regulated low...

There aren't that many ways to implement an opamp. The differencies lies in the choice of opamp, and the way the return currents are handled (you can call it the power supply if you want) - which IMO is just as important as the L/R channels: resistors/capacitors, batteries, IC or discrete...

If the impedance curve isn't totally flat, which it isn't, you'll get a slightly altered frequency response.

IMO it has nothing to do with impedance. "pretty harsh in mid-highs and highs department... and sounds kind of thin..." is just the way AD8610/20 sounds, expensive or not. Maybe you should try other opamps. Maybe not the best, but "bestish", is LME49720. It's easy to find, cheap and sounds good...

Quote: Originally Posted by FallenAngel Interesting thing I found out today with my PPAv2 - AD744 (comp output) doesn't like class-A bias in the amp (anything above 2mA and it starts to output DC like crazy) and AD829 (comp output) REALLY doesn't like class-a bias and goes haywire with...

I think you have to show us the result of the soundcard loopback, but it's natural for a class AB amp to show increasing high order distortion under load.

There are a lot of tweaks you can do to alter the sound of SS amps. The choice of transistors have a major influence. You can even alter between bipolar, JFET and MOSFET if you make the design versatile enough. By adding CFP and/or cascode the sound is altered. You can also play around with...

Quote: Originally Posted by compuryan I would expect the RCA to be better sonically. Of course the difference would be small and immeasurable. It is measurable (crosstalk). I wonder if it's audible?

Just to illustrate what happens in this circuit (I have no generic buffer symbol, so I use a discrete diamond buffer instead, but it should make no difference): with no PIMETA resistor R7, R14 in the schematic above (it looks exactly the same with a 100R resistor) with a 10k resistor...

Tangent, since you're not using the 1 nF cap bypassing the 10 k input resistor suggested by National I don't think 10 k is an appropriate value. Besides, the LMH6321 is inside the loop of an opamp in PIMETA and is run open loop in the data sheet. I think PIMETA is deemed to be unstable with a 10...