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...

You still need some batteries, input jack, on-off switch, and maybe a charger and a DC jack. Are you thinking of gluing all those parts together?

Since you're using NE5532, you'll need more than one 6F22 battery. The spec'ed minimum voltage is 10. If you want this amp small, I think you have to make your own box. http://www.head-fi.org/forums/f6/ver...lu-box-418271/

Horse, good thing for you opamps aren't made by IKEA. Then they'd have a name instead of a number. Your condition is called synesthesia. Some people have it others don't. Colors can be associated with a lot of things like sounds, shapes, numbers and letters. No wonder we perceive sound...

Back on track, has someone compared it to the Zero DAC? There are a couple of different DAC's on Ebay. Most of them use CS4398, but others use PCM1793, TDA1543, AD1852 etc. As I understand it CS4398 sounds (too) detailed, forward and a bit grainy while AD1852 sounds smoother and maybe...

Quote: Originally Posted by linuxworks I wish someone could show me some sound that entered your home stereo that did NOT pass thru at least 10 op amps (in the studio, at mastering, at many places) before it got to you. I know you know this but the anti-opamp crowd really makes me...

Thank you kvant for the EE perspective. I've heard and measured this effect, but I wasn't familiar with the formula. A low impedance point for the return currents is IMO essential for a natural stereo image. I think one must keep power supply and how the amp handles the return currents apart...

Quote: Originally Posted by Horse The limits of a CMOY don't really lie in C2. The metallized polypropylenes are perfect. No they're unnecessary. They're large, cost money and can do nothing but degrade the sound.

Are you really sure you need C2 at all? I think probably not. Remove it and stop worrying about capacitor quality

I've built several solid state amps from the ground up, without any knowledge at all - I've picked it up along the way. Looking at schematics, hanging around Diyaudio.com and playing around with LTSpice have done it for me. There are so many options. All of them will measure well and sound OK...

Quote: Originally Posted by gurusan He is talking about power caps..... Yes and I'm also talking about power caps. They're very much in the audio path, sinking/sourcing the return currents. That's why 3 channel amps, amps with shunt regulators or any other methods of getting a...