I've loved the PX100 from Sennheiser, and as they are not available anymore I am not aware of a quality alternative these days. HD650 for example are too much heavy and big, while they have similar sound signature. But are there any other light weight headphones with similar sound quality?

I've read from many places over the net that sony is known to manipulate their players in such a way that ATRAC will sound better than MP3. Is this still true? I'm getting an NW-A806 -player which should support MP3, AAC, WMA and ATRAC3+ but I haven't found any information if they have changed...

I haven't been able to figure this out..I'd like to use a DAC chip PCM1770 from TI. The datasheet tells me that I need to supply System clock, 11.2896 MHz, Bit clock 32 x sampling frequency = 44100 * 32 =1.41MHz, and LR channel clock. I wonder how I'm supposed to generate those clocks. I can...

I'm just building a small Cmoy and I want to add a bass boost. I have only 1uF caps here and it's too large value. Will the bass boost work if I put two of these caps in series, 1uF + 1uF, will it be same as 0.5uF ? That way I could get the shelving frequency to 170-200Hz which should be OK.

If I built an amp with smd components, I can make it a lot smaller if I use both sides of the PCB. I can put the gain stage and other components on the top side and buffers on the bottom side. Is this somehow harmful to the audio signal, does it care a bit about things going on on the other...

I am building a low voltage amp for IEMs..I Plan to use 1-2 cell lithium battery so my voltages will be something in the range of 4-8Volts. I like the sound of my PPA v2 and I'd like to have a discrete diamond buffer like the one on PPA. Will it work with voltages this low?

I'm building a custom Pimeta clone with multi-loop feedback disabled and OPA551 as a buffer for all channels. I was building the amp but then I found out that I have only 2 OPA551s, so I guess I'll leave the one from ground channel. Is it possible to use an amp with active ground channel without...

There are many so called high end amps, PPA v2, M³, and so on. are there differences in sound quality between those? Let's take the PPA v2 and M³, there shouldn't be too much difference in price and most people seem to leave the battery board from the PPA so they are both desktop amps. The M³...

I have a question. Is it possible to use my PPA v2 amp to drive my regular speakers? Is there any reason why this would be a bad idea? I have small 2-way hifi speakers, 8 ohm impedance, and I don't need much amplification. Just some music while in bed, and the bass boost of my PPA would be...

Is there some reason for not using tantalum caps for decoupling purposes? For example, in PPA V2 there are electrolytics and some film caps for opamp decoupling but why not use tantalums, they are smaller and cheaper.

I'm wondering how much I need offset voltage to break headphones? I made a mistake when connecting an external dac to my PPA and tried to listen for some 30 secs with my HD650s. There was no sound..tried again..nothing..now I found out that there has been a short from virtual ground to V- and...

I have a pocket PIMETA and I'd like to use it with my MP3-capable Cell phone but the problem is that everytime the cell phone rings, or searches for network, or receives an sms etc., I hear this annoying noise which is actually really loud with low impedance phones. I have tried to solve it...

I have been trying to get some records now when I have all the equipment, senn HD650, PPA v2-amp and good CDP but the problem is that many of my records sound very bad! I have one great CD, it's "Sailing to Philadelphia" by Mark Knopfler, and it's just a wonderful album with great songs and very...

I have etymotic ER-6i IEMs and I find their sound too thin for my tastes..I tried a little trick..edited a song on Cool Edit Pro -audio editor and played with the EQ settings..I applied a high cut and lowered levels from 2000Hz to 6000Hz, and boosted the bass. After listening to that song...

I'm building a portable pimeta where I can't fit the alps blue velvet pot. I've tried the small alps that Tangent sells, but I find it hard to control the volume level because my ETYMOTIC ER-6i headphones are so sensitive. Would a digital potentiometer be a good option for a high quality...

I'm building a portable Pimeta amp..the enclosure is 106 x 56 x 23 mm, and I'm thinking about using Lithium Polymer battery. I have two 750 mAh cells, and three 250mAh cells. So the voltage options I have are 3.7 or 7.4 volts. I have hyperacusis (overly sensitive hearing) so I don't need...

I just bought Senn HD650. I paid a lot of money for it so that's why I'm a little worried.. So is it normal that there is kind of "open box" feel with HD650? There aren't any seals or plastic to be removed, just a gray box which opens up and there they are ready to be used. The clerk at the...

I have built a personal audio device using one opa 2132 for signal amplification and filtering. The problem is that the frequency response is not good with my Etymotic ER-6is. The higher frequencies are weak and when I change to Sennheiser PX100 which have 32 ohm impedance, the higher...

I finished a pimeta, but there seems to be a problem.. When I use it with Koss Porta Pros, everything is fine, low offset voltage and all but when I plug in my AKG headphones with 600ohm impedance, I get some problems. When I turn the volume up to a good listening level, all the buffers get...