jtfoo

I gotta agree that the DT880 has superd bass defination. On a noisy rock tract, I can follow the bass line very closely. While on my other cans, the bass are line one lump with no definition. Very much like to see how a pic of your cone tweak on your DT880.

Now then I read this Too late, my wife already wash for me... Any better ways to rid the pads of smell?

Does the padding or foam of your headphone gets smelly? My grado125 is beginning to smell (probably from the sweat accumulated from its previous owner and mine). Lucky can detach easily to wash and sun it. Hopefully the foam won't disintegrate under the sun. Now, kinda worry for my DT880. If it smells, just don't know how to take it out for washing and sunning.

I believe the JR4556 has now become NJM4556AD(also high current opamp) in New Japan Radio catalog. The NJM4556AD can be found at RS at $1.60 only.

I don't run in my headphone or amp. Reason is I'm too anxious and can't wait to use them out of box or out of soldering iron.

Sorry to be direct, are your price going the lower than what's quoted by MBD? Usually dealers get ot price their stuff lower then the distributor.

Tried playing Metallica on those high end tube system at someone place. Almost fell asleep. Felt that the speed was slow. On my SS amp with Meta42 as a Pre, then I can feel the rythm and pace, and of course the music was dynamic and flowed very fast.

Progress , still in the process of plucking up the courage to work with high voltage of the tube.. I'll reading and surfing to get my understanding first and going thru my insurance.. Look at this project from headwise, which indicate a near EMP clone, not exact though. http://headwize2.powerpill.org/projects/sh...e=cmoy5_prj.htm

I'm done for the headphone part.. But headamp, this DIY thing is too addictive. In my plans to built are the Corda HA-1 and maybe the Morgan Jones, which incidently a near clone of your EMP.

Should be lower impedance more harder to drive, as it requires more current from the amp to give the same wattage of a higher impedance speaker/headphone.. Remember Watts = I^2 X R.

Not me, I've no experience with buliding a tube amp either. In fact I thought you're the one who'll be doing the Morgan Jones tube amp.

Ok, thanks to Gouki & Ablaze, I got my eggo at $93.6. But I bought it at the basement shop instead. I guess all these shops might be linked coz the price quite standardise. I only had about an 1/2 hr to compare with my grado125 and Beyer DT880, with only one song, 'I wanna be sedated' by the Ramones. Initial impression is the sound fills around your head. Very opposite from the grado, which the sound is either left, right or centre. I like a little bit of brigthness and forwarding sound, so this piece of rock music really rocks on the eggo. The bass is better than the grado, you can hear it's rumble. But it's is not in the league with the DT880, where I can follow the bass line closely. On the Eggo, I can hear the bass line, but kind of hard to follow. On the grado, where got bass line to follow? Myabe it's the harshness of th grado, that I only wanted to take it off asap, that's why didn't notice the bass line. I felt at this price, the eggo is really worth the money. Now my preference of my headphones would be DT880, while alternating with the Eggo on certain music.

Cmoy is a simple textbook implementatin of a non-inverting opamp application. You'll be surprise that some expensive headamps just simply use this circuit and charge a premium for it. The sound for the cmoy is decent with opamps like OPA2132, 2134. But it's a fun beginners diy project. I'm using the OPA2134, and it can't drive my Grado125(low impedance,32ohms) to loud volume. Lot's of distortion. For low impedance headphones like the Grado, try the Apheared'47. It's like a curret boost version of the cmoy. http://headwize2.powerpill.org/projects/sh...pheared_prj.htm For meta42, visit tangent's site, http://tangentsoft.net/audio/meta42/index.html . Esmtimate cost for whole project is about $250 when you use quality components. Meta42 is miles ahead of the cmoy and apheared imho.

Hi El, What's the difference between the HFI650 Trackmaster and DVD edition?

I got my PCBs, AD8620+Adapter, EL2001s all from Tangent. Took about 5 working days to reach S'pore. The EL2001s are cheaper with Tangent when I compare them to RS components & Farnell. Tangent do sell the parts without the PCBs, if you intend to do them on a breadboard. My jack is a brandless imitation of Neutrik. Got some problem with contacts, but manage to fix it. Got it from SLT at only $2.50.

How timely. I've just finished my Meta42 yesterday. I ordered the parts from Tangent, his PCB is very well done and compact. Here're some shots of my Meta42, http://www.pbase.com/jtfoo/meta42 I gave up on any wallwart powersupply including Laptop power supply and use batteries instead. For long lasting batteries, I went for Seal Lead Acid battery. No hum. But there'a a slight hum when I use a AC power CD player, Rotel CD1070. I solve it by grounding the Vol pot housing. First impression, is the dynamics of the amp is very good. Much better than the apheared47(OPA 2134). THe Bass is strong and low which I attribute it to the the 1.5uF DC blocking cap. Had a brief chance to use it as a preamp on my stereo setup. And for that short moment I thought I liked the speed and dynamic of the Meta42 preamp. It may well replace my AKSA tube preamp, but I need more time to evaluate that.

I don't know how to explain DC offset. Experts pls correct me if I'm wrong. Ideally the signal should have a DC offset of 0 volts. so say a AC 2V pk-pk signal will be a +1V and -1V wave. If say there's an DC offset of positive 100mV (0.1V) offset in one of the channel. the resultant wave will have high peak of +1.1V and low peak 0f -0.9V Let's say there's a gross DC offset of 3V, then the same 2Vpk-pk AC signal will have maximum peak at 4V and minimum peak at 2V. This peak at 4V could be potentially damaging.

Has to be in DC mode, coz we're looking for DC offset.. If your readings are in the range of 0.1mV in DC for both channels, then it's good. BTW, pls share how to test for DC leakage.

Hi Ablaze, You can check for DC offset very easily if you have a interconnect with stereo plug at both ends of the cable. Just plugged it into the headphone jack, and measured from the expose end. With your amp turned on, but don't play any music, just measure the the voltage across the Left wrt Ground and Right wrt Ground. Refer to the below pic from headwize for left/right pin.

I like "Wish you were here" best.. Excellent musicianship on 'shine on your crazy diamonds'. I like 'dark side of the moon' 2nd. Try to listen to "time" for Dave Gilmour's haunting guitar solo... excellent..

See if you can measure the DC offset of your output. DC offset is undesirable, and too much of it can kill the speaker. I guess it's the same for headphone. I'm not sure what is the allowable value for the DC offset, but I guess the diy guys at echoloft might be able to help.

Larry Hifi, basement in People's Park.

At the moment I wouldn't dare to approach the Gilmore yet. Think I'll stick to opamps base for the while till a little more confidence is built up fro myself. Northern Oak, where can get supply of 2SK389 and 2SJ109? Previously I tried to source for the 2SK389, but cannot find in the whole of SLT. In the got to order from overseas, and the shipping cost more than the FET itself.

I voted others. Coz I only know how to copy others people's design that are found on the web. Something like playing lego with a soldering iron.

dgps, Since you're going to the States, the HD580 can be had for USD150. But they only ship to USA address and American credit card. http://www.newegg.com/app/ViewProduct.asp?...rtby=14&order=1