Magnet field strength GREATLY decreases with distance, it's not going to affect sound quality.  The only real issue is what HC pointed out, they can wipe out the magnetic strip on credit /etc cards but even then you'd have to wipe it against them.   The main concern I'd have is how you're...

^  Or a forum for people that can't stand when others offer a different opinion?   Suggesting something, spending the time to do so even if it doesn't agree with your ideal, tends to be the opposite of not giving a crap.  Is the ultimate goal to be an expert at op amps, or to end up with a good...

It's like polishing a turd.    Ok, not really but the point to the CMOY design is small size, simplicity, low cost.  All the time spent, could be spent on something better which is a large part of why this forum exists, that people move on to better sounding amps.   Edit:  The rest I wrote...

You know how to cut paper with scissors, right?  What if it was thicker paper, you can do that too?  Well, there's this thick paper like stuff but it isn't paper, due to growing on big animals that go "moo".  Take a piece of the animal (wait till it's dead, it's safer that way) and cut it to the...

lol, resume.  Let's get real.  Put a price on the contract work.  Anyone handy with tools and having some materials can build according to a specification with no experience in headphones at all... but what you're looking for might be the opposite, someone who likes to do things their way...

Well, it is the D. I. Y. forum, what skills are you lacking? For the price of having someone do it you could gain some gear and skills. I'm not familiar with this mod but it can't be much more than having a soldering iron/solder, drilling a couple holes and adding the needed plugs and sockets...

I like the less is more philosophy myself, though a couple things happen.  One is that if your buffer is in the global (opamp) feedback loop you mitigate sonic effects of the buffer.  Another is that while we could wish for the perfect opamp to drive cans, manufacturers tend to pimp the low spec...

I believe the buffered version is more accurate, because when you swap similar current capacity opamps on a CMOY, it changes the sound more than if you swap the same opamps when they're behind a buffer, and more than if you keep the same opamp and swap in different buffers, UNLESS you were...

I'm not referring only to high listening levels, at any level loud enough you can hear the details of the music (more than background music) I hear a difference... though each person's idea of a high-volume threshold can differ too. 

^  depends on how you define "good", if by good you mean an unusually high output current for a DIP8 opamp then yes it's somewhat true.  On the other hand, does one really build an amp with a restriction that it's only adequate for 30-50 Ohm cans?   The website you referenced is, to put it...

The most economized way to do it would be from scratch.  Find a piece of foam the density that you want, cut out a couple doughnut shapes and adjust their height to be suitable for the density of the foam, then buy at least a couple square feet of nice cloth from a fabric store and cover them.  ...

Is that a TL072 opamp?  If so, [EEK!] using something else with higher current or paralleling two of them like in an A47, or paralleling two of something else especially, is the next upgrade.  None of the old popular opamps for CMOYs do very good driving a load (cans), it's just sort of the...

It is repairable, BUT you must get the pieces perfectly mated together or the coil will rub the magnet housing. Before trying to glue it, set the plastic in place, see if it fits well, and you might try passing an audio signal through it to see if it distorts unusually. If not, you should be...

1amigo, it's an old topic, Fred may not be monitoring it anymore.   I keep the iron moving but move it very slowly.  I'd assume the minimum length of time would depend on how thick your copper is and the total area you're covering... some small PCBs stay entirely under the iron during the...

Organic polymer caps have made good strides over recent years. Now they're becoming quite common on PC motherboards, video cards, in values like 16V/330uF. I think they're a bit overkill for an analog audio amp though, except if you're building something to give to the grandchildren some day...

While I am also insisting you check voltages before handling circuits, there is also the option to build bleeder resistors into your design, or just add them across the caps on existing designs. Don't assume they did their job, but be glad you spent that 4 cents on resistors... you never know...

Yes/no/maybe. If the cord it replaces is frayed or of insufficient gauge to keep it from being an impedance it ought to be replaced. On the other hand, the power travels from the power company many miles, to the house, throughout the house, the last few feet (if the proper gauge for the...

I find crimp connectors less reliable. If you twist the wires and aren't going to flex the joint, soldering them and covering with heatshrink tubing should be fine. Keep in mind this is assuming other proper design (regardless of how you connect them), chassis is grounded if metal and the supply...

Solder falls into the realm of voodoo science. Pick what works best for you, what you like the smell of or whatever, but if it costs more you're probably overpaying for aesthetic rather than important per function, reasons. Regular 60/40 and 63/37 low cost solder is not hard to use and most...

STK2125 being the output power amp IC, yes it seems there is a good chance that is the problem. I'd probably desolder and pull it off the PCB and measure supplyl voltage, and L/R signal strength at it's input (I mean the now empty spot on the powered PCB - being careful since there could be high...

I find no difference whatsoever, unless it's an ancient cord where the wire was frayed and that is cut out, or the outlet seriously degraded and the new plug makes different contact. Usually an improvement with a different plug is only placebo effect, IMO.

You'll probably have to DIY, by noting the types of pins and sockets and ordering the appropriate individual parts from somewhere like Digikey, then soldering on the wires. If you don't have an iron or soldering skills this might be a good project to get your feet wet on that.

You can use many many complimentary pairs of transistors, but my general impression is if you use those with lower current rating you end up with a more harsh sound and less controlled bass. The BC327/337 happen to have high current for TO-92 size, but if your amp case has enough clearance you...

Quote: Originally Posted by Zaubertuba Seriously, your line of (very well thought-out) reasoning points me right back to a balanced JISBOS-with-gain that was suggested to me on another thread, or a balanced Pimeta like you're suggesting. Do you have any other reasons for suggesting the...

Quote: Originally Posted by Zaubertuba Responding to a post I made in the opamp thread about my "quest for greater soundstage," murrays pointed out the following: I realized my amp is already wired so L+ and L- utilize a set of opamps and R+ and R- use the other set, so there...