cclragnarok

Moving the transformer looked kind of complicated, so I bent the pin away using a plier. I just plugged in a new fuse, and everything seems to work (and sound) perfectly fine. I wasn't looking directly at the amp when the shorting happened. Now that I thought about it a little, the little flash probably just came from the fuse. I wonder where the smoke came from though. Maybe the insulation on the wires. Anyway, thanks a lot for the help.

Thanks for the suggestion. I will go buy a replacement fuse and try it out.

Thanks a lot for the quick reply. I understand that the shorting problem definitely needs to be fixed before using the amp again. Considering that smoke was coming out of the unit, do you think some other parts might need to be replaced?

Uh oh.... I think I have much bigger problems now than the tubes not biasing properly. :'( I opened up the 007t today to swap the tubes out. Before I actually did anything, I saw that one side of the fuse holder was bent, and wasn't actually clamping down the fuse. There was still contact though, so the amp was working before. I figured that it would be better if the fuse was actually clamped down on both ends, so I used a piece of floss, and restored the fuse holder to the shape that it was supposed to be. Obviously I didn't notice it at this point, but this also caused that side of the fuse holder to touch one of the pins on the power transformer. I plugged the power cord back in and switched on the 007t. Right away, I saw a few small flashes, and a bunch of smoke (which kind of smelled like solder) started coming out of the power supply section, around where the big capacitors are. I switched the 007t off and unplugged the power cord, but I guess the damage has been done. The fuse also blew. I'm not sure when it did, but it probably wasn't fast enough. Here are some pictures I just took after all this happened: What do you guys think (how bad is the damage, what parts need to be replaced, etc)?

Thanks for the info. I bought 8 tubes, and had the seller give me the tube tester readings of each of them. I think the numbers are transconductance values, which isn't ideal, but I guess it's better than nothing. Hopefully, I'll be able to group them into 4 pairs, but I am a bit worried about the sections not being well matched on some of the tubes.

I just received my Omega II yesterday. Unfortunately, I don't have enough money for a KGBH or even a KGSS, so I'll be driving it with an SRM-007t for now. I bought some Toshiba tubes for the amp, but they aren't matched pairs. I hope I won't have too much trouble biasing the amp after I put in the new tubes. The current chain of components: foobar + asio4all -> Trends UD-10 -> CIAudio VDA-2 + VAC-1 -> VRX-1 -> SRM-007t -> Omega II

Thanks for the answer. This makes a lot more sense. I was just wondering since the description of the 007t says that it has "no transformer or inverting amplifier in the signal path." To answer my other question, I tested the inputs using a multimeter yesterday, and it looks like the RCA input does work as an SE loop out for the XLR input.

So the output also becomes single ended, with the maximum output voltage halved?

This is kind of a random question, but does anyone know how the XLR/RCA input on the SRM-007t works? If I switch the input to XLR, and feed the amp balanced (+, -, and gnd) signal, would the RCA input work as a single ended (+ and gnd) loop out? I've actually tried this, and it seems to work. I hope I'm not somehow shorting the L and R - signals together when I do this. Also, I am assuming that the amp is simply "fully balanced" (+ and - are separately amplified with respect to gnd) when the input is switched to XLR. What happens when the input is switched to RCA?

I think that means "white cathode follower," but I don't know much about amp design, so I have no idea how that is different from a regular cathode follower.

But you weren't using headphones that can vaporize dust particles.

If an electrostatic headphone is powerful enough to do that, I'm not sure I want it on my head.

Maybe the input clock and DAC clock are separated using some sort of a buffer, and the second optical is used for feedback rate control? Then it wouldn't matter whether or not TOSLINK is used to transfer the data.

It all makes sense. Like I said, I think we are hearing (mostly) the same thing, we just have different preferences on what we like to hear.

I actually (mostly) agree with your description of the SR-404 sound, except I think the flaws are subtle enough that the SR-404 is still a very good headphone overall. In comparison to the SR-404, every high end AT I've tried (W5000, AD2000, L3000) was more colored in the midrange IMO. I also thought that the Qualia had a more offensive tone than the SR-404. That said, I think I might be able to get used to the sound signature of these headphones as well if I get longer listening sessions with them. \ Oh well. All I'm saying is that every headphone has its flaws (though some have fewer flaws than the others). Different people choose to tolerate different flaws, and some people might even like a headphone more because of its flaws. I personally find the sound of the SR-404 very good overall. I should probably shut up now considering the fact that I might sell my SR-404 soon.

I'm glad to hear that, since we seem to have similar tastes. My current plan is to try the esp-950 or save money for the Omega II. I'm not sure which one is the better idea, so I guess I'll just wait for a good deal on either of them. As for my head, it's just too big, and my forehead is too wide.

From what people say about the K1000, I think I would like the way it sounds. Unfortunately, the fit is even worse than the SR-404. In fact, the fit is so bad I can't even try them. :'(

The K701 is actually my main headphone right now. I guess this just shows how different people are. I've tried headphones like the K501 (a little cold and hard sounding), HD650 (a little too dark), AD2000 (colored midrange), L3000 (just colored), Qualia (sounds metallic), etc, and I think I'd rather have the K701 or SR-404 sound.

I bought the SR-404 with the SRM-313 more than a year ago. Considering the comfort issues, I would have sold them a long time ago if I didn't like the sound. I do think the Omega II is significantly better though. So is the HE90.

Too bad I didn't know this before I bought the SR-404 from you. I actually like the sound quite a bit. Unfortunately, I have an unusual fit/comfort issue with the lambda design. It's hard to enjoy the sound when my head hurts. Maybe it is time to start planning an upgrade to the Omega II.

If you are talking about the main DAC chip, this thing uses the PCM1792 (TI's flagship along with the PCM1794).

My K701 also sounded a little shrill/edgy at first. I tried to listen to them for a little while (maybe 10 or 20 minutes), and my ears started hurting. That was the first time I actually felt real pain from listening to a pair of headphones. After that, I burned them in for a few days, and they never hurt my ears again.

I guess I shouldn't introduce myself then.

Really?

Isn't that what happens in the Corda Opera and Cantate?