So, I have been listening to the OG's for hours these past two days and I come away with three things that irk me.
The first is that any recording that has drums, are very recessed. Almost to the point they are on a second layer beneath the mids. On my stock GE tubes you do not hear this, it is exactly where it should be in the mix. My other headphones are the same way as far as hearing the drums on the same level as the other instruments. There also seems to be a tonality issue as well.
Second is I am noticing missing detail on particular recordings. On the song "Treefingers" by Radiohead, right in the middle of the song there is this faint slide guitar the goes from the R to L. I can hear this on my other cans and on the GE tubes. But the OGs do not pick this up. There are other recordings where slight details are missing as well.
Thirdly, the bass is weaker than the GE tubes. I know the HE-500 has been somewhat criticszed for its bass being somewhat flabby, but considering I have heard raves over a liquid tight bass on the OG, I am disappointed.
I also know the HE-500 are not noted for their imaging, but this flaw becomes more apparent with the OGs.
When I first used the OG, I was sort of amazed by the quality. In fact, the bass was actually extremely good when I fired it up for the first time. But after the 2nd, 3rd, 4th, etc. it seems to me it has lost that sort of magic and these tubes are a bit ho-hum.
I do plan on getting the LCD2's next month, so I am going to keep the OGs for now.
But I can confirm what others have said before, these aren't a good match with the HE-500. Of course take this with a grain of salt until I spend about 50 hours or more with them.