Originally Posted by HeadphoneAddict
Here are my notes I took as I rolled opamps in my D2 and listened:
1) I am first listening to the ISL55002 in main (replaced the 1364) and and THS4032 in the second spot (replaced NE5532). This is really nice with the ALO modded 780's (in same room as sleeping wife, so no open phones).
It is not what I expected, but rather with strong bass, smooth highs that are less accentuated than stock when teamed with the 780, and it's very transparent. Pianos and snares are crisp and attack and decay is good. Drums sound good, and bass guitar is tight. Saxophone are nice but maybe a liittle of the warmth is missing on those. Diana Krall's voice in "Temptation" does not have sibilance, and that is my test track for sssssibilance. I have no trouble hearing the knocking artifacts from the piano in "Departure Bay", from pedals and such. Next, the 6172 x 2.
2) Immediately I hear the sound is more forward with the LM6172 x 2, and some of the background is pushed out of the way to make the singer come forward. It is a more intimate warm mellow sound, reminiscent of the first time I heard the Meier Headsix.
The sound of the piano pedals is more of a booming low frequency background noise, makes me want to look up an look for where it coming from. Saxaphones seem to be lacking a little bit of the reedyness, but they are warmer.
Playback volume seems lower too. YIKES!!! I just flipped to high gain since the volume was low, and lost the left channel! And it's not the headphones or macbook. This is gonna suck - unplugging it and turning it off didn't bring the left channel back, and all I did was flip the gain switch just now.
3) Can't believe I am continuing this after my scare. Turning off, unplugging, and removing and replacing the the opamps with stock ones got me both channels back. It sounded good enough that I almost quit right there. But, I wouldn't be a HeadphoneAddict if I didn't keep going.
I think that one LM6172 (soic on browndog) plus stock NE5532 offers more volume than two 6172, and offers a less closed in sound, while still being a little intimate. This still tames the treble for me.
I immediately swapped the 1364 back in, and I moved back from 1st row to 3rd row, with a slight jump in highs and less warmth. The two 6172 has me ON the stage, but I like one LM6172 + NE5532 better than two 6172.
Leaving the NE5532 I then swapped in the THS4032 in the main, and the intimacy dropped more, and the venue opened up without boosting the treble much.
Then the ISL55002 went in, and the treble came back up, soundstage remained wide open and not forward, and it reminded me of the 1364.
The 6172 went back in, and I still liked it more (although all of them sound good). Next I will try replacing the NE5532.
4) I put the DIP 6172 back in place of NE5532, while the SOIC/browndog 6172 was still in main, and left channel is gone again.
I put NE5532 back in and I have both channels.
So, I swapped the DIP version to the main, and moved the SOIC/browndog to the second IC = same missing lt channel. Then I pulled the SOIC from the secondary IC, put the NE5532 back in, both channels are back.
So, either 6172 works in main, but I can't use both or I lose left channel. Wierd.
So, I kept the DIP 6172 in LR, and pulled the NE5532 to install the THS4032. WOW! This combo works for me better than ISL55002 as the main opamp with the THS4032, which is more distant in the mids. But, the bass kinda big when using these HFI-780, but tolerable (any more bass and I'd be worried). With this cpmbo, the saxophone regains that magic, with a combination of BOTH warmth and reedyness. LIVE NIGHT CLUB JAZZ MUSIC SOUNDS LIVE. I am having difficulty changing this or stopping the music. "Help, I'm listening to music and I can't get up"!
You have to try the LM6172 in place of the 1364 and the THS4032 in place of the NE5532. I am leaving this alone for now. And still listening. Can't... pull... myself... away...
5) Then the D2 battery ran out. So, I set it aside to charge, and started playing with my 3G nano and Headsix, changing it to low gain for my livewires. Another Wow. I am still listening to that setup 2 hours later!