[Alydon]

Quote:

Originally Posted by ROBSCIX /img/forum/go_quote.gif @maarek99, I forgot the 627 is single channel so yes, you will need a single to dual channel adapter. If the caps are too close to the socket to allow for the 627 in a adapter to be used, you can use a dip 8 socket to extend the socket upwards clearing the caps.

Cheater!

Good idea tho. Hadn't thought of plugging in another DIP8 to make the socket taller...

Quote:

Originally Posted by ROBSCIX /img/forum/go_quote.gif @riderforever, I have actually been interested in such units for a while and some swear there is a burn in factor and others say no such thing as there is really nothing on the unit to burn in. I guess you can make up your own mind if you have the unit there.

Of course, the same can be said of any piece of audio equipment. There are people on these boards who have said headphones don't need burnin either.

I'd luv to try one of these discreet units out but the reported lack of bass extension has me a little concerned. So I'm hoping burnin *is* a factor and it'll get better for riderforever over time...

 

[ROBSCIX]

I haven't heard a lack of bass when I have listened to some discrete opamps nor have heard mention of it.

 

[Alydon]

Good to know that you haven't heard any. That eases my concern a bit.

However, in riderforever's post 2 pages back he does mention a lack of extension:

Track after track, however, I feel like something of the impact and energy of the original configuration is missing, as well as bass extension.... I need more time to confirm these impressions and I like to find an opamp for the I/V with additional weight for the bass, to counterbalance the effect of the Burson.

I haven't yet read any opinion that specifically mentions bass extension as being good or bad other than the above post by riderforever. Hence my concern and my hope that it will improve for him during burnin - if such a device actually benefits from burnin, that is...

 

[Shahrose]

So Alydon, I tried the LM6172 in the buffer spot with 2xLME49720 and surprisingly, it sounds quite different from before. The bass no longer cuts out, and there's no unneeded warmth to the sound (still add warmth, but not excessively). I believe it wasn't making contact properly before because now it sounds great. I feel like it's a compromise between the sound of 3xLME49720 and 1xLME49720/2xJRC2114d without most of the drawbacks.

The 3xLME49720 have a larger/airier soundstage, but not by much and the JRC2114 have more solid and hard-hitting bass (a bit more defined too), but again, not by much.

The JRC2114 have this upper treble harshness that just seems to grate on you. In fact, I feel there's a lot of things wrong with the treble when I'm using those. They have excellent bass/midrange though, maybe the best of any opamps I've used.

Anyways, I'm keeping the 1x LM6172/2x LME49720 for now to test it further.

Upon further testing and comparisons with 3xLME49720. I found the LME49720 have a more realistic tone (because they don't have that lower midrange hump of the LM6172), however, their bass is slightly less defined and a bit less punchy than the LM6172. Also, the LME49720 sound a bit more distant, and smoother. In addition, the LME49720 have a wider soundstage than the LM6172.
I have yet to find the perfect opamp combination. What's important to take away from all this is, there is no one best magic combination. Everything has pros and cons and you have to find your own sound. I've tried my best to describe the sound differences among all these components. In the end it'll be up to the listener to decide which he/she prefers.

Edit: If you ever want to see what I prefer, just check my profile, because it keeps changing. After going through all of these opamps twice to verify the differences and make sure they were all seated properly, I've come back to the 3xLME49720s for their sheer soundstage size and depth and smooth tonality.

 

[Shahrose]

Quote:

Originally Posted by ROBSCIX /img/forum/go_quote.gif I haven't heard a lack of bass when I have listened to some discrete opamps nor have heard mention of it.

I really think the discrete opamps are designed optimally for higher voltages. I'm not surprised they aren't performing up to snuff with the STX, but perhaps that will change with time.

 

[Dodger1]

I just finished comparing my old setup, LM6172's in the I/V spots and an LT1364 in the buffer, to LME49720's in the I/V spots and an LM6172 in the buffer.

I compared the two setups with my AD900's, through the headphone out jack of my STX; with Dolby headphone enabled. I've ended up giving a slight nod to the 49720's but it was a close call; close enough that I ended up switching between the two setups twice.

 

[zzzmonster]

Quote:

Originally Posted by Shahrose /img/forum/go_quote.gif So Alydon, I tried the LM6172 in the buffer spot with 2xLME49720 and surprisingly, it sounds quite different from before. The bass no longer cuts out, and there's no unneeded warmth to the sound (still add warmth, but not excessively). I believe it wasn't making contact properly before because now it sounds great. I feel like it's a compromise between the sound of 3xLME49720 and 1xLME49720/2xJRC2114d without most of the drawbacks. The 3xLME49720 have a larger/airier soundstage, but not by much and the JRC2114 have more solid and hard-hitting bass (a bit more defined too), but again, not by much. So I feel this is the best setup so far...and we've converged on our choices finally. The JRC2114 have this upper treble harshness that just seems to grate on you. In fact, I feel there's a lot of things wrong with the treble when I'm using those. They have excellent bass/midrange though, maybe the best of any opamps I've used. Anyways, I'm keeping the 1x LM6172/2x LME49720 for now to test it further.

Does this setup sacrifice the midrange,maybe we just need another new opamp in the buffer to tame the jcr2114?

 

[Shahrose]

Quote:

Originally Posted by zzzmonster /img/forum/go_quote.gif Does this setup sacrifice the midrange,maybe we just need another new opamp in the buffer to tame the jcr2114?

No, it doesn't sacrifice the midrange. It just makes it a bit less prominent and more distant. With the JRC's the midrange surrounds you because of its wide soundstage and its smooth tonality gives voices a hefty, visceral feeling (and makes voices more upfront in general). However, the treble issues have been present even with the LM4562, LME49720, LT1361, OPA2107, and LM6172 all in the buffer spot with the JRCs, so I think the buffer may not be sufficient to rectify the treble response of the JRCs, but I may be wrong.

 

[zzzmonster]

I have to confess I like the voices upfront, cos in a rock music, in most other setups, the vocals drowns out. That I why I hope to keep the JCR2114 and swap the buffer,maybe with something else not yet tested...

Link: diyAudio Forums Archive - Opamp Comparisons

 

[ROBSCIX]

Quote:

Originally Posted by Shahrose /img/forum/go_quote.gif I really think the discrete opamps are designed optimally for higher voltages. I'm not surprised they aren't performing up to snuff with the STX, but perhaps that will change with time.

Actually the STX swings from +12 to -12 volts which is enough to use discrete opamps. They were performing fine with the STX from what I have heard.

As for the other post about the bass, Like any opamp used for the buffer, if it is not a good match with the I/V amps, you can get very different signatures some will sound good and others not so much.

 

[fzman]

question for those of you using the 49720s-- are you using the metal can parts? they definitely sound better, but are a bit of a hassle to bend into shape. Once done, however, they stay put. i even put a pair of the metal can 49710s on a brown dog, and got it to stay in (I've got an htpc case, though, so they are side-ways, not upside down).

the pair sounded a teeny bit better than the dual-pkg 49720.

Just finished a headphone amp using the metal can current feedback 49713s, powered by an amb sigma22 psu which i built. Haven;t hooked it up to the essence computer yet, but it sounds good from the prodigy hd-2 deluxe, using a pair of lt1028s on a brown dog adapter.

sheesh, this is fun!!!!

 

[ROBSCIX]

Have you compared the DIP8 to the metal can modules of the 49720?

 

[ROBSCIX]

I think I will be checking out some discrete units and I will let you guys know if your interested.

 

[Bojamijams]

Of course we are

 

[Shahrose]

Quote:

Originally Posted by ROBSCIX /img/forum/go_quote.gif I think I will be checking out some discrete units and I will let you guys know if your interested.

I've been waiting for your impressions for a while now.