[mrarroyo]

What Op-Amp is used in the Micro? BTW I just ordered one.

 

[kugino]

Quote:

Originally Posted by mrarroyo What Op-Amp is used in the Micro? BTW I just ordered one.

finally ordered one, huh miguel!

my supermini IV was sent back for the final tweaks the middle of last week and i got an email yesterday that it is on its way back to me. so for those of you waiting to send yours in, it's quite fast.

i've decided to sell mine as i have a glut of portable amps...but i, too, did think that the supermini IV did not drive my k81dj and ksc-75 to extremely loud levels coming out of my nano. had i been using some high-ohm headphones i certainly didn't think the supermini could drive them very well...maybe i'm wrong. but i only have IEMs and low-ohm cans so can't test this for sure. i will do a little listening test with the supermini IV and some other portables i have before selling it...

 

[digitalcat]

And it's set at higher gain?
Quote:

Originally Posted by kugino i've decided to sell mine as i have a glut of portable amps...but i, too, did think that the supermini IV did not drive my k81dj and ksc-75 to extremely loud levels coming out of my nano. had i been using some high-ohm headphones i certainly didn't think the supermini could drive them very well...maybe i'm wrong.

 

[aluren]

Quote:

Originally Posted by mirumu The veil you mention sounds like it could be the treble roll off we talked about here a while ago. That was certainly what I found with my 99% SM IV and my E500s. I don't believe the buffers affect this, I've tried other buffer combinations. As far as I'm aware, the number of buffers only affects the current supplied to the headphones. My guess it that it's the opamps causing the problem (I'm hoping it's not inherent in the amp design) although I can't really comment until I get mine back from the upgrade. When kaushama and I posted to Xin's forums about the treble roll off he suggested using a OP275 opamp in channels 3&4.

yeah i've read about the treble roll off issue and i thought that since my amp was shipped after xin had 'perfected' the design, i didn't really thought that the treble roll off would be a problem. i will take your advice and try the OPA275 in the 3&4 channels.

what tools would be preferred to use to remove opamps from the board? i've used a small screwdriver and kind of 'pry' it out, but i figured it will be quite damaging to the board. if a tweazer is suggested, does anybody know where i can buy one? thanks in advance.

 

[mirumu]

Quote:

Originally Posted by aluren yeah i've read about the treble roll off issue and i thought that since my amp was shipped after xin had 'perfected' the design, i didn't really thought that the treble roll off would be a problem. i will take your advice and try the OPA275 in the 3&4 channels.

You'll probably get to try the OPA275 before me then, I won't have my amp back for a while.

I figure Xin must have suggested it for a good reason.

Quote:

what tools would be preferred to use to remove opamps from the board? i've used a small screwdriver and kind of 'pry' it out, but i figured it will be quite damaging to the board. if a tweazer is suggested, does anybody know where i can buy one? thanks in advance.

Well you can get dedicated IC extractors but I don't know if there's room around the chips to use one of those on the SM IV. I've never found tweezers much good for removing chips, personally I just used a small screwdriver gently on good leverage points that won't hurt the surrounding components.

 

[aluren]

i already have the opa275, but i find it hard to remove opamps in the 3rd channel... yeah i've used a screwdriver to try to pry it out, but i tend to somehow not pry it out straight, and i end up bending the tip. it's already happened 3 times with my opa627 and i don't wanna break an expensive opamp. but i guess the screwdriver is the best way huh mirumu?

 

[mirumu]

Quote:

Originally Posted by aluren i already have the opa275, but i find it hard to remove opamps in the 3rd channel... yeah i've used a screwdriver to try to pry it out, but i tend to somehow not pry it out straight, and i end up bending the tip. it's already happened 3 times with my opa627 and i don't wanna break an expensive opamp. but i guess the screwdriver is the best way huh mirumu?

At a guess, it might make things easier if you take out the buffer for channels 3&4 first. That one is quite easy to remove I find being on the bottom of the board and with it out you would have a bit more room around the opamp.

Edit: I also don't really pry them out, I get a flatter screwdriver and turn it back and forth under the opamp. That stops too much pressure being put on the amp if it suddenly comes free.

 

[aluren]

wow you're right, mirumu. i've just put the opa275 in the 3/4 channel and the veil is completely gone! i am so impressed with the e500. good stuff! thanks for the advice!

EDIT: i shouldn't say "completely gone", but rather, it is better than the OPA2134. that opamp pretty much put a blanket over the sound and everything sounds muddy. with the OPA275, the sound is revealed a bit more. i need to do more listening before saying anything else.

 

[aluren]

another question i have is, do opamps need to be burn in? it seems like everytime i switch opamps, the sound tend to be pretty harsh at first...

 

[mirumu]

Quote:

Originally Posted by aluren wow you're right, mirumu. i've just put the opa275 in the 3/4 channel and the veil is completely gone! i am so impressed with the e500. good stuff! thanks for the advice!

Well I was only passing on Dr. Xin's advice. Now I'm really looking forward to getting my amp back and putting one of those in there too.

 

[mirumu]

Quote:

Originally Posted by aluren another question i have is, do opamps need to be burn in? it seems like everytime i switch opamps, the sound tend to be pretty harsh at first...

Not sure 100% but I have heard many comments from people complaining of opamp harshness before they've burnt in. I do remember Dr. Xin saying somewhere on his forums that the SM IV needs some burn in time too.

 

[jamato8]

Quote:

Originally Posted by aluren another question i have is, do opamps need to be burn in? it seems like everytime i switch opamps, the sound tend to be pretty harsh at first...

Everything envolved with the electron flow needs some time to settle. There are the internal components of the opamp and so forth.

 

[Cuppa]

I've got a default config on order (with I assume the 134 opamps). I've not had a shipping notice yet and am UK based so opamps are a little harder to obtain.

Should I ask for the 275 setup while I can instead based on the above re treble rolloff, or a maxout potentially?

My phones are Shure e4c and Grado BD GS-1000.

 

[goto2003]

OP275 and AD8610 are more detailed than OPA627, let alone OPA2134. BB chips tend to be rich and dark.

 

[aluren]

another question, my xinfeed doesn't seem to make a difference when i turn it on. is there suppose to be very very subtle difference that takes time to adapt?