Asus Essence One Headphone Amp/DAC (CeBIT 2011)
May 22, 2013 at 3:19 PM Post #2,131 of 3,573
I wasn't meaning that you need to use the LME49710HA's, or that those come stock, just that I used the same opamps at both the headphone out and RCA out.
 
You could try placing different op amps at the headphone out though to alter the sound to your taste.
Since the LME49600 opamps are only located at the headphone out I would guess that is the source of the shrillness.
 
May 23, 2013 at 2:15 PM Post #2,132 of 3,573
Quote:
Well, both the headphone amp section of the E1 and the amp that I have (parasound Zamp) use torodial transformers, so that part of both designs is similar.
 
Beyond that, I don't have much to compare design-wise.
 
I'm using a stock Muses, so I presume this to be my setup:
 Balanced/ Un-balanced I/V:4 x MUSES 01
● Balanced/ Un-balanced LFP: 2 x MUSES 01
● Balanced/ Un-balanced Buffer: 3 x LM4562NA
● Headphone: 2 x LME49600
 
Which is from the Asus website... that's different from the LME49710HA's that mwindham08 has been referring to...
 
I'm not sure what I/V, LFP, and Buffer refer to. Still learning this stuff.

I will try and explain simply from memory, different opamps in the circuit perform different tasks such as:
 
I/V -> Current(I) to Voltage(V) converters: DAC chips are current output components so they require a I/V conveter, some chips have this converter built in and others use external I/V sections.
mosthighe endDAC chips dorequire externalI/V sections as this allows more flexibility for design and sound quality development.
 
LPF-> Low Pass Filter. to put it simply, it filters out everything except the signals you want, which is within the audio bandwidth.  They are typically used to remove the high frequency component/artifacts
that can be present on the DAC chips output. The audio signal being the lower frequency part of the signal, hence LPF.
 
Buffer-> Justbuffers to signal and/or provides level conversion to the signal for output or prior to being sent to another circuit component such as an Amp..etc.
Some opamp circuit positions will have a very pronounced affect on the overall sound quality/signature and others, not so much.
 
Hope that helps.
 
May 29, 2013 at 9:31 AM Post #2,133 of 3,573
Hi guys,

I have finally picked up an order of E1 from Centre Com in Australia yesterday. It was out of stock so I had to pay a deposit and wait for the stock to come in. At first they said I had to wait for 2 to 3 weeks but then they said 3 to 5 days because apparently they've found out that the supplier has one LAST stock.

I opened it just now with anticipation but to found out that it has a few scratches on the front panel already and out of the 2 accessory boxes, one of them was empty. So my question is, do you guys reckon my unit has been opened and returned before? Or could this be a refurbished item? Or maybe the built process was so poor the unit got scratched while it was being built??

Are there any good ways to find out? I have ask Centre Com before the purchase to see if there is a possibility this LAST stock was a returned or refurbished stock but they said they only sell new stocks.

THANKS! :)
 
May 29, 2013 at 10:09 AM Post #2,134 of 3,573
Quote:
Hi guys,

I have finally picked up an order of E1 from Centre Com in Australia yesterday. It was out of stock so I had to pay a deposit and wait for the stock to come in. At first they said I had to wait for 2 to 3 weeks but then they said 3 to 5 days because apparently they've found out that the supplier has one LAST stock.

I opened it just now with anticipation but to found out that it has a few scratches on the front panel already and out of the 2 accessory boxes, one of them was empty. So my question is, do you guys reckon my unit has been opened and returned before? Or could this be a refurbished item? Or maybe the built process was so poor the unit got scratched while it was being built??

Are there any good ways to find out? I have ask Centre Com before the purchase to see if there is a possibility this LAST stock was a returned or refurbished stock but they said they only sell new stocks.

THANKS!
smily_headphones1.gif


You should return it if it's damaged. Empty box is normal, the extra box is for a region like europe that use different power cables in different areas so its boxed with more than one cable
 
It's up to you but I would return it and wait for the newer E1s to ship
 
Good luck
~Steve
 
May 29, 2013 at 12:47 PM Post #2,135 of 3,573
You should return it if it's damaged. Empty box is normal, the extra box is for a region like europe that use different power cables in different areas so its boxed with more than one cable

It's up to you but I would return it and wait for the newer E1s to ship

Good luck
~Steve


Thanks Steve,

Do you think they will take the return if the scratches are only light scratches? Plus, I'm not sure if they can get anymore stocks, as it's not listed on their website anymore.

bwt...I have just ordered 6 Muses01 from a seller on Aliexpress for about 110 USD shipped (can't wait to get them). The seller also recommended me to get the OPA128SM/883, which he said was the BEST amp!
 
May 30, 2013 at 1:54 AM Post #2,137 of 3,573
Yeah ill definitely report back as to whether or not this seller is legit. He did send me photos of the importation declaration for of those amps. We also spent quite a long time chatting on the website regarding to these amps... :wink:

I'm going to bring the E1 back to Centre Com tomorrow and see what they say. Even if they can't replace the unit, I think it's only fair if they give me a partial refund. I'm not paying nearly 400 bucks for a scratched unit!!
 
May 30, 2013 at 10:33 PM Post #2,138 of 3,573
Quote:
Yeah ill definitely report back as to whether or not this seller is legit. He did send me photos of the importation declaration for of those amps. We also spent quite a long time chatting on the website regarding to these amps...
wink.gif


I'm going to bring the E1 back to Centre Com tomorrow and see what they say. Even if they can't replace the unit, I think it's only fair if they give me a partial refund. I'm not paying nearly 400 bucks for a scratched unit!!

Or you could just contact Asus Australia http://www.asus.com/au/support/
 
May 31, 2013 at 1:31 AM Post #2,139 of 3,573
Yeah I have. They said it's very unlikely the scratches would've got there during assembly. They told me to go back to Centre Com and ask them to ask their distributor.

Anyways... I just got back from centre Com today and they told me they will let me know what the distributor says on Monday or Tuesday. They've also said feel free to use the unit. But I don't think I'll use it at all because it might decrease the chance of me exchanging it for another unit if I actually use it.

Man... This is tough... It's sitting there in front of me and I can't even use it ;(

I also have a gut feeling that this is not going to go anywhere, they will probably just said it was a brand new unit and bad luck you're stuck with it ;(
 
May 31, 2013 at 3:00 AM Post #2,140 of 3,573
Quote:
Yeah I have. They said it's very unlikely the scratches would've got there during assembly. They told me to go back to Centre Com and ask them to ask their distributor.

Anyways... I just got back from centre Com today and they told me they will let me know what the distributor says on Monday or Tuesday. They've also said feel free to use the unit. But I don't think I'll use it at all because it might decrease the chance of me exchanging it for another unit if I actually use it.

Man... This is tough... It's sitting there in front of me and I can't even use it ;(

I also have a gut feeling that this is not going to go anywhere, they will probably just said it was a brand new unit and bad luck you're stuck with it ;(

Long story and if you want to know more about this problem go back about 20 pages or so, most E1 standard editions have a channel imbalance including my unit. So if I was you I would be seeing if the E1 you have also has this imbalance, test with a mono track if you can, and for some magical reason you find out it doesn't have the imbalance problem you shouldn't return it and live with scratches
 
Let us know how you go
~Steve
 
May 31, 2013 at 7:13 AM Post #2,141 of 3,573
So from what I have been reading which is the whole 143 pages of posts here... The imbalance problem only occurs at low volume right?

I'm not sure if I want to actually try the unit until I hear back from centre Com next week though. You reckon I should?
 
May 31, 2013 at 8:33 AM Post #2,142 of 3,573
Quote:
So from what I have been reading which is the whole 143 pages of posts here... The imbalance problem only occurs at low volume right?

I'm not sure if I want to actually try the unit until I hear back from centre Com next week though. You reckon I should?

 
I have to adjust the balance every time I turn it on, even if last time was perfectly balanced, however for most people its not this severe
 
May 31, 2013 at 2:03 PM Post #2,143 of 3,573
Must be lucky, my stock version has no imbalance with rca,xlr or headphone out(and this is even on low volume). Got it around the end of february, might have been some changes? or that im lucky.
 

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