[WiR3D]

Quote:

 
 
I know these posts were over a week ago, I just wanted to note...
 
The 'common perception' is logical.  You can construct a DAC section and amplifier section on the same circuit board, or you can construct a DAC section and amp section on two seperate circuit boards, with two enclosures surrounding them, so what is the difference?  The difference is... if you get a nice rectangular piece of circuit board and connect them again... nothing.   This is also known as a cable, unless cables have some sort of issue.
 
So back to my situation - I'm not looking for the ultimate DAC or a DIY project right now, I just want something that doesn't have hints of colour or tint in the signal path for experimentation purposes and peace of mind.  For example if I want to try the OPA1611 versus OPA827 in my DIY amplifier, I wouldn't feel right with the Lite-DAC with 2x AD847 supplying the signal, let alone the TeraDak if it improves with film caps and fancier resistors.
 
I know NOS sounds pretty weak compared to modern OS chips, and if you scored them in 10 different categories from 1-10 OS would easily win, but NOS does win in at least 1 category I am fairly certain of (via my listening, not specs), which is why it's still used today in various high-end projects.
 
I might be chasing a ghost asking for advice on a 'pure' DAC which is just a lonely chip with nothing around it, but I hope my clarification makes sense that some DAC's are purer than others.  For the end result it may not be very important factor, but for evaluation purposes you need as little colour as possible.
 
In other words a pre-amp might be technically better to have in some situations for the end result, but if you're building or evaluating an amplifer you don't want a weak sounding pre-amp supplying it right...

I like your thinking, I support this question

 

[qusp]

what exactly IS the question?

 

[kiteki]

The op-amp choice behind the RCA in my DAC affects the sound of the amplifer it's connected to.
 
The OPA2604 behind the line-out in my Teclast T51 has a '2604' sound to it.
 
In both cases there is one variable too many, I'm just looking for - or looking for knowing what to look for - in a DAC or DAP that can avoid this variable.

 

[qusp]

only if you use a current out dac and drive your headphones directly from the IV convertor. only certain chips are suitable for this however, as only some chips are capable of dealing with the fast glitch energy of the current output; let alone at the same time as being loaded with headphones many completely unsuitable opamps are used for IV.
 
the interaction between stages will be mitigated somewhat if you use a proper buffer after the IV like BUF634 or LME49600.
 
in general though no, there will always be another variable, even if its just how well a certain chip will drive the cable. your best bet is just to make sure you keep either the amp, or the dac circuitry unchanged for the duration of each test of the other link in the chain.
 
from what ive seen however you seem to struggle with this =)
 
i'm not sure why though, you have multiple headphones you will try and will be trying multiple amps. find one you like, however the combination comes to be, who cares, just leave it and stop fiddling. an amp should perform on its own merits with multiple sources anyway.

 

[iamdacow]

hey guys maybe you can help me i have a 9v jds cmoy bb and i am looking to pair it with my jh16s, es5s and westone4s can anyone recommend a chip that is good for these earphones i want a clean and clear sound which i can easily pick out details with fantastic treble without sacrificing soundstage, mids lesser bass is ok as long as the opamp is very clear thanks

 

[qusp]

recommend something other than a cmoy for those headphones , youre right to put most of your money into headphones, but I think youve taken that a bit too far. no opamp 'upgrade' is going to turn a cmoy into a great amp

 

[iamdacow]

Quote:

recommend something other than a cmoy for those headphones , youre right to put most of your money into headphones, but I think youve taken that a bit too far. no opamp 'upgrade' is going to turn a cmoy into a great amp

Yeah i do have a good amp for those cans however i got the cmoy just for fun so what could i get as an op amp?? Thanks

 

[Jimlad]

So I've decided to take the plunge into high-end audio and I've ordered myself some Sennheiser HD800s and a Matrix M-Stage amp. As a source, for now I think I should be able to get away with using my computer; I'm using an Auzentech Prelude card which has AKM-4396 DACs, which I'm told should be pretty good.
 
My question is, since I'm aware that opamps can make a big difference to the sound, is it worth me spending a little bit extra and upgrading the opamps in either the Auzentech or the Matrix (or both)? The Auzentech uses a LM4562NA for front stereo channels (which is what I'll use as my source), while the Matrix uses a OPA2134. The alternative is that I go for an external DAC, but that would probably be an order of magnitude more expensive and I don't know if it'll be that much better.
 
I was thinking maybe I should replace both the sound card and amp opamps with pairs of OPA827s or maybe ADA4637-1s, but honestly I'm open to all recommendations since I'm pretty new to this. I assume I'm going to have to use an adapter to connect them from dual chip to single socket - anyone know where I can get something like this in the UK? Also, for the opamps, is mouser the best place to go?

 

[kiteki]

only if you use a current out dac and drive your headphones directly from the IV convertor. only certain chips are suitable for this however, as only some chips are capable of dealing with the fast glitch energy of the current output; let alone at the same time as being loaded with headphones many completely unsuitable opamps are used for IV.
 
the interaction between stages will be mitigated somewhat if you use a proper buffer after the IV like BUF634 or LME49600.
 
in general though no, there will always be another variable, even if its just how well a certain chip will drive the cable. your best bet is just to make sure you keep either the amp, or the dac circuitry unchanged for the duration of each test of the other link in the chain.
 
from what ive seen however you seem to struggle with this =)
 
i'm not sure why though, you have multiple headphones you will try and will be trying multiple amps. find one you like, however the combination comes to be, who cares, just leave it and stop fiddling. an amp should perform on its own merits with multiple sources anyway.

 
Thanks for the answer, that's the kind of specific answer I was looking for, plus it led me to further searching and info.  I have been driving headphones directly from the IV however the AK4396 is voltage-out it seems, I wonder what a good current-out DAC is?  When you say buffer after the IV, do you mean current-out DAC into passive IV, into the amplifier with a buffer chip into the op-amp?  Just curious, what happens if you used a chip not designed as a buffer as a buffer?  Like LT1115, or some video op-amp?
 
I think if you made a blog in NwAv style centered around building a DAC, or an amplifer, it would be a refreshing read, since you seem to focus on scopes and specs a lot while being open minded to some other concepts as well, while he refuses to even measure AD797.
 
Just my pov.
 
 

Yeah i do have a good amp for those cans however i got the cmoy just for fun so what could i get as an op amp?? Thanks

 
You will have to focus on op-amps which sound good supplied from a single 9V battery (+-4.5V).
 
Or you can just buy a selection and try your luck.  AD797ANZ fits your description of sound at least.
 
 

So I've decided to take the plunge into high-end audio and I've ordered myself some Sennheiser HD800s and a Matrix M-Stage amp. As a source, for now I think I should be able to get away with using my computer; I'm using an Auzentech Prelude card which has AKM-4396 DACs, which I'm told should be pretty good.
 
My question is, since I'm aware that opamps can make a big difference to the sound, is it worth me spending a little bit extra and upgrading the opamps in either the Auzentech or the Matrix (or both)? The Auzentech uses a LM4562NA for front stereo channels (which is what I'll use as my source), while the Matrix uses a OPA2134. The alternative is that I go for an external DAC, but that would probably be an order of magnitude more expensive and I don't know if it'll be that much better.
 
I was thinking maybe I should replace both the sound card and amp opamps with pairs of OPA827s or maybe ADA4637-1s, but honestly I'm open to all recommendations since I'm pretty new to this. I assume I'm going to have to use an adapter to connect them from dual chip to single socket - anyone know where I can get something like this in the UK? Also, for the opamps, is mouser the best place to go?

 
I use the AKM AK4396 too.
 
My favorite sound with all op-amps I have considered, is OPA827 in the DAC, and OPA627 in my amplifer.
 
Those are pretty expensive at mouser, so I'd go with an ebay seller with 99-100% feedback and you'll save a lot of money, at least that's what I've done.

 

[PurpleAngel]

Quote:

So I've decided to take the plunge into high-end audio and I've ordered myself some Sennheiser HD800s and a Matrix M-Stage amp. As a source, for now I think I should be able to get away with using my computer; I'm using an Auzentech Prelude card which has AKM-4396 DACs, which I'm told should be pretty good.
 
My question is, since I'm aware that opamps can make a big difference to the sound, is it worth me spending a little bit extra and upgrading the opamps in either the Auzentech or the Matrix (or both)? The Auzentech uses a LM4562NA for front stereo channels (which is what I'll use as my source), while the Matrix uses a OPA2134. The alternative is that I go for an external DAC, but that would probably be an order of magnitude more expensive and I don't know if it'll be that much better.
 
I was thinking maybe I should replace both the sound card and amp opamps with pairs of OPA827s or maybe ADA4637-1s, but honestly I'm open to all recommendations since I'm pretty new to this. I assume I'm going to have to use an adapter to connect them from dual chip to single socket - anyone know where I can get something like this in the UK? Also, for the opamps, is mouser the best place to go?

I would say to keep the Prelude for now. plug the Matrix M-stage straight into it.
On eBay, there is a seller (frugalphile), who sells LME49990NA SOIC op-amps pre-soldered on to a dual SOIC to DIP-8 adapter, ships from Canada. They might be a good choice for the Prelude.

 

[SpudHarris]

Quote:

So I've decided to take the plunge into high-end audio and I've ordered myself some Sennheiser HD800s and a Matrix M-Stage amp. As a source, for now I think I should be able to get away with using my computer; I'm using an Auzentech Prelude card which has AKM-4396 DACs, which I'm told should be pretty good.
 
My question is, since I'm aware that opamps can make a big difference to the sound, is it worth me spending a little bit extra and upgrading the opamps in either the Auzentech or the Matrix (or both)? The Auzentech uses a LM4562NA for front stereo channels (which is what I'll use as my source), while the Matrix uses a OPA2134. The alternative is that I go for an external DAC, but that would probably be an order of magnitude more expensive and I don't know if it'll be that much better.
 
I was thinking maybe I should replace both the sound card and amp opamps with pairs of OPA827s or maybe ADA4637-1s, but honestly I'm open to all recommendations since I'm pretty new to this. I assume I'm going to have to use an adapter to connect them from dual chip to single socket - anyone know where I can get something like this in the UK? Also, for the opamps, is mouser the best place to go?

 
PurpleAngel mentioned LME49990 and I agree. I've bought about 6-8 off the same seller, he ships quickly and his soldering is faultless. In the UK I use Farnell for most purchases but have started using a smaller company lately who seem a bit cheaper - Timeline Components.

 

[Jimlad]

Thanks for the advice, guys. How do you find the LME49990 compares to the OPA827? Since it's not too pricey I think I might just buy two pairs and first replace the opamp in the Auzentech, then see how it goes and try replacing the Matrix opamp to see how much of a difference it makes. That said, should I expect to hear much of a difference with the LME49990 in the Matrix?

 

[kiteki]

Thanks for the advice, guys. How do you find the LME49990 compares to the OPA827? Since it's not too pricey I think I might just buy two pairs and first replace the opamp in the Auzentech, then see how it goes and try replacing the Matrix opamp to see how much of a difference it makes. That said, should I expect to hear much of a difference with the LME49990 in the Matrix?

 
Haven't heard any LME's yet.
 
The difference is pretty subtle, and yet significant at the same time.  I showed my portable amp to someone at a headphone store (him not having any idea what was inside of it), and he described the the sound of it exactly how the OPA627 is often described online.
 
When I had a 'mystery box' of op-amps and listened to all of them, my two favorites happened to be the two most popular choices when I looked them up.
 
It seems like Auzen is a fan of the OPA627 too - http://www.auzentech.com/site/products/opamp_intro.php
 
In my opinion, if you use it you should put it in both the sound-card and the amp, or OPA827 in the sound-card, to get the 'right' sound, pairing OPA627 in the amp with a JRC in the DAC / sound-card doesn't sound 'right', at least in my limited experiments.
 
Then there is always synergy - with the headphones, speakers or IEM's you're using, and the DAC chip.
 
Music, and which studio it's recorded in, isn't very important at all, aside from trying different tracks from complicated electronic music, to a solo acoustic instrument or voice, and being very familiar with the sound of your standard / favorite equipment, which takes a while I think.
 
If you focus on details, like whispers or faint tapping, I don't think you'll hear any difference, the difference is in the overall character, like 'digital' or 'analog' sounding.

 

[kiteki]

p.s. This thread may interest you, you'll most likely get more difference in sound from these op-amps than the standard ones out there - http://www.head-fi.org/t/412110/burson-discrete-opamp-v2-in-auzentech-x-fi-prelude
 
http://www.audio-gd.com/Pro/diy/OPA/OPAEN.htm
 
For example you can try LME49990 verus dual OPA-SUN.

 

[Mad Max]

OPA827 rules.
 

 
I think that it could still benefit from a little more bypassing.  =p
 
 
LME49990 is great, too.