[Welly Wu]

I checked out John_JCB's thread but I'm kind of wondering which other op-amps can be rolled with the Emmeline HR-2. I'd prefer to see a complete list even with some repeated op-amps being represented anyway. How do I roll op-amps with my Emmeline HR-2? Mine did not come with any other op-amps other than the AD797 and zero instructions or diagrams on how to do it. Thanks.

 

[Ray Samuels]

Op-Amps rolling for Emmeline HR-2..

Welly Wu...I was planning to send you the instructions soon on how to do the IC's rolling on Emmeline, & I will mail them very soon.
Here is a list of some of many op-amps that will do so very well with your amp:
AD797, AD825, AD8610, OPA604, OPA637BP, OPA627BP, LT1028.
LT1115, OPA134 & the list keeps on going. I am sure there are many other headfiers who know some other good op-amps.
PPL sugested some really good ones that he had tried with HR-2.
Cheers.
Ray Samuels

 

[Welly Wu]

Mr. Samuels,

Thank you for your reply. Which op-amp in your opinion provides the greatest retrieval of details from music? Thanks.

 

[john_jcb]

While you are awaiting the instructions you need to have a little tool that really makes it easy. The tool looks like a big pair of tweezers with a small 90 degree bend at the end. You can get them at Radio Shack or any other electronics store.

It is real easy but just take your time and make sure the pins are aligned with the sockets.

 

[Welly Wu]

Mr. Samuels,

Thank you for your reply. Which op-amp in your opinion provides the greatest retrieval of details from music? Thanks.

 

[Ray Samuels]

Welly...
Depending on your system, you can tweak the sound to your liking. If your source or headphones are on the bright side then The AD797 will do great, A warm source with tube output, the OPA627BP does a remarkable job. For a balanced source & headphones the LT1028 is super. Also keep in mind the interconnectors, as they tend to give warm, balanced or bright input to the amp. There are many factors that you have to play with to make the sound that pleases you. Remember what might sound great to you, might sound different to some other person.
Cheers.
Ray Samuels

 

[john_jcb]

Here is a picture of the tool you need:

It slips right under the op amp and you pull it right out.

 

[gpalmer]

Originally I really wanted to do some IC rolling with the HR-2 but since it got back from having Ray work on it it's sounded so good that I don't want to tweak anything! I am curious though, is there a danger of wearing anything out if you swap the op amp too often? How do we identify which op amps are suitable, are there specifications they have to meet? I know not all op amps are packaged so that they can be plugged in like this, how do we tell which ones can be?

 

[Ray Samuels]

Hi gpalmer....
A single Audio op-amp in an 8 pins package are all compatible.
Which means they all have the inverted input as pin #2 The none inverted input is pin #3 & the output is #6. Having two voltages that are opposite of each others in polarity, pin # 4 is the input for the negative voltage while pin # 7 is the input of the positive voltage. That means you can replace any of these op-amps with each others & have no problems. In some op-amps pins 1, 8 & 5 are used to perform some other functions that if they are inserted in some other amps no harm will be done. On the other hand you have the other op-amps that come again in the 8 pins package but it has two op-amps built into that packege. Which is used to operate both the left & right channel. One single example is AD8610 & AD8620 The 10 stands for one op-amp being inside of this 8 pins chip, the 20 stands for two op-amps on board.
Yes there are some op-amps that operate on a sigle power supply. Which means you will need the positive & ground only.
So if you really want to know if a certain chip works on your amp you can get the PDF of that chip & compare it to yours as to inputs/output & power supply before you attempt to insirt that op-amp in your amp.
Cheers.
Ray Samuels

 

[ppl]

I like the AD8065 in the HR-2 this OPA to me sounded better overall in this Amp than the AD797, AD-843, OPA-627,LT1028. This was using Sony MDR-7506, Grado HP-1 and SR225. I tried the Senn HD-600 but did not spend alot of time in them with the HR-2.

The AD-8610 and AD-8065 provided the HR-2 with a more nutral sonic presenentation on the Grado and sony can's than the others. I dod not like the AD797 it has too much grain for Highly revealing Headphones. The MRD 7506 Brought this imeaditaly to my attention and once i heard this it also was apperent on the Grados just not as in your face as on the 7506's.

The AD-8065 and AD-8610 sound different and YMMV I did these listening tests with MY PC using a M Audio 96/24 and assorted wav. and quality MP3's as well as MPEG Music Videos. I also used the Maridian cd player that Wilson M Also provided with Good interconnects of whitch i can't at the moment remember what Kind thay were. I used a standard shielded AC power cord on the HR-2 as Ray recomended.

 

[john_jcb]

PPL,

Thanks? Just what I need are some more things to try. I have a pair of OPA604AP's to try as well. They have been here for a week or so but I have not swapped them out yet. The number of Op Amps seems almost endless and each one has their own sonic character.

BTW How much are the AD-8065 and AD-8610's?

 

[Welly Wu]

Hi all! Please clarify something for me (as I have yet to receive my instructions for swapping out op-amps): does my Emmeline HR-2 use ONE op-amp or is it a set of op-amps that I must replace in order to "season" the sound? Can someone find the picture with the HR-2 removed of its black cover and circle the place where the op-amp is located on the circuit board so I have a better idea where it is and what it looks like? Thanks.

 

[markl]

Quote:

I dod not like the AD797 it has too much grain for Highly revealing Headphones.

That's an interesting observation, and I agree that the AD797s are not as supernaturally "clean" as the OPA627s (the only other op-amp I've rolled so far). But with my Sony R10s (pretty resolving cans), I found that the little extra "sparkle" and ever-so-slight edginess (and miniscule dash of grain--no denying it's there) the AD797s provide is not objectionable given all the other positives they had for me vs. the comparitively neat and tidy OPA627s. As I point out in my review, the OPAs were very respectable, but a bit too conservative for me. The AD797s are more involving and frankly rock harder to these ears. Welly, I did a pretty big comparo of the two op-amps in my review, maybe that will help you.

ppl,
Do the AD8065s plug directly into the HR-2, as I recall one of the AD replacement ICs had to have some work done to it to make it fit in the socket.

Also, where is a good place to get AD8065s and what is a good price for them? Thanks.

Mark

 

[john_jcb]

Quote:

Originally posted by Welly Wu Hi all! Please clarify something for me (as I have yet to receive my instructions for swapping out op-amps): does my Emmeline HR-2 use ONE op-amp or is it a set of op-amps that I must replace in order to "season" the sound? Can someone find the picture with the HR-2 removed of its black cover and circle the place where the op-amp is located on the circuit board so I have a better idea where it is and what it looks like? Thanks.

Welly Wu,

Look at the picture of the amp in this thread

http://www4.head-fi.org/forums/showt...threadid=47986

Towards the right you will see two square devices that have blue components above and below them. These are the two op amps. If you look closely you will see the name of the op amp stenciled on it. You will also notice a small notch that is used for alignment. When you install the new op amp the notch always must be at the same end as it was in the original. Both op amps must be replaced when you roll them.

 

[Ray Samuels]

Welly my freind...
I am trying to catch up with you. You are just too fast for me.
Instructions on rolling op-amps & how to remove the emmeline HR-2 top cover, & which pin is #1 & how to make sure the op-amp is lined up with it's socket. Also how does an op-amp looks like to poeple who don't know what they are looking for, All that is coming your way. I do not leave you with out making sure that you know what you are dealing with. Please give me some time to get all than done. You now enjoy the sound that you have so you get very used to it's characteristics & sonic before you can roll op-amps. it is too soon You would not hear the differance until you know how the first one sounded to your ears. Also remember that when you install the new op-amp, Just like a tube, you woun't really know how it is sounding unless you break it in for at least 100 hours of music before you can compare it. Once they are burned in then you can do the comparison. For those headfiers that order the Emmeline HR-2 with an extra set of OP-AMPS I make sure that I burn-in the extra set before I ship it with the amp. Once they are broken-in then listening to sonic differances is enjoyable thing to do. John_JCB does a lot of IC rolling & comparison between three or four of his op-amps in his posetion & he did write a thread regarding the op-amp rolling, he could help.
Cheers.
Ray Samuels