[Audio Addict]

Quote:

Originally posted by CRESCENDOPOWER After I listen to 797 for a while I'll give Todd a call. Thanks!

I thought you had the 8610 op-amp and wanted to try the AD797. I am not sure if Todd carries the 8610 or not.

Sorry about the confusion.

 

[CRESCENDOPOWER]

.

 

[kaiwei]

Please post impressions!

 

[Welly Wu]

Okay, so I re-read some of the links provided and I decided on the AD8065 op-amp. I'll call Mr. Samuels to get some.

I need that Radio Shack tweezer. Okay.

1. Unplug the power & make sure the red light is off

2. unscrew the top allen screws on both the front and rear of the amp

3. Lift up the top metal case

4. Look for the AD797 op-amps in the rear half of the amp in between those two blue thingies.

5. Pull up one using the tweezer. Put in AD8065 in exactly the same way I pulled up the AD797; should be something akin to pre-school shape matching, no? Anyway, make sure that PIN #1 which is located directly to the left of the cutout matches with PIN #1 on the PCB. Make sure all of the other pins fit into their appropriate slots on the PCB.

6. Repeat with op-amp #2

7. Replace the cover, re-screw the holes, plug in the power

8. Wait 100 hours before I can hear a slight change in sound.

Am I getting this right?

 

[ppl]

The AD-8065 is like the AD-8610 and is an SMT device requiring one of those Brown Dog adaptors like the AD-8610. In the HER using Sony MDR-7506, Grado HP-1, and Grado SR-225 the AD-8065 was my favorite op amp the top end is smoother than with the AD-8610 and the Bass Tighter. The top octave is more extended on the 8065 yet is not thrown in your face like the AD-8610. I did not like The AD-797 in the HR-2. if the op amp was not changeable and i had to judge the HR-2 using the stock op amp i would not have liked the amp much at all and would not have spent a week listening to it. With the AD-797 installed the upper mids are Brash while smearing the Brass all into one homogeneous Tsh. Tsh.. Tsh and the mids on voice was full of grain. Switching to the OPA-67, AD-8610, AD-8065 cured most all of this and most notable the Brass. The sonic flavor of all the op amps was slightly different. if i were to use the HR-2 with HD-600 or HD-580s then i would use the AD-8610 for a more prominent upper octave.

 

[Welly Wu]

PPL wrote, "The AD-8065 is like the AD-8610 and is an SMT device requiring one of those Brown Dog adaptors like the AD-8610."

Does this mean that the AD-8065 op-amp can not work with the Emmeline HR-2? Please explain. Thanks.

 

[ppl]

The AD-8610 and the AD-8065 are surface mount devices and the HR-2 requires a DIP package. you need an adaptor to adapt tese into the HR-2 Tangent sells the Brown Dog SMT to DIP-8 adaptors
http://tangentsoft.net/audio/shop/details/adapter3.html
a SMT device such as the AD-8610 and AD-8065 looks like this
http://www.lcaudio.dk/comp/ad825.jpg
a dip Looks like this http://www.lcaudio.dk/comp/ad844.jpg

the adaptor you need looks kike this http://cimarrontechnology.com/index....PROD&ProdID=12

Todd you might consider the AD-744 smooth and forgiving

 

[Welly Wu]

Well, after much trepidation and frequent phone calls to Mr. Ray Samuels himself, I have finally figured out how to switch operational amplifiers. I now have installed the AD8065 with the Brown Dog operational amplifiers. It will take all of this week and weekend before I notice the differences. I will write a mini review to keep everybody abreast of the situation; this operational amplifier seems to have garnered some piqued interest in Head-Fi for some reason.

 

[Welly Wu]

Quick update:

I've broken one of my AD8065 op-amps mounted on the Brown Dog adaptor.

Before I broke it, I heard a lot of background hiss when I use my Ultimate Ears UE-10 PRO. I guess it is because they are so damned sensitive and have an extremely low impedance level. They picked up this annoying hiss sound that I could not get rid of until I swapped back to the AD797 op-amps. I think it may have something to do with the slew rate of the AD8065 + UE-10 PRO. I might test it by doing an asynchronous pairing of the AD797 + AD8065.

 

[Welly Wu]

Scratch that! I just installed both the AD8065 & 797 op-amps side by side and I hear NO HISSING SOUND whatsoever. I think I know why: I selected the HiBit and Legato PRO profile #3 which is supposed to be "solid and balanced" but turned out to be extremely dark and warm. I think that in conjunction with the pair of AD8065 produced a hissing sound. Anyway, I just placed an order for more op-amps with Mr. Samuels. I'll keep this thread active until I get them and burn in each one.

 

[Welly Wu]

I just got my single AD8065 mounted on a Brown Dog Adaptor and a pair of LT1028 operational amplifiers from Mr. Samuels for my Emmeline HR-2. I will burn them in over the next two weeks and post my mini-review of their sound characteristics herein. I can not express to you how much of a profound shift in tonal balance, details, and blackness between notes occurs whenever I change op-amps. I like the AD797 for popular and rock music because it's got mojo. I love the AD8065 for classical music because it is dark, smooth, and very detailed. I have yet to try the LT1028 but I decided to buy it for jazz, showtunes, and vocal music; I think I made the right decision.

I will keep researching more op-amps to purchase over the next several months. There are not enough op-amps to satisfy my very wide musical tastes. Yet, these are enough and I am grateful to Mr. Samuels for designing a killer headphone amplifier in the Emmeline HR-2. It is indeed like a happy marriage for me!

 

[Welly Wu]

This question is directed to Mr. Samuels or anyone who has expertise knowledge and is willing to help me out.

I would like to know whether my Emmeline HR-2 headphone amplifier can use the OPA4743 operational amplifier: http://focus.ti.com/docs/prod/folder...t/opa4743.html ?

I am intrigued by HeadRoom Corporation's claim that it sounds "dry and down the middle...more neutral and articulate." Is it possible to roll this specific op-amp? Thank you very much for your help!

 

[Ray Samuels]

Hi Welly Wu...
The answer to your question regarding this op-amp is NO, you can not use it in Emmeline HR-2, as HR's power supply is +- 12VDC, while the op-amp is MAXed at +-6VDC, if installed in the HR-2 it will just burn. OPA743 8 pin DIP is the single version of the OPA4743 which has 4 op-amps in one package.
Cheers.
Ray samuels

 

[Welly Wu]

Quote:

Originally Posted by Ray Samuels Hi Welly Wu... The answer to your question regarding this op-amp is NO, you can not use it in Emmeline HR-2, as HR's power supply is +- 12VDC, while the op-amp is MAXed at +-6VDC, if installed in the HR-2 it will just burn. OPA743 8 pin DIP is the single version of the OPA4743 which has 4 op-amps in one package. Cheers. Ray samuels

Dear Mr. Samuels:

Does this mean that I can use the OPA743 (8 PIN DIP) with my Emmeline HR-2?

Best Regards:

Welly Wu

 

[Ray Samuels]

NO, you can not use this op-amp in the HR-2 at all.
Sorry.
Ray Samuels