[HeadphoneAddict]

Quote:

Originally Posted by andrew jc /img/forum/go_quote.gif Larry did the OPA627AU SOIC soldered onto a 2:1 show up yet? Just wondering thanks...

Yes, I had just gotten caught up in adding the HR Microstack to one of my other reviews, and didn't get around to posting it here.

The OPA627 performs in the White very much like it does in the Red. Vs the LM4562 it is a little smoother and more transparent, with slightly less treble and slightly more bass than the LM4562. So, everything I said about 627 in the Red still applies.

The LT1364 in the white is like combining the bass of the 627 and the treble of the 4562, but without as much transparency or smoothness (refinement) as I got with the 627.

So, overall the sound is more relaxed and flowing with the 627, and more sparkly and punchy with the 4562 and 1364. With 250-300 hours of burn in, using the 4562 in the white is still a good choice, but the OPA627 excels with classical or bright headphones.

 

[Michael415]

Thanks for the super review! It sounds like this could be a (the green) great option for my office rig. I am so glad to hear you reviewed them with the D2000 which is what I use at work.
I haven't pulled the trigger yet and in your view would I be better served to get a separate DAC, like a fubar II and a Red, or just the Green? The source is my MacBook Pro.

 

[HeadphoneAddict]

I have the Fubar III here for review, and haven't spent much time with it yet, but so far I don't think it is as good as or better than the Green.

The HR Micro DAC with the Red (using AD743 or OPA627 opamps) is audibly superior to the Green (which itself is pretty good). I am using the Red to drive my STAX and HE60 via an SRD-7 Pro transformer out of the speaker jacks, and it rivals my SRM-1 Mk2 Pro (and might even be slightly better). It is just a great little amp.

If you have an optical or coax DAC that doesn't have usb, the green does a great job of USB to Optical/Coax out conversion. Sure, there's cheaper USB to S/PDIF converters out there, but not ones that can drive speakers while feeding the headphone out to a small powered subwoofer (when you aren't using the headphone jack for private listening) - while at the same time sending a digital S/PDIF signal into your main rig.

The Green is part of my basement electrostatic rig driving an SRD-7SB for SR-Lambdas, and I sold my spare SRM-1 Mk2 Pro after I got this.

 

[Michael415]

Thanks for the detailed reply. It sounds like the Green will be the way for me to go. I will be only using it for phones, and the sound doesn't need to be uber crystal clear like my home setups but I would like something solid, good sounding, and compact in size. Open to other suggestions though that are somewhere around Greens price point. What got me started is I burned in the Denon's on my SP MPX and I know how wonderful they can sound with a little bit of power behind them. Currently at work I am running them straight out of the headphone output and its just not doing them justice.

 

[Harryo]

I would like to change the op-amp in my Travagan Red but am not sure what allen headed bolts need to be removed in order to access the present op-amp.

So far have just tried removing the four allen headed bolts on the front panel and gently pulling on the front panel but it doesn't move.

There are three allen bolts on the right side of the casing, do they also have to be removed, also notice that there is a Philips headed type bolt on the rear panel and was wondering whether this might also have to be removed?

Any help is appreciated.

Cheers - Harryo

 

[HeadphoneAddict]

In addition to the four front screws, the three side screws must be un-done, and the single philips screw too (which holds the RCA jacks in place).

Then you can slide the circuit board with volume knob forward about half way, in order to reach the opamp like in the photos in my review. You cannot slide the circuit board out all the way because of the cable going from the RCA jacks to the board. I could not unplug the cable from the RCAs to the circuit board, but also I was afraid that if I did get it unplugged then I might not get in plugged back in, so I left it attached (and only slid the circuit board out part-way).

 

[Harryo]

Thanks for that info HeadphoneAddict. I have just removed all the screws that you mentioned and slid the circuit board part-way out of the casing.

It is tempting to try to unplug the leads from the circuit board but as you mention it might be problematic trying to plug the leads back in so will not attempt it.

Harryo

 

[Covenant]

You rock, Larry

 

[HeadphoneAddict]

(Larry blushes)

 

[Harryo]

Just an update on my attempt to change op-amps.

The morning started well when I dropped a pint of milk in the kitchen which resulted in glass and milk going everywhere, I should have realised this was an omen of things to come!

Firstly removed the LM4562 and replaced it with an AD743 switched the amplifier on heard the usual click then total silence!

Replaced the LM4562 and everything was fine tried a second AD743 and once again was greeted with silence.

Removed this AD743 and popped-in an LT1364 which worked fine, I quite like the sound of this op-amp so have left it in for the time being.

Will have to see whether I can get hold of some other AD743 op-amps to try, the ones I tried have a white oblong at the top right-hand size with the letters JNZ in it.

Harryo

 

[mimi]

In case you're not aware, AD743 are single op-amps, you need 2 AD743s on a single to dual adaptor if you are going to use them as replacements for the LM4562.

Quote:

Originally Posted by Harryo /img/forum/go_quote.gif Just an update on my attempt to change op-amps. The morning started well when I dropped a pint of milk in the kitchen which resulted in glass and milk going everywhere, I should have realised this was an omen of things to come! Firstly removed the LM4562 and replaced it with an AD743 switched the amplifier on heard the usual click then total silence! Replaced the LM4562 and everything was fine tried a second AD743 and once again was greeted with silence. Removed this AD743 and popped-in an LT1364 which worked fine, I quite like the sound of this op-amp so have left it in for the time being. Will have to see whether I can get hold of some other AD743 op-amps to try, the ones I tried have a white oblong at the top right-hand size with the letters JNZ in it. Harryo

 

[HeadphoneAddict]

Right, look at my photo of the Red in Post #2, where I have the TWO single channel opamps on a 2:1 adapter.

I prefaced the opamp rolling section of my review by saying that I could not fit a 2:1 adapter in the White, so I would try it in the Red. I guess I wasn't clear enough that the OPA627, AD797, and AD743 are all single channel opamps and must be used in pairs (on adapter).

 

[Harryo]

Thanks Mimi and HeadphoneAddict re the advice on the AD743 op-amp, I had no idea that it was a single channel op-amp, at least I have learned something new!

Will now get hold of a 2:1 adapter and try the AD743's again.

Harryo

 

[Tokenganjaclan]

Anyone know if they are having any troubles due to the Quake? I plan on making a RED buy this coming week. thx..Back to topic

 

[HeadphoneAddict]

I haven't heard of them having any problems. And, if you want to help them, show your support and order one.