[Andrea]

LOL, those thingies are funny

 

[jamato8]

Quote:

Originally Posted by Dexdexter /img/forum/go_quote.gif Cheers for that, Andrea! OK, filter back on!

Those are great! I may give up listening and just watch them. .... nah. . I can do both!

Hey Andrea, you are surrounded.

 

[Filburt]

Hmm, the OPA277/2277 is a curious choice for an audio application. As far as I can tell, the OPA277/2277 seems primarily designed for DC and near-dc instrumentation applications, rather than something like an audio application. Douglas Self encountered over 18db/octave climb of harmonic distortion past 4KHz in his tests (under "no load"), and TI's own datasheet shows a very rapid climb past 5KHz on a 10k ohm load with, I'm guessing, as near-zero capacitance as possible. Driving a headphone, I suspect the distortion will be considerably higher. Some of this may be due to the low slew rate of 0.8V/usec, which is less than twice the speed of the old u741.

Andrea - Yes, the AD8397's oscillation woes occurred primarily on the Ground channel ("third") of the PINT. However, that problem seems to have been caused by a problematic feedback configuration (aggrivated by driving a capacitive load) that was remedied by the board modification that modified that configuration. I don't know what your problem is with the 3 channel topology, but you seem to exercise very little in the way of discretion whilst engaging in your polemics over it. I suspect at least some of the things you keep trying to attribute to it (and other things) have more to do with the designs and component configurations your experience is based on rather than something endemic to having an active ground.

 

[Dept_of_Alchemy]

Quote:

Originally Posted by chris_ah1 /img/forum/go_quote.gif Oh *** Haven't even receieved mine yet as it is in the mail I think and already there is a new one - he could've let me know considering I kept on asking about whether other opamps could be put in...............I only ordered it a week or so ago too!!!!! I'm really miffed tbh. I expected such things from IT, but not from the headphone amp world. Xenos and portaphile have taken ages to bring new products in...same with larocco...not norm.

Happens all the time. Think Little Dot.

 

[Andrea]

Quote:

Originally Posted by Filburt /img/forum/go_quote.gif Hmm, the OPA277/2277 is a curious choice for an audio application. As far as I can tell, the OPA277/2277 seems primarily designed for DC and near-dc instrumentation applications, rather than something like an audio application. Douglas Self encountered over 18db/octave climb of harmonic distortion past 4KHz in his tests (under "no load"), and TI's own datasheet shows a very rapid climb past 5KHz on a 10k ohm load with, I'm guessing, as near-zero capacitance as possible. Driving a headphone, I suspect the distortion will be considerably higher. Some of this may be due to the low slew rate of 0.8V/usec, which is less than twice the speed of the old u741.

Exactly. Although, Norm disagrees.

Quote:

Andrea - Yes, the AD8397's oscillation woes occurred primarily on the Ground channel ("third") of the PINT. However, that problem seems to have been caused by a problematic feedback configuration (aggrivated by driving a capacitive load) that was remedied by the board modification that modified that configuration. I don't know what your problem is with the 3 channel topology, but you seem to exercise very little in the way of discretion whilst engaging in your polemics over it. I suspect at least some of the things you keep trying to attribute to it (and other things) have more to do with the designs and component configurations your experience is based on rather than something endemic to having an active ground.

In fact - I should repeat - it's nothing more than what it is... nothing scientifically orderly, just a feeling (but the feeling is all there). Note that my complaints incidentally regard op-amp based 3 channel amps (Go-Vibe v5, Portaphile), not those with big mosfets for output stages like the M^3.

Simple fact (for my ears as usual)... A Xenos 0HA-REP with an AD823 and 2 AD8397's inside sounds obviously better than whatever Go-Vibe v5 or Portaphile X^3 with BUF634's. It's not by chance that after much thought I've decided that my new - last - 0HA-REP will be modified with an LM4562 and two AD8397's... I do have high expectations.

 

[Dexdexter]

La-la, lalala, la-lee, la-lee, lalala!

 

[Abouna]

An awful lot of opinion based on an amp no one has heard yet. Considering Norms reputation, I would be quite surprised to find this new version lacking compared to the older version.

Considering also Andreas constant crowing about the Xenos (and apparent bashing of the GV5), I also find his opinion hard to accept. I have read some good from him but the way he swoops in with the Xenos at every occasion and is so quick to criticize other amps is a turn off. Sorry Andrea.

 

[Dexdexter]

So, Andrea, will you be ordering a Go-Vibe V5S from Norm, or do you intend to keep on posting here about it based solely on theory and extrapolation of op-amp impressions from other amplifiers?

 

[Andrea]

Quote:

Originally Posted by Dexdexter /img/forum/go_quote.gif So, Andrea, will you be ordering a Go-Vibe V5S from Norm, or do you intend to keep on posting here about it based solely on theory and extrapolation of op-amp impressions from other amplifiers?

What!?? I don't intend anything such... Were it for me, I'd have left this thread after my two posts in the first page - so much for my interest in this thread.

But thanks anyway for having entertained me some more.

 

[hciman77]

Quote:

Originally Posted by Fr. John /img/forum/go_quote.gif An awful lot of opinion based on an amp no one has heard yet. ... I would be quite surprised to find this new version lacking compared to the older version.

This looks like an opinion based on an amp no one has heard yet

 

[DDF]

Quote:

Originally Posted by Andrea /img/forum/go_quote.gif Nice mixture of real & inventively imagined advantages. I'll leave you with: "if you're convinced by what you hear, you have all the good reasons to defend it. I don't"

You yourself pointed towards Rescue Toasters posts as indicative of the strength of your position. I showed, with engineering fact and logic, not invention nor opinion, why his posts and those supporting his position were clearly in error and what some clear benefits of 3 channel are.

We are all left to our own judgements regarding sonic quality, but your post just went well beyond that, as an empty disregard of engineering fact. You can not argue away engineering assessment with the same cavalier prejudices you use to espouse your subjective impressions. Engineering doesn't work that way, or we'd still be squating over a hole in the forest and chasing wilderbeasts with sharpenned sticks.

Every discussion with you boils down to "tastes great" "less filling" because you refuse to recognize and discuss content beyond your subjective impressions. You've slipped now into self parody where even reason doesn't hold sway in your court.

That's the definition of a troll. It poisons the discourse and renders useless any well meaning effort.

 

[Abouna]

Quote:

Originally Posted by hciman77 /img/forum/go_quote.gif This looks like an opinion based on an amp no one has heard yet

You got me

. I think this sentence is justified by the part you left out about Norm's rep. At least a bit.

 

[tigger]

Quote:

So, Andrea, will you be ordering a Go-Vibe V5S from Norm, or do you intend to keep on posting here about it based solely on theory and extrapolation of op-amp impressions from other amplifiers?

Fair question

And the answer:


Quote:

Originally Posted by Andrea /img/forum/go_quote.gif What!?? I don't intend anything such... Were it for me, I'd have left this thread after my two posts in the first page - so much for my interest in this thread. But thanks anyway for having entertained me some more.

Let the truth be known!

I really hesitated before posting this, but it sure is relevent here!

This is an actual email I received from Andrea approx. 2 weeks ago before the V5S announcement:

"Hi Norm,

I'm Andrea (the one of head-fi).

I've had a sudden change of mind about the Go-Vibe v5. I have the feeling that now I may appreciate it much more than I did initially. In light of this 'inspired feeling', I'd want to ask you if you'd still allow me to order a new amp, within a few days (once I have the money). In any event, and whatever my findings about the amp should be this time, you can be confident that I won't be speaking badly of your amp on head-fi anymore. I'm anxious to read your reply.


Kind regards,

Andrea"

My answer was;

"I have no problem with a re-order, but it won't sound any different from your first Go-Vibe V5."

Never heard another word from him.

Feel free to form your own opinions

 

[dw6928]

thank you Norm. I think I, for one, have made my opinion about these posts and their content very clear. It is time for
it to end and move on.

 

[hciman77]

Quote:

Originally Posted by Fr. John /img/forum/go_quote.gif You got me . I think this sentence is justified by the part you left out about Norm's rep. At least a bit.

Well, I once had one of Norm's amps and it was very very nice. I have no reason to suppose that any other amp he makes will be made with any less care or conscientious design... I was just amusing myself with a bit of gentle petard-hoisting.

Of course I had no reason to suppose that England could lose a test match having declared their first innings on 551 and having a lead of 97 going into the last day with 9 wickets standing........just goes to show you never can tell