[EnOYiN]

Quote:

Originally Posted by Contrastique /img/forum/go_quote.gif That's an astonishing price for such a beautiful headphone. I thought they would be way more expensive! Of course you need an amp to par with them but still...

They are dynamic headphones and I believe that I read somewhere that they are at 100 Ω. I am still looking for some clear specs somewhere. Either way. The larroco could probably power them quite well, if not really well.

 

[Contrastique]

Quote:

Originally Posted by EnOYiN /img/forum/go_quote.gif They are dynamic headphones and I believe that I read somewhere that they are at 100 Ω. I am still looking for some clear specs somewhere. Either way. The Larocco could probably power them quite well, if not really well.

That would be great but I'm not sure. They did a pretty lousy job powering the K701's for example. When I see these hps I get the feeling they need a lot of power to sound at their best or at least to get them close to their full potential.
I could be wrong though. I don't have any experiences with these hps besides my lovely encounter with them at the meet.

Maybe Duggeh could chime in here again as he seems to know a lot about them...

 

[mrarroyo]

Quote:

Originally Posted by Contrastique /img/forum/go_quote.gif That would be great but I'm not sure. They did a pretty lousy job powering the K701's for example. When I see these hps I get the feeling they need a lot of power to sound at their best or at least to get them close to their full potential. I could be wrong though. I don't have any experiences with these hps besides my lovely encounter with them at the meet. Maybe Duggeh could chime in here again as he seems to know a lot about them...

You as well as many others must listen at extremely loud levels. When I had my LaRocco PRII MkII it rarely went past 9 o'clock even with the K701. As a comparison I am currently listening to an AKG K501 driven by an Oritek 4.1 DAC and the volume is below 9 o'clock.

Interestingly enough the output of the Oritek 4.1 DAC is about half of my Arcam DiVA CD73 (2.2 Vrms). As you can imagine when I use the Arcam the volume pot is set even lower.

I am very confused!

 

[Duggeh]

Quote:

Originally Posted by EnOYiN /img/forum/go_quote.gif They are dynamic headphones and I believe that I read somewhere that they are at 100 Ω. I am still looking for some clear specs somewhere. Either way. The larroco could probably power them quite well, if not really well.

96dB efficiency and 100ohms impedance. For the Model 2.
95db and 100ohms for the Model 1

don't know and 4ohms for the AMT.


You'll have an easier time driving the Ergo 2 than the K701, and have a better sounding headphone as well.

 

[Contrastique]

Quote:

Originally Posted by mrarroyo /img/forum/go_quote.gif You as well as many others must listen at extremely loud levels. When I had my LaRocco PRII MkII it rarely went past 9 o'clock even with the K701.

Ow, I'm not talking volume here but rather sound alone. They sounded dull and boring out of my Larocco and I had the feeling they were capable of much more than that. They lacked impact and speed though had very pleasant silky-like mids from what I recall.
Now, as I haven't yet heard them being more powerful driven it could be that that's just there soundsig which I happen to not really like because of the above comments, I'm not sure but I had the feeling they were underamped.
Hans told me something similar.

If the Ergo's are more easy to drive, well, that would be awesome and definitely something I would like to hear!

 

[mrarroyo]

Then it must be the amp, IMO the K701 are not dull or boring.

 

[Jelle Schrijver]

Quote:

Originally Posted by Contrastique /img/forum/go_quote.gif Ow, I'm not talking volume here but rather sound alone. They sounded dull and boring out of my Larocco and I had the feeling they were capable of much more than that. They lacked impact and speed though had very pleasant silky-like mids from what I recall. Now, as I haven't yet heard them being more powerful driven it could be that that's just there soundsig which I happen to not really like because of the above comments, I'm not sure but I had the feeling they were underamped. Hans told me something similar. If the Ergo's are more easy to drive, well, that would be awesome and definitely something I would like to hear!

strange, locked up the spec of your amp and on itself it's fast enough. I've noticed that amps with a slew-rate lower then 40 V/µS always sounded slughish. But the larocco is much faster with it's 70-75 V/µS. And given the impedance of the K701, the larocco should be able to blow it up.
Mayby the problem is the feedback loop and the K701 reflects a lot of signal back on its cable?! Then the feedbackloop picks it up again and the result is a very short kinda delay mudding things up. That's the reason that the PPA uses a 3 amp to catch the currents coming from the headphones.

For the more techy's among us, have a read over at altmann SPLIF. This could be a way to decouple the amp from the headphone. Am not sure if/or it will work, but the chip TLE2426, mounted between + and - of the battery and the mass connection of the headphone ONLY connected to the chips 0V connection. Sound much simpler then the 3rd ampchannel and would propebly do the same thing.

and talking serious modding here, that tube-o-later stuff on the op-apamp sounds like a good idea. I think, reading all his websited and absorbing his knowledge, it is a carbon (dutch:grafiet) subspended in a natural resin (dutch: natuurlijke hars zoals dennehars). To apply mix all ingredients and use alcohol so make the resin liquid. Apply, let alchol dry and you're set.

Anyhow, just kicking some idea's around and putting in my 2 cents worth. (now everything is 2 cents off

)

 

[Ferrari]

Quote:

Originally Posted by Jelle Schrijver /img/forum/go_quote.gif For the more techy's among us, have a read over at altmann SPLIF. This could be a way to decouple the amp from the headphone. Am not sure if/or it will work, but the chip TLE2426, mounted between + and - of the battery and the mass connection of the headphone ONLY connected to the chips 0V connection. Sound much simpler then the 3rd ampchannel and would propebly do the same thing.

NO, it doesn't ! By using the TLE2426 rail splitter chip, you can create a "virtual signal ground", nothing more or less.
But still, this "virtual signal ground" is passive... as all other "passive ground" in conventional 2-channel amplifiers.

Conventional 2-channel "passive ground" amplifier differs from 3-channel "active ground" amplifier in the way how the return current from the drivers (from the speakers in the headphone) is handled. A conventional 2-channel "passive ground" amplifier just dumped the return current from the drivers into the "virtual signal ground" (= "passive ground") created by the TLE2426 rail splitter chip (the "ground" wire of the headphone is connected to chips 0V point, according to you).

As opposed to 2-channel "passive ground" amplifiers, in a 3-channel "active ground" amplifier, the "ground" wire of the headphone is driven by a third channel of the same topology as the left and right channels (thus 3 amplifiers of the same design). The "active ground" (ground channel amplifier) sinks or sources the return current from the drivers, and this is fundamentally different from what the "virtual signal ground" (= "passive ground") does in a conventional way.

 

[Jelle Schrijver]

@ ferrari

but........

the whole idea is to keep the reference ground for the voltage amplifying opamp clean from those return currents.

3ch topology does this by adding a 3rd amplifier tied to ground, so the opamp sends the returning current back to the PSU to maintain 0V at its output and also input.

The way i understand the TLE2426 works, is that it takes the + (Top leg) and the - (bottom leg) PSU and creates a voltage out right between these too. So this becomes a reference 0V (middle leg).

In the case the TLE does not sense its output, then the current from the headphone mass can not flow anymore (because the TLE is ONLY connected to + and - PSU and is in no way connected to our precious reference ground the opamps use (the use there own TLE like PPA). In that case something is gone blow or there is no sound by lack of flowing current.

In the case the TLE does sense its output (middle leg), which i think is how it works, then any current (and thus voltage) wil upset the 0V reference and it will bleed away the acces to get back to 0V. In doing so differting the current back to the PSU and keeping it clear from our opamp reference 0V. My only concern is when there is an offset between opamp reference 0V and the 0V created by the TLE headphone side. This could introduce a offset and so burn a headphone by DC current.

My scanner/printer is currently down, so i can not chalk a schematic too clear this out. Also i have to find a place on the internet to store the photo to be referenced here. If it is still not clear and there is interest in this topology, please let me know, then i will try to post a schematic of what i am meaning.

In any case, i believe that a complete amp channel to differt the returning current is a bit over the top and a more simpler solution could be invented here to do the trick. (making the whole schematic smaller and more energie efficient, which are great bonuses for a portable amp).

And what do you think of using the SPLIF in the PPA design? The buffer makes it very easy to insert such a topology. My only concern is how it will effect the offset. (DC servo perhaps?) And what resistor value to use for baising the reference feedback loop and how this will influence the gain.

 

[Ferrari]

Quote:

Originally Posted by Jelle Schrijver /img/forum/go_quote.gif @ ferrari but........ the whole idea is to keep the reference ground for the voltage amplifying opamp clean from those return currents. 3ch topology does this by adding a 3rd amplifier tied to ground, so the opamp sends the returning current back to the PSU to maintain 0V at its output and also input. The way i understand the TLE2426 works, is that it takes the + (Top leg) and the - (bottom leg) PSU and creates a voltage out right between these too. So this becomes a reference 0V (middle leg). In the case the TLE does not sense its output, then the current from the headphone mass can not flow anymore (because the TLE is ONLY connected to + and - PSU and is in no way connected to our precious reference ground the opamps use (the use there own TLE like PPA). In that case something is gone blow or there is no sound by lack of flowing current. In the case the TLE does sense its output (middle leg), which i think is how it works, then any current (and thus voltage) wil upset the 0V reference and it will bleed away the acces to get back to 0V. In doing so differting the current back to the PSU and keeping it clear from our opamp reference 0V. My only concern is when there is an offset between opamp reference 0V and the 0V created by the TLE headphone side. This could introduce a offset and so burn a headphone by DC current. My scanner/printer is currently down, so i can not chalk a schematic too clear this out. Also i have to find a place on the internet to store the photo to be referenced here. If it is still not clear and there is interest in this topology, please let me know, then i will try to post a schematic of what i am meaning. In any case, i believe that a complete amp channel to differt the returning current is a bit over the top and a more simpler solution could be invented here to do the trick. (making the whole schematic smaller and more energie efficient, which are great bonuses for a portable amp). And what do you think of using the SPLIF in the PPA design? The buffer makes it very easy to insert such a topology. My only concern is how it will effect the offset. (DC servo perhaps?) And what resistor value to use for baising the reference feedback loop and how this will influence the gain.

Why should you want to add that into a well performing 3-channel active ground amplifier like the PPAV2 ?
What is the benefit then? Adding some more parts? more cumbersom wirings? creating some trouble which you not sure how to fix? increasing the cost?

About your described concern, there is no foundation for that from electronics engineering viewpoint!
If you think that there is a foundation for that, I would love to hear.

 

[Jelle Schrijver]

@ ferrari,

it's about ditching the third channel all together, so making it
1) smaller, for portable applications.
2) cheaper, less parts easier schematic
3) bringing 3ch topology to other 2 channel amps.

if moved this topic to here

 

[moriez]

Guys, dont see a better option than to put my request here. I would really like to hear a Ray Samuels portable amp, preferably the Hornet. Is there any dutchee here who would like to introduce me to it? Like a short meet somewhere not too far from Limburg?

 

[hoosterw]

Quote:

Originally Posted by moriez /img/forum/go_quote.gif Guys, dont see a better option than to put my request here. I would really like to hear a Ray Samuels portable amp, preferably the Hornet. Is there any dutchee here who would like to introduce me to it? Like a short meet somewhere not too far from Limburg?

Hi, if you would take the time to visit our shop after the summer holiday break I would happily let you listen to all major RSA's and most other amps that are in the top 10 listed including the iQube.

Nuenen is near to limburg no?

AudioXperience | Specialists in Audio & Head-Fi*»*AudioXperience

rgds Hans

 

[bjarnetv]

since this thread has already been bumped; did anyone else end up buying ergo2s?

i ended up buying a used pair, and they really exceeded my expectations; they really deserve more attention then they are getting!

 

[yepyep_]

Quote:

Originally Posted by Dexdexter /img/forum/go_quote.gif

Hmm the ed9 earpads look a lot smaller than the ones in 750's. Are they really smaller ?