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Analog Squared Paper Discussion and Appreciation Thread. - Page 75

post #1111 of 3477
Quote:
Originally Posted by GermanGuy View Post

 

Any comments how this combo sounds would be highly appreciated :-)

 

Spacious, detailed, airy, and only very slightly euphonic, but in a good way. Really enjoying this combo.

post #1112 of 3477
Thanks for all your facinating explanations. I do NOT have a RWAK100-s ( fixed Line out) but a RWAK100 ( variable headphone out ).
post #1113 of 3477
Quote:
Originally Posted by TIMITS View Post

Thanks for reminding me Ian.  I did read AnakChan's review some weeks ago but forgot about it. 

 

But it was with the RWAK100 then. Ian's comment's made me curious about the RWAK100-S now with my upcoming TUR-06.

post #1114 of 3477
Oh my, its confusing with this player, so i can't remember as I did not look closely at the one I listened to, does the AK100 have a line out at all or is it all through the HP jack.. A bit off if it does not considering most would use it with an external amp.

In the case it is variable I would try no volume at all then and see where that takes you.. TIMITS idea as well of trying another source (as long as it is good quality!) is worth doing if you can!
post #1115 of 3477
Quote:
Originally Posted by woodcans View Post

 

Spacious, detailed, airy, and only very slightly euphonic, but in a good way. Really enjoying this combo.

 

Oh, and I cannot reiterate this enough. The blackest, blackest background I have ever heard (not heard) ever.

post #1116 of 3477
Woodcans. I found that with this combo in reverse as well, really really silent tubes! So glad your enjoying the amp, I hope this weekend you get more time to listen to it!
post #1117 of 3477

I'm about to show how technically challenged I am ... but if it helps ... There has been quite a bit of discussion about the relatively high output impedance on the stock AK100 (20 ohms) and how this can adversely affect headphones with a low impedance.  Could this be a factor with the TU -05b?  A problem with output impedance on the AK100 and input impedance on the amp?  I have seen other discussions relating to linking pre-amps to amps and there is a general rule of thumb that the power amp should have an input impedance at least 10 times the output of the pre-amp.  I looked up on the Audio Squared Paper website but input impedance values are not listed.  This link explained in a very visual way (garden hose analogy) how output and input impedance are related: http://whirlwindusa.com/support/tech-articles/high-and-low-impedance-signals/

post #1118 of 3477
Quote:
Originally Posted by TIMITS View Post

I'm about to show how technically challenged I am ... but if it helps ... There has been quite a bit of discussion about the relatively high output impedance on the stock AK100 (20 ohms) and how this can adversely affect headphones with a low impedance.  Could this be a factor with the TU -05b?  A problem with output impedance on the AK100 and input impedance on the amp?  I have seen other discussions relating to linking pre-amps to amps and there is a general rule of thumb that the power amp should have an input impedance at least 10 times the output of the pre-amp.  I looked up on the Audio Squared Paper website but input impedance values are not listed.  This link explained in a very visual way (garden hose analogy) how output and input impedance are related: http://whirlwindusa.com/support/tech-articles/high-and-low-impedance-signals/

I think typical input impedance for Amp are more than 10 kΩ. 1 or 20Ω doesn't matter to those higher impedance.

 

Those RWAK100 that they use are modified to have output impedance less than 1Ω too.


Edited by mtthefirst - 7/19/13 at 7:00pm
post #1119 of 3477

Thanks again for your inputs, and thanks GermanGuy for the technical explanation.

 

Now I understand: with a load of 100 Kohms (instead 25 Ohms with an headphone attached to it), there is NO bi-amplification because... the RWAK100 do not deliver to the TU-05 any power, just voltage. Is it correct ?

 

And as a side effect, since the current drain on the RWAK 100 is much less...we have much better battery life and less distortion at the RWAK100 level. Is it correct also ? 

 

Now, As I said  before, I have a RWAK100. This is a AK100 just modified to have a lower headphone output impédence to drive better the low impedence headphone like the TH900. So this modification is of NO use with a TU-05 that has a ... 100 Kohms load. So the RWAK100 is definitively not the best solution to drive an external AMP since it does not provide a "real" line out.  Indeed, the TU-05 is connected to the RWAK100's Headphone jack ( Vinnie's recommendation is then to use the RWAK100 at 100% power in order to totally bypass the digital volume control, and to have the cleanest possible line out signal.  Something in the 1.8 volts).

 

So... the best solution to feed the TU-05 will be the RWAK100-S (or even better ...a RWAK120-S when Vinnie (RWA) makes it available), the one that has a better DAC chip and....a REAL line out (without any volume control, with a fixed 2volts signal).

 

Since I already have a RWAK100, I will wait and purchase a RWAK120-S when Vinnie makes it available: it's like a RWAK100-S, with a "pure" fixed level line out, with NO volume control, but... with TWO DAC chips instead of ONE for better soundstage and channel separation.  The RWAK120-S is a RWA's modification to the iRiver AK120.

 

But again, I need to find the best interconnect. -->  Should I use silver based or copper based interconnect ?  from who ? 

 

And... what is the best way to tube break-in ? 

 

 

 

And THANKS FOR YOU ALL.   I FEEL REASURED NOW and I will immediatly start "tube rolling" tests starting with those 2 :

 


Edited by bmichels - 7/19/13 at 11:57pm
post #1120 of 3477
Best way to break in tubes is to play music and enjoy! Same as the amp. Just play music and enjoy. If I am going to be close by I sometimes just leave the amp on playing music for a couple of hours to speed things up but this being a tube amp I would not leave it whilst in use.

By the time you get the new player the amp will be burned in and then with your new player you can really enjoy the amp!

As to interconnect, If your going to change your player I would wait till it arrives and you have an idea of what it sounds like. Then you can choose your interconnect more effectively. As to make up of the interconnect. For me I am preferring the Kimber copper cable but others like a silver.

Again, though it is good to have a better quality cable I have found there have been greater increases in SQ tube rolling personally. Having said that the Kimber is more transparent than the Cardas it replaced!
Edited by ianmedium - 7/20/13 at 12:36am
post #1121 of 3477

bmichels - just some thoughts:

 

your player is an excellent one - no need to change anything at the moment.

 

if setting the player to max. volume bypasses whatever - just do it.

 

there are but there is not a real electronical difference between a good low impedance hp out and a line out - except the power the output can deliver - keep it as it is for the moment.

 

if there were an ak100  with real line out, this line out would NOT be able to drive a headphone because not designed to be powerful, but more precise, distortion free.

 

impedance mismatch between output to input causes some unwanted alteration of the signal, but NOT at this very low frequencies up to 20 KHz, this will be more important for RF, but not here.

 

if you change too much parameters in a system at the same time you loose the ability to get a result for each change that can be verified or later predicted.

 

i would propose (from important to less important for the sound)

 

set your amp to one impedance setting, i recommend 16-120 ohms and keep it.

 

don' use the stock tubes, replace them with better ones.

 

it was the MOST IMPORTANT POINT  to get the sound i was exspecting !!!!!!!!!!!!!!!!!!!

 

give them some burn-in time with real music playing volume set to a normal level you would listen to, hp connected to the amp, let it play for some hours.

 

do some tube rolling or follow a recommendation here to find the tube set and sound you prefer (lots of articles here).

 

a new interconnect is the last step of really fine tuning the sound.

 

edit:

 

your first question: as long as we speak of power amplification, there is no need of bi-amplification - yes

 

there is no notable difference in battery life, because the avarage power consumption is not that high for the ak100 amplifier  - the point is that a normal player (small size, small housing, small battery, small capacitors) can't be designed to have the power reserve and impulse power capabilities as a big amp, for a hard hitting bass pulse you need 100 times the power for some milli seconds.


Edited by GermanGuy - 7/20/13 at 1:35am
post #1122 of 3477
For those who are not familiar with the AK DAP, herewith a bit descriptions:
Original players released are known as AK100 and AK120.

Vinnie from Red Wine audio then do few modifications on the AK100 such as bypassing the headphone out stage from 22-ohm to be less than 1 ohm.
This modification is called as RWAK100.

On the later stage, Vinnie do further modifications by replacing the default WM8470 chip to WM8471 chip, by passing the amp section and knock off the volume knob (please CMIIW) and some other mods that transforms the DAP to be a pure transport.
It has to be paired with an amp.
This one called as the RWAK100S.

I own the RWAK100 and AK120, hence your thoughts are really tickles my curiosity, bmichaels.

I've put my interest on the RWAK100S or RWAK120S, but hardly found any extended reviews.

AnakChan reviews on the A2S paired with the RWAK100 are really interesting.
And by that, I'm pretty comfortable with my units then.

But the idea to get a "pure transport" sounds pretty interesting as well.

Bmichel, looking for your further findings.
post #1123 of 3477
Quote:
Originally Posted by GermanGuy 

 

...if there were an ak100  with real line out, this line out would NOT be able to drive a headphone because not designed to be powerful, but more precise, distortion free.

Thanks for your advices.

 

As for a "ak100  with real line out", well... this is exactly what the " -S " version of RWA mod is:  the RWAK100-S:.

 

Line out

The RWAK100-S modification also hardwires the analog line-output stage following the WM8741 directly to the headphone output jack. Therefore, the headphone output stage is completely bypassed and the headphone output jack is converted to a true, 2Vrms line-output.

Hardware volume control removal

Since the digital volume control functionality is completely disabled, we also remove the volume wheel that exits from the left side of the AK100, and we plug the hole so the RWAK100-S is slimmer by 5 mm – and simply looks cleaner.

post #1124 of 3477

bmichels,

 

I use this interconnect (0.5 metre) - http://epiphany-acoustics.co.uk/products-page/cables/solaris-ii-mj2-mini-jack-to-mini-jack-interconnect/ - and can honestly say that it's the best 20 quid that I've ever spent on a cable. It's silver plated and ultra pure oxygen free copper wire. `Sounds' very transparent without any brittle/bright artifacts typically found with pure silver cables. 

 

 

Cheers,

Andy.

 

Originally Posted by bmichels View Post

Thanks again for your inputs, and thanks GermanGuy for the technical explanation.

 

Now I understand: with a load of 100 Kohms (instead 25 Ohms with an headphone attached to it), there is NO bi-amplification because... the RWAK100 do not deliver to the TU-05 any power, just voltage. Is it correct ?

 

And as a side effect, since the current drain on the RWAK 100 is much less...we have much better battery life and less distortion at the RWAK100 level. Is it correct also ? 

 

Now, As I said  before, I have a RWAK100. This is a AK100 just modified to have a lower headphone output impédence to drive better the low impedence headphone like the TH900. So this modification is of NO use with a TU-05 that has a ... 100 Kohms load. So the RWAK100 is definitively not the best solution to drive an external AMP since it does not provide a "real" line out.  Indeed, the TU-05 is connected to the RWAK100's Headphone jack ( Vinnie's recommendation is then to use the RWAK100 at 100% power in order to totally bypass the digital volume control, and to have the cleanest possible line out signal.  Something in the 1.8 volts).

 

So... the best solution to feed the TU-05 will be the RWAK100-S (or even better ...a RWAK120-S when Vinnie (RWA) makes it available), the one that has a better DAC chip and....a REAL line out (without any volume control, with a fixed 2volts signal).

 

Since I already have a RWAK100, I will wait and purchase a RWAK120-S when Vinnie makes it available: it's like a RWAK100-S, with a "pure" fixed level line out, with NO volume control, but... with TWO DAC chips instead of ONE for better soundstage and channel separation.  The RWAK120-S is a RWA's modification to the iRiver AK120.

 

But again, I need to find the best interconnect. -->  Should I use silver based or copper based interconnect ?  from who ? 

 

And... what is the best way to tube break-in ? 

 

 

 

And THANKS FOR YOU ALL.   I FEEL REASURED NOW and I will immediatly start "tube rolling" tests starting with those 2 :

 

post #1125 of 3477

Thanks Andy, that interconnect looks exceptionally good value.

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