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Analog Squared Paper Discussion and Appreciation Thread. - Page 74

post #1096 of 3496
Add to that 1T4T.

DL92 is also known as 3S4 and N17 and CV820
DF91 is also know as 1T4 and CV1971
DF904 is also known as 1U4

The CV nomenclature is a British Military designation.
If you see tubes marked with "JAN" then these also are military tubes, "JAN" is normally found on US tubes but can be found on other countries tubes. "JAN" stands for Joint Army and Navy.

Hope that helps and welcome!
Edited by ianmedium - 7/19/13 at 9:56am
post #1097 of 3496
Quote:
Originally Posted by GermanGuy View Post

df91, df 904 , df96?    dl92 

 

Quote:
Originally Posted by ianmedium View Post

Add to that 1T4T.

DL92 is also known as 3S4 and N17 and CV820
DF91 is also know as 1T4 and CV1971
DF904 is also known as 1U4

The CV nomenclature is a British Military designation.
If you see tubes marked with "JAN" then these also are military tubes, "JAN" is normally found on US tubes but can be found on other countries tubes. "JAN" stands for Joint Army and Navy.

Hope that helps and welcome!

Thanks guys! Am I right to say that I will be needing quad-matched tubes for these amps to work?

post #1098 of 3496

i don't even use matched tubes! and the amp sounds much! better than any other amp i own.


Edited by GermanGuy - 7/19/13 at 11:26am
post #1099 of 3496
Quote:
Originally Posted by darkarn View Post

Thanks guys! Am I right to say that I will be needing quad-matched tubes for these amps to work?

You need two of the 3S4's and two of the DF91's or their derivatives. The 3S4 is the power stage and the DF91 is the voltage gain stage (the 1T4T is the voltage gain stage as well!)
post #1100 of 3496
Quote:
Originally Posted by darkarn View Post

 

Thanks guys! Am I right to say that I will be needing quad-matched tubes for these amps to work?

 

Matched usually implies tubes with very similar or identical measurements from a tube measureing device. I don't believe any of mine are 'matched' pairs. And as far as I can tell, Ian and GG aren't using matched tubes. I don't think the sets we have purchased have even been tested.

post #1101 of 3496
Woodcans is right, None of mine are matched by measurement. However, there is something called batch match which means two tubes of the same make and type made in the same factory at the same time. Place and date match.

And I have found some benefit to that though it is not hard a fast as a rule!

What I would not do is to have two different manufactures tubes in the same section of the amp. For instance. I have 3S4 Phillips and 1T4 Mullards in their respective sections at the moment. I would not have a Phillips and Mullard in the 3S4 section. I have tried it and it does not sound great in my experience!
post #1102 of 3496

Got it....biggrin.gif

 

 

But, I really need to educate my "old ears" because I have to admit that for the time being, strait out of the box, I cannot really tell a difference (in a blind test) between my Fostex TH900 directly plugged into the iRiver RWAK100 and when the TU-05 is in between amplifying the iRiver RWAK100 signal !  This is quite disapointing, expecialy since I am sure that is my ears that are bad, not the TU-05 ! mad.gif

 

May be with (1) a better interconnect line out cable, (2) some tube break-in and (3)  some tube rolling,  I may start to perceive a real benefic to plug the TU-05 into the RWAK100 ??  But.... as I said, I should rather spend time to break-in... my ears ?? 

 

 

And this bring 2 more questions : 

 

1 - What is the best way to use the headphone jack as line-out:  The RWAK100 set At full volume (75), with in this case the TU-05's volume at 12 O'clock  or  The RWAK100 set at anlower volume (like 65) and the TU-05's volume at 3 O'clock ?   In which situation does the RWAK-100's headphone jack offer the cleanest "pseudo line-out" signal: 65 or 75 ?

 

 

2 - Another question about external Amps in general:  Let's say that with the headphone plugged strait in the RWAK100, I need to have the RWAK's Volume set at 65 for a good listening volume.  Now, if I use the TU-05's in between the RWAK100 and the headphone, If I I have also the RWAK' volume at 65, then the TU-05's volume is at 3 O'clock for the same listening volume.

 

So. what does the TU-05 amplify since the RWAK 100 output is at the same volume position (65) with the help of the TU-05 or Without the TU-05 ?  How can the External AMP (not just this one, any external amp) can help to provide a better sound if the RWAK100 already provide sufficient volume by itself ? Where is the help from the external Amp ???

 

And If we push the logic all the way, and use the RWAK100 at 100% (75) when using the external Amp, then I can say that the external Amp "De-amplify" since at 12 O'clock it bring down the listening volume to an acceptable level while with the headphone directly connected to the RWAK100, the volume is too loud !?? So....how this " DE-Amplification" can help for a better sound ?

 

I am very very sorry for this last stupid question, but this is something that I don't really understand.

 

thanks in advance

 

 

 

 

PS : Any suggestion for a very good interconnect cable between the RWAK100 and the TU-05 ?  And if possible from an european source otherwise, the shipping cost for a cable will be higher than the cost of the cable itself ...

 

PSS : does the TU-05 needs some break in ?  Or just the tubes ?  how to do this ?  is it necessary each time I use new tubes ?

 

 

 

HELPPPPPPPP........   :-)


Edited by bmichels - 7/19/13 at 1:59pm
post #1103 of 3496
Firstly, forget about the interconnects at this stage, good ones make a difference but they won't transform something from bad to good!

Secondly, i had to look at your player on RWA's sight. I see that he has wired the HP out as a line out From what I read I would not have any volume on the player. I don't quite understand what he has done but it reads that when connected to an amp the HP signal is not in operation. So first try turning the volume down although if this is a by pass that should not matter!

The 05 does need burn in but it sounds good right off the bat I found but it and the tubes do benefit from warming up. so let some music play for 20 minutes.

So, first, turn the volume on the AK100 off completely, as I say, If I read it correctly you should just have a pure line out from the HP socket so it should bypass the amp on the player

This is what I took from RWA's site.




"Q: How much better does the RWAK100-S sound compared to the RWAK100 used a source feeding a portable headphone amplifier?
A: Remarkably better! The main reasons for this are:

The WM8741 is a better sounding dac, especially when using its minimal phase digital filter to eliminate pre-ringing
The digital volume control is completely eliminated – so no attenuation of the digital signal occurs
The output is a true-line out signal taken from the analog output stage that follows the WM8741 and is hard-wired to the 1/8” (3.5mm) stereo output jack - so the headphone output stage is completely bypassed as well."
post #1104 of 3496
Have you charged the amp fully before using it? I very much recommend you do that! Also, whilst the stock tubes are good I would use your better tubes right off the bat but this is why I have said what I have said in the past. Tune it to your ears with the different tubes.

I find the sound is better if the amp is on its highest gain setting regardless of the headphones. If yours has a variable gain then set it to the highest position.

These are important points so I will bold them..


Do not adjust the gain when the amp is on. Always turn the volume to zero when plugging and unplugging headphones or source. Make sure headphones and source are plugged in before switching on (if you have a seperate on/off switch that is!) Do not change tubes with the amp switched on! Make sure the amp is fully charged before use and do not let the battery run to completely empty!
post #1105 of 3496

okay - i will start with some questions:

 

do you use the stock tubes?

 

if yes - the sound is not that amazing - replace them with better ones.

 

your fostex has an impedance of 25 ohm

 

 - which impedance settings was your amp ordered with and did you tried both?

 

with my amp, my grados with 32 ohm impedance sound better with the 16-120 ohm setting than with the 8-32 ohm setting - higher impedance setting normally results in more highs, the stock tubes sound more warm to dark than analytical.

 

input voltage

 

tested with the colorfly c4 the tu-05 accepts 2 volt max input voltage without any problem, a normal sign of a too high input voltage would be starting distortion.

 

the higher the input voltage, the better the s/n signal to noise ratio, but as the tu-05 is dead silent, you can set the player to about 66% to start with.

 

for the next points to explain here is a very simple schematic of a similar amp (but NOT the tu-05) with two tubes and the same principle build (single ended amp) but only for a very simple kind of comparison, experts please stop reading here):

 

 

from left to right one channel:

 

the first part the signal goes through normally is the potentiometer (your volume knob, here 100 k ohm). it divides the input signal voltage to a fraction of the original voltage (i.e you can adjust volume), this will result in a signal with less equal or max. equal voltage of the input signal.

 

here is no amplification, and as the imput impedance (here 100 kohm) is usual in the range of 47 kohm so much higher than the output impedance of the player (some ohms) no power needed, only voltage.

 

as there is nearly no current floating, the output power of your player is not requested or needed, only the voltage is important!

 

the signal then comes to the first tube, the voltage amplification stage (df91 in the case of the tu-05) where the signal voltage is amplified up to the tube anode voltage of the tube as maximum  but i don't know the internal max. voltage of the tu-05). 

 

the second tube stage (the dl92 in the case of the tu-05) normally has a voltage amplification of one or near one, decouples the first tube from the headphone but can deliver much more current, so one could say current amplification stage.

 

and as power is calculated 'current x volts' you now have the power to drive the headphone.

 

like any other highend player the rwak100 itself is designed to drive headphones (as the tu-05 is, so no big difference in output power and gain), in this case you could think of just an impedance and power convertor, but a main benefit is that the rwak battery and power is now only needed for the digital signal conversion but not power hungry amplification. the amplification is done externally by the much more stable tu-05. for example the colorfly c4 has some degradation in bass sound quality due to the weak battery at high volume level, loud music (but the quality can be dramaticaly improved by connecting the c4 to an external usb power pack).


Edited by GermanGuy - 7/19/13 at 4:40pm
post #1106 of 3496
Fascinating GG, you made that easy to understand which is quite a feat seeing as I am as technically minded as a lemon!

GG, this is what I took from RWA's website about the AK100 RWA

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.

This is the page that came from..
http://redwineaudio.com/mods/rwak100
post #1107 of 3496

Hi bmichels. I don't have the amplifier but am following these conversations with interest.  Just a thought.  The RWAK100 looks like a fantastic piece of gear but just in case there might be a 1 in a 1000 chance that the synergy between the player an amp might not be copacetic how about experimenting with a different source?  

post #1108 of 3496

yes, 2V rms is the standard so i assume there may be a problem covered by my questions.

post #1109 of 3496
Timits.

i thought AnakChan had used an identical rig and he did for his review, check it out, all seems well with synergy!
http://www.head-fi.org/products/analog-squared-paper-tu-05b/reviews/9072
post #1110 of 3496

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

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