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Analog Squared Paper Discussion Thread. - Page 201

post #3001 of 3712
Originally Posted by AnakChan View Post

After reviewing both I bought the TUR-06 but that was because size mattered to me. I think the 05 is probably more neutral and overall leans more towards an audiophile's sound whereas the 06 leans towards a more fun sound mainly due to a slight bass emphasis. I chose fun in the end for myself.
post #3002 of 3712

I ordered the high quality transformers. So I now have all the best parts. I can't wait for February.

post #3003 of 3712

the modder's diary part 17:


first of all i removed everything from the tu-05 where i was not sure of the pure improvement:


- the added coupling capacitors (wrong type not for audio)

- thicker twisted power cable between amp and internal psu

- the added voltage regulator board and capacitors (work in progress)


at the moment i am using the second psu board (anode voltage not changed) to run the tu-05 as original as possible



reading the posts and questions about the standard and enhanced output transformers i thought it's time to do something for all of us so here is the




Often SE output transformers are made using EI cores. the name is the result of the two parts looking like an "E" and an "I":



The small distance between "E" and "I" is called "GAP" and needed for the core not to get into saturation, getting magnetized because of the (low) DC current constantly floating in the case of and Single Ended (SE) tube amp.


This is a TU-05 output transformer:



and here one of my tu-05 output transformers after beeing opened:



as can be seen it uses a EI core:


The important point is the gap:


- the wider the gap, the lower is the risk to run into saturation,

- BUT the wider the gap, the lower the inductance and so the bass response

- the smaller the gap, the higher the risk to get the core saturated

- BUT the smaller the gap, the higher the inductance and so the low frequency and bass response


So to possibly improve the bass of the tu-05 by modifying the installed transformers it is nessesary


- to open them

- reduce the gap between "E" and "I"

- close them again


overall there should be room for improvements as the original output transformers are


- specified for an output power of 3 watt

- specified for a DC current of 20mA

- the tu-05 is far below this specifications, so a smaller gap should not result in a saturation of the transformer cores


Read more: (Click to show)

first step is to remove the frame around:


bending and opening the 4 metal tonques holding the core in the frame:




lots of glue used to hold everything together so now using a very thin and sharp knife to more or less carefully bend and widen the metal frame:



the slit between core and metal frame is glued (above the knife) and has to be widened:



after that you can bend the left and right side of the frame to the left and right side:



to remove the frame completely the easiest way is to use a pliers and some force:



this is the output transformer without frame:



unfortunately the "I" is glued to the "E" (glue between the first metal layer and the "I") so again use a sharp and thin knife to get the "I" removed:







here is the output transformer without the "I", the "I" on the right:



the correct width of the gap is usually provived by putting something in between "E" and "I", usually paper. in the case of the tu-05 transformer it is a small piece of plastic, obviously and no need to mention glued, so let's remove it using the same technique:



(on one transformer it was glued on the "I", but on the "E" in the case of the second transformer)


to know the size of the gap provided (this is important) i measured the thickness of the plastic foil (several times):



to provide a smaller gap i used paper cut into stripes:



to finally apply them you need just 2cm pieces of the stripes:



the paper above has a thickness of 0.08mm so i tried a different one with only 0.025 mm (two put together = 0.05):



if you don't know the thickness of your paper you can often just calculate the thickness (if you have a scale and enough paper or a milligram scale as i have) because usually paper has a weight per square meter value when buying it (letter paper for example 80 grams per square meter).


here the paper is put on the transformers before re-inserting the "I"s:



here the transformers with paper and the "I"s inserted (NO glue needed!):



and here the transformers closed with frame around (bend with a bench wise):



The SE Output Transformers now have a gap of (2x 0.05) = 0.1mm instead of 2x 0.12)=0.24mm.


finally to avoid soldering the wires each time some connectors added, so you can just use a screwdriver to connect wires to the transformers:



and here connected to the tu-05:



that´s it!


i haven't listended to the original tu-05 output transformers for a long time but as far as i remember bass response is improved (gap is smaller, so it must be improved, the question is if the improvement is big enough to be heard).


For example listening to J.S.Bach, Toccata und Fuge d-moll, the rumble and noise from the traffic outside is better to hear than before.


don't expect wonders as the output transformers and so the cores are really small, but nevertheless overall the sound has a little bit more body and "ground" so beeing sligtly more "complete" and as this mod is very easy to perform and gives you maybe just this small extra bit of bass you may want, .....

Edited by GermanGuy - 1/1/14 at 3:36am
post #3004 of 3712
Originally Posted by Sam Edwards View Post

I ordered the high quality transformers. So I now have all the best parts. I can't wait for February.

i am sure everybody here fully understands this. i know this from waiting for my amp .... some time ago .. last century? ... oh no, just 5 or 6 month ago... . so happily awaiting your first listening impressions.

post #3005 of 3712

Hey GG,

I'm tempted to have my TU-05 shipped to you for some quick mods on it's way from Japan to California. You could throw in your favorite tubes, if you had extras, upgrade the jacks, and give me USB power in the form of an external battery pack. Let me know if you're interested.

BTW I ordered the Sennheiser HD800's to go with it. So I want High/Low impedance to also use my CIEM's?

And I really do want to reserve serial no 001 of the GG Balanced Single Ended Triode Amp. I'm not joking.

Kind Regards

post #3006 of 3712
Originally Posted by GermanGuy View Post

a component definetely worth upgrading is or are the 3.5mm jacks. the best-of-best i found is this one:





price is about 5 Euro per piece, available on all major electronic stores.

Hey GG,

Do you have to modify the case to put one of these in? What kind of solder?


post #3007 of 3712

i am far away from beeing able to modify other tu-05, mainly because i have not the environment to drill holes without scratches on the case and the modifications i made are not that easy if done after the amp was build. the much easier solution is to send an email to shikada-san:


if you want to have this jacks, send shikada-san an email with the component and


- ask him to directly integrate the lumberg 3.5mm jacks.


other modifications shikada-san can do:


- connect pin 4 and 5 of the DF91 sockets, so you can also use the excellent RFT or other DF97


- not directly connect the pin1 of the DL92 tube sockets, but connect them providing a switch, so that the 1.4 volt power of the pin1 of the DL92 sockets can be switched on and off. this enables you to use the DL92 in power save mode or to use the excellent 1S4 tubes. the problem here will be that the tu-05 case is made using a CNC machine and shaper based on a CAD drawing, don't know if your case is already made, i paid about 400 Euro for my custom extended tu-05 case without holes.


- there is not enough space inside the tu-05 case to provide two output transformers, so you also here should ask shikada san. the main problem will be that there is no impedance switch with enough positions to select all the output impedances you may want (within the "Flat design" of the tu-05 case), solution could be something like a NK switch type NR (very small and fitting the requirements to be used (voltage, current), but must to be placed on the front panel:




half inch diameter:



- ask if the custom made HD800 transformer he has mentioned in an email to me could be also made to have low AND high impedance settings and which impedance settings you want.


i am not working on an balanced amp, only a double mono design.


i have just interrupted drilling the holes for a bottlehead crack like chassis when reading your post, so thanks for bringing my HD800 output transformers into my mind, maybe have to provide two additional holes for them


as solder i tried to use leadfree mundorf supreme silver/gold solder and others, but all this leadfree solder is a nightmare to solder, doesn't flow, to much heat needed, horrible, the only way to solder it at home is to use a protective gas like Nitrogen or Carbon Dioxide (i hope), just bought a CO2 gas zylinder some days ago to test this after having build a gas nozzle around the soldering iron, the gas has to be preheated by for example on of this SMD hot air soldering stations modified with an input for the CO2 and a magnet valve.


as solder you should use standard solder with 1.0 mm diameter AND standard solder with 0.5mm diameter both with lead and some silver.


USB charging - let me think of an easy solution for all of us.


P.S. hope shikada-san does not get crazy when eventually beeing asked for all this modifications

Edited by GermanGuy - 12/30/13 at 11:33am
post #3008 of 3712

the modder's diary part 18:


today i drilled and shaped the prototype chassis for a tu-05 desktop case to play with different tube sections that also would fit into a tu-05 case using a double side copper plated pertinax sheet:



to give you a better impression here with components:



More pictures: (Click to show)





Function of the different components:



and here finally cut to fit into the wooden frame:



Edited by GermanGuy - 1/1/14 at 3:38am
post #3009 of 3712

I've just tried this combo in the past hour and I'm absolutely loving it! The TUR-06 has enough grunt to drive Alpha Dogs, give it a nice bass, crystal highs and it's fast and dynamic. I'm really loving this setup at the moment.



post #3010 of 3712
Originally Posted by AnakChan View Post

I've just tried this combo in the past hour and I'm absolutely loving it! The TUR-06 has enough grunt to drive Alpha Dogs, give it a nice bass, crystal highs and it's fast and dynamic. I'm really loving this setup at the moment.



What is between the iPhone and the TU-06 ?  IS it a DAC ?  Which one ? 

post #3011 of 3712
Originally Posted by bmichels View Post


What is between the iPhone and the TU-06 ?  IS it a DAC ?  Which one ? 


That's a VentureCraft DD 12V Limited Edition DAC but it has 2xMuses01 "preamp" OpAmps in it. It's for iOS only.

post #3012 of 3712

Hey GG,

I think it's probably best to let Shikada-San make the design that he created. But it's awfully exciting to see what you're coming up with. 


post #3013 of 3712

the modder's diary part 18a:


just finalized the sub-chassis for my tu-05 desktop prototype:



More pictures: (Click to show)



the first level is for all the audio and signal parts, the second level for the internal power supply:



bottom side with dynavox cones:



top side with the wooden frame around:


Edited by GermanGuy - 1/1/14 at 3:40am
post #3014 of 3712

The Astell & Kern AK240 !  Our next source for the TU-05 / TUR-06 ? 


In the February 2014 issue of The Absolute Sound there's an ad for the new Astell & Kern AK240.

There's not a lot of info so I'm hoping they'll show it at CES next month and.... that it has a true line-out...

Edited by bmichels - 12/30/13 at 11:59am
post #3015 of 3712

after designing my own headphone and now building my own amp this may prevent me from building my own player :-)

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