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post #2521 of 3712

one day, four parcels - a lot of parts and components arrived today:


the switches, the silver/gold wires and the silver/gold solder:




The 50 cent Radiotechnique DF91:



The tube prototyping pcb boards:



and a large collection of other components and parts like transistors, capacitors, resistors, cables, screws and nuts, transformers, inductivities, potentiometers, other switches, LEDs, zener diodes, bridge rectifiers, pcb connectors and much more:



These parts and components are not for the modification of the amp, but how to say, if you want to play LEGO, you need enough bricks to build, test and play with.

Edited by GermanGuy - 10/22/13 at 9:40am
post #2522 of 3712
Originally Posted by ianmedium View Post

I somehow think the tubes will beat solid state in this application as it has been designed for tubes after all, but who knows!

Oh, and just realized this was my 4000th post! So glad it was on the ASP thread!


congratulations for that. i think that all the thread members including me are happy that your post count is increasing by posting here! i am waiting for my post count to reach 1000, but what's the number one could think of as next step to reach when already having posted 4000 times!

post #2523 of 3712

okay, i think i am (nearly) complete now to start modding my amp (after the new case has arrived, the invoice for the second internal power supply board allows me to order it and after i have analyzed the existing tu-05 to buy all resistors and capacitors needed, and a LC meter is also not seleected and ordered up to now), but most important


- today i found and ordered the output transformers i was looking for (and i hope that i understood everything correctly what i tried to learn about output transformers to have selected the right one):



2x Tango H-5S Single End Output Transformers (used)


Processed By eBay with ImageMagick, R1.1.1.M2b


Processed By eBay with ImageMagick, R1.1.1.M2b


Primary impedance: 5kΩ
Secondary impedance: 4, 8, 16 , 32 Ω
Power output: 10w
Frequency response: 60Hz - 80kHz (-2dB))
Primary inductance: 11H-17H (50mA)
Power loss: 0.4 dB (16 Ω)
Max Allowable Current: 65mA
Dimensions: 65L x 65W x 70H mm
Weight: 0.9kg each

if i understood everything right:


- the frequency response (bass 60Hz) is measured for a power output of 10w

- as the tu-05 has only 40mW (per channel), bass frequency response should be much better

- the output transformers have an additional primary SG tab, usually at about 43%

- so should have something like 0 - 3k - 5k primary impedance selectable


- the tube is not seeing the output impedance as written on the secondary tabs ( 0 - 4 - 8 - 16 - 32 ohm),

- but the impedance of the headphone connected multiplied by the ratio between primary and secondary side,

- so with the 16 and 32 ohm secondary tabs it should be possible to match the impedance of my HD800 or even an Beyerdynamic T1.


they were only (just kidding) 470 Euros including shipping and import taxes (not kidding), so some dry bread and cold water is recommended now until i get my next salary, try to not even think about any selection mistake.


as i have bought all parts (except the resistors and capacitors) to build a copy of the important tu-05 parts i can now start to


- measure all voltages and currents delivered by the internal power supply board

- measure or look at the types and parameters of all internal resistors and capacitors to buy new ones

- build two copies of the DF91 and DL92 stages with the tube prototyping boards

- Option - design and build to DL stages with higher output power

- combine and adjust the power supply boards (the Step up and Step down DC/DC converters) to provide the needed voltages

- make a complete double mono setup on my workbench

- optimize the hole power supply chain

- start testing and listening to the new components, output transformers, switches etc ...


before modding the existing tu-05.

Edited by GermanGuy - 10/23/13 at 11:28am
post #2524 of 3712
Originally Posted by GermanGuy View Post

While ordering a standard collection of electronic parts and components i found that the german electronic tools and parts shop i ordered the parts from also offered some tubes, so i checked this and found them selling NOS DF91 tubes (in german language tube = Röhre). while there is no guarantee which manufacturer you get tubes from on the picture a Radiotechnique DF91 was shown so i ordered ten pieces just for fun.


And you won´t believe i got 10 NOS Radiotechnique DF91 looking like fresh from the factory in the original cardboxes for 50 european cent per piece !



Unfortunately it costs 22 euros to ship a .5 euro tube to the US...

post #2525 of 3712
if you want some i can send you four of them, the tubes free of cost as i have 14 of them at the moment, shipment is 5 euro as i know from sending the cleaning kits to the distributors.

btw, did you get a cleaning kit from woodcans or ianmedium? don't know if they are 'out of stock' but i can make new ones.
post #2526 of 3712
Originally Posted by GermanGuy View Post

if you want some i can send you four of them, the tubes free of cost as i have 14 of them at the moment, shipment is 5 euro as i know from sending the cleaning kits to the distributors.

btw, did you get a cleaning kit from woodcans or ianmedium? don't know if they are 'out of stock' but i can make new ones.

Hey GG,

I would love this if you can spare them. I'll send you a PM with my address. Please let me paypal you the money. It sounds like your project is costing quite a bit. 

Ian is sending me a cleaning kit, and woodcans offered about 15 minutes later.

This is a great group!

post #2527 of 3712
sam edwards - got your payment
post #2528 of 3712

some additional parts arrived today:


2x philips DF97, two matched pairs of EL86, 4x tesla 1L33 / 1s4, 1x tung-sol 1s4:



additional pcb prototyping boards, different sized spacers and the mini heatsinks for the dc/dc transformer boards:



the large magnifier lens with lights:




and yesterday the philips frequency counter:


Processed By eBay with ImageMagick, z1.1.0. ||B1

Edited by GermanGuy - 10/24/13 at 11:56am
post #2529 of 3712

can't wait that all parts and especially the se output transformers have arrived to stop only posting parts and conponents but instead start writing about music, sound and hopefully improvements which can be implemented with a benefit for all of us!

post #2530 of 3712


post #2531 of 3712

German guy, I am 100% behind you for this BIG project, but... I am anxious for you  that the result could not be exactly what you expect ?


 Indeed, i read in one article the following about hardware design:


"Designing of audio equipment is really the fight for the least distortion in sound reproduction or, if you prefer, showing as many advantages as possible, hiding flaws and sketching by the designer an intended end result. Obtaining the "desired" sound is always the result of many attempts, correcting the values of individual items, making changes in the circuit-board layout, or its location in the chassis, etc., etc. All components work together to create a new quality. When one of the 100 elements is wrong, it will affect the others (change their operating characteristics) and disrupt their proper operation. It's a kind of a domino effect.
We also need to realize that it is not about changes in the order of 10 or 20%. Not even one percent but only one part mille will often be important. For example – moving a capacitor on the circuit-board by a few centimeters (or an inch) closer to the grounding will trigger changes in the sound, and yet the wiring diagram (as well as measurements and computer simulations) won’t show any change. After all, it’s "only" one ten-thousands of Ohm of circuit path resistance which is, however, easily perceptible to the human – not to mention the audiophile – ear. It’s hard to imagine how precise the sense of hearing is!"


so, even it it is nor really " black magic", it seems that there are much more involved than "wiring diagram & measurements" to make a very good amp ! 


what is your feeling about this ?

post #2532 of 3712
I completely agree! It's like jumping into cold water the first time and as i know from debugging measurement systems, there will be a hard time for learning and a lot of mistakes and trial and error. But that's the normal way of life, if you like walking through nature, the walking is the fun part, not (but also) reaching the destination.

I am sure i will spend a lot of money in wrong components, accidently destroy some tubes, drill a hole into the case at the wrong position.

I see the problem that i have no experience with own build audio electronics up to now but think i am able to learn, so the next year will be very interesting!

But maybe that's one of the reasons i have decided to build a copy of the amp to test and listen to components before modding the tu-05 itself, and at the end i have at least a modded or unmodded tu-05 and a hopefully good sounding desktop amp or maybe a desktop amp with EL86 and up to 2x 5 watt output as the output transformers selected are capable of this.
Edited by GermanGuy - 10/25/13 at 9:40am
post #2533 of 3712

what is the general waiting period the Tur-06?



post #2534 of 3712
Listening with a headphone vs. Reality:

I had a great afternoon today! Went to town to buy differnt metallic colors to have a selection of different options to paint the amp (and also to learn and test this before), bought some food and also the parts to construct a metal bending tool to make the sub-chassis for the modded amp, but when walking from the food store to the hobby market (asking for the shortest way to save some time) ....

There was some nice organ music in the air, i followed the music, there was a church where the music came from, the door not locked, so i went inside, there was a young woman playing to exercise for a concert, i asked if i could just sit down and could listen, she agreed, and so

I had a one hour organ live concert alone in a large church sitting at the best place, a great real pipe church organ, excellent play, wonderfull acustics!

What a great experience!!!

After that i must say that for one second i thought of throwing away my audio equipment, at least i now know how my next grado style headphone should sound (have got some new ideas how to build a headphone that could be able to be much more 3D like sounding) as this great experience of sound and space isn't reproduced by any headphone i know.
Edited by GermanGuy - 10/25/13 at 10:47am
post #2535 of 3712
Originally Posted by gmahler2u View Post

what is the general waiting period the Tur-06?


2 to 3 months at the moment?!
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