[LV26]

  I had the exact same realization Went and bought some Beyerdynamic phones right after.

Hello,
Thanks for the answer.
What Beyer`s can you recommend?
 
-- Regards,
Victor
 
P.S.
Very BIG discount for AKG Q701 at amazon.com
 

List Price:	$479.00
Price:	$199.99 & FREE Shipping.
You Save:	$279.01 (58%)

 

[Kirnupiima]

To accomodate Bijou's high output impedance you'll basically want 250ohm or 600ohm variant from either DT880, DT770 or DT990 models based on sound preference. My personal pick would be DT880.
 
Or go with Tesla 1 (always 600ohm) like I did because I do stuff like that on a whim 

 
 
Have fun with the project!

 

[LV26]

What DT`s you use (600 Ohm)?
Tesla very cheap for me, OMG

I joke... I want more $$$ from my boss! Or change company where I work...
 
-- Regards,
Victor

 

[bhjazz]

(I hope that my wife is not reading this forum.

)
 
-- WBR
Victor

 
 

I joke... I want more $$$ from my boss! Or change company where I work...
   
-- Regards,
Victor

 
LOL!
 
It seems you are in the same world as us in the states.  These things are all too familiar!  

 

[LV26]

Yeah...
All humans are similar.
 
I was in USA year ago. Boston - Detroit - LA - SF - (around Bay Area)
Nice country, nice peoples!

 
-- Regards,
Victor

 

[bhjazz]

Victor!
 
Did we lose you to the shopping bug?  Hope your build is going well.  Let me know if you are getting all the parts you need!
 
Brian

 

[LV26]

Hello,
I`m OK. Just collect all parts (from tubes to screws).
Heatsinks was missed and reordered at Digi
+ some MOSFETS ordered too.
 
STM STP7NM50N, much better IRF820 - very low Rds 0.78 Ohm.
IRF820`s Rds is 2.6 Ohm. BTW IRF820 is a obsolete (as I know).
 
Case drawing done (basically modification for semi-custom case).
I`m totally rethinking about chassis. Will do "open tube" design 210 x 290 mm. only (A4 paper format)
 
I will finish with transformer testing today.
 
Preliminary:
 
Without Loads:
 
U(sec1) = 274-276 VAC
U(sec2) = 275-278 VAC
U(sec3) = 6.78 VAC
 
With Loads:
 
U(sec1) = T.B.D.
U(sec2) = T.B.D.
U(sec3) = 6.33 VAC @ 4.22A (Rload = 1R5)
 
-- Best Regards,
Victor
 
P.S.
 
Transformer test result:
 
Tested with HP 3457A bench multimeter
 
Under full load`s (simultaneously):
 
 
U(sec1) = 267.3 VAC @ 108.4 mA (Rl = 2.4664 kOhm)
U(sec2) = 263.6 VAC @ 106.7 mA (Rl = 2.4688 kOhm)
U(sec3) = 6.23 VAC @ 4.22A (Rl = 1R5)
 
I think 3.7 V delta between HV channels is not a problem

 
6.3V Load
3x 0.5 Ohm 25W resistors (serially connected)
 
Photo:
 

 
HV load`s
 
12x 3.3 kOhm, 2W (NOS USSR OMLT-2 type

) resistors "cluster"
Each "cell" combined from 4x 3.3 kOhm resistors in parallel connection.
3x "cells" connected serially.
 
Photo:
 

 

[bhjazz]

Homemade test loads - Very DIY!  I like it.
 
I can't find the STP7NM50N in a quick google search, I think the part is not available here.  Have fun with that one.  The IRF820B is what was listed at Cavalliaudio.com, but the major suppliers seems to have many other variations of that one.  Confusion!
 
I'm glad to hear things are coming along well.   Have fun and enjoy the journey!

 

[LV26]

Hello,
I`m going to assemble power supply today. All components delivered.
STP7NM50N available at Digi-Key
http://www.digikey.com/product-search/en?lang=en&site=us&vendor=0&WT.z_cid=ref_findchips0311_dkc_buynow&mpart=STP7NM50N
 
Regards, Victor

 

[LV26]

Hi.
1-st step complete

 
Power supply done.
Now will test with 100 kOm load for some hours.
STP7NM50N`s work well.
Will continue Monday. Need wait for case.
 
-- Regards, Victor

 

[bhjazz]

Many thanks for the link to the STP7NM50N.  I'll grab a few!

 

[LV26]

Hi,
Some additional info:
 
Some P/N for MOSFET-N with lowest Rds
(but cost more)
 
1) IXYS IXKP24N60C5M (not on stock)
2) Fairchild FCPF9N60NT (available)
3) STMicro STP11NM50N (available)
 
 
-- Regards, Victor
 
P.S.
Use www.findchips.com for part search.
Very nice search engine.

 

[LV26]

Hello,
All board stuffed.
Some pictures (sorry for quality), will upload better photos soon.
Still waiting for case. I think all will be finished next week.
 
Regal`s mod used, R2 socketed with machined golden contacts from disassembled DIP-16 chip socket (SAMTEC).
http://www.digikey.com/product-detail/en/110-93-316-41-001000/ED3316-ND/14041
 
Also Mill-Max have a lot of nice sockets (but DIP sockets cheaper)
http://www.digikey.com/product-detail/en/0255-0-15-80-30-84-04-0/ED1121-ND/3516731
 
AMP boards LED circuits not used (I`m try avoid additional noise from rectifying diode

)
 
All parts soldered using STANNOL 0.5 mm. (Pb free)
Sn 95.5
Ag 3.3
Cu 0.7
 
 

 
 
 

 
== Best Regards,
Victor

 

[Kirnupiima]

Beautiful soldering! I should also flip the components to the others side so I could then display the tubes in the open air, regret not doing that in the first place.

 

[LV26]

Thanks, Kirnupiima
I like solder

 
My first idea was place boards into closed case (more safe).
But my friends recommend me use open air style.
After some hard thinking I agreed with it

 
-- Regards,
Victor