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Bijou All Tube Futterman Headphone Amplifier - Page 273

post #4081 of 4182
Quote:
Originally Posted by Kirnupiima View Post
 

I had the exact same realization :D 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%)

Edited by LV26 - 3/2/14 at 2:37pm
post #4082 of 4182

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 :wink_face: 

 

Have fun with the project!

post #4083 of 4182

What DT`s you use (600 Ohm)?

Tesla very cheap for me, OMG :biggrin:

I joke... I want more $$$ from my boss! Or change company where I work...

 

-- Regards,

Victor

post #4084 of 4182
Quote:
Originally Posted by LV26 View Post

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

 

-- WBR

Victor

 

 

Quote:
Originally Posted by LV26 View Post

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!  

post #4085 of 4182

Yeah...

All humans are similar.

 

I was in USA year ago. Boston - Detroit - LA - SF - (around Bay Area)

Nice country, nice peoples!:beerchug:

 

-- Regards,

Victor

post #4086 of 4182

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

post #4087 of 4182

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 :rolleyes:

 

6.3V Load

3x 0.5 Ohm 25W resistors (serially connected)

 

Photo:

 

Intel(R) IPP JPEG encoder [7.0.1041] - Jul 19 2011;

 

HV load`s

 

12x 3.3 kOhm, 2W (NOS USSR OMLT-2 type :cool:) resistors "cluster"

Each "cell" combined from 4x 3.3 kOhm resistors in parallel connection.

3x "cells" connected serially.

 

Photo:

 

Intel(R) IPP JPEG encoder [7.0.1041] - Jul 19 2011;


Edited by LV26 - 3/19/14 at 4:48am
post #4088 of 4182

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!

post #4089 of 4182

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

post #4090 of 4182

Hi.

1-st step complete :cool:

 

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


Edited by LV26 - 3/21/14 at 12:14pm
post #4091 of 4182

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

post #4092 of 4182

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.


Edited by LV26 - 3/21/14 at 12:13pm
post #4093 of 4182

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 :cool:)

 

All parts soldered using STANNOL 0.5 mm. (Pb free)

Sn 95.5

Ag 3.3

Cu 0.7

 

 

Intel(R) IPP JPEG encoder [7.0.1041] - Jul 19 2011;

 

 

 

Intel(R) IPP JPEG encoder [7.0.1041] - Jul 19 2011;

 

== Best Regards,

Victor


Edited by LV26 - 3/25/14 at 2:47am
post #4094 of 4182

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.

post #4095 of 4182

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 :cool:

 

-- Regards,

Victor


Edited by LV26 - 3/25/14 at 5:55am
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