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Bijou All Tube Futterman Headphone Amplifier - Page 275

post #4111 of 4179

Victor - you're really moving along.  Neat!

post #4112 of 4179

Just ran across a decent site for stranded, cloth-covered 600v wire.  They sell 10', 50' and 100' lengths of 20awg and 18awg.  It looks like 50' of 20awg is only $16.  At least that's what ends up in the cart.  

 

Anyway, if anyone is looking for MORE WIRE, this looks like a nice deal. 

 

http://www.radiodaze.com/category/397.aspx 

post #4113 of 4179

Hi

Nice wires...

But I can`t wait for delivery.

I want to finish Bijou ASAP :atsmile:

 

For B+ I use custom cable (acoustic cable + fiberglass isolating tube)

1st on photo

2nd - heater wires (2x twisted AWG -20 in shield)

3rd - chassis ground (Like 1st without white fiberglass tube)

 

 

 

-- Regards,

Victor

post #4114 of 4179
Quote:
Originally Posted by bhjazz View Post
 

Just ran across a decent site for stranded, cloth-covered 600v wire.  They sell 10', 50' and 100' lengths of 20awg and 18awg.  It looks like 50' of 20awg is only $16.  At least that's what ends up in the cart.  

 

Anyway, if anyone is looking for MORE WIRE, this looks like a nice deal. 

 

http://www.radiodaze.com/category/397.aspx 

 

That's the wire I used for the B+ on my Bijou. I used shielded SPC for the heaters, FWIW.

post #4115 of 4179

I was thinking about the shielding long after I had shut off my machine last night.  Where did you get your shielded SPC?

 

Thanks!


Edited by bhjazz - 4/18/14 at 4:33pm
post #4116 of 4179

John's Teflon shop on ebay.

post #4117 of 4179

Hello,

 

I use two wires cutted from old PC power supply unit (AKA "silver box)".

I twist 2 wires and place into shield (removed from other cable - coaxial or shielded RG45)

Finally I place twisted wires with shield into fiberglass tube.

(2nd cable on my photo from post #4113)

 

Now I have a nice cable without waithing and $$$.

 

I think Funch talk about:

http://www.ebay.com/itm/Audiophile-Cable-Mil-Spec-Silver-Shielded-M27500-20SC2S014Teflon-/331178088669?pt=US_Audio_Cables_Adapters&hash=item4d1bc098dd

 

Regards,

Victor

 

P.S.

I decide to use shielded heater cables starting my Bijou build.

Only one end of cable must be connected with chassis ground.

 

All case work DONE :cool:

I`m on finish. But short timeout because holidays.


Edited by LV26 - 4/19/14 at 5:22am
post #4118 of 4179

Actually, it's this.

http://www.ebay.com/itm/10-20-AWG-Shielded-Silver-Teflon-Wire-Coax-/380885022546?pt=US_Audio_Cables_Adapters&hash=item58ae843752#ht_139wt_1242

 

The wire you linked to should work just fine.

 

I didn't connect the shielding on mine, and it's still dead quiet.

 

Here's an underhood pic of mine. I had to use a separate heater transformer, since the 6H30 input tubes heaters draw more current than

the stock transformer could handle. The two thick twisted green wires coming from the left are the heater wires. The heater transformer I chose

is 6A. I probably should have used a 4A, as I had to use a 10W resistor to bring the voltage down to 6.3V.  

 

http://www.head-fi.org/g/i/1014036/a/39075/bijou-highly-modified/


Edited by funch - 4/19/14 at 11:36am
post #4119 of 4179

Hello, Funch

Very interesting and original build.

I hope the sound is a simply perfect!

 

-- Regards,

 

Victor

post #4120 of 4179

When are you going to put it in an enclosure? 

 

Why use a 6H30 for input tube? 6DJ8 has lower input capacitance by a factor of about 4.

 

How many volts is that 10W resistor? 

post #4121 of 4179

Are your questions for LV26 or me?

post #4122 of 4179

funch

post #4123 of 4179

In order:

 

It's in an enclosure. Hammond base w/cage.

 

Early in the Bijou thread, one of the builders (can't remember whom) tried and liked the 6H30 as an input tube. I tried

it and like it also better than the stock Russian one from Glassjar. It's listed on Alex's site as an alternative. I've tried

a 6DJ8 but still like the 6H30 better.

 

The big resistor was neededd to bring down the heater voltage. I selected a 6.3V/6A Hammond transformer, but probably

should have gone with one rated at 4A.

post #4124 of 4179

I'm thinking about casing options for a Bijou, specifically the power supply, and even more specifically heat management. It looks to me like the big-power items are the rectifier tube, mosfets, and a couple of power resistors.  I'm expecting to place the EZ81 in open air, but want to make sure I'm providing sufficient sinking and dissipation for the rest of the components.

 

With 6922 and 6N6P tubes, can anyone give me an idea of how many watts I should expect to be dissipated by:
 R7 and R8

 Q1 and Q2

post #4125 of 4179

Hello

There are many Bijou builds with "close case" style.

I think without any problem`s.

 

-- Regards, Victor.

 

P.S.

You can use different MOSFET with lowest Rds(on)

and bigger heatsinks

 

See link for MOSFET`s replacement

http://www.head-fi.org/t/277541/bijou-all-tube-futterman-headphone-amplifier/4080#post_10375065

 

P.P.S

If you really need this

Use

http://www.cavalliaudio.com/diy/bijou/images/250VBijouPSVoltages.gif

and calculate power P=Ur^2/R for resistors. For MOSFETS similar, but you need measure current with load (AMP boards) attached.

(simplest way). Or use MOSFET datasheet and findout Rds for given "operation point" of MOSFET. Or use SPICE simulator. :cool: 


Edited by LV26 - 4/29/14 at 12:49pm
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