[Jrossel]

Has anyone driven low impedance cans with their Bijou? 
I would like to know if the amp can drive  24 Ohm  headphones?
 
Thanks for your help.
 
Jeff

 

[yiancar]

without, less interference and less things to cross out when things dont sound correct however i need to mention that i use HD650 so my phones have rather high independence

 

[yiancar]

Quote:

Has anyone driven low impedance cans with their Bijou? 
I would like to know if the amp can drive  24 Ohm  headphones?
 
Thanks for your help.
 
Jeff

There are some good opinions in very early posts, try searching the thread a bit . Overall though most people use high impedance phones with the amp
 

 

[Coupe]

Amazingly beautiful and humbling builds!  You guys are incredible!

 

[balderon]

Quote:

Has anyone driven low impedance cans with their Bijou? 
I would like to know if the amp can drive  24 Ohm  headphones?
 
Thanks for your help.
 
Jeff

I have had no issues driving 40Ω LCD-1 or 25Ω Denons with JJ ECC99 drivers.
 

 

[vlb]

Wow, you guys really master the art of casing.
 
I hate casework and since I decided to go p2p and dual mono with separate chassis power supplys I have to suffer through a lot of it. And now I have to add an extra section to the amp chassi to house film capacitors and remote controll unit...
 
Anyway, a have o few problem and hope you can help.
 
Is there any solvent I can use to get superglue of aluminium?
Where do I find those "rings" you put around the tube sockets to cover the screws?

 

[balderon]

Try acetone based nail remover to dissolve the superglue.
 
Take a look at the accessories at vt4c. http://www.vt4c.com/shop/program/main.php?group_id=2

 

[mugdecoffee]

Quote:

Has anyone driven low impedance cans with their Bijou? 
I would like to know if the amp can drive  24 Ohm  headphones?
 
Thanks for your help.
 
Jeff

I tried mine with a pair of 32ohm Grados and thought it sounded pretty bad, very flat and bland sounding.  Not sure if that was a problem of impedance or just pairing.
 

 

[yiancar]

Quote:

Wow, you guys really master the art of casing.
 
I hate casework and since I decided to go p2p and dual mono with separate chassis power supplys I have to suffer through a lot of it. And now I have to add an extra section to the amp chassi to house film capacitors and remote controll unit...
 
Anyway, a have o few problem and hope you can help.
 
Is there any solvent I can use to get superglue of aluminium?
Where do I find those "rings" you put around the tube sockets to cover the screws?

 


Quote:

Try acetone based nail remover to dissolve the superglue.
 
Take a look at the accessories at vt4c. http://www.vt4c.com/shop/program/main.php?group_id=2

 
As Balderon told vt4c has some amazing stuff My rc sockets, tube sockets and transformers  are also from there. It has some awesome cases too My casework was done by hifi2000 and some of my noobish autocad skills
 
Also can you guys point me to some good rotary switches? I need to make a passive xlr source selector and i dnt really see the point of using relays
 

 

[jdkJake]

Also can you guys point me to some good rotary switches? I need to make a passive xlr source selector and i dnt really see the point of using relays

I am fond of these:

http://www.goldpt.com/selector.html

 

[vlb]

My bijou is up and running again after a few mods. Now using 6n6p as output, I was really dissapointed as first, the sound was lifeless and sharp to the ears. After 20 hours burn its much better but still not sure if its better than ecc99. 
 
Im going to run it without chassi for a few weeks at least to try more mods. I have to rebuild the chassi to fit my huge output caps...
Running dual mono so Ive got some spare power right now.
 
The next mod will be to try 6n30p as input and bias it at around 15-20 mA. Im not 100% on how to do it yet, but Im working my way through Morgan Jones books.
 
Im thinking about the possibillity to use 6n30p as output, do you think it would be worth a shot?
 
Il need to determine how much current I can draw from the PS to. Im thinking about monitoring B+ with a scope while applying an increasing load with resistors, would this be a good method?
 
My half finished build, currently runnings as preamp for Magnepan 3.5s:
http://imageshack.us/photo/my-images/88/20110712404.jpg/
 

 

[yiancar]

Ur psus are pretty nice in my trial with 6n6p i didnt really like it even after some days of listening ecc99 for me, What caps are u using?
About a dummy load you can try this http://www.youtube.com/watch?v=8xX2SVcItOA or this http://www.hlektronika.gr/forum/showthread.php?t=45738&highlight=dummy+load second link is in greek but if u use google translate ull get some nice info. both are active dummy loads therefor the max value will be mode accurate than using resistors
 
U may need to change the fet though to be able to survive 250v

 

[vlb]

Thanks, Im pretty sure it will look good when its all done...
 
Im Using 120uf 900v film caps, Ive lso removed the cathode bypass caps and replaced c1 with 40uf film. Theese mods made the sound very controlled and dynamic. Next Im going to try if bigger caps at c3 and c4 will make a difference.
 
Regals mod was a big improvement to, and in my taste NFB makes the sound smother and more detailed.
 
Thanks for the tips on the load!
 
Have you compared your balanced build to an unbalanced?
 

 

[yiancar]

As i have a balance/unbalanced switch (similar to the b22 circuit) the comparison was done (with both unbalanced and balanced sources).
The balanced mode seems more full and dynamic than the unbalanced one. I want to describe it as powerful but without the meaning of more volume. As most balanced setup bijou is improved .
 
In my setup i changed the coupling caps with film  and the bypass caps with mundorf silver in oil. Ur 120uf is the c5 cap? if so isnt it small in contract to the 470uf of the electrolytic that was there?

 

[vlb]

Im sorry to hear that
Of course I want it to be even more full and dynamic. But I dont want to build all this one more time. It would be pretty riddiculess too, some kind of dual mono, dual mono and a total of 6 chassis...
 
Yes my 120uf is in C5 position.
Since Im using Hd650 (330ohm) 120uf gives -3db at 4hz and 98% signal level at 20hz. 470uf -3db at 1hz and 99,8% at 20hz. I dont think you can hear that difference, but you surely will hear better clarity in the sound with films.
 
 
Post explaining how to get a graph on it. Both online and on a texas ti.
 
http://www.head-fi.org/forum/thread/277541/bijou-all-tube-futterman-headphone-amplifier/3870#post_7431430
http://www.head-fi.org/forum/thread/277541/bijou-all-tube-futterman-headphone-amplifier/3870#post_7433127
 
Have you tried your bijou as a preamp?
I think it brings a nice tube touch to the sound espially in the summer when I cant use my 250w tubeamp, I can´t stand the heat and the amp eats 16 6550s every 2000hours.