Head-Fi.org › Forums › Misc.-Category Forums › DIY (Do-It-Yourself) Discussions › Restoring my balanced Beta 22
New Posts  All Forums:Forum Nav:

Restoring my balanced Beta 22

post #1 of 12
Thread Starter 

Hi guys, i would like tho show you my restored Beta 22.

It was built 1 and half year ago by an italian guy, you can see how it was here.

I decided to put it in a single chassis, and to change cables, attenuator and connectors.....

This is how it looks now, restored by me...... since i'm not an expert, it has been an hard work!

http://imageshack.us/g/1/9870407/

I used an HIFI2000 Pesante Dissipante 5U chassis, Airtech 7n OCC Copper cables and VampireWire connectors.

post #2 of 12

It looks very nice. I like how you used the cast cases as shields.

post #3 of 12
Thread Starter 

Thanks!

post #4 of 12
Thread Starter 

Well, it's not mu metal but i'm not hearing any noise......

post #5 of 12

I think you done a marvellous job.

But... the guy who did the board stuffing did a sloppy job and why tombstone the resistors?

Anyways the job you did looks great congrats fra107.

post #6 of 12
Thread Starter 

Thanks!

 

Sorry but i don't understand, what is "tombstone"??? If i translate it by google it's something about dead! biggrin.gif

 

Anyway, i'm waiting for some vynil adhesive, it will looks like this in a few days........

 

 

1000

post #7 of 12

Tombstone - the resistors have been mounted vertically like a tombstone :-)


Edited by Fred_fred2004 - 11/19/12 at 4:00am
post #8 of 12
Thread Starter 

Thanks Fred,

 

i don't know why he mounted the resistors like a tombstone, i just know that my Beta is sounding very very good! beyersmile.png

 

The Airtech cable is incredible!

post #9 of 12

They're not really tombstone resistors, they're attached to transistors, not the PCB.

 

It looks like the builder has used JFETs with resistors gate->source to set them as CCS in place of the current reference diodes. 

post #10 of 12
Thread Starter 

Is it something about initial setup trimmers?

post #11 of 12
Quote:
Originally Posted by fra107 View Post

Is it something about initial setup trimmers?

No.

 

It's the current references. CR1 - CR8 on the schematic.

Internally, a current reference diode is a JFET with the Gate and Source internally connected, which will operate at the IDSS (saturation current) of the JFET.

 

In your B22, the builder has substituted these for JFETs biased with a resistor.

If it has been done correctly, then circuit performance shouldn't suffer, except for looking horrible.

post #12 of 12
Thread Starter 

Thanks Dingo, i hope it has done correctly......

New Posts  All Forums:Forum Nav:
  Return Home
Head-Fi.org › Forums › Misc.-Category Forums › DIY (Do-It-Yourself) Discussions › Restoring my balanced Beta 22