The No.1 Website for Pro Audio
What is a current production replacement for Toshiba 2SC3329BL?
Old 1 week ago
  #1
Lives for gear
 

What is a current production replacement for Toshiba 2SC3329BL?

I found a thread where Jim Williams mentioned replacing all of the BC184s transistors in a GAP pre73 to lower the noise floor. He suggested using the Toshiba's but they are no longer in production it seems...

UTSource said they would sell me some, but they have terrible reviews for fakes and such and I dont know how to test each one, is there a modern production replacement for the Toshiba's people would recommend?
Old 1 week ago
  #2
Lives for gear
 
gyraf's Avatar
 

Do you have an estimation of how much you can expect to gain in noise distance?

I'm not really sure it's a real-world feasible thing to do, probably many other alterations that are higher yield per hour spent..

/Jakob E.
Old 1 week ago
  #3
These are .5 nv/hz/sq noise speced transistors. The Hitachi 2SC2546 is equivalent but also out of production. Yes, they will lower the hiss in the Neve designs.
Old 1 week ago
  #4
Lives for gear
 

Thank you Jim, what do you think about the ON semi/motorola mpsa18? I came across that being a suitable upgrade as well, and much easier to find. I did manage to located one Hitachi source on eBay, but waiting on a quantity answer from them.


Quote:
Originally Posted by Jim Williams View Post
These are .5 nv/hz/sq noise speced transistors. The Hitachi 2SC2546 is equivalent but also out of production. Yes, they will lower the hiss in the Neve designs.
Old 1 week ago
  #5
Lives for gear
 
gyraf's Avatar
 

I wonder how much reduction in hiss (improvement in noise figure) can be expected from an operation like this?

The residual hiss is far from the weakest part of this circuit, IMO..

/Jakob E.
Old 1 week ago
  #6
Gear Addict
Horowitz and Hill took extensive noise measurements of small signal bjts for AoE 3rd edition. Get the book for details but the good old MPS8099 (now produced by Central Semi and available at Mouser) was measured at 0.37 nV/sqrt(Hz). There are a few better ones in terms of noise but all things considered (Cob, Early voltage, noise vs. Ic, beta vs. Ic, etc.) this one looks pretty good to me. I don't know the circuit though, so check out the datasheet to see if it's a suitable replacement. Pinout is EBC, so no leg twisting required.
Old 1 week ago
  #7
Lives for gear
 

Thank you @ Cabirio ill take a look, they're for a Neve 73 pre (the golden age project pre73). While I have all this free time I figured I start fiddling with and improving upon my gear at home.
Topic:
Post Reply

Welcome to the Gearslutz Pro Audio Community!

Registration benefits include:
  • The ability to reply to and create new discussions
  • Access to members-only giveaways & competitions
  • Interact with VIP industry experts in our guest Q&As
  • Access to members-only sub forum discussions
  • Access to members-only Chat Room
  • Get INSTANT ACCESS to the world's best private pro audio Classifieds for only USD $20/year
  • Promote your eBay auctions and Reverb.com listings for free
  • Remove this message!
You need an account to post a reply. Create a username and password below and an account will be created and your post entered.


 
 
Slide to join now Processing…
Thread Tools
Search this Thread
Search this Thread:

Advanced Search
Forum Jump
Forum Jump