diyAudio - View Profile: Cro maniac
Go Back   Home > Forums > Members List

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

Cro maniac Cro maniac is offline

diyAudio Member

About Me

  • About Cro maniac
    Biography
    I was born as very young :)
    Location
    Zagreb, Croatia
    Interests
    Cycling, hiking, diy (not just audio), repairing everything I can lay my hands on
    Occupation
    Telecommunications
    Country
    Croatia
    Real Name
    Dubravko Mrakuzic

Statistics

Total Posts
Blog
Wiki
General Information
  • Last Activity: 25th August 2014 09:08 AM
  • Join Date: 2nd February 2004

Contact Info

Instant Messaging
Send an Instant Message to Cro maniac Using...
This Page
http://www.diyaudio.com/forums/members/cro-maniac.html

Blog

Latest Blog Entry

Posted 29th January 2010 at 07:58 PM by Cro maniac Comments 0
Posted in Uncategorized
I finally gathered some will to deal with my Pass B1 project. I drawed the board in Protel and bought the components at Farnell almost 6 months ago, but never got time/mood/will to assemble it. Wednesday was my day off at work and I had nothing to do at home so I decided it is the Pass B1 day . I printed and made the boards, drilled the holes and lacquered them. Couple of hours later they were ready for soldering the components.
But hey, there is a bag full of 2SK170's that need to be matched prior to soldering ! I managed to get 3 matched pairs and I need only 2. Good enough
My version is the one with Salas regulator with R6 mod so I used the leftovers from matching in supply.
Now, everything is soldered and in place except input coupling 1uF caps and pot that I yet need to buy.

Now when it's nearly completed I don't sleep thinking how should the case for the preamp look like. I would really like to make it from wood.

Posted 27th January 2010 at 08:27 AM by Cro maniac Comments 0
Posted in Uncategorized
Yeah, my first blog entry !

I have spent whole day in matching output transistors for poweramp I'm building for a friend.
I found out that Vbe tracks gain pretty good (the transistors with higher gain have proportionally higher Vbe), so I think the painful matching of Vbe at various collector currents is pretty much useless because Vbe spread can be already seen in DC current gain.

If I think of Vbe tracking gain, it is good, because transistor that needs more Vbe will be less opened, but it has higher gain, so collector current will be more equal between devices.
I have 10 pairs of MJ21193 / MJ21194 and plan to use 4 pairs per channel.
Transistors are ordered directly from Onsemi and the NPN's all come from the same batch but PNP's are from 2 different batches and that can be clearly seen from measurements because there is a big mismatch in gain between the 2 batches.

Fortunately, the ones from the same batch are pretty...
Hide this!Advertise here!

New To Site? Need Help?

All times are GMT. The time now is 03:58 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2