B1 Buffer Preamp - Page 253 - diyAudio
Go Back   Home > Forums > Amplifiers > Pass Labs

Pass Labs This forum is dedicated to Pass Labs discussion.

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
Reply
 
Thread Tools Search this Thread
Old 27th June 2010, 05:06 PM   #2521
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
the drop from 1k0 to 330r will let receiver see a lower source resistance and at the same time raise the RF filter just over an octave.
This may be audible. Worth trying.
__________________
regards Andrew T.
  Reply With Quote
Old 27th June 2010, 07:03 PM   #2522
Atilla is offline Atilla  Norway
diyAudio Member
 
Join Date: Jul 2008
If that helps, I'm using 220s at the output of my B1 and it seems stable. The dual-supply version of B1 also uses 220 for output resistor I believe. I don't have an oscilloscope to measure if there's any difference though. You can give it a shot.
  Reply With Quote
Old 27th June 2010, 08:10 PM   #2523
Arick is offline Arick  Canada
diyAudio Member
 
Arick's Avatar
 
Join Date: Dec 2008
Location: Montréal
Quote:
Originally Posted by Arick View Post
Fair enough, I will try to draw a plan and post it. By reading previous posts, I though it was ''relatively'' simple...not shore anymore
Following my last post, finally got the time to draw the way I want to connect my balanced version of the B1. What is not shown on the drawing is the switch to change the input from balanced to RCA and the 4 gang potentiometer. Any suggestions?
Eric
Attached Images
File Type: jpg BalancedB1.jpg (104.5 KB, 930 views)
  Reply With Quote
Old 27th June 2010, 08:15 PM   #2524
Nick77 is offline Nick77  United States
diyAudio Member
 
Join Date: Dec 2009
Location: Austin Tx
I just finished my B1 thank you Nelson for sharing.

I have a question:

I have almost 100 hrs on unit and still sounds rather dark and recessed. I have 4 Takman rex carbon resistors in the signal path. I have heard they are warmer but i am getting to much warm and they can take while to settle down. I am ready to remove at least two but wondering if anyone knows if they might still open up with a few more hrs???

Thanks

Last edited by Nick77; 27th June 2010 at 08:22 PM.
  Reply With Quote
Old 27th June 2010, 10:04 PM   #2525
Atilla is offline Atilla  Norway
diyAudio Member
 
Join Date: Jul 2008
I'd say, if you aren't used to it in a 100 hours, something is wrong and you might want to see if you change something.

As for the whole burn-in of components, I wouldn't touch that with a 100-feet pole. It can get scary

I mean, if you change something in the system, whatever it is - transistors/caps/resistors/voltage/bias, and it sounds better then you're happy you improved your system. That's the charm of DIY, after all.

Burn-in, psychoacoustic conditioning, whatever you want to call it can't correct mistakes, or the fact that you bought a component from a weird source and it turned out to be a fake and you didn't realise in time. Those things happen sometimes.

BTW, my B1 uses resistors from my "by-the-pound" bag. Whatever they are, they seem to sound perfectly OK in both my amp, preamp and headphone amp so far.

Last edited by Atilla; 27th June 2010 at 10:07 PM.
  Reply With Quote
Old 27th June 2010, 10:52 PM   #2526
diyAudio Member
 
regiregi22's Avatar
 
Join Date: May 2009
Location: Madrid (Spain)
Yeah, a pair of sinlges resistors are not going to completely change the sound character of a device. It can influence it, but I don't think it will solve your problem.
__________________
diyAudio, doing it as big as you can, JUST BECAUSE WE CAN!
  Reply With Quote
Old 27th June 2010, 11:43 PM   #2527
diyAudio Member
 
Join Date: Sep 2004
Location: North Carolina,
Quote:
Originally Posted by regiregi22 View Post
Yeah, a pair of sinlges resistors are not going to completely change the sound character of a device. It can influence it, but I don't think it will solve your problem.
I will let you know how it works.
  Reply With Quote
Old 30th June 2010, 09:04 PM   #2528
diyAudio Member
 
east electronics's Avatar
 
Join Date: Jan 2006
Location: Athens GREECE
made my shelf a B1 ( a generic construction that suffers from a few errors ) that still plays amazingly well

veroboard simple material good quality transitors ... other than that a very simple thing

things i liked
bandwidth dynamics ultralow noise nice colours warm doesnt strech almost any kind of music ...works very nice ... sounds also very crisp and linear

only thing that puzzled me a bit is that it seems that it sounds better with 24 volt supply than it sounds with 18 is there a reason for that or simply my imagination ???

eventhough generic construction actually meet almost all measuring specs

way to go Papa thank you very much
Attached Images
File Type: jpg Εικόνα020.jpg (79.4 KB, 784 views)
File Type: jpg Εικόνα021.jpg (79.0 KB, 768 views)
__________________
SERVICE ΕΝΙΣΧΥΤΩΝ ΚΑΙ ΙΑΠΩΝΙΚΩΝ ΜΗΧΑΝΗΜΑΤΩΝ ΗΧΟΥ www.eastelectronics.gr
  Reply With Quote
Old 30th June 2010, 09:40 PM   #2529
diyAudio Member
 
chrismercurio's Avatar
 
Join Date: Aug 2006
Location: Silicon Valley
I never tried 24v. It sounds better at 18v than at 9v, 12v, or 15v and I stopped there because everything improved so much at 18v. What do you find the difference to be between 18v and 24v?

Chris
  Reply With Quote
Old 30th June 2010, 10:32 PM   #2530
diyAudio Member
 
east electronics's Avatar
 
Join Date: Jan 2006
Location: Athens GREECE
i would say that sound is warmer and more balanced with 24 volt ... also seems thathigh is more clean and tollerant ... that might be a small detail but still audible

Also if in the front is a class AB amplifier this type of diference is not that obvious ... but with a class A amplifier begins to be more audible

kind regards sakis
__________________
SERVICE ΕΝΙΣΧΥΤΩΝ ΚΑΙ ΙΑΠΩΝΙΚΩΝ ΜΗΧΑΝΗΜΑΤΩΝ ΗΧΟΥ www.eastelectronics.gr
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
buffer/preamp? TheDriver41 Chip Amps 2 3rd October 2004 09:40 AM


New To Site? Need Help?

All times are GMT. The time now is 04:56 PM.


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