B1 Buffer Preamp - Page 39 - 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 1st August 2008, 10:43 AM   #381
BURNER is offline BURNER  Thailand
diyAudio Member
 
Join Date: Nov 2003
Location: Bangkok
Quote:
Originally posted by Zen Mod



certainly ;

besides that - I wrote "...... even less" .

in any case - if you have problems with offset - then make small delay circuit which can switch off relay after 5-10 seconds ; relay contacts connected as short from output side to gnd
Thanks Choky

I'll go for 30+ sec
  Reply With Quote
Old 1st August 2008, 11:15 AM   #382
Zen Mod is offline Zen Mod  Serbia
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
Quote:
Originally posted by BURNER


Thanks Choky

I'll go for 30+ sec

off course - in my previous post I meant on delay circ which will switch ON relay after some time ....... output of buffer is grounded via NC contacts .

plain delay circ with small darlington , few resistors and cap is good enough
__________________
my Papa is smarter than your Nelson !
clean thread; Cook Book;PSM LS Cook Book;Baby DiyA ;Mighty ZM's Bloggg;Papatreasure;Papa... by Mighty ZM
  Reply With Quote
Old 1st August 2008, 02:36 PM   #383
diyAudio Member
 
Join Date: Jan 2008
Location: Brooklyn, NY
Default Some help please

Hi,

A newbie here again.

I just want to copy the original B1 design without doing much work on the PSU, as I feel it is safer if I use something ready made.

So, I would be grateful if someone could tell me if in principle this 18V PSU would work:

http://www.effectpowersupplies.com/1...62&doy=1m8</a>

Many thanks

Antonio

[url]
  Reply With Quote
Old 1st August 2008, 02:40 PM   #384
udailey is offline udailey  United States
diyAudio Member
 
Join Date: Mar 2008
All you need is a cheapie $5 or less wallwart. Honestly.
You probably have one in your basement in that box o' cables and other junk you dont need anymore but since it was attached to something that cost a lot like a computer or router we seem to keep them in a big ol' box.
Just find one that is around 18V and you will be fine. It needs only 20ma so I doubt you can find an 18VDC wallwart that wont work.
Uriah

edit: in regards to your website
http://www.effectpowersupplies.com/1...supply-7-p.asp
will work fine, but its overpowered and expensive.
  Reply With Quote
Old 1st August 2008, 02:53 PM   #385
diyAudio Member
 
Join Date: Jan 2008
Location: Brooklyn, NY
Thanks Udailey,

I have not found 18V ones anywhere. What I found in shops are 9V and 12V ones.

Edit:
I think I will use two 9v ones and follow Zen Mod's kind suggestion: http://www.diyaudio.com/forums/showt...92#post1569192

I will keep looking.

Gosh, I hate the electrical part if DIY :

Regards

Antonio
  Reply With Quote
Old 1st August 2008, 03:05 PM   #386
troystg is offline troystg  United States
diyAudio Member
 
troystg's Avatar
 
Join Date: Apr 2004
Location: In a dream... Please don't wake me.
I have MANY 48VDC supplies available if they could be adapted to work. Note they are 120-240VAC compatible.


If anyone is interested they're free + shipping.

Here is a link someone ELSE has on ebay. I just have several of the same ones that are free and taking up space.

http://cgi.ebay.com/CISCO-AIRONET-Vo...QQcmdZViewItem
__________________
Troy
Thinking positive doesn't make things better, it makes you a better person.
  Reply With Quote
Old 1st August 2008, 03:09 PM   #387
diyAudio Member
 
Join Date: Jan 2008
Location: Brooklyn, NY
Thanks Troy, but I read somewhere that the B1 requires between 18VDC and 24VDC.
  Reply With Quote
Old 1st August 2008, 06:55 PM   #388
The one and only
 
Nelson Pass's Avatar
 
Join Date: Mar 2001
Quote:
Originally posted by A Sanchez
Thanks Troy, but I read somewhere that the B1 requires between 18VDC and 24VDC.
I have run those buffers as high as 40V.
  Reply With Quote
Old 1st August 2008, 07:03 PM   #389
Salas is online now Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
No problem indeed.
Attached Images
File Type: jpg screenshot.jpg (14.7 KB, 2762 views)
  Reply With Quote
Old 2nd August 2008, 06:33 AM   #390
Salas is online now Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
Guys, I have looked in an old parts box and I have 10x 2N5459 and 6x 2SK170BL. The 5459s bunch around 5-6mA Idss. And I measured 2 matches. 2x5mA & 2X5.2mA. The 170s are 6.9, 8.7, 7.7, 6.8, 8.2, 7.35 mA.
What do you think? Use the 5459 pairs for an attempt on a hopefully capacitorless B1, or prefer the 6.9+6.8, 7.7+7.35 mA 2SK170s? The 5459s have a dB or so more noise on paper, but for a line buffer isn't a big deal. ----The main question is, do 2SK170s sound detectably better than mundane N-JFETs, when noise is not an issue?---- Does anybody know? Nelson?

I can make it on perfboard, complete with 317-337 symmetric supply and lose at least the input cap. I will also use an output delay relay circuit if the equilibrium offset is very low so to lose Cout too, and avoid turn on thumps. The 5459s look like yummy matched pairs for that goal, and I can save the 2SKs for some single ended 2 stage zero feedback MM preamp where I can match their gain by Rs. I can not find more 2SKs right now at the shops.

Basically it will be nice to have a tiny buffer box that sounds decent and is mobile. Interesting to see how it performs against my preamp too (in attachment).
Attached Images
File Type: jpg 6v6gt-pre.jpg (84.7 KB, 2557 views)
  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 08:40 AM


New To Site? Need Help?

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