Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Pass Labs This forum is dedicated to Pass Labs discussion.

B1 preamp build thread
B1 preamp build thread
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 13th January 2018, 01:32 PM   #351
Zen Mod is online now Zen Mod  Serbia
Official Court Jester
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
B1 preamp build thread
swap hot wires going from selector to inputs on pcb

if problem stays in same channel , problem is on pcb

if problem moves to other channel , problem is in your wiring from RCAs to selector
__________________
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 13th January 2018, 01:57 PM   #352
folkdeath95 is offline folkdeath95  France
diyAudio Member
 
folkdeath95's Avatar
 
Join Date: Sep 2011
Location: Brittany, France
Just tried it: Problem stayed on the same channel.

Don't if it can help: I tried to listen the right channel (the problematic one) alone. I have to turn the pot to 2 or 3 o'clock to have a good sound volume, but the sound is awful ad there are some loud noises ("pop", "boom" or things like these).
__________________
Petite Onken/Altec 414-8B+Altec 808-8B/GPA aluminium diaphragm/Altec 811; Firstwatt Aleph J Clone; Firstwatt B1 clone; Technics SP10; Sphinx Myth9 MkII

Last edited by folkdeath95; 13th January 2018 at 02:12 PM.
  Reply With Quote
Old 13th January 2018, 02:05 PM   #353
Zen Mod is online now Zen Mod  Serbia
Official Court Jester
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
B1 preamp build thread
check those few resistors values
check all solder joints

check proper position of JFets (N where N goes , P where P goes)
__________________
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 13th January 2018, 02:31 PM   #354
folkdeath95 is offline folkdeath95  France
diyAudio Member
 
folkdeath95's Avatar
 
Join Date: Sep 2011
Location: Brittany, France
OK. I don't think I'll have time to do this during the rest of the week-end. I'll do it on sunday evening.

Thanks for your help.
__________________
Petite Onken/Altec 414-8B+Altec 808-8B/GPA aluminium diaphragm/Altec 811; Firstwatt Aleph J Clone; Firstwatt B1 clone; Technics SP10; Sphinx Myth9 MkII
  Reply With Quote
Old 13th January 2018, 03:00 PM   #355
AndrewT is offline AndrewT  Scotland
R.I.P.
 
Join Date: Jul 2004
Location: Scottish Borders
Quote:
Originally Posted by AndrewT View Post
Please remember that the input is a TWO (2) wire connection. Input connects to CW and to CCW
The output is also a TWO wire connection. Output comes from W and CCW.

Do not break any of those 4 wires. All are needed to pass the signal from the source to the receiver.
Quote:
Originally Posted by folkdeath95 View Post
Attachment 656537

The problem I have is that the sound is weak and distorted on the right channel..............
you have twisted the wires going to the attenuator incorrectly.

the Attenuator should have an input pair running from CW and CCW
And then an output pair running back to W and CCW.
You have twisted W and CW together and left the Signal Return separate from both.
__________________
regards Andrew T.
  Reply With Quote
Old 14th January 2018, 09:59 AM   #356
folkdeath95 is offline folkdeath95  France
diyAudio Member
 
folkdeath95's Avatar
 
Join Date: Sep 2011
Location: Brittany, France
Quote:
Originally Posted by AndrewT View Post
you have twisted the wires going to the attenuator incorrectly.

the Attenuator should have an input pair running from CW and CCW
And then an output pair running back to W and CCW.
You have twisted W and CW together and left the Signal Return separate from both.
Hi Andrew. Thanks for your help.

I'm not sure to understand correctly what you mean. Sometimes, pictures make things easier to understand, so let's go.

Here is the wiring I've done:
cablage moi.jpg

IN connected to CW
OUT connected to W
GND connected to CCW

Here is your solution, if I understand it correctly:
cablage andrew.jpg

IN connected to CW and CCW
OUT connected to W and CCW
(I haven't drawn any connection to GND because you don't talk about it, but I presume there's one.)

There are two things I don't understand:
-When I look to the pictures of B1 made by other people, I can see that they have only 3 wires from PCB to potentiometer.
Some examples:
1042d1368374900-first-watt-b1-clone-diyaudio77.jpg
1037d1368374900-first-watt-b1-clone-diyaudio02.jpg
02small.jpg

-The left channel works perfectly. If the wiring was wrong, both channel should have the same problem, no?

Or am I missing something?

Regards.
__________________
Petite Onken/Altec 414-8B+Altec 808-8B/GPA aluminium diaphragm/Altec 811; Firstwatt Aleph J Clone; Firstwatt B1 clone; Technics SP10; Sphinx Myth9 MkII
  Reply With Quote
Old 14th January 2018, 10:40 AM   #357
AndrewT is offline AndrewT  Scotland
R.I.P.
 
Join Date: Jul 2004
Location: Scottish Borders
The twisting, or non twisting may have nothing to do with your problem. (but the capacitive coupling between the high level output wire and the lower level input wire may affect the two channels differently).

Your first pic omits the twisting of the signal Flow/Hot Input wire and the signal Flow/Hot Output wire.
Your drawing is NOT what you built.
The connection from the Output of the B1 is a TWO wire connection from CW and CCW. These are the two that should be a coaxial cable or a twisted pair cable.
These connect to IN and GND of one channel of the vol pot.

The output of the Vol Pot is W and GND. This is also a two wire connection and can be a coaxial or a twisted pair. This TWO wire pair goes to the B1 Input where it connects to W and CCW.
When you have these two sets of two wire connection completed you will realise you have duplicated the CCW wires. There are two on each channel. This creates a loop which will pick up interference. But the interference on the very small loop in the small signal (attenuated) route has been lessened and overall the two twisted pairs (or two coaxials) will give a cleaner signal.

Do not just copy other folks work unless you have proved to yourself that it is better than all other methods. There are thousands of Members on this site that do not understand that current flows around loops and that ALL current that leaves a Source MUST RETURN to that Source. Current does not Flow out along a single wire. A single wire is a broken connection.
__________________
regards Andrew T.

Last edited by AndrewT; 14th January 2018 at 10:44 AM.
  Reply With Quote
Old 14th January 2018, 03:42 PM   #358
folkdeath95 is offline folkdeath95  France
diyAudio Member
 
folkdeath95's Avatar
 
Join Date: Sep 2011
Location: Brittany, France
Quote:
Originally Posted by AndrewT View Post
The twisting, or non twisting may have nothing to do with your problem. (but the capacitive coupling between the high level output wire and the lower level input wire may affect the two channels differently).

Your first pic omits the twisting of the signal Flow/Hot Input wire and the signal Flow/Hot Output wire.
Your drawing is NOT what you built.
I'm sorry. I didn't draw the wiring with the cables twisted because I didn't know it was that important. I realise this was a mistake.
I use twisted pairs from a Cat5e cable to make my wiring beause it's easy to work with, but if IN and OUT cables are twisted, that's mainly by chance.
Well, it's a wrong layout, if I understand you correctly.

Quote:
The connection from the Output of the B1 is a TWO wire connection from CW and CCW. These are the two that should be a coaxial cable or a twisted pair cable.
These connect to IN and GND of one channel of the vol pot.

The output of the Vol Pot is W and GND. This is also a two wire connection and can be a coaxial or a twisted pair. This TWO wire pair goes to the B1 Input where it connects to W and CCW.
I think I begin to understand what you're explaining, but I'm not sure.
Is this drawing right?
1.jpg

Quote:
Do not just copy other folks work unless you have proved to yourself that it is better than all other methods. There are thousands of Members on this site that do not understand that current flows around loops and that ALL current that leaves a Source MUST RETURN to that Source. Current does not Flow out along a single wire. A single wire is a broken connection.
When you're a beginner like me, you have no choice but to look at what other people do and follow their examples. That's what I did when reading 6L6's tutorial. That's what I'm doing when I follow Zenmod's and your explanations to help me to solve my problem.

If the drawing above is corresponding to what you mean, I'll try it tonight.
__________________
Petite Onken/Altec 414-8B+Altec 808-8B/GPA aluminium diaphragm/Altec 811; Firstwatt Aleph J Clone; Firstwatt B1 clone; Technics SP10; Sphinx Myth9 MkII
  Reply With Quote
Old 14th January 2018, 05:42 PM   #359
Russellc is offline Russellc  United States
diyAudio Member
 
Join Date: Mar 2003
Location: midwest
B1 preamp build thread
Quote:
Originally Posted by folkdeath95 View Post
I'm sorry. I didn't draw the wiring with the cables twisted because I didn't know it was that important. I realise this was a mistake.
I use twisted pairs from a Cat5e cable to make my wiring beause it's easy to work with, but if IN and OUT cables are twisted, that's mainly by chance.
Well, it's a wrong layout, if I understand you correctly.


I think I begin to understand what you're explaining, but I'm not sure.
Is this drawing right?
Attachment 656812



When you're a beginner like me, you have no choice but to look at what other people do and follow their examples. That's what I did when reading 6L6's tutorial. That's what I'm doing when I follow Zenmod's and your explanations to help me to solve my problem.

If the drawing above is corresponding to what you mean, I'll try it tonight.
Just a beginner here too, nothing twisted, dead quiet and works perfectly.

Russellc
Attached Images
File Type: jpg 20180114_123347[1].jpg (993.8 KB, 236 views)
__________________
Pass B-1 preamp, Pass BA3 preamp, Pass F-5 Amp, Pass F-6 Amp, Pass BA-3 Amp, Pass M-2 amp, Pass Aleph J amp, Pass Pearl 2 Phono pre Tekton Enzo, Altec A7, Econowave JBL 2235H & B&C CD

Last edited by Russellc; 14th January 2018 at 05:51 PM.
  Reply With Quote
Old 14th January 2018, 05:47 PM   #360
Russellc is offline Russellc  United States
diyAudio Member
 
Join Date: Mar 2003
Location: midwest
B1 preamp build thread
One crosses (or appears to) on one side a little differently than the other. This messed me up first initial wiring attempt. I usually have all neatly twisted, but did not here. This was my second diy Pass project after F5. Not twisted, I dont know if its because of no gain or what, but it is silent as the grave. So I never "fixed" it.

Russellc
__________________
Pass B-1 preamp, Pass BA3 preamp, Pass F-5 Amp, Pass F-6 Amp, Pass BA-3 Amp, Pass M-2 amp, Pass Aleph J amp, Pass Pearl 2 Phono pre Tekton Enzo, Altec A7, Econowave JBL 2235H & B&C CD

Last edited by Russellc; 14th January 2018 at 05:52 PM.
  Reply With Quote

Reply


B1 preamp build threadHide 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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
B1 builders thread Bas Horneman Pass Labs 728 12th March 2018 06:45 PM
Help diagnosing B1 Build (newbie) dasfreak Pass Labs 4 30th November 2010 01:56 AM
help with b1 + gainclone build crappyjones123 Pass Labs 4 25th June 2009 09:56 PM
B1 Preamp - Help Me! Professor smith Pass Labs 173 21st October 2008 03:55 PM


New To Site? Need Help?

All times are GMT. The time now is 08:38 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio
Wiki