F5X -- the EUVL Approach - The Build Thread - Page 12 - 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 2nd May 2012, 07:23 AM   #111
diyAudio Member
 
Join Date: Feb 2010
Location: Dallas Fort Worth area, Texas
Patrick,

Business demands seem to keep my responsiveness here slow. My sincere apologies.

I will check all of the questions posted and update the BOM with corrections or clarifications where needed.

Information for measuring JFETs is here. The chart with details for selecting various JFET Idss values and the corresponding degen and drain resistors is here.

I'll post the bias article for those who need it already here ASAP.



Dave
  Reply With Quote
Old 2nd May 2012, 09:31 PM   #112
ramallo is offline ramallo  Europe
diyAudio Member
 
ramallo's Avatar
 
Join Date: Nov 2004
Location: Madrid
Send a message via Skype™ to ramallo
I started today mounting the amplifier, and probably this are a dumb questions:

-K1530/J201 (close to unobtainium) or K3497/618 (I have the GB set)?.

-Cascode or not? (16V supply)

-Optional Protection Circuit or not? (Main amplifier board)

-CRC or regulated?.

-Anybody have the R45, R46 for sale? (SUSUMU 5R1 OHM 0805 SMD 1%), the minimum in Mouser are 5000 units

Probably this questions had a answer in the multiple threads, but I'm very doubtful. I'm sorry in advance.

Cheers
__________________
Happiness is a warm soldering iron
  Reply With Quote
Old 2nd May 2012, 10:45 PM   #113
NicMac is offline NicMac  Italy
diyAudio Member
 
NicMac's Avatar
 
Join Date: Feb 2009
> K1530/J201 (close to unobtainium)
In a week or so I will be posting good news with respect to the unobtaniun. Please follow this thread.

> K3497/618 (I have the GB set)?.
These are for the regulated supply. In the works. Keep.

> Cascode or not? (16V supply)
Not. Benefit not fully tested at this moment. In the works.

> Optional Protection Circuit or not? (Main amplifier board)
Your call I guess......

> CRC or regulated?.
CRC until the new regulated supply has been fully tested.

> Anybody have the R45, R46 for sale? (SUSUMU 5R1 OHM 0805 SMD 1%), the minimum in Mouser are 5000 units
Ask ashaw. There is a GB for small components and I believe this is one of them.
  Reply With Quote
Old 3rd May 2012, 05:36 AM   #114
EUVL is offline EUVL  Europe
diyAudio Member
 
Join Date: Oct 2003
> K1530/J201 (close to unobtainium)

You will be catered for by 3 gentlemen who have taken on this enormous task of procuring 1000 FETs and matching them by curve tracing at 16V 2A 60C.
Just count the hours, say 10 minutes a FET.

> K3497/618 (I have the GB set)?.

Keep them for now. The first tester who tried both prefers K1530/J201 in the amp.

> Cascode or not? (16V supply)

If you have to have an answer today then cascode.
But since you can add it in later easily, I would build standard to start with.
Why spoil your joy with experimenting progressively ?



> Optional Protection Circuit or not? (Main amplifier board)

If you ask me definitely.
I have expensive speakers.

> CRC or regulated?.

CRC until the new regulated supply has been fully tested, as Nic said.

The first tester also preferred Regulator.
But he is going to build it all in the case and report later.
How late depends on his workload. But the regulator sinks are expensive.

Again since this can be upgraded later without too much work, why not start with CRC first ?

> Anybody have the R45, R46 for sale? (SUSUMU 5R1 OHM 0805 SMD 1%), the minimum in Mouser are 5000 units

Not true.
You can get 1 piece also :

DK #RL12S5.1FCT-ND 0.29 Euro a piece.



Patrick
__________________
xen-audio.com
  Reply With Quote
Old 3rd May 2012, 09:18 AM   #115
ramallo is offline ramallo  Europe
diyAudio Member
 
ramallo's Avatar
 
Join Date: Nov 2004
Location: Madrid
Send a message via Skype™ to ramallo
Nice,

Thanks to both of you.
__________________
Happiness is a warm soldering iron
  Reply With Quote
Old 3rd May 2012, 11:46 AM   #116
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
I am using a pair of 10r in parallel.
They cost 1p each coming to ~0.024 euro for the 5ohm equivalent.
__________________
regards Andrew T.
  Reply With Quote
Old 3rd May 2012, 12:35 PM   #117
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
What are the radial 1r0 resistors for?
__________________
regards Andrew T.
  Reply With Quote
Old 3rd May 2012, 10:20 PM   #118
alazira is offline alazira  United States
diyAudio Member
 
alazira's Avatar
 
Join Date: Jun 2007
Location: Las Vegas
Blog Entries: 1
Quote:
Originally Posted by AndrewT View Post
What are the radial 1r0 resistors for?
If you mean the Fukushima's, then they are for the CRC.
  Reply With Quote
Old 5th May 2012, 12:56 PM   #119
diyAudio Member
 
oneoclock's Avatar
 
Join Date: Oct 2010
Default Bad resistor

Bad news. I measured resistor 47 Oh. R9, R16, R29 R32.

7 are very close to 47 Oh.
1 measures 39 Oh. (the bottom in the photo). I think a lot difference. I do not trust and have to measure all. 8<((
Click the image to open in full size.

Last edited by oneoclock; 5th May 2012 at 01:03 PM.
  Reply With Quote
Old 5th May 2012, 01:46 PM   #120
EUVL is offline EUVL  Europe
diyAudio Member
 
Join Date: Oct 2003
May I suggest you post at the GB thread with your measurement of all 8 resistors, plus details of the equipment and method used.

This issue is a GB issue which is best sorted out at the GB thread.
It probably will have a better chance also of drawing the attention of the right people who can resolve this.


Patrick
__________________
xen-audio.com
  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
F5X -- the EUVL Approach EUVL Pass Labs 873 18th December 2014 03:13 PM
Potential EUVL F5X designed case user distribution check pchw Group Buys 1004 27th February 2013 04:32 PM
GB 2SK3497/2SJ618 for EUVL F5X or other projects pchw Group Buys 266 8th April 2012 07:05 PM
[B]PRP resistor group buy for the EUVL F5X build[/B] NicMac Group Buys 70 4th February 2012 05:20 PM
New Saburo Build thread Wha' DIYa know? Full Range 94 17th October 2010 05:49 PM


New To Site? Need Help?

All times are GMT. The time now is 05:26 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