F5 Turbo Builders Thread - Page 182 - 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 23rd April 2013, 03:37 PM   #1811
WalterW is offline WalterW  Netherlands
diyAudio Member
 
Join Date: Oct 2012
Location: Utrecht
I don't understand what is not ideal? Should the grounds of both PSU's be closer together? What if I connect both grounds with very thick wire or copperstrips?
How do I get it ideal?
__________________
Pass F5, F5Tv3, ACA, Aleph J, DDDAC1794, DCB1, BA3-preamp, VFET CSX1.
  Reply With Quote
Old 23rd April 2013, 03:42 PM   #1812
diyAudio Member
 
buzzforb's Avatar
 
Join Date: Oct 2010
Location: Burlington, NC
Jumper wire is not ideal, but i think you are at point of diminishing returns. If it doesnt hum, who cares.
__________________
...Shape the sound , Man!
  Reply With Quote
Old 23rd April 2013, 03:46 PM   #1813
WalterW is offline WalterW  Netherlands
diyAudio Member
 
Join Date: Oct 2012
Location: Utrecht
Ok, I'll make the jumper wire massive then...
__________________
Pass F5, F5Tv3, ACA, Aleph J, DDDAC1794, DCB1, BA3-preamp, VFET CSX1.
  Reply With Quote
Old 24th April 2013, 02:16 AM   #1814
omishra is offline omishra  India
diyAudio Member
 
Join Date: Nov 2008
Location: PNQ, MH
Quote:
Originally Posted by WalterW View Post
I don't understand what is not ideal? Should the grounds of both PSU's be closer together? What if I connect both grounds with very thick wire or copperstrips?
How do I get it ideal?
When to connect both grounds together? (Same transformer)
IMO if you have derived both channel PS from same secondaries of one transformer then you are going to get one ground loop when both inputs grounds are connected. Then you need to connect both grounds together at the output of PS. This case applies mostly for floating ground not necessarily transformer CT as ground. But ground from same transformer CT may also need this.
If its required to connect both grounds together then I suggest using thickest copper wire (at least 4X of transformer lead thickness).

When its not required?
While both channel PS are distinct, I mean two transformers or different secondaries, then its not required. Here both grounds are separate. It does not matter if they are connected together. While connecting both of these (floating?) grounds one must use ground isolaters to keep them distinct.
  Reply With Quote
Old 30th April 2013, 08:16 AM   #1815
NicMac is offline NicMac  Italy
diyAudio Member
 
NicMac's Avatar
 
Join Date: Feb 2009
Default 2SK1530 and 2SJ201 for F5 and F5 Turbo

I would like to alert F5 Turbo builders that I have just put up for sale in this thread a significant number of the very good Toshiba 2SK1530 and 2SJ201 MOSFETs perfectly suited for the F5 and F5 Turbo variants.

Here is what Mr. Pass has to say about these Mosfets in the F5 Turbo manual:
"A number of DIYers have speculated on or even tried the Toshiba 2SK1530 and 2SJ201 Mosfets. These are really nice (discontinued) audio transistors and are very fine for F5's, but keep in mind that with a 12 amp rating they have a smaller maximum current than the Fairchield parts. This will not prevent them from sounding very good, however, and I do recommend them in general."

The quality of device matching is extraordinary (@ operating conditions) and I have set the price so that everybody should be able to enjoy these fantastic Mosfets without breaking the bank.

Enjoy
  Reply With Quote
Old 30th April 2013, 09:45 AM   #1816
emyeuoi is offline emyeuoi  Italy
diyAudio Member
 
emyeuoi's Avatar
 
Join Date: Oct 2010
Location: South Korea
Thanks Nic!

You have PM

Ciaooo
  Reply With Quote
Old 30th April 2013, 09:21 PM   #1817
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 NicMac View Post
I would like to alert F5 Turbo builders that I have just put up for sale in this thread a significant number of the very good Toshiba 2SK1530 and 2SJ201 MOSFETs perfectly suited for the F5 and F5 Turbo variants.

Here is what Mr. Pass has to say about these Mosfets in the F5 Turbo manual:
"A number of DIYers have speculated on or even tried the Toshiba 2SK1530 and 2SJ201 Mosfets. These are really nice (discontinued) audio transistors and are very fine for F5's, but keep in mind that with a 12 amp rating they have a smaller maximum current than the Fairchield parts. This will not prevent them from sounding very good, however, and I do recommend them in general."

The quality of device matching is extraordinary (@ operating conditions) and I have set the price so that everybody should be able to enjoy these fantastic Mosfets without breaking the bank.

Enjoy
Has anyone built a F5T with the toshibas? I was wondering if the source resistance or bias needs to be changed.
  Reply With Quote
Old 30th April 2013, 09:44 PM   #1818
henryve is online now henryve  South Africa
diyAudio Member
 
henryve's Avatar
 
Join Date: Jun 2008
Location: Strand
I have not finished mine yet, but plan on using those Toshibas. I am going to use 1.2k resistors for R11, R12 for the lower Vgs of the Toshiba devices. That is all that I am aware of.
  Reply With Quote
Old 30th April 2013, 09:49 PM   #1819
NicMac is offline NicMac  Italy
diyAudio Member
 
NicMac's Avatar
 
Join Date: Feb 2009
Quote:
Originally Posted by alazira View Post
Has anyone built a F5T with the toshibas? I was wondering if the source resistance or bias needs to be changed.
Nelson say: "or even tried the Toshiba 2SK1530 and 2SJ201 Mosfets", but I guess this refers to the F5/F5X and not the F5 Turbo.
Nevertheless, I see his comment as a warm invitation to try

I don't need the power of the F5 Turbo, but I do hope that the (very) low cost of the Toshiba FETs I'm offering will inspire somebody to try and report back.
I guess one would lean towards more output devices and lower bias in the case of the Toshiba's to keep current/fet lower, but that is just my unqualified guess
  Reply With Quote
Old 30th April 2013, 10:11 PM   #1820
evanc is offline evanc  United States
diyAudio Member
 
Join Date: Sep 2009
Location: New Jersey. About 1 hour from NYC and 1 min. from the beach
OK so I didn't build it , but thanks to the extreme generosity of a fellow member I have been listening to this for a few hours. Fairchild outputs. I simply put the boards in place of my f5 boards, set the bias and sat back to listen. WOW... At first I had the bias set very conservatively, but at .5 amp per device this thing really sings. As the name implies it sounds like my f5 only on steroids. I will be adding the diodes to this build tomorrow and will report any difference. As it stands, after running a few hours, the output fets seem to have settled at 56c and the sinks are 48c. I attached some pics...don't laugh..
Evan

55 47
Attached Images
File Type: jpg f5 turbo 001.jpg (215.3 KB, 300 views)
File Type: jpg f5 turbo 002.jpg (217.3 KB, 291 views)
__________________
http://www.evancotler.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
F5 Turbo Circuit Boards chchyong89 Pass Labs 2347 14th July 2014 02:19 PM
B1 builders thread Bas Horneman Pass Labs 696 14th July 2014 12:57 PM
F5 Turbo is posted Nelson Pass Pass Labs 635 6th April 2014 10:51 AM
F5 turbo problems Rob Dingen Pass Labs 17 11th January 2013 08:38 PM
F5 Turbo ............. if only !!!!!! a.wayne Pass Labs 23 21st January 2012 02:24 AM


New To Site? Need Help?

All times are GMT. The time now is 02:33 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