F5 power amplifier - Page 1284 - 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 22nd January 2013, 12:29 AM   #12831
labjr is offline labjr  United States
diyAudio Member
 
Join Date: Apr 2003
Location: MA
According to Linear Systems, they were at BAF last fall with samples. They told me soon and I told them they've been saying that for at least 5 years. So I don't know what the hold up is.
  Reply With Quote
Old 22nd January 2013, 04:46 AM   #12832
kcray is offline kcray  Indonesia
diyAudio Member
 
Join Date: Aug 2010
Location: Indonesia
Quote:
Originally Posted by flg View Post
I heard some of us have had some in hand! Maybe at BAF last fall???
At any rate, they are still available ju$$t a few dollars more
Stock is running low, a few definitely not enough, some still not enough, a bunch would be adequate,

Quote:
Originally Posted by labjr View Post
According to Linear Systems, they were at BAF last fall with samples. They told me soon and I told them they've been saying that for at least 5 years. So I don't know what the hold up is.
Samples!?, sound promising
  Reply With Quote
Old 22nd January 2013, 12:28 PM   #12833
diyAudio Member
 
jackinnj's Avatar
 
Join Date: Apr 2002
Location: Llanddewi Brefi, NJ
You can use 2SJ74GR -- these are around. Best if you buy a bunch and get a matched pair to parallel 2. 2N5460 can be used -- noisier by several dB -- different pinout. 2N5460 Idss ranges from less than 1mA up to 4.5mA, transconductance from just under 1mS to over 5mS. The lower transconductance means that you won't get the very low THD attainable with the original F5 and BL devices, but it's in the same ballpark. DIY is about experimenting.
  Reply With Quote
Old 23rd January 2013, 01:40 AM   #12834
kcray is offline kcray  Indonesia
diyAudio Member
 
Join Date: Aug 2010
Location: Indonesia
Hi,
Thank Jack for the info and suggestion,

I've also been suggested to use 2SK366 and 2SJ107 as the substitute pair, they have closely match parameters with 2SK170/2SJ74, with higher gm and lower PD.
But sadly this pair also in unobtainium realm.

Well for one stop build, it is ok to have few pair with premium price, but IMHO DIYers need more for trial and error experiment.

As stated earlier by Labjr, Linear System were at BAF last fall with samples. At least now they have something, instead of words for nearly five years, let's hope for the best.

For now I will build a stock F5, next will try other F5's circuits and outputs variaton.

Thanks
  Reply With Quote
Old 23rd January 2013, 12:41 PM   #12835
labjr is offline labjr  United States
diyAudio Member
 
Join Date: Apr 2003
Location: MA
I don't understand why Toshiba stopped making them if there was a demand?
  Reply With Quote
Old 23rd January 2013, 12:45 PM   #12836
diyAudio Member
 
Join Date: May 2005
Location: Lisbon Portugal
Quote:
Originally Posted by labjr View Post
I don't understand why Toshiba stopped making them if there was a demand?
A few thousand a year isn't enough to justify keeping making them. There is a lot of demand here indeed, but we diyers are just a drop in the ocean.

And fewer companies are using them, only niche manufacturers like pass labs, and maybe a few more.
  Reply With Quote
Old 23rd January 2013, 12:47 PM   #12837
labjr is offline labjr  United States
diyAudio Member
 
Join Date: Apr 2003
Location: MA
It isn't just the DIY market that used them. Why did they make them in the first place?
  Reply With Quote
Old 23rd January 2013, 01:56 PM   #12838
diyAudio Member
 
jacco vermeulen's Avatar
 
Join Date: Oct 2004
Location: At the sea front, Rotterdam or Curaçao
Send a message via Yahoo to jacco vermeulen
Because Japanese manufacture for Japanese.

You are American, not Japanese, reason why it's a bit harder for you to understand.


Quote:
Originally Posted by Zen Mod View Post
bummer ; Ball-less ZM
(eer, my shorts feel like there's a third one residing within the premises, and it's a biggy)
__________________
The buck stops Here

Last edited by jacco vermeulen; 23rd January 2013 at 02:07 PM.
  Reply With Quote
Old 23rd January 2013, 03:31 PM   #12839
slungu is offline slungu  Germany
diyAudio Member
 
Join Date: Nov 2010
Location: Germany
Default Higher voltage lower bias

Since I plan to eventually build both a F5 and a gainclone, but having not that much of efective speakers, but with pretty high load ( the speakers are these ), I was thinking about building one nice cased power supply with 2x24V secondaries and use it both for a LM3886 based amp and for a F5 that would see much higher rail voltage compared to the stock 24V, but lower the bias below 1A. What effect would this have on the behavior of the F5 ? From the turbo paper I understood that adapting some resistor values I could do without "turbo". Only question is : what do I get ? I would get an amplifier that goes faster into Class A/B that the stock F5 ? Has anybody tried this without doubling the output MOSFET's ?

Regards, Stefan
  Reply With Quote
Old 23rd January 2013, 05:22 PM   #12840
sangram is offline sangram  India
diyAudio Member
 
Join Date: Sep 2002
Location: India
The input FETs are not safe above 30V or so. You will need a cascode.

It will work fine if you use the cviller F5c boards and use just one output pair. Keep dissipation within the 30W target per device and you will be fine.

400VA sounds about right as a universal power supply.
  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
Rockford Fosgate Power 20001 bd amplifier power rating?? pachoorion Car Audio 8 8th May 2011 10:49 PM
Power transformers versus amplifier output power..what is your option? destroyer X Solid State 38 9th May 2009 05:23 PM
McIntosh Power Amplifier Power Guard johnnyrt Solid State 2 23rd August 2007 10:22 PM
Output power for a power amplifier Progg70 Solid State 33 10th September 2006 08:44 AM
Amplifier 3000 Wats Rms Power + Smps Higcht Power Bestiality MARAVILLASAUDIO Class D 1 5th November 2004 04:06 PM


New To Site? Need Help?

All times are GMT. The time now is 03:12 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