Marsh headphone amp from Linear Audio - Page 63 - diyAudio
Go Back   Home > Forums > Amplifiers > Headphone Systems

Headphone Systems Everything to do with Headphones

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 3rd April 2013, 01:22 PM   #621
diyAudio Member
 
jackinnj's Avatar
 
Join Date: Apr 2002
Location: Llanddewi Brefi, NJ
The component kits i'm sending out now include 2SD669AC and 2SB649AC output transistors -- rather than the MJE210G/MJE200G. i have about 25 kits of the semiconductor components including the 2N5457/2N5460's matched.
  Reply With Quote
Old 3rd April 2013, 03:23 PM   #622
diyAudio Member
 
Join Date: Jan 2013
Quote:
Originally Posted by jackinnj View Post
The component kits i'm sending out now include 2SD669AC and 2SB649AC output transistors -- rather than the MJE210G/MJE200G. i have about 25 kits of the semiconductor components including the 2N5457/2N5460's matched.

Hi,
Will these kits be suitable for CafeNoir's boards for the HA and will I need two for two boards or are the kits "stereo"?
Finally can you pls let me know the cost incl shipping to the UK mainland (actually then BEST part of the mainland.......WALES _)
Thanks
Martin
  Reply With Quote
Old 5th April 2013, 12:03 AM   #623
Telstar is offline Telstar  Italy
diyAudio Member
 
Join Date: Dec 2007
Location: Italy
Afaik The circuit is the same, only the pcb is different.

I have instead a question for jackinnj: have you listened to both output stage transistors?
If so, what's your opinion? If not, can you send me a pair of the hitachi
__________________
"The total harmonic distortion is not a measure of the degree of distastefulness to the listener and it is recommended that its use should be discontinued." D. Masa, 1938
  Reply With Quote
Old 5th April 2013, 01:22 AM   #624
diyAudio Member
 
jackinnj's Avatar
 
Join Date: Apr 2002
Location: Llanddewi Brefi, NJ
Quote:
Originally Posted by Telstar View Post
Afaik The circuit is the same, only the pcb is different.

I have instead a question for jackinnj: have you listened to both output stage transistors?
If so, what's your opinion? If not, can you send me a pair of the hitachi
You need 8 -- i have ur address!

I became intrigued with them because of the Randy Slone articles -- they have higher hfe, higher ft -- but are no longer in production -- i have beacuoup and will send you a set!
  Reply With Quote
Old 5th April 2013, 05:22 AM   #625
RNMarsh is online now RNMarsh  United States
diyAudio Member
 
RNMarsh's Avatar
 
Join Date: May 2012
Location: 2457 Cascade Trail; Cool, CA. 95614
Could I try 2 pair also?

Thx-Richard Marsh
  Reply With Quote
Old 5th April 2013, 12:05 PM   #626
Telstar is offline Telstar  Italy
diyAudio Member
 
Join Date: Dec 2007
Location: Italy
Quote:
Originally Posted by jackinnj View Post
-- i have beacuoup and will send you a set!
Thanks, I definitely want to try them
I have 3pin sockets, so I will also try my favourites (Rohm 2SD1763/2SB1186).
In a couple weeks I should finally start to build this amp.
__________________
"The total harmonic distortion is not a measure of the degree of distastefulness to the listener and it is recommended that its use should be discontinued." D. Masa, 1938
  Reply With Quote
Old 15th April 2013, 02:26 AM   #627
BlueRob is offline BlueRob  Mexico
diyAudio Member
 
Join Date: Dec 2008
Richard / Jack,

I´m a bit intrigued in the use of Panasonic resistors (metal oxide) seen and described in Jack´s BOM and boards.

I´ll appreciate if you guys could elaborate a bit more on the subject and the possibility of using metal film instead.

Thanks,


Rob.
  Reply With Quote
Old 15th April 2013, 02:37 AM   #628
diyAudio Member
 
jackinnj's Avatar
 
Join Date: Apr 2002
Location: Llanddewi Brefi, NJ
Quote:
Originally Posted by BlueRob View Post
Richard / Jack,

I´m a bit intrigued in the use of Panasonic resistors (metal oxide) seen and described in Jack´s BOM and boards.
It's simple -- Nelson used them in various First Watt designs -- they are inexpensive (availble from Digikey) and compare quite favorably measurement-wise with the more expensive variety. I claim no prize for originality.
  Reply With Quote
Old 15th April 2013, 03:36 PM   #629
diyAudio Member
 
Join Date: Feb 2010
Default Output transistors

I wanted to try 2sc5171/2sa1930 transistors pairs for the output stage, as they have great characteristics, and are available on Mouser.

I am pleasantly surprised with the results: the whole batch has an Hfe within 10-15%. More importantly, NPN and PNP have very close characteristics (see graph below).

They have clearly become my favourite devices for the job: Beta and Ft is higher than MJE200/MJE210, and they can sustain higher voltage too. Flat Hfe as a function of current.
Really great transistors in my opinion.

The only issue is they have reversed pin, so they must be soldered backwards...
Attached Images
File Type: jpg IMG-20130328-00140.jpg (233.8 KB, 421 views)
File Type: png Hfe Graph.png (12.9 KB, 405 views)
  Reply With Quote
Old 16th April 2013, 10:37 PM   #630
diyAudio Member
 
Join Date: Jan 2013
Hi CafeNoir,
I am still gathering the bits for your boards, work permitting, but funnily enough I have these transistors as they are used in pairs in the JLH Ripple Eater over on Gregs site
Greg's Web Site
So I will use them (Remembering to revers them). Will all the other componets work with them as your BOM?
Martin
  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
FS: Meier Audio Corda Headphone Amp jtwrace Swap Meet 5 29th February 2012 11:34 AM
Histoically significant - Phase Linear audio pre-amp bobcul Swap Meet 0 21st February 2012 08:16 PM
Headphone amp with mixed-in telephone audio krfjr1965 Solid State 3 10th March 2010 03:50 PM


New To Site? Need Help?

All times are GMT. The time now is 05:39 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