Very Cheap Valve preamplifier - diyAudio
Go Back   Home > Forums > Amplifiers > Tubes / Valves

Tubes / Valves All about our sweet vacuum tubes :) Threads about Musical Instrument Amps of all kinds should be in the Instruments & Amps forum

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 10th August 2003, 02:35 AM   #1
diyAudio Member
 
Join Date: Jan 2003
Location: Australia
Default Very Cheap Valve preamplifier

Would this valve preamplifier be suitable as a headphone amp?

http://www.oatleyelectronics.com/kits/k055.html

http://www.oatleyelectronics.com/pdf/k055.pdf
  Reply With Quote
Old 10th August 2003, 02:57 AM   #2
diyAudio Member
 
Join Date: Apr 2002
Location: orange ca
Send a message via AIM to travis
http://headwize2.powerpill.org/index.htm

you probably seen that site already
__________________
donuts
  Reply With Quote
Old 10th August 2003, 04:57 AM   #3
halojoy is offline halojoy  Sweden
On Hiatus
 
Join Date: Nov 2002
Quote:
VALVE PREAMP KIT: Hear valve sound by connecting this stereo all-valve preamplifier to your existing equipment. Uses two 6J6 double triode valves. Safe kit, as it only uses about 60V for high tension rail. Can be used at line level with guitar amplifiers, hi fi, recording equipment and mixers. Requires 12V / 1A AC power supply. Kit includes a suitable plastic case. PCB: 154 x 89mm.

PUBLISHED: Electronics Australia Magazine September 1996.

KIT PRICE: (K055) $66
It uses 6J6 at low voltage 60V. I don't know about that tube.
Strange that it should have 12VAC as supply ....

I am not sure I would chose this one.
As you say the price is low.
Maybe good for to start with, experimenting,
and maybe you can tweak it a bit.

halo
  Reply With Quote
Old 10th August 2003, 07:56 PM   #4
diyAudio Senior Member
 
fdegrove's Avatar
 
Join Date: Aug 2002
Location: Belgium
Hi,

Quote:
Would this valve preamplifier be suitable as a headphone amp?
Not likely, output impedance is rather too high.

If you look at the circuit you'll also notice the tubes have hardly any gridbias which means they're being driven positive with a CDP as line source already.

Halo,

The 12V AC is simply the two 6.3V heaters wired in series.
The 6J6 is the same as the European ECC91...not exactly an audio tube in my book.

Cheers,
__________________
Frank
  Reply With Quote
Old 12th August 2003, 02:39 PM   #5
w00t is offline w00t  Singapore
diyAudio Member
 
Join Date: Aug 2003
Location: Singapore
Click the image to open in full size.

Based on the schematic as in the link in post #1. Driving my al' cheapo cans currently.
  Reply With Quote
Old 13th August 2003, 02:38 PM   #6
w00t is offline w00t  Singapore
diyAudio Member
 
Join Date: Aug 2003
Location: Singapore
I just heard this tube, the quality of the soudn coming out of it is really bad . A solid state preamp could so better
  Reply With Quote
Old 23rd April 2010, 03:21 AM   #7
anzic is offline anzic  Australia
diyAudio Member
 
Join Date: Apr 2010
Hi all,

I know this is a really old post, but I am desperately trying to track down a copy of the K055.PDF from Oatley Electronics that has the schematic for this 6j6 preamp as mentioned in the first post.

Oatley dont have it anymore and can't get it off their website even with wayback machine/archive.org.

If anyone has a copy and can help it would be very appreciated.

Cheers,
Anzic.
  Reply With Quote
Old 9th June 2010, 10:45 AM   #8
diyAudio Member
 
Join Date: Sep 2004
Location: Malaysia
Hi Anzic,
Understand you been looking for the schematic and i do have a copy...and also have the original project kit unassembled and sitting in my store for the last 8 years..... and coincidently getting into this valve project...Would be great if we could discuss about this ...pls drop a me mail at franbargain@yahoo.com...thanks
  Reply With Quote
Old 10th June 2010, 01:35 AM   #9
anzic is offline anzic  Australia
diyAudio Member
 
Join Date: Apr 2010
TRANSDUCEReng,

Email sent, thanks :-)
  Reply With Quote
Old 12th June 2010, 01:05 AM   #10
diyAudio Senior Member
 
fdegrove's Avatar
 
Join Date: Aug 2002
Location: Belgium
Hi,

What about a single 12AX7 with current for the first anodoe anode, active RIAA in the loop and a current sink for the CF second triode?

Cheers,
__________________
Frank
  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
Simple Valve Preamplifier mangrovejack Tubes / Valves 15 7th April 2008 01:34 AM
elektor 'valve preamplifier' project fermatsEnigma Elektor 1 8th January 2008 05:41 PM
TLP Nirvana valve preamplifier kit for sale supernet Swap Meet 6 4th November 2007 11:39 PM
EI transformer for valve preamplifier for sale supernet Swap Meet 0 5th June 2007 09:40 PM
6C33C-B Valve Preamplifier kristijan-k Tubes / Valves 10 10th January 2003 02:17 PM


New To Site? Need Help?

All times are GMT. The time now is 10:02 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