need a good low parts phono tube preamp schematic.... - Page 5 - 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 25th March 2010, 05:31 PM   #41
diyAudio Member
 
Join Date: Mar 2010
Hi Ivey

I know this goes against what you said earlier about the 12AU7 being different but would your schematic work with the 12AX7's(I have lying around). Also i live in the Uk so i presume I just have to watch what Im doing with the transformer and the rest should be ok? Plus I a new to this so i don't know what the output stage for the 12AU7 stage will be and the 12AT7 stage also, could you tell me?
  Reply With Quote
Old 22nd December 2010, 05:21 AM   #42
bman22 is offline bman22  United States
diyAudio Member
 
Join Date: Dec 2010
Hello all,

I recently came upon access to sever thousand like new tubes. I have a really nice Bang & Olufsen record player, and I would like to build a tube preamp for it. I have access to 12AX7's and AU's, as well as many many other tubes. Im just wondering what the best tube to use would be, and also, as I live in the US, I don't have 250v running through my walls, so, should I look for a transformer, or are there any schematics that use 120v? If you have any good schematics for a full out amplifier as well, I may be interested in that too.
  Reply With Quote
Old 22nd December 2010, 10:33 AM   #43
SY is offline SY  United States
diyAudio Moderator
 
SY's Avatar
 
Join Date: Oct 2002
Location: Chicagoland
Blog Entries: 1
No matter where you live, you need a transformer. Running direct off mains is insanely dangerous.

Given the question, I would look toward a prepackaged kit. Avoid Chinese Ebay vendors.
__________________
The more you pay for it, the less inclined you are to doubt it.- George Smiley
  Reply With Quote
Old 22nd December 2010, 10:27 PM   #44
bman22 is offline bman22  United States
diyAudio Member
 
Join Date: Dec 2010
I have neither the want or money to purchase a kit, as they are quite expensive (usually due to the inclusion of the tubes, which I already have), and also because i think building your own is much more fulfilling. I have been looking around for a suitable transformer, but have yet to come upon a great one. Anybody have a link or model number for a good transformer?
  Reply With Quote
Old 22nd December 2010, 10:51 PM   #45
diyAudio Member
 
aardvarkash10's Avatar
 
Join Date: Mar 2007
Location: Auckland, NZ
**** about face. The power transformer is the LAST thing you look for since it's specification is going to be determined by your circuit.

Many have built the Hagermann phono stages in there varoius forms - ss, octal and nine-pin.
SY (just above you) has an excellent phono design - His Masters Noise - see the link to the article on the homepage here.
There are plenty of others including Pete Millett's designs.
Many have geneological links back to the RCA RIAA design which is easily sourced on-line.

regardless of how you do it, to do it properly requires top quality parts. Kit or otherwise, its not a cheap or easy exercise since you are dealing with a very low signal level in a very noisy environment.

A kit at the very least gives you a higher level of outcome certainty.
__________________
"Folks, you can't prove truthiness with information. You prove truthiness with more truthiness. In a process known as truthinessiness." - Stephen Colbert, The Colbert Report
  Reply With Quote
Old 22nd December 2010, 10:53 PM   #46
SY is offline SY  United States
diyAudio Moderator
 
SY's Avatar
 
Join Date: Oct 2002
Location: Chicagoland
Blog Entries: 1
I should also point out that tubes might be $30-50 or so for any reasonable design. If that's choking you, LP is not your medium.

If you build it yourself from any design that requires you to figure out layout, grounding, and the like, your chances of success are close to zero. Phono stages are the trickiest bits to get right.
__________________
The more you pay for it, the less inclined you are to doubt it.- George Smiley
  Reply With Quote
Old 23rd December 2010, 03:11 AM   #47
bman22 is offline bman22  United States
diyAudio Member
 
Join Date: Dec 2010
Well, in that case, could you suggest a preamp kit, preferably about as cheap as you can get. I know tubes are an expensive subject, but, with as many as I have access to, it seems just like a waste to NOT use them.
  Reply With Quote
Old 23rd December 2010, 07:18 AM   #48
diyAudio Member
 
aardvarkash10's Avatar
 
Join Date: Mar 2007
Location: Auckland, NZ
Glassware has two options, both currently showing out of stock!

Some swear by Broskie, some at him, but you can't deny the build quality - it will probably be worth the wait...
__________________
"Folks, you can't prove truthiness with information. You prove truthiness with more truthiness. In a process known as truthinessiness." - Stephen Colbert, The Colbert Report
  Reply With Quote
Old 23rd December 2010, 02:16 PM   #49
Previously: Kuei Yang Wang
 
Join Date: Nov 2002
Hi,

Quote:
Originally Posted by bman22 View Post
I have neither the want or money to purchase a kit, as they are quite expensive (usually due to the inclusion of the tubes, which I already have), and also because i think building your own is much more fulfilling. I have been looking around for a suitable transformer, but have yet to come upon a great one. Anybody have a link or model number for a good transformer?
I would agree with others, worry about the transformer last.

I suggest that you read the original thread for my (KYW is my alter ego) simple Phono:

DC Phono Thread - includes the "Valve El Cheapo Design"

There is also "build" thread with many problems in the build being resolved which will help giving you a good idea of the issues implementing a Phonostage.

Kofi Annan in +B Plus

It is REALLY worthwhile taking the time to go through all of it.

Afterwards build whatever you like, my design, Tim De Paravicini's EAR834 (which is surprisingly good given what it is) or anything else taking your fancy.

Ciao T
  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
Good Phono preamp circuit? PeterMoreton Solid State 45 30th November 2011 11:49 AM
Tube Phono Preamp PCB Ebay? are these any good fortytwo Tubes / Valves 12 7th July 2009 01:47 AM
DIY tube phono preamp ? abacus Analog Line Level 2 16th September 2008 11:08 PM
Question about phono preamp schematic jn2630 Tubes / Valves 11 3rd January 2008 01:36 AM
phono tube preamp? karma Tubes / Valves 7 4th July 2003 01:19 PM


New To Site? Need Help?

All times are GMT. The time now is 01:52 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