looking for a pre-amp schematic - 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 3rd August 2008, 08:37 AM   #1
diyAudio Member
 
Join Date: Sep 2007
Default looking for a pre-amp schematic

Hi

I was thinking of building a class-D amplifier from a kit but i got chatting to a retired guy who used to play around with valve hi-fi back in the 1960s and he has convinced me to spend a bit more and build an all-tube system

however, I don't know where to look for schematics (or a kit would be even better) and i was hoping that there would be a thread on here with links to circuit diagrams or maybe a link to a site that has them

it would be for a phono pre-amp (to connect up to a Technics turntable with an Ortofon cartridge) with two stages of amplification - so i guess it would have 4 tubes (???)

and this leads me to my second (and probably stupid) question : why are there no knobs and other controls on the pre-amp projects in the photo gallery on here ?

I think i would want 3 source inputs (Phono, Tuner Aux), bass, midrange and treble controls, volume control, balance control, headphone jack ... and apparently it would also require internal filters to make the incoming phono signal more linear across the frequencies but i can't find any info about this

so - has anyone got any ideas about where i might find schematics for this kind of pre-amp ?
  Reply With Quote
Old 3rd August 2008, 08:45 AM   #2
diyAudio Member
 
Join Date: Sep 2007
I suppose that basically it would be like this

http://en.wikipedia.org/wiki/Image:Technics-suc01.jpg

but would use tubes for amplification

thanks for any help you can give
  Reply With Quote
Old 3rd August 2008, 10:50 AM   #3
diyAudio Member
 
Join Date: Apr 2004
Location: Monroe Township, NJ
The reason you don't see tone controls is their negative impact on sound quality. Surprisingly few recordings benefit from tone control circuitry. Good tone control circuitry is not simple and should be completely defeatable.

Phono preamps are among the most difficult of projects to execute well. IMO, you would do well to tackle something else, 1st.

You said an all tubed system would be assembled. What sort of speakers are you planning on using?
__________________
Eli D.
  Reply With Quote
Old 3rd August 2008, 01:49 PM   #4
diyAudio Member
 
Join Date: Sep 2007
Quote:
Originally posted by Eli Duttman
The reason you don't see tone controls is their negative impact on sound quality. Surprisingly few recordings benefit from tone control circuitry. Good tone control circuitry is not simple and should be completely defeatable.


ok fair enough.

Quote:
Phono preamps are among the most difficult of projects to execute well. IMO, you would do well to tackle something else, 1st.
so if i build just the power amp (which, I agree, seems a lot simpler to put together) what should i use to pre-amplify the phono signal ?


Quote:
You said an all tubed system would be assembled. What sort of speakers are you planning on using?
I don't know yet - my existing speakers are so apallingly awful that I'm looking around for some decent second-hand ones
  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
DBX 500 schematic d3imlay Solid State 0 2nd August 2008 05:12 PM
F3 schematic kenev Pass Labs 2 24th January 2008 03:24 PM
Need Six-pac amp schematic Sarge Tubes / Valves 1 31st July 2004 08:30 PM


New To Site? Need Help?

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