Making a Preamp - diyAudio
Go Back   Home > Forums > Amplifiers > Solid State

Solid State Talk all about solid state amplification.

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 28th February 2006, 05:02 PM   #1
Unkle77 is offline Unkle77  England
diyAudio Member
 
Join Date: Feb 2006
Location: The Green Belt
Question Making a Preamp

Hi, Im new to diy electronics and the workings of amps, I have a bsc in physics and am now doing a masters, and Ive done a bit of electronic here and there but nothing useful.

Basically my ultimate plan is to make my own amplifier so that I can have total control over the specification and sound it produces.

But first I want to do something to warm myself up and my friend has just the thing.
He needs preamp for connection between his Decks and amplifier.

So what I need to do is find a design for a preamp, I have found the following and was wondering if you experts think this is a good idea or if you have anything to add. All help would be much appreciated.

Links:

http://www.mitedu.freeserve.co.uk/Ci...udio/gmpre.htm
http://sound.westhost.com/project25.htm
or maybe this?
http://www.paia.com/riaa.htm

#I think this was the right thread to post in#
  Reply With Quote
Old 28th February 2006, 05:09 PM   #2
Bazukaz is offline Bazukaz  Lithuania
diyAudio Member
 
Bazukaz's Avatar
 
Join Date: Nov 2005
Location: Vilnius
Send a message via Skype™ to Bazukaz
Depending on what you need :
http://sound.westhost.com/projects-2.htm
  Reply With Quote
Old 28th February 2006, 05:25 PM   #3
lineup is offline lineup  Sweden
diyAudio Member
 
lineup's Avatar
 
Join Date: Dec 2005
Location: the north
Default Re: Making a Preamp

Quote:
Originally posted by Unkle77
Hi, Im new to diy electronics and the workings of amps, I have a bsc in physics and am now doing a masters, and Ive done a bit of electronic here and there but nothing useful.

Basically my ultimate plan is to make my own amplifier so that I can have total control over the specification and sound it produces.

But first I want to do something to warm myself up and my friend has just the thing.
He needs preamp for connection between his Decks and amplifier.
Audio preamplifier or headphone amplifier
is best 'warm up projects' in amplifier making.
So, your plan is perfect!

- Usual value of voltage gain in preamps is x4 ( +12dB ).
This will take care of most modern sound sources.

- Preamp can have input impedance like 22 - 47 kOhm.

- Good also if it able to drive downto 2.2 kOhm loads, while keeping good sound quality.

- Power supply is often regulated, to give a clean and constant performance.

__________________
lineup
  Reply With Quote
Old 28th February 2006, 07:11 PM   #4
latala is offline latala  United Kingdom
diyAudio Member
 
Join Date: Feb 2006
Location: staffordshire
please advise what do you want the preamplifier to do
the decks i assume are turntables? if so what cartridfe are you using moving magnet moving coil
do you require tone controls ?
recording facilities ?
what power amp do you think you will use ?
i try to make a wish list and the approach that ideal
will you want a quick lash up on vero or will you want to make it on a pcb
have you any thoughts re ic or discreet devices
regards
trev
  Reply With Quote
Old 1st March 2006, 12:58 AM   #5
Leolabs is offline Leolabs  Malaysia
diyAudio Member
 
Leolabs's Avatar
 
Join Date: Dec 2004
Location: Bukit Mertajam
Send a message via MSN to Leolabs
Dealing with OPAMPs should be a good choice.
  Reply With Quote
Old 3rd March 2006, 08:46 AM   #6
Unkle77 is offline Unkle77  England
diyAudio Member
 
Join Date: Feb 2006
Location: The Green Belt
Thanks for the responses.

Bazukaz – Yeah was looking at them, trying to work out which one best suites me, don’t really have the knowledge at the mo.

Lineup - Thanks could u give me any more info on power supplies

Latala - I think the cartridges of the turntables are moving magnets, don’t really know as I can't find any damn info on this anywhere!! but they are new and from what I could find I’m guessing MM.

The power amp he is using is a Cambridge Audio A5.

I do note require tone controls as they can be done using the power amp.

I will probably make it on PCB (been doing a bit of research into this) may as well get a bit of practice with this before I do anything more complicated.

I’m not sure if I want to use an IC or discreet devices, the IC will be easier but that isn’t really a plus for me. I want the circuit that sounds better/deforms the input less.

He won’t be needing recording facilities either, that will be something I’ll do later
  Reply With Quote
Old 3rd March 2006, 09:28 AM   #7
lineup is offline lineup  Sweden
diyAudio Member
 
lineup's Avatar
 
Join Date: Dec 2005
Location: the north
I thought you were going to build an ordinary preamp.
This is an easy project for a starter.
Gain needs only be x4.


If is a phono RIAA preamp you will build, is totally another thing.
A high quality RIAA phono amplifier (or a good microphone amp) is NOT an easy project.
Why?
Because of the high gain needed.

Instead of x4 you will need x100-400 for MM pickup amplifier.
Because of this high gain, also any noise from power supply
will be amplified with same gain!


There are many different RIAA projects to chose from.
They can be from very simple one Op-Amp to very advanced.
I would go somewhere in between.

And I would say, pick a good existing project.
Follow instructions and pay great attention to the practical building directions,
regarding power supply construction and how to wire everything.

I would say you should pick some good documented variation
at ESP sound projects RIAA phono pages.
I think you already have the link in your first post.


Even for me or some other good with amplfiers,
to make an own RIAA project from scratch is a lot of difficulties.
Both good amp circuit, good power supply design and correct practical build
as well as good component quality is needed to get a performance without troubles.


Before and while study and order components, consult other experienced people here.
Most of them will give you good advices on details, what to do or dont, and avoid you going wrong.

Some of the posters however may (and most surely will)
recommend very advanced, complicated and difficult stuff.
These you do not have to listen to. Not too much.
They are in the high end audiophile league,
where you always should have the best and most extreme setup in your home.
Even if they never have proved they have better sound.
Not that one living soul can hear anyway. And this is what counts.



ESP at http://sound.westhost.com/
is down to earth and still very good quality for us more normal DiyAudio Guys.
Most of his stuff is better, than what you can buy for twice the price,
compared to build it yourself.

__________________
lineup
  Reply With Quote
Old 3rd March 2006, 04:12 PM   #8
diyAudio Member
 
Join Date: Dec 2003
Location: Buenos Aires, Argentina
Default line preamp

Hi, Uncle77.
i think that maybe you`re trying to make a line level preamp.
That`s a relatively easy task, as lineup and the other members have told you.
ESP projects are really good; the site have a lot of additional info regarding electronics.
My debut was, a pair of years ago, with a very simple preamp based in only one opamp.
That pre was suited for headphones listening, and also good for feeding a power amplifier.
For starters, and to get some basic info, check out

http://headwize.com/projects/index.htm.
http://headwize.com/projects/showfil...=opamp_prj.htm

The second URL have good info about particularities, tips and tricks to design headphone preamps. The majority of them can be tweaked to be used as simple line preamps, only with a reduction in gain.

Another Diyaudio popular favourite is a derivative of the Burr Brown opamp-buffer combination -something like a turbocharged preamp, capable of drive long cables and heavy loads-.
Check out http://focus.ti.com/lit/an/sboa065/sboa065.pdf
or http://www.pha.inecnet.cz/macura/buffer_en.html
The design of the later URL has no gain -is a buffer, with gain 1, designed to give a little more ooomph to weak or anemic sources, like some cheap cd players-; with some modifications in the gain it can be transmutated into a very good an simple preamp.
You can check some threads here in Diyaudio related to that specific topology, with various tweaks

Im using currently something very similar, with very nice results.

Enjoy!
  Reply With Quote
Old 14th March 2006, 11:27 AM   #9
Unkle77 is offline Unkle77  England
diyAudio Member
 
Join Date: Feb 2006
Location: The Green Belt
Heres some questions:

Would a modern turntable such as technics 1210's or and equivalent turntable need a RIAA preamp or just a normal line level preamp.

I believe i need the line level one as what i want is for the signal to just be amplified. I will leave the fancy stuff until i know what i am doing.

So shall i make this:
http://www.pha.inecnet.cz/macura/buffer_en.html

or, this one?
http://www.mitedu.freeserve.co.uk/Ci...udio/gmpre.htm

Or
http://sound.westhost.com/project88.htm

In the bottom on i will not be including the balance or volume controls as my future diy amp will do this.

I will probably do the bottom one, do you guys think this is wise?

Cheers again
  Reply With Quote
Old 14th March 2006, 11:34 AM   #10
Spev is offline Spev  United Kingdom
diyAudio Member
 
Join Date: Jun 2005
Location: uk
Surely the mixer between decks and amp acts as the preamp in this instance? No other pre should be required.
  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
Making and onboard bass guitar preamp Skywalker83 Parts 8 17th October 2012 04:28 AM
Pumpkin preamp - More Boring Making Thread Zen Mod Pass Labs 505 4th June 2008 08:22 PM
Regulate the high voltage making better sound? (Preamp) 9999 Tubes / Valves 20 20th January 2005 05:21 PM
Making a preamp?! phoshious Solid State 3 24th July 2002 05:23 AM
how would i go about making a new passive preamp design Diederick Solid State 8 3rd December 2001 12:46 AM


New To Site? Need Help?

All times are GMT. The time now is 06:08 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