diyAudio

diyAudio (http://www.diyaudio.com/forums/)
-   Tubes / Valves (http://www.diyaudio.com/forums/tubes-valves/)
-   -   What preamp should I build? (http://www.diyaudio.com/forums/tubes-valves/115115-what-preamp-should-i-build.html)

OzMikeH 9th January 2008 02:53 AM

What preamp should I build?
 
I've never built a tube project before, I do maintain some simple tube equipment (although it does pull several amps at 6kV). I'm an experienced electronics tech so I'm not afraid of a complex design.

I'm looking for a preamp design or kit, I'd prefer something that can be done point-point because I'm not set up for making PCBs. I will consider kits as well.
I have a faulty Tektronix 545B CRO I can salvage a power supply and sockets from, maybe even tubes.

My requirements:
Some gain, 6dB is plenty.
volume control.
one unbalanced line in, one line out.
Very high sound quality, high resolution, not muddy or overly warm.

Nice to have:
Balanced line out.
no really obscure parts.
an output topology suited to coupling direct to my active crossover without buffers.

Can anyone point me to a few threads or sites? There's plenty of preamps out there, many with boutique parts, but I have no way of knowing which of them actually sound good.

arnoldc 9th January 2008 03:01 AM

26!!! :cool:

KP11520 9th January 2008 03:25 AM

Hi Mike,

The other day, I saw someone asking for a decent Tube Phono Stage schematic to build a stage as his first project.

One guy recommended a kit to make it easier for the "First" project and pointed to this site. They make Preamp/Linestages and Amps too. The site looked interesting but I can't vouch for where they sit in the pecking order. Take a look: http://www.bottlehead.com/et/et.html

Oh, like he said, Eileen is not included with any of the products!

You might ask the forum what they think!

Regards//Keith

staggerlee 9th January 2008 03:28 AM

12b4
 
Here's a nice thread for you to digest This pre sounds great and can be as simple or complicated as you like: 12b4

cerrem 9th January 2008 03:34 AM

Just my 2 cents....
There are some key things to note....
I would say the power supply is the most critical section of the pre-amp..... ALthough having good PSRR is nice, I still like using very low impedance power supplies.... I usually like to use a triple Darlington arrangement for the pass element...
Most important is to protect your V_reference, whatever you use protect it...for example if you use a Zener string for your reference, make sure to feed it with a PNP constant current source for example....
If you ever add a phono-stage....you will see how critical the power supply can be...
Typically when you say you want high resolution, to me that means a high gm tube....this tends to make the little things jump out more....
As for the output of the pre-amp....the norm is to use the resistor loaded cathode follower....also a high gm tube is good for lower output Z..... The resistor loaded follower is not all that linear for large signal analysis....so a current sink is typically used in the cathode to maintain a constant current, this will greatly help linearize the follower .....

Chris

Poindexter 9th January 2008 04:22 AM

Try this.

I've made a lot of line amps, and this is the daddy so far.

http://www.audiotropic.net/Demo/littleMoeb.gif

If interested, let me know, and I'll show you the power supply and stuff.

Hau'oli Makahiki Hou,

Poinz

planet10 9th January 2008 05:11 AM

Quote:

Originally posted by Poindexter
If interested, let me know, and I'll show you the power supply and stuff.
I'm interested in anything you do Poinz

dave

Poindexter 9th January 2008 05:21 AM

Thazz why you my idol, Dave.

You want the whole circuit? I'm working up a page about it, but it'll take a little time. I do have various working schems, though.

Best,

Poinz

zacster 9th January 2008 05:37 AM

The Aikido at Tubecad.com is an easy build, but it is board only. You need parts (There may be a kit available) and a power supply, chassis, jacks etc... But you're a tech, so this shouldn't be too hard. Bottlehead is good too. I've built both a BH and an Aikido, and my vote goes to the Aikido on sound, but BH on ease of build, mostly because it is a complete kit.

planet10 9th January 2008 06:55 AM

Quote:

Originally posted by Poindexter
Thazz why you my idol, Dave.

You want the whole circuit? I'm working up a page about it, but it'll take a little time. I do have various working schems, though.
:)

Take your time... can't rush the cook...

dave


All times are GMT. The time now is 04:19 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