MSH Tube Preamp




Introduction: MSH Tube Preamp

My first post was for a 6V6 Type AB Power Amp.  This is the tube preamplifyer that I used with it.  I know how everyone likes a ratts nest as I do so here we go.  Found the schematic I wanted to use on the internet.

 Below are the web sights where I got the schematic.  Fred did a nice job of describing this so please use his web sight and view the artical on a studio tube pre amp.  He had other nice articals as well.

This schematic was presented by Fred Nachbaur.
©1998 - 2004 by Fred Nachbaur. All Rights Reserved. This information may be freely used for personal, non- commercial use only.

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Step 1: Disclaimer

While this document describes a plan to build an electronic device that has about 180 volts DC under the chassis caution must be followed. I will not be held responsible for any injuries incurred from some one following this document. Nor will I

MSH MODEL-1 PREAMP (Michael S. Holden) makes no representations about the suitability of this information for any purpose. It is provided "as is"
MSH MODEL-1 PREAMP (Michael S. Holden) disclaims all warranties with regard to this information, including all implied warranties of merchantability and fitness, in no event shall MSH MODEL-1 PREAMP (Michael S. Holden) be liable or any special, indirect or consequential damages or any damages whatsoever resulting from loss of use, data or profits, whether in an action of contract, negligence or other tortious action, arising out of or in connection with the use or performance of this information.

This information may include technical inaccuracies or typographical errors.

MSH MODEL-1 PREAMP (Michael S. Holden) may make improvements and/or changes in the information at any time.

Step 2: Power Supply


 For a monaural circuit, the simple power supply detailed as part of the Standalone phono preamp and reproduced below should be entirely adequate. T1 and T2 are both 12-volt, 0.5-ampere units.

Step 3:

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    5 Discussions


    8 years ago on Introduction

    There's anything wrong with building a project that was specifically put on the internet so people would build it...

    But just an FYI-- Fred Nachbaur, the author/creator of this preamp (and the well-known "Real McTube" project) passed away in 2004. So you might want to remove the part about emailing him...


    Reply 8 years ago on Introduction

    This should have read:
    I don't think there's anything wrong with building a project that was specifically put on the internet so people would build it...


    8 years ago on Introduction

    Hi gmoon good to here from you. I did not know he has passed on. However I did email this address and got a reply. I know that you have heard this story before but I cannot find the response in my e-mail. I never looked for any names just remember the statement "It is incredible that you did this from just a schematic”. I think I will e-mail again to see if I can get the same answer back. Will keep you posted. P.S. I am not finished with this intractable hope to refine soon.


    Reply 8 years ago on Introduction

    It's not a big deal, Michael. I'm sure Fred would have been pleased--the info was posted so people would use it.

    I just thought you might want to remove that part about the email, that's all.


    8 years ago on Introduction

    gmoon, I did research and My mistake. I thought I sent a request to Fred and I did not. I was confused with the reply I got about the 6V6 power amp this is the reply I got from Jim Calvert:

    I am very pleased to have been of some help. That's a pretty good amplifier, with well-designed feedback, and th 6V6 is a very capable tube. You are a pretty skilled constructor to have made it work just from the circuit diagram.

    Best wishes,

    Jim Calvert

    ----- Original Message -----
    From: Michael
    Date: Thursday, July 2, 2009 6:13 pm
    Subject: J. B. Calvert, 6V6 HiFi feed back

    > I read your article
    > A High-Fidelity Tube Amplifier
    > Composed by J. B. Calvert
    > Created 30 October 2001
    > Last revised 2 November 2001
    > I wanted to build a low watt tube amp to see if I could find that
    > good old
    > sound of late.
    > Your article inspired me to try it.
    > I built the amp from the RCA Receivers Tube Manual. I have an PDF file
    > with information and details on building it. You may be interested.
    > Thanks for pointing the unusual push pull amp out. By the way it sounds great.
    > Many have questioned the 6V6 bias.
    > Thanks,
    > Michael S. Holden

    gmoon do you think if it is OK to leave this post?