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<!-- #thumb --> <p>A friend of mine brought over a schematic of an Audio Research tube preamplifier yesterday. *This is but one of several I have been studying as of late. *One of the characteristics I find as an interesting pattern is that none I have studied are direct coupled; meaning at a minimum the output of the preamplifier are all capacitor coupled.</p>
<p>This is interesting because the vast majority of solid state designs are all sans capacitors in the signal path. *Direct coupled. *In fact, we work hard at removing these sonic changers from the musical path.</p>
<p>Capacitors, in general, soften the sound of music passing through them. *I don’t want to say blurred, because the best capacitors certainly do no such thing, but soften is the best I can come up. *And soften isn’t a very good word. *Soften would indicate a reduction of transient information, a slowing of the signal. *Modern tube preamplifiers are extremely fast and transient accurate. *And cap coupled. *I wish I had a better description of what they do. *I don’t.</p>
<p>One other pattern observation is their simplicity. *The tube designs I’ve investigated are one, perhaps two devices long for the signal path. *Most solid state designs have far more parts.</p>
<p>It is fascinating to me that tube preamps do all the wrong things as far as we solid state designers might think: add capacitors in the signal path and use crude, low tech amplification designs.</p>
<p>If it’s not obvious to you, I am rethinking all that I know and take for granted in preamp design.</p>
<p>As Albert Einstein once said “If you can’t explain it simply, you don’t understand it well enough”.</p>
<p>I’ll keep you up to date as things become apparent.</p>
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[Source: http://www.pstracks.com/pauls-posts/preamps-2/11477/]
<p>This is interesting because the vast majority of solid state designs are all sans capacitors in the signal path. *Direct coupled. *In fact, we work hard at removing these sonic changers from the musical path.</p>
<p>Capacitors, in general, soften the sound of music passing through them. *I don’t want to say blurred, because the best capacitors certainly do no such thing, but soften is the best I can come up. *And soften isn’t a very good word. *Soften would indicate a reduction of transient information, a slowing of the signal. *Modern tube preamplifiers are extremely fast and transient accurate. *And cap coupled. *I wish I had a better description of what they do. *I don’t.</p>
<p>One other pattern observation is their simplicity. *The tube designs I’ve investigated are one, perhaps two devices long for the signal path. *Most solid state designs have far more parts.</p>
<p>It is fascinating to me that tube preamps do all the wrong things as far as we solid state designers might think: add capacitors in the signal path and use crude, low tech amplification designs.</p>
<p>If it’s not obvious to you, I am rethinking all that I know and take for granted in preamp design.</p>
<p>As Albert Einstein once said “If you can’t explain it simply, you don’t understand it well enough”.</p>
<p>I’ll keep you up to date as things become apparent.</p>
<center><a href="http://www.pstracks.com/pauls-posts/preamps-2/11477/emailpopup/" onclick="email_popup(this.href); return false;" title="Forward to a friend and help us engage more readers" rel="nofollow"><img class="WP-EmailIcon" src="http://www.pstracks.com/wp-content/plugins/wp-email/images/email.gif" alt="email More on preamps" title="More on preamps" /></a>*<a href="http://www.pstracks.com/pauls-posts/preamps-2/11477/emailpopup/" onclick="email_popup(this.href); return false;" title="Forward to a friend and help us engage more readers" rel="nofollow">Forward to a friend and help us engage more readers</a></center><br /><!-- // MAILCHIMP SUBSCRIBE CODE --><center><a href="http://eepurl.com/eSzBY">Get new and fresh stories like this each morning by joining the folks reading Paul's Posts. Click here </a></center>
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[Source: http://www.pstracks.com/pauls-posts/preamps-2/11477/]