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<!-- #thumb --> <p>…is that it leads to success. *Perhaps the hard way, but sometimes it’s the only path there.</p>
<p>Thanks for all the kind words of encouragement about the amp not living up to what I wanted but, here’s the thing about failing, it pushes you harder to succeed and in the process of figuring the problem out great things usually emerge.</p>
<p>If everything just went according to plan life’d be pretty boring – and for those of us afraid of failure (and who isn’t?) – once we get over the initial disappointment most of us roll up our sleeves and really get moving. *So, on that note, what will be my first steps?</p>
<p>As I’ve been traveling as of late and enjoying time off in the northern parts of our country I’ve been contemplating what to do – why would the amp sound somewhat closed in, less open and have a stiff top end that sounds recessed? *What are the probable causes? *It occurs to me that when we designed the new all FET front end stage that we had to resort to a constant current source on the FET gain transistor. *The reason for this was greater linearity and because we’re using MOSFETS for the outputs of the analog gain stage, keeping a constant current helps bias these devices. *But there’s a problem with a constant current source connected to a gain transistor – far more gain than is perhaps manageable – because the current source looks like an infinite resistor.</p>
<p>One of the hallmarks of a “closed in” sound that we learn, as designers, can sometimes be attributed to the problem of too much open loop gain – in other words, too much gain before feedback results in too much feedback – and this, in my experience can be the cause of such a sound. *So as soon as I am back from my trip I’ll figure out a way to keep the constant current source working, yet limit the open loop gain so the amount of feedback is low. *We’ll see what that does.</p>
<p>Some of the most open sounding preamps and amps have little to no feedback and that’s for a reason – this very problem I am describing. *No feedback at all has its problems, and too much has them as well.</p>
<p>I’ll let you know what we find as we dig a bit deeper.</p>
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[Source: http://www.pstracks.com/pauls-posts/failure/11170/]
<p>Thanks for all the kind words of encouragement about the amp not living up to what I wanted but, here’s the thing about failing, it pushes you harder to succeed and in the process of figuring the problem out great things usually emerge.</p>
<p>If everything just went according to plan life’d be pretty boring – and for those of us afraid of failure (and who isn’t?) – once we get over the initial disappointment most of us roll up our sleeves and really get moving. *So, on that note, what will be my first steps?</p>
<p>As I’ve been traveling as of late and enjoying time off in the northern parts of our country I’ve been contemplating what to do – why would the amp sound somewhat closed in, less open and have a stiff top end that sounds recessed? *What are the probable causes? *It occurs to me that when we designed the new all FET front end stage that we had to resort to a constant current source on the FET gain transistor. *The reason for this was greater linearity and because we’re using MOSFETS for the outputs of the analog gain stage, keeping a constant current helps bias these devices. *But there’s a problem with a constant current source connected to a gain transistor – far more gain than is perhaps manageable – because the current source looks like an infinite resistor.</p>
<p>One of the hallmarks of a “closed in” sound that we learn, as designers, can sometimes be attributed to the problem of too much open loop gain – in other words, too much gain before feedback results in too much feedback – and this, in my experience can be the cause of such a sound. *So as soon as I am back from my trip I’ll figure out a way to keep the constant current source working, yet limit the open loop gain so the amount of feedback is low. *We’ll see what that does.</p>
<p>Some of the most open sounding preamps and amps have little to no feedback and that’s for a reason – this very problem I am describing. *No feedback at all has its problems, and too much has them as well.</p>
<p>I’ll let you know what we find as we dig a bit deeper.</p>
<center><a href="http://www.pstracks.com/pauls-posts/failure/11170/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 The thing about failure" title="The thing about failure" /></a>*<a href="http://www.pstracks.com/pauls-posts/failure/11170/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/failure/11170/]