Forums
New posts
Search forums
What's new
New posts
Latest activity
Members
Registered members
Current visitors
Log in
Register
What's new
Search
Search
Search titles only
By:
New posts
Search forums
Menu
Log in
Register
Install the app
Install
Audio and Video Talk
Valves / Vacuum Tubes
Valve output transformer question
JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding.
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an
alternative browser
.
Reply to thread
Help Support AVForums:
This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Message
<blockquote data-quote="Den123" data-source="post: 983358" data-attributes="member: 13454"><p>Good Evening Mr Ampdog and all the other knowledgeable souls on this forum. </p><p>Some of you may recall, I am busy planning my next amplifier, a valve amp. I have settled on one of the designs shown to me here on the forum, the one I have named "Sy's KT88 amp". I'll post a pic of the schematic shortly.</p><p>My question is this: My output transformer has only 4 and 8 ohm taps, while the schematic shows the feedback coming from the 16 ohm tap. I actually have two questions:</p><p>What is the effect of using the same tap that the speaker is using? At first I thought I might pick up inductive induced "activity" (speaker damping/regeneration), but then I thought any induced feedback will still pass through the transformer to the other taps. Your thoughts?</p><p>Secondly, if I was to use the 8 ohm tap, I would like to re-calculate the 39k feedback resistor (R22). To work out the potential divider ratio, can I just use R22 and R4 as the divider?</p><p>You input is welcome.</p></blockquote><p></p>
[QUOTE="Den123, post: 983358, member: 13454"] Good Evening Mr Ampdog and all the other knowledgeable souls on this forum. Some of you may recall, I am busy planning my next amplifier, a valve amp. I have settled on one of the designs shown to me here on the forum, the one I have named "Sy's KT88 amp". I'll post a pic of the schematic shortly. My question is this: My output transformer has only 4 and 8 ohm taps, while the schematic shows the feedback coming from the 16 ohm tap. I actually have two questions: What is the effect of using the same tap that the speaker is using? At first I thought I might pick up inductive induced "activity" (speaker damping/regeneration), but then I thought any induced feedback will still pass through the transformer to the other taps. Your thoughts? Secondly, if I was to use the 8 ohm tap, I would like to re-calculate the 39k feedback resistor (R22). To work out the potential divider ratio, can I just use R22 and R4 as the divider? You input is welcome. [/QUOTE]
Insert quotes…
Verification
Post reply
Audio and Video Talk
Valves / Vacuum Tubes
Valve output transformer question
Top