huangyong 0 Report post Posted November 16, 2004 (edited) just to share with you all. this schematic works!! had made a single channel prototype last week. i combine a few features of Szekeres variant in headwize. Edited November 16, 2004 by huangyong Share this post Link to post Share on other sites
bpribadi 0 Report post Posted November 16, 2004 Are you sure there is no resistor in paralel with C1? Wait for you to make 2 channels, so you can tell us how it sounds That's the most important thing rite Share this post Link to post Share on other sites
huangyong 0 Report post Posted November 16, 2004 bram, yes, the U2 and C1 serve as DC servo. in my prototype, the DC output is measured at around 10mV. (prototype using lousy opamps, lm358). lack of fund now, cant make a proper amp using good parts. Share this post Link to post Share on other sites
jtfoo 0 Report post Posted November 16, 2004 Looks chim.. What's the voltage regulator for ? Share this post Link to post Share on other sites
huangyong 0 Report post Posted November 16, 2004 The voltage regulator (LM317) serve as the constant current source(CCS). You can find this information in LM317 datasheet. I use the CCS instead of a 5W resistor because the temperature increment will change the resistance and the current will not be constant anymore. In this configuration, the voltage across the LM317 is always 1.25V, with the 10ohm resistor there, i set the idle current at 1.25V/10ohm = 125mA. Read this in headwize. Share this post Link to post Share on other sites
nakedtoes 0 Report post Posted November 16, 2004 Where did u get the voltage regulator?? i am looking for one that can voltage max at below 28volt.. Share this post Link to post Share on other sites
infinitriX 0 Report post Posted November 16, 2004 Where did u get the voltage regulator?? i am looking for one that can voltage max at below 28volt.. LM317s are all over SLT. BTW, don't get what you are typing. Share this post Link to post Share on other sites
huangyong 0 Report post Posted November 17, 2004 Where did u get the voltage regulator?? i am looking for one that can voltage max at below 28volt.. Are you trying to make a constant current source or making a voltage regulator? Share this post Link to post Share on other sites
huangyong 0 Report post Posted December 9, 2004 going to make a complete amp this week. trying out a MOSFET power supply. btw, i have done a Tube Buffer, check this out: echoloft i recommend this project for all newbies. it's very easy, suitable for those first time tubies. Share this post Link to post Share on other sites
nakedtoes 0 Report post Posted December 9, 2004 I got a voltage source that varies from 12v to 35volts i need a regulator to regulate it at max 28volt.. Share this post Link to post Share on other sites
huangyong 0 Report post Posted December 10, 2004 It's time to show you my first tube project (prototype). the tube is NOS Jan 6922. the buffer gives much fuller and richer tone, but reduce soundsatge slightly. overall, it's good for that simple circuit. YEAH..my first tube.. Share this post Link to post Share on other sites
digi01 0 Report post Posted December 10, 2004 neat buffer.what amp is it to feed? I am glad to look more and more tube diy in SGH.congratulations!!! Share this post Link to post Share on other sites
huangyong 0 Report post Posted December 10, 2004 Currently it's feeding my computer desktop speaker.. no speaker setup yet.. and headphone amp is in the process of making.. Share this post Link to post Share on other sites
bpribadi 0 Report post Posted December 10, 2004 Cool! Congratulation! I also want to see more tuber from sgheadphones Share this post Link to post Share on other sites
huangyong 0 Report post Posted December 12, 2004 After days, now the tube buffer starts to shine.... tube really needs burn-in.. My setup: Creative Nomad Jukebox 2--> Altec Lansing speaker (forgot model, bought 2 years ago) When speak of desktop speaker, people would normally think it's crap.. bright at the highs and too boommy at the lows.. I did an A/B comparison; with and without the tube buffer. (The tube buffer does anttenuate the sound a bit.) after going through the tube buffer, the sound is rich, warm and fuller. the overall tone is much relax and easier to listen. Another important point is the there's depth is the music, which really amaze me. In the past, my setup had no sense of space and the 2D effect is really boring.. now i can hear a liitle bit of depth.. "cool" In conclusion, my setup sounds better than those sub$500 branded mini-Hifi. just my 2 cent. Share this post Link to post Share on other sites