siriuz 0 Report post Posted January 16, 2006 @kube: yea i'm going to have an LED part. reminds me! i forgot to get purple LED from slt basement today RLED will depend on the voltage of the LED and how much current you want to feed it. i'm really getting very forgetful! Share this post Link to post Share on other sites
Kippei 0 Report post Posted January 16, 2006 Koba weekdays should be open until 9 pm... I have became quite a regular there to the extend that the auntie and his son know me. Share this post Link to post Share on other sites
squalle 0 Report post Posted January 16, 2006 haha same, I've become koba regular too. and always come late one might have met you kippei btw, go ahead with the PCB, but for sizes of components, kube you have to keep track what's the most easily available in singapore. but, if only you guys wanna wait. I'm trying something now wanna change the power stage (op-amp stage) to something else that can output more current Share this post Link to post Share on other sites
siriuz 0 Report post Posted January 16, 2006 (edited) i was thinking of the dynalo output stage actually edit: but i think its abit overkill, so what's squalles idea ? the one you stated on headwize, the szekeres buffer? Edited January 16, 2006 by siriuz Share this post Link to post Share on other sites
squalle 0 Report post Posted January 16, 2006 yea but have to work on the DC offset too else quite no point rite? solve 1 prob (too low of output current) and introduce another (DC offset, which solved with using output cap) Share this post Link to post Share on other sites
siriuz 0 Report post Posted January 16, 2006 (edited) what the 0.1uf cap between the tube and the opamp for arh? edit: the dc-coupled version of the szekeres doesnt have an output cap, so why not? Edited January 16, 2006 by siriuz Share this post Link to post Share on other sites
squalle 0 Report post Posted January 16, 2006 0.1uF is the high pass filter coz it's going to op-amp from the B+ of the tube haha gotta look for wat it means by the DC coupled of szekeres. is it the one that the gate is biased at certain voltage? I am thinking along that line Share this post Link to post Share on other sites
squalle 0 Report post Posted January 16, 2006 this is the one that I am thinking too LOL Share this post Link to post Share on other sites
siriuz 0 Report post Posted January 16, 2006 (edited) yea thats the one i'll go experiment around with drawing pcbs later edit: but i heard szekeres very sensitive to power supply right ? the psu that the soha is designed around isnt that good Edited January 16, 2006 by siriuz Share this post Link to post Share on other sites
squalle 0 Report post Posted January 16, 2006 ermmm I've got myself another big trafo and providing another seperate supply first Share this post Link to post Share on other sites
huangyong 0 Report post Posted January 16, 2006 i was thinking of the dynalo output stage actually edit: but i think its abit overkill, so what's squalles idea ? the one you stated on headwize, the szekeres buffer? siriuz, i raised this idea in Head-fi before, having hot debate there, what you need is balanced output to drive the output stage. I drwan one circuit before, let me dig it out. Share this post Link to post Share on other sites
huangyong 0 Report post Posted January 16, 2006 something like this Share this post Link to post Share on other sites
1bit 0 Report post Posted January 17, 2006 is this interpretation correct, huangyong? the opamps make differential output then converted back to single output by the transistors? i see, it makes the circuit complicated but you don't need high-pass filter anymore nice how do you end up with 511 ohm for the resistors vlue, btw? i see that you try to make balanced inputs for the opamps you might wanna add a resistor to the positive input of opamp #2 too, i think perhaps 511/2 ohm to make it balanced as well Share this post Link to post Share on other sites
squalle 0 Report post Posted January 17, 2006 lost the bid in the last second of it damn Share this post Link to post Share on other sites
siriuz 0 Report post Posted January 17, 2006 @huangyong: i still haven't figured out how any of that stuff works yet @squalle: oh.. lost the bid arh. buy tube from well audio or koba better? Share this post Link to post Share on other sites