dreamie

ablaze, how did u desolder the 5532s? thanks

is there a pic to sumarise everything? Thanks again.!

hehe.. sorry for clone poasting ablaze's thread, but taht threadis seriously getting too long.. can anyone provide me with a link to a webby stating the mods that can be done? Thanks a million. Mods: Delete this if u dun like it

from what it looks.. a transformer and a 7824 regulator? Since a 7824 can limit current up to 1A. If so then non-switching.

Where to buy these cute little tin cans

tubes... yummy!

OK.. i take it that the R2 value wont affect the sound quality adveresly. sch hols are coming

nah.. not using it with my tube preamp.. using semiconductor with semiconductor, glass with glass.. currently looking out for the Rozenblit T8 OTL amp schematic.. seems to only be available in Audio Reality.. btw, so R2 (pin 3 to ground at the input signal rail) being changed to 10K is alright? Thanks for all your input.

i omitted C1 (black gates are just outta my budget ) but used R5. I bought the parts anyway.. might as well use them. Thx for all your input.

The resistor from Pin 2 to ground is NOT R2!!! R2 is from In(+) pin to ground. ie. Pin 3 to ground on single-opamps! ops.. 2 wrongs make a right R2 on this image i meant. Correct? Thanks for all your inputs too

KK... I you use non-inverting amplifier. Gain = Rf/Ri + 1 Rf is the resistor between pin 2 and 6. Ri is the resistor between Pin 2 and ground. Increasing that resistor will give you louder sound... Hmm.. according to this forumla i should be getting a gain of 2, if i followed the original one which used 100k, the gain would be 1.1. am i correct? Thanks for all your inputs.

It's pretty difficult to get the OPA2132/ 2134 series of opamps to oscillate. Guess you got a short or wrong connection on the opamp somewhere. If you used dual voltage rails, you MUST connect the virtual ground (or PS ground) to the audio ground. It's not advisable to change R2 to 10K unless you don't have a pot for volume control. i Dont have a pot for volume control...

Heh.. i reckon it got hot because I did them on a project board and they oscillated. Anyway, how would changing R2 (Pin 2 to ground resistor) to 10K from 100K affect the whole circuit? thanks.

btw, i just realised i used 10k as the resistor to ground from pin 3 of OPA134. this wasnt the one i tested though.. this was the one i soldered. .. i think this will result in louder sound..

I smell of the burnt smell soon after it was switched on. Only touched it after a few minutes of shutting down. It could be due to oscillations, cause i did it on project board.

As above. Wanna build a OTL amp but i'm afraid that the impedence, if not matched, will damage the tubes and circuit. What do u guys think?

THe OPA134 on mine got hot. anyway, i also tried to modify the circuit. 1) Removed input capacitor (save $$.. blackgate too ex. ) 2) Output load resistor value is 49.9ohm instead of 50ohm to 100ohm. 3) LED using 150ohm resistor from positive and grounded to 0V (not 10K across +4.5 and -4.5). May need to change the resistor value if i decide to use 2x 9V. Using the gold stereo jacks (female) u can get from Kaichin. $0.80 each. Still in development stage. Size is about 1 3/4 of a 9V battery. Any comments on the modifications? Thx for reading.

you're here

ah... thanks..

cant find soundstage

What does those terms u guys use refer to? like soundstage, cans.. etc.. thx. can be a faq to others too

cool.. i thot analog dun give samples..

where do u guys get the ad8620 from?

speaking of DIY, anyone knows where i can buy teflon tube or sumthing like that? wanna insulate some cables i'm gonna make..

Yes, you can buy it. They'll ask you for your license though. LOL.. ASK and Silicon at SLT didnt ask for mine