And of course before I change to stereo I will do a last comparing resistor, CCS and MU follower...
HI
Can I ask if is possible cooking something my good old 500VA r-core ?
With 39Vdc I haved draw 2A bias,cold like a dead, probabily good for 4A....
Caps 40k for ch.
Tnx
Can I ask if is possible cooking something my good old 500VA r-core ?
With 39Vdc I haved draw 2A bias,cold like a dead, probabily good for 4A....
Caps 40k for ch.
Tnx
Very high 100Hz rectification buzz plus its first harmonic and their beat though. Should be pushed down further. But no 50Hz hum, that's good. I.e. no fields or gnd loops.
Yes Salas .....you are right! I was very astonished to see that 100 Hz and 200 Hz peak! Normally I have a 50 Hz peak.
Why do I get this different peak and what can I do against him and I hear no hum....!
Gerd
🙁 mine is huming like a beast . but as i remember other big toroids amp was buzzing before i probably have DC on the main. 200W variable resistor is not
a good idea the heat is so high that the wood of my case is now broken😱.
long is the road....🙂
a good idea the heat is so high that the wood of my case is now broken😱.
long is the road....🙂
Sorry to hear that !
My 13 Ohm chain consists of five 50W resistors and they make on their own heatsink as big as the one for the SK82 even more heat......
Did you build the PSU like Mike suggested? But I have nevertheless only 42 deg Celsius on the sinks surface
My 13 Ohm chain consists of five 50W resistors and they make on their own heatsink as big as the one for the SK82 even more heat......
Did you build the PSU like Mike suggested? But I have nevertheless only 42 deg Celsius on the sinks surface
Last edited:
🙂Your variable resistor is nevertheless a good idea, I am still fighting to get closer to the sweet spot, even 0,5 Ohm make a remarkable deviation from the point.🙂
100Hz is double the mains frequency (as coming out from bridge rectification cycling), 200Hz is its first harmonic, 300Hz is 1st's and 2nd's beating product plus smaller ones up higher. If you can't hear any ZZZZ noise then its just something in your measuring rig. Such harmonic noise gives ''grunge'' to midbass when present making it seemingly bigger also. What you can do is increase amp's PSRR with CCS or use filtering in the PSU. Choke or capacitance multiplier.
Hi Salas, thanks for your answer....🙂
I just creeped into my open baffles to the tone tubby, there is only a very very faint hum... so I suppose it is this time more the measuring rig.
At any case you had a very good look at my data.......🙂
still waiting for resitors and the IRF you suggested.... good that only the amp is mono and not me.....😀
I just creeped into my open baffles to the tone tubby, there is only a very very faint hum... so I suppose it is this time more the measuring rig.
At any case you had a very good look at my data.......🙂
still waiting for resitors and the IRF you suggested.... good that only the amp is mono and not me.....😀
Way too hot inside that case, and that's probably not making your transformer happy either. Move those resistors outside or get bulbs. Have a look at my post on resistors, the ones I used are 4 times as big, and I used three for each channel.
Keep going, you're almost there. 🙂
At approx. .1% THD, predominant second, I'd say you're doing quite well. 🙂
Now, twist the knob and watch the spectrum change. Fun, fun, fun.
BTW, are those 50V caps?
Elna 10000uF/63V......
Yes i saw already the change... But i did not change during hearing.....
Yes i saw already the change... But i did not change during hearing.....
Thanks, just checking.
My guess is the junk at the bottom is souncard / PC related, at least in part. Is that at 1W?
You could do a loopback and check the residual spectrum.
My guess is the junk at the bottom is souncard / PC related, at least in part. Is that at 1W?
You could do a loopback and check the residual spectrum.
Last edited:
i lost my AAA but i ordered 2X 800W thick film resistor with heatsink and 2 3,3ohm 100W .. and a isolation TRansformer .. i' m on the run 🙂
I am speechles........even with AAA.....what big jump!
That will solve your problems I suppose, do you need more heatsinks?
Would be nice if you could keep your wooden case, looks better than these mostly cheap metallic cases that are mine.
Maybe I will change too, but keeping the heatsink area!
Hope my trans- and re- sistors will come soon...
And I built up in the evening the SK79 and SB624 circuit I posted some days ago, again too late to hear loud, but it seems not contra productive to the SIT amp.....😀
That will solve your problems I suppose, do you need more heatsinks?
Would be nice if you could keep your wooden case, looks better than these mostly cheap metallic cases that are mine.
Maybe I will change too, but keeping the heatsink area!
Hope my trans- and re- sistors will come soon...
And I built up in the evening the SK79 and SB624 circuit I posted some days ago, again too late to hear loud, but it seems not contra productive to the SIT amp.....😀
Hi everybody,😀
some news,
1. I could change my wire resistors today against thick film resistors.... that is a heavy difference.......I was shocked.....I like it much more!
2. my new arranged Mufollower was better than the wire resistor version, more alive...but more cap dependent, two caps.....and now compared to the thick film solution, less precise and a bit veiled, but more bass with my tone tubby/lowther and more gain.....
the affair stays amusing.......
and Salas, CCSs must wait still a bit, I have to change the PSU from 48V again back to 27 or 18......😀😀😀
some news,
1. I could change my wire resistors today against thick film resistors.... that is a heavy difference.......I was shocked.....I like it much more!
2. my new arranged Mufollower was better than the wire resistor version, more alive...but more cap dependent, two caps.....and now compared to the thick film solution, less precise and a bit veiled, but more bass with my tone tubby/lowther and more gain.....
the affair stays amusing.......
and Salas, CCSs must wait still a bit, I have to change the PSU from 48V again back to 27 or 18......😀😀😀
Gerd,
What brand, how many of what wattage thick film resistors. I have thought about parralleling a few 100W thick film types.
What brand, how many of what wattage thick film resistors. I have thought about parralleling a few 100W thick film types.