If you have an acount at ONsemi, you can request folowing samle kits.
https://www.onsemi.com/PowerSolutions/kitDetail.do?id=150WAUDIOKIT/D
https://www.onsemi.com/PowerSolutions/kitDetail.do?id=AMPAUDIOKIT/D
https://www.onsemi.com/PowerSolutions/kitDetail.do?id=AMPAUTOKIT/D
"150w Audio Transistor" kit is a very special one. It contain two peers of mjw0281/0302 from the same lot, 10% hfe matched.
Maybe because of them I obtain a so good offset ...
https://www.onsemi.com/PowerSolutions/kitDetail.do?id=150WAUDIOKIT/D
https://www.onsemi.com/PowerSolutions/kitDetail.do?id=AMPAUDIOKIT/D
https://www.onsemi.com/PowerSolutions/kitDetail.do?id=AMPAUTOKIT/D
"150w Audio Transistor" kit is a very special one. It contain two peers of mjw0281/0302 from the same lot, 10% hfe matched.
Maybe because of them I obtain a so good offset ...
Hi roender,
From what I have seen of those parts, a random sample is almost as good. These things are close!
-Chris
From what I have seen of those parts, a random sample is almost as good. These things are close!
-Chris
Just got in.
I might sort out the cabling a little tonight, but I'll leave powering up 'till the morning as I'm quite tired at the moment. The PSU is dual mono after the trannie, (300VA 30-0-30 unwound to give 25-0-25) and uses MBR20100 diodes with three Philips 6800uF per rail. Should do the job.
Quick check for tomorrow, bias is minimal with the pot clockwise or counter clockwise?
I might sort out the cabling a little tonight, but I'll leave powering up 'till the morning as I'm quite tired at the moment. The PSU is dual mono after the trannie, (300VA 30-0-30 unwound to give 25-0-25) and uses MBR20100 diodes with three Philips 6800uF per rail. Should do the job.
Quick check for tomorrow, bias is minimal with the pot clockwise or counter clockwise?
Hi Al, 6800x3 should perfectly fit... I use 22000uf here. (but with standard metal bridge rectifier)
The bias trimpot is minimum at turned clockwise. But you're already on the safe side putting it into middle position. Even turning it to maximum gives only ~1A. No blow here.
Mike
The bias trimpot is minimum at turned clockwise. But you're already on the safe side putting it into middle position. Even turning it to maximum gives only ~1A. No blow here.
Mike
Hi Al,
Yes, just center your pot. If it's 500 R you will end up with no to very little bias current. My pots ended up in almost exactly the same spot. Have a look at my pictures, way back some where. 😉
Pavel?
Al just wants a quick, no mind answer as he is short on time.
-Chris
Yes, just center your pot. If it's 500 R you will end up with no to very little bias current. My pots ended up in almost exactly the same spot. Have a look at my pictures, way back some where. 😉
Pavel?
Al just wants a quick, no mind answer as he is short on time.
-Chris
Re: The most beautifull, and clean, internal construction
Thanks Carlos. It's amazing what you can do with a bit of oak and a recycled DVD player case. 😉
I'm having fun here, it's running in mono whilst I solder up the other channel, and I keep stopping to listen! I'll never be finished at this rate! 🙂
destroyer X said:
Thanks Carlos. It's amazing what you can do with a bit of oak and a recycled DVD player case. 😉
I'm having fun here, it's running in mono whilst I solder up the other channel, and I keep stopping to listen! I'll never be finished at this rate! 🙂
Hi Al,
So, you like it I guess? 😉
It's a nice amplifier. I had no doubts you'd enjoy it. BTW, beautiful job on the case. WAF should be high.
-Chris
So, you like it I guess? 😉
It's a nice amplifier. I had no doubts you'd enjoy it. BTW, beautiful job on the case. WAF should be high.
-Chris
anatech said:
Well, I've finished the other channel and it's ready to install, but I want to finish listening to this CD first! 🙂
Al, why not pausing the CD and continue it in stereo ? 😀
Wow, 5 simultaneous multimeters plus a scope ?
BTW, which outputdevices are you using ? MJL3281/4281/0281 ?
Mike
Wow, 5 simultaneous multimeters plus a scope ?
BTW, which outputdevices are you using ? MJL3281/4281/0281 ?
Mike
MJE3281/1302, with MJE15032/3 drivers, and an MJE340 for bias.
Hmm, too many DMMs? One for each rail, bias, DC offset, and a backup. 🙂
The CD has just finished, I'd better drink my tea and fire up the iron.
Hmm, too many DMMs? One for each rail, bias, DC offset, and a backup. 🙂
The CD has just finished, I'd better drink my tea and fire up the iron.
Hi Al,
What Mike asked.
What I am waiting for are your listening impressions. If you are using the MJW0281 and MJW0302, my lowest THD point was at 22 mA. You may want to compare at that level and higher. If you don't need to "cook" them, don't.
-Chris
Edit: Al! Cool, your post just appeared above mine. Weird.
What Mike asked.
What I am waiting for are your listening impressions. If you are using the MJW0281 and MJW0302, my lowest THD point was at 22 mA. You may want to compare at that level and higher. If you don't need to "cook" them, don't.
-Chris
Edit: Al! Cool, your post just appeared above mine. Weird.
