SYMEF amplifier

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#382
For an EF output stage expect 20 to 25mVre through 0r22re.
That comes out at ~100mA of bias through each pair.
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Yes, the big improvement was moving from 13 to 26mV. There's not much difference going higher, at least that I can perceive.

I just stayed at 46mv. across two resistor emitter.theres something I read in books about gm doubling.when you try to bias a class b output as same as class a.besides my heatsink could not handle more heat.height is 3.75" which is very small.
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Perhaps it's better to go with only 26 mV for safety. I have big heatsinks but as I said above there's little difference going higher.

did you make another amp? and make it stereo.and how's the new dawn 1diffqc amp?
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Yes, I did. 🙂 The 1DIFFQC sound similar to the SYMEF but there are some differences. I don't know how much the TIP outputs are contributing for a different sound or if it's just because topology is different, but the DIFF sounds a little more mellow and with a little less treble. They are both very good performers and it's hard for me to pick one over the other.

p.s.
next time be aware of the polarity and stick to safety region.
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The poor guy saw 35V reversed at his terminals! It was hot as hell!😱

Guys, I need your help in this: I'm going in circles soldering and desoldering capacitors, deciding wich to use. The truth is that I don't fully like any electrolytic I've tried. The industrial types like lelon and panasonic seem more fluid but there's something wrong tonaly with them. The Silmic's, althout very smooth, kill the energy of the sound. The Nichicons KZ are almost good but the top end is a bit harsh or confused - I don't know what words to use to better explain this. So I ask you guys: what is your advice? And is there any bypass that works as a solution (electrolytic + film)? What are your feelings about electrolytic caps - how do you choose wich ones to use? You built the SYMEF and perhaps the DIFF with wich types of caps?

Thanks.
 
#387
.....more builders needed

.......your opinion counts, This amplifier is based on a model that predicts you will like it , a lot. But don't take my word for it, try it and let us know your opinion. You could always checkout the good job done by Drow and Paulo by reading the whole thread or visiting Gallery
 
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#388
Hi Harrison,

....I don't know how fast your customs is Paulo, maybe you get it between now and 5th
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It would be a birthday gift 😉

Portuguese customs are slow, it takes about 2 months for things to get cleared. But not every package is picked for inspection and tax - I'm hoping boards isn't because should be a small package looking like a letter or documents and not be inspected.
 
#390
now I sing for you.... use text to speech

Happy birthday to you, happy birthday to you, happy birthday dear Paulo, happy birthday to you, how old are you now, how old are you now, happy birthday dear Paulo happy birthday to you, I went to the zoo, I went to the zoo and I saw a ..... and I thought.....
 
#391
Happy birthday, you share one with my cousin within 3 days
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Thank you Harrison. 🙂 Nice singing😉 Happy birthday to your cousin!

The boards are stuck at customs. In about two weeks I'll receive a letter asking me to send them a purchase bill so they can calculate taxes. They're going to check if the bill is true and then, after about a month, they release the package.
 
#394
Thank you Harrison

Look what the mail man brought today:

Thanks Harrison!🙂
 

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