Thanks..
Thanks and Yes Mr. Mile see attached..
Hey wow Willy that looks fantastic !
Regards
Juan
Thanks bro...
Attachments
Wow! Does that 5P stay cool enough laying flat inside that enclosed case? What kind of bias are you running on it? Is there a heatsink on the two 2 pair units?
Thanks, Terry
I do see the fan but how much air flow in that short case and how does the fan get air to the two 2 pair amps? I'm not saying it isn't working, I'm trying to learn something here. I have 4 pair of these boards built. It would be nice to know I don't need much heatsink.
one fan pulling the heat to outside. i think one fan is not enough
hi wiilj did u load at full volume? what is the heatsink temperature?
hi wiilj did u load at full volume? what is the heatsink temperature?
I didn't tried it yet in full volume and heavy used or for a battle, I just set this in minimum bias settings around 14mV across .47R/5W just enough to handle the heat of my small heat sink, temp is about 25-50 deg. about half way volume, my room and glass window is vibrating so much if crank up the volume so I just use this in normal purpose only just to enjoy the sound quality of this amp and my electronics hobby...😉
Well, optimal bias is not really related to the output power. It is set with the lowest x-over distortion in mind. 14mV across .47R gives us roughly 30mA, which is suitable for CFP output topology, but not enough for EF output stage, where some 70-90 mA would be the optimum. Even if you use it at the power of couple of watts. An under-biased output stage will give significant distortion increase at low power.
Cheers,
Valery
dear apex,
can i use MJE15030, MJE 15031 in place of 2SA1837 2SC4793 respectively. if yes what changes will made. thanks masood
Does different transistors make a difference in sound quality? Or it's all about reading the data sheet and choose the best? I don't mean one slow transistor compare to one higher speed. I mean if you compare two transistor that can do the job, can there be any difference in sound.
I thought only different brand of tubes can have difference in sound characteristics.
I thought only different brand of tubes can have difference in sound characteristics.
Even in the same batch (same brand same type) transistors can have different characteristics (that's why there are Y/GR/BL/V ratings). Just like tubes (that changes characteristics over time).
Now in some certain circuits this characteristics difference can be critical can be less (for amplifier measured performance).
Sometimes there's no best transistor, in that some transistors work optimally in different conditions (so plug and play will not work to judge which one is better).
And in most cases (if not all), yes, the difference is audible.
I don't mean transistors that have different specs, of cause you need to look at the hfe, fT, power handling, max voltage and current etc. but I am referring to the same transistor ( 2N3055 for example), just different brands. Can they make a difference in sound? Or one transistor sounds better than the other.
Yes, I know even the same badge can be a little different. Data sheet only guaranty the minimum spec, transistor can work over the limit, but not guarantied. But there are so many transistors to choose, you can always find one that suit your needs, not by hand pick ones that can perform over the spec.
The reason I ask is because I worked a lot with of transistors ( not in hifi audio amps). I only look at the data sheet and choose one that fits my requirements, one with multiple sources, readily available. But I do notice in hifi world people are very finicky about things that I don't worry about, like brands. That's the reason I ask.
From my experience, transistors don't get old or degrade. They either work or they die.
Yes, I know even the same badge can be a little different. Data sheet only guaranty the minimum spec, transistor can work over the limit, but not guarantied. But there are so many transistors to choose, you can always find one that suit your needs, not by hand pick ones that can perform over the spec.
The reason I ask is because I worked a lot with of transistors ( not in hifi audio amps). I only look at the data sheet and choose one that fits my requirements, one with multiple sources, readily available. But I do notice in hifi world people are very finicky about things that I don't worry about, like brands. That's the reason I ask.
From my experience, transistors don't get old or degrade. They either work or they die.
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