Yes, I have the same understanding of limits. I didn't mean set the current gain to limit pos current at the same current as neg. I suggest setting bias as high as your heat sinks can take, then setting current gain so current limits for the pos with speakers load equals voltage limit for neg swing.
Ex.
36 v rails gives output max (neg) 32v
32v @ 8 ohm = 4 amp
your max bias 2.6A
set current gain to allow pos swing to give 3.9 amps
These are arbitrairy numbers I made up for easy math.
Ex.
36 v rails gives output max (neg) 32v
32v @ 8 ohm = 4 amp
your max bias 2.6A
set current gain to allow pos swing to give 3.9 amps
These are arbitrairy numbers I made up for easy math.
Brian,
now I understand what you mean.
In this example you´ve set ac-current gain to below 50% (2.6A would give 5.2A at 50% ac-current gain) but what if (like in my case) you have to set the ac-current -gain to very high values to reach the current at a given voltage?
What do you think is the advantage of doing it this way and not going for 50%?
william
now I understand what you mean.
In this example you´ve set ac-current gain to below 50% (2.6A would give 5.2A at 50% ac-current gain) but what if (like in my case) you have to set the ac-current -gain to very high values to reach the current at a given voltage?
What do you think is the advantage of doing it this way and not going for 50%?
william
Brian Donaldson said:
wuffwaff said:
Maybe my question is not strictly concerned with considered problem but did anyone of You measure dumping factor with ac current gain about 50% and with higher gain ?
My expierences based on Aleph3 but with one output transistor not pair but with DC bias set to 2A gives me "poor" ( about 40 not 100 as it should) dumping factor and asymethric cliping for loads much lower than 8 Ohm ( 3.4 Ohm in my case which is lowest impedance of my speakers).
Seting ac current gain to
about 70% gives me dumping factor about 90 and more symethrical clipping. What do You think about that ?
Regards
Jacek
Wuffwaff, you're right again, you could set the current gain higher and have more current if needed and a higher damping factor. My alephs were not used for bass, and I listened and tweeked to get what I liked. my choice was the lower AC gain number with higher bias. My point was that symetric clipping for your load is a good way to set the amp up. Also if you're under heatsinked, you can get the extra output with current gain and not melt.
It's DIY, play with it. Tour mom won't tell you it's nasty
It's DIY, play with it. Tour mom won't tell you it's nasty
cowanrg said:its interesting that an a topic thats been discussed at least 50 times on the forum and can easily found be searching even needs to be discussed
Searcher found only 5 threads where there are dumping factor
words and I did not find in them any what concerns in satisfied way my question. Do You imagine I will be reading manually all threads ?
If You know tell me what threads say about my problem
BTH I have impression that many people build different Alephs without checking electrical parameter of their constructions. I'm almost sure that their clones do not work enough good as they could. Faith makes miracles.
Regards
Jacek
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.