Is this for a sub?
.
If so then the 12 FET version of this amp will do it.
http://www.diyaudio.com/forums/showthread.php?postid=991050#post991050
You'll need an 800va 67v 0v 67v* transformer and humungous DC section.
Layouts available here http://www.adam.com.au/cgpap/QuasiWeb/index.htm
Select the "Actrk400 / 600" link. The 12 FET version will deliver just over 400 watts RMS into 8 all day with adequate heatsinking (a lot). Might even do 4 ohms with lighter duty i.e; sub amp.
* = unloaded.
Cheers
Quasi
.
If so then the 12 FET version of this amp will do it.
http://www.diyaudio.com/forums/showthread.php?postid=991050#post991050
You'll need an 800va 67v 0v 67v* transformer and humungous DC section.
Layouts available here http://www.adam.com.au/cgpap/QuasiWeb/index.htm
Select the "Actrk400 / 600" link. The 12 FET version will deliver just over 400 watts RMS into 8 all day with adequate heatsinking (a lot). Might even do 4 ohms with lighter duty i.e; sub amp.
* = unloaded.
Cheers
Quasi
Build Quasi's N-channel Mosfet amp. Depending on whether your friend's 15" driver is 8 or 4 ohms, configure the amp for 200 watts into that impedance and then bridge to get to your 400 watts mark. It is a very stable amp, even into 2 ohms and the voltages you will be working on are pretty low.
Samuel Jayaraj said:
I think Samuel means the amp in this thread.
http://www.diyaudio.com/forums/showthread.php?s=&threadid=43331&perpage=10&pagenumber=1
Yep a proven and stable amp with over a hundred modules built. But I want someone to build the first one of the other one.
A bridged pair would do the job easily though. In any case do not to run an Nmos500 at anything over 80v rails.
Cheers
quasi said:
Quasi, I am willing to build it provided you assure me that you have completed simulations and are satisfied in every respect. This is because I don't have too much time these days to troubleshoot the amp, just in case it is not optimised as yet.
What is your gut feeling. Should the boosted +ve voltage amp sound better than the Nmos?
Hi Samuel,
I have built the 6 Fet version of the amp and have tested it, but only on the bench. Whilst it seems to be "excellent" it has not been in service yet.
Having said that I have built a 10 FET version of that amp that is similar in design. It uses the extra +ve rail but uses a cascode second stage with with FETs providing a fixed voltage across the driver transistors. This amp performs well, but not as good as the Nmos series.
So if you're after a proven design that has stood the test of time, build an Nmos350 or Nmos500.
This begs the question though, has anyone built any of the amps found here? http://www.diyaudio.com/forums/showthread.php?s=&threadid=53264&perpage=10&pagenumber=1
I do know a couple were built earlier in that thread.
Anyway sorry about hijacking your thread Leolabs.
Cheers
Q
I have built the 6 Fet version of the amp and have tested it, but only on the bench. Whilst it seems to be "excellent" it has not been in service yet.
Having said that I have built a 10 FET version of that amp that is similar in design. It uses the extra +ve rail but uses a cascode second stage with with FETs providing a fixed voltage across the driver transistors. This amp performs well, but not as good as the Nmos series.
So if you're after a proven design that has stood the test of time, build an Nmos350 or Nmos500.
This begs the question though, has anyone built any of the amps found here? http://www.diyaudio.com/forums/showthread.php?s=&threadid=53264&perpage=10&pagenumber=1
I do know a couple were built earlier in that thread.
Anyway sorry about hijacking your thread Leolabs.
Cheers
Q
quasi said:
How do you further qualify "excellent". Are the sonics better than the Nmos series?
You may be aware that I have built the Nmos with 6 FETs and powered with +-63volts DC (with some modifications). This may not qualify as Nmos350 but I was just offering to test an assured schematic, taking the lead, so to speak.
Tell us a little more about "excellent" and I will give it a try with 10 FETs and +-84 volts (+94 for input stage) since I have such a torroid rated at 1.1KVA and a dozen IRFP264s.
Hi Sam, I have answered your question here http://www.diyaudio.com/forums/showthread.php?postid=1236811#post1236811
We should leave this thread dedicated to Leolabs enquiries.
Cheers
Q
We should leave this thread dedicated to Leolabs enquiries.
Cheers
Q
!
Maybe this?!
Maybe this?!
An externally hosted image should be here but it was not working when we last tested it.
Hi Viktor,
Nice schematic. One problem I see though. If the zener on the gates of the positive rail output Fets ever turned on then it or the MJE15034 would be destroyed (probably both). If the MJE15034 went short cct (unlikely probably blown to bits) the output stage is at risk.
Cheers
Quasi
Nice schematic. One problem I see though. If the zener on the gates of the positive rail output Fets ever turned on then it or the MJE15034 would be destroyed (probably both). If the MJE15034 went short cct (unlikely probably blown to bits) the output stage is at risk.
Cheers
Quasi
And you'd also want some kind of DC fault protection between the amp and the speaker, either a relay or a crowbar thyristor.
I'm inclined to suggest buying a used "pro" amp if high power is the goal. Heatsinks, transformer, output devices, filter caps and a case can add up to more than you'd pay for a used amp; maybe even more than a new Chinese-made amp like a Behringer.
I'm inclined to suggest buying a used "pro" amp if high power is the goal. Heatsinks, transformer, output devices, filter caps and a case can add up to more than you'd pay for a used amp; maybe even more than a new Chinese-made amp like a Behringer.
For 400W I have found this 3d posted by Fjromero
http://www.diyaudio.com/forums/showthread.php?s=&threadid=90098&perpage=10&pagenumber=5
bye
http://www.diyaudio.com/forums/showthread.php?s=&threadid=90098&perpage=10&pagenumber=5
bye
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