"Sound-vice, you do not need to worry about distortion.
It sounds very clean (and silent), with a strong and powerful bass. Very well controlled."
Mmmm.... People were saying the same about Alephs... I build one. I dont thinkg so. Bad measured results may warn you...
It sounds very clean (and silent), with a strong and powerful bass. Very well controlled."
Mmmm.... People were saying the same about Alephs... I build one. I dont thinkg so. Bad measured results may warn you...
Mmmm.... People were saying the same about Alephs... I build one. I dont thinkg so. Bad measured results may warn you...
I build one. Ummmm, which one ?.
Bad measured results may warn you. Ummmm, which one ?.
Your experience of both ?.
Eric.
I build one. Ummmm, which one ?.
Bad measured results may warn you. Ummmm, which one ?.
Your experience of both ?.
Eric.
Ad 1 - Aleph3
Ad 2 - eg. THD, sq. wave pass, etc. Are you able to set the amp up only by ear? If yes I envy. I would like to have such analyser in my head too.
Ad 2 - eg. THD, sq. wave pass, etc. Are you able to set the amp up only by ear? If yes I envy. I would like to have such analyser in my head too.
Koy;
Don't worry about your writing. Some of the worst spelling
on this site comes from native english speakers ....
What didn't you like about your aleph?
-herm
Don't worry about your writing. Some of the worst spelling
on this site comes from native english speakers ....
What didn't you like about your aleph?
-herm
N-channel-sound...
I have been comparing the N-channel with amps from
Dynamic Precision, http://www.dynamicprecision.no and Electrocompaniet, http://www.electrocompaniet.no, (and an old Adcom), It seems to be a bit more forward and "pushy" compared w. the master of analytic, (Dynamic Precision), and has a quick, deep and hard bass. And, just as important, I have not singled out any "flaws", and is a joy to use. Not even a problem w. pops or noice when turning on or off.
My advice (for what it's worth) TRY IT!
Arne K
NORWAY
BTW. I use AudioVector S6 speakers, http://www.audiovector.dk,
front end: modified Marantz CD-14, Monarchy Audio DAC, Oracle Delphi + other modified or diy-units.....
I have been comparing the N-channel with amps from
Dynamic Precision, http://www.dynamicprecision.no and Electrocompaniet, http://www.electrocompaniet.no, (and an old Adcom), It seems to be a bit more forward and "pushy" compared w. the master of analytic, (Dynamic Precision), and has a quick, deep and hard bass. And, just as important, I have not singled out any "flaws", and is a joy to use. Not even a problem w. pops or noice when turning on or off.
My advice (for what it's worth) TRY IT!
Arne K
NORWAY
BTW. I use AudioVector S6 speakers, http://www.audiovector.dk,
front end: modified Marantz CD-14, Monarchy Audio DAC, Oracle Delphi + other modified or diy-units.....
Cobra2- aleph: Loss of details and space ( comparing to my Thule Auido) and corresponding somewhat high distorsion.
MTW35N15E Mosfet in N-Channel amp???
Is it OK to use MTW35N15E mosfet`s in this amp?
What will be the difference comparing to the IRFP240?
I have a lot of this mosfet (840pieces) and would like to use it to something (like an ampliifer).
Datasheet:
http://www.onsemi.com/pub/Collateral/MTW35N15E-D.PDF
Is it OK to use MTW35N15E mosfet`s in this amp?
What will be the difference comparing to the IRFP240?
I have a lot of this mosfet (840pieces) and would like to use it to something (like an ampliifer).
Datasheet:
http://www.onsemi.com/pub/Collateral/MTW35N15E-D.PDF
Re: Less power?
CAN THIS AMP VORK ON A 2 X 90 V ??? CAN IT BE MODIFIED VOR THAT VOLTAGE ?
mik said:Can this amplifier give less output power with lower supply rail or there is another way to do this because I don't so much power and since everybody telling nothing but good about this amp it is worth to givit a try.
CAN THIS AMP VORK ON A 2 X 90 V ??? CAN IT BE MODIFIED VOR THAT VOLTAGE ?
Re: Less power?
CAN THIS AMP VORK ON A 2 X 90 V ??? CAN IT BE MODIFIED VOR THAT VOLTAGE ?
mik said:Can this amplifier give less output power with lower supply rail or there is another way to do this because I don't so much power and since everybody telling nothing but good about this amp it is worth to givit a try.
CAN THIS AMP VORK ON A 2 X 90 V ??? CAN IT BE MODIFIED VOR THAT VOLTAGE ?
Re: MTW35N15E Mosfet in N-Channel amp???
If I don't remember wrong you should choose FET's with Rdson as high as possible (for your power needs). Less than 0,3-0,5 ohms is pure waste. Think decibels in power loss when you calculate. 1 or 2 dB's doesn't matter.
Low Rdson FET's have large caps and can be hard to get working in a source follower (self oscillation). This FET have max 5 nF (ugh!) as Cgs and up to 300 pF as Cgd. The old Hitachi from stone age had less than a factor 10 at all values!
As a conclusion: You may succeed but not without testing and development.
2002tii said:
If I don't remember wrong you should choose FET's with Rdson as high as possible (for your power needs). Less than 0,3-0,5 ohms is pure waste. Think decibels in power loss when you calculate. 1 or 2 dB's doesn't matter.
Low Rdson FET's have large caps and can be hard to get working in a source follower (self oscillation). This FET have max 5 nF (ugh!) as Cgs and up to 300 pF as Cgd. The old Hitachi from stone age had less than a factor 10 at all values!
As a conclusion: You may succeed but not without testing and development.
The gate C in the N-channel design has little to do with it Objective performance, I have used N-channel devices with Gate C of 7nf with great results.
It is a fact that this design requires Mosfets with a high forward transconductance. Mosfets such as the Hitachi 2sk1058 Lateral type. Just won't work as they have a siemens rating of 1
Types as the MTW35N15E have a rating of 18. Which is very high.
Will have no trouble working in this design.
Its is also very important that the supply voltage with the existing design not exceed 75 volts.
At least not without resigning the thermal tracking circuit as the Gate threshold voltage on these types of mosfets drop as the supply voltage increases closer to 100 volts.
Having said all of this peranders is correct in saying high Rson devices will be more thermally stable in designs such as the n-channel design.
Cheers
Anthony Holton
www.aussieamplifiers.com
It is a fact that this design requires Mosfets with a high forward transconductance. Mosfets such as the Hitachi 2sk1058 Lateral type. Just won't work as they have a siemens rating of 1
Types as the MTW35N15E have a rating of 18. Which is very high.
Will have no trouble working in this design.
Its is also very important that the supply voltage with the existing design not exceed 75 volts.
At least not without resigning the thermal tracking circuit as the Gate threshold voltage on these types of mosfets drop as the supply voltage increases closer to 100 volts.
Having said all of this peranders is correct in saying high Rson devices will be more thermally stable in designs such as the n-channel design.
Cheers
Anthony Holton
www.aussieamplifiers.com
Member
Joined 2002
Thanks for your answer Anthony.
I thought I read somewhere on your web site that one could use any industrial Mosfet.
Not just my bad memory then 🙂
Can I compansate for the low Rdson by using bias resistors with higher resistance?
Or do I just have to use bigger heatsinks???
Or doesn`t this help at all?
I`m not 100% sure how an thermally unstable amp behaves, and what I can do to cure it...
I thought I read somewhere on your web site that one could use any industrial Mosfet.
Not just my bad memory then 🙂
Can I compansate for the low Rdson by using bias resistors with higher resistance?
Or do I just have to use bigger heatsinks???
Or doesn`t this help at all?
I`m not 100% sure how an thermally unstable amp behaves, and what I can do to cure it...
MTW35N15E mosfet in N-channel
Hi!
I also would like to know if any parts have to be changed for using the MTW35N15E mosfets in this amp.
Please enlighten us!
ArneK
PS.: My other N-channel amp. works perfect.
Hi!
I also would like to know if any parts have to be changed for using the MTW35N15E mosfets in this amp.
Please enlighten us!
ArneK
PS.: My other N-channel amp. works perfect.
Member
Joined 2002
Well my n-channel is still running smooth. i have come to the conclusion that it needs a better heat sink, so this weekend i will be changing the heat sink. some thing a little thicker on the base. : O ) but other than that it runs smooth and fine. : O ) great work Anthony E Holton. : O )
BTW, Mr. Holton...
I'm going to make balanced/XLR inputs, and use Jensen Trafos (JT-11P-1) for balanced conversion, can I then remove the input cap? Would there be DC after the cap?
Arne K
I'm going to make balanced/XLR inputs, and use Jensen Trafos (JT-11P-1) for balanced conversion, can I then remove the input cap? Would there be DC after the cap?
Arne K
Member
Joined 2002
I have 2 problems so far.
One my amd gets hot with no load or any signal input why. i have a new heat sink on it with 1/4 base with 40 finns on it and 3" on all directions.
2 when my amp is on no input but a speaker atached there is a buzz. when i hook up my preamp i get a faint hiss and a litle bit of humm
my transformer is a toroidal 300va 2 x 50v
and 2 x 15,000mf caps @125v
ANy sujestions.
One my amd gets hot with no load or any signal input why. i have a new heat sink on it with 1/4 base with 40 finns on it and 3" on all directions.
2 when my amp is on no input but a speaker atached there is a buzz. when i hook up my preamp i get a faint hiss and a litle bit of humm
my transformer is a toroidal 300va 2 x 50v
and 2 x 15,000mf caps @125v
ANy sujestions.
Recheck your bias setting...
Also you have not mentioned if the buzzing is happening in the same amplifier module. If it is then increase the supply filtering.
Cheers
Anthony
Also you have not mentioned if the buzzing is happening in the same amplifier module. If it is then increase the supply filtering.
Cheers
Anthony
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