Dr. EM
Unfortunately I have not the exact spice models for those lateral.
I would rather use components I can play with in SPICE
But I have these models:
ECX10N20 ECX10P20
And I have used:
ECF20N20 ECF20P20
ECF10N20 ECF10P20
MiiB.
I use HEXFET this time IRFP240/9240
And they need at least, I have a feeling, 10 mA
and as the MOSFETS are ZETEX ZVP/ZVN3310A = TO-92, 625mW
they do not safely take 35v x 10 mA = 350mW
Well, at least they would get hot.
MY rule of the thumb is at least 5 mA for Laterals and 10 mA for HEXFET
But, yes, I have seen less current in use. Also by Nelson Pass.
2SK170 takes 40 Volt.
I did not think about, forgot, that maybe a cascode would be in place.
Say the power supply puts out, at some time, 2x40 VDC
Unfortunately I have not the exact spice models for those lateral.
I would rather use components I can play with in SPICE
But I have these models:
ECX10N20 ECX10P20
And I have used:
ECF20N20 ECF20P20
ECF10N20 ECF10P20
MiiB.
I use HEXFET this time IRFP240/9240
And they need at least, I have a feeling, 10 mA
and as the MOSFETS are ZETEX ZVP/ZVN3310A = TO-92, 625mW
they do not safely take 35v x 10 mA = 350mW
Well, at least they would get hot.
MY rule of the thumb is at least 5 mA for Laterals and 10 mA for HEXFET
But, yes, I have seen less current in use. Also by Nelson Pass.
2SK170 takes 40 Volt.
I did not think about, forgot, that maybe a cascode would be in place.
Say the power supply puts out, at some time, 2x40 VDC
Some amplifiers using MOSFET will exhibit distortion with mostly 2nd harmonic
and then nicely falling higher harmonics.
This is how TUBES do, too.
In this case MOSFET can come closest to the TUBE SOUND.
It has been descibed as 'warm sound'.
The opposite would be clean, analytic, sound.
But far from all MOSFET amplifiers have mostly 2nd harmonic.
Regarding my published amplifiers in this topic
they have so low THD distortion, that they probably NOT add to sound at all.
But if such amplifier does, it could be a MOSFETish or TUBE sound.
Lineup,
I like the simplicity of this design.
Just before I saw this thread I was working on the design of something very similar in LT spice, but mine had a BJT ltp input. I ended up giving up as I had trouble getting the bias and DC offset set up as the resistor values are always very critical and hard to tweak in the software.
Anyway, if you feel like taking the design a little further I would like to see a version with lower rail voltages and class A operation using IRFP240/IRFP9240 and ZVN/P 3310. All of these parts are available from digikey.
As usual, love your work!
I like the simplicity of this design.
Just before I saw this thread I was working on the design of something very similar in LT spice, but mine had a BJT ltp input. I ended up giving up as I had trouble getting the bias and DC offset set up as the resistor values are always very critical and hard to tweak in the software.
Anyway, if you feel like taking the design a little further I would like to see a version with lower rail voltages and class A operation using IRFP240/IRFP9240 and ZVN/P 3310. All of these parts are available from digikey.
As usual, love your work!
Hi Ontoaba,
You just built an amplifier, not even "finished", and a prototype with bad components, but think that it is the best sounding amp you have ever heard and tried!!
The chances are, you are still far away from the "best", or the amp tricked your ears
Hi Ontoaba,
You just built an amplifier, not even "finished", and a prototype with bad components, but think that it is the best sounding amp you have ever heard and tried!!
The chances are, you are still far away from the "best", or the amp tricked your ears
Hi Ontoaba,
The chances are, you are still far away from the "best", or the amp tricked your ears
I'll more like this amp if it really could trick my ears. BTW, I am never heard very expensive tube amps.I am still using some metalfilm resistor and pp caps and the vas using 2Ssc3956e/2sa1541e. They aren't really bad.
Hi, lineup.
I have problem with the real sound belong to, tubeish, mosfetish, or modern ampish?
Most good sounded modern amplifiers makes my ears sick before reaching 3hour listening with my audax loudspeakers, but it last longer with many small loudspeaker in series-paralel.
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JFET HEXFET HEXFET
This is slightly different version to previous.
Can it be more simple than this to get hifi?
1. One JFET 2SK170 with current feedback
2. Two IRF610 and IRF9610 for volt amp
3. Two IRFP240 and IRFP9240 for current out
Sum 5 transistors!!!!
The amplifier makes like 50 Watt with THD ~0.050%
Image shows 40 Watt out at THD 0.015%
At 1 Watt THD is so low as 0.00068%
This is slightly different version to previous.
Can it be more simple than this to get hifi?
1. One JFET 2SK170 with current feedback
2. Two IRF610 and IRF9610 for volt amp
3. Two IRFP240 and IRFP9240 for current out
Sum 5 transistors!!!!
The amplifier makes like 50 Watt with THD ~0.050%
Image shows 40 Watt out at THD 0.015%
At 1 Watt THD is so low as 0.00068%
Attachments
Of the several designs posted by lineup here to which one are you referring with the comment above ?
cheers
mike
True. What you say.You could also keep the fine zetex mosfets and let them drive a pair of Laterals that has only half the input capacitance... I like this circuit concept....
But as you know there is a shortage of 2SK1058/2SJ162.
I like to help people to get transistors they can more easily find.
And IRFP240/IRFP92440 are pretty much standard.
What I gather, these laterals are now more exotic components.
AKSA, thanks for posting here.
Your word is always something to respect.
Do really IRFP240/9240 have negative tempco above 200mA.
I thought it was only laterals.
If it is possible to simplify the bias circuit, I am open for this.
On the other hand, using this VBE-multiplier does not hurt.
I should say I have tried one version with bootstrap.
To make it even more simple.
It is certainly possible, but I feel better with CCS.
I am a guy hunting low THD. What we call Hifi. To the last decimal.
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swordfishy
I would be happy if someone tried my circcuit in a real project.
Thanks for your interest.
Of course we can run it in 2A or 1.5A.
I suuggest lower supply to +/-25 Volt, with one 2x18VAC transformer.
And increase bias to 1.5A.
This will cost like 75 Watt to dissipate at heatsink.
I would say we keep Q1.
Because it is, I think, more simply.
Otherwise, if we do not use zener, there will be plenty of diodes and LED and trimpot to replace it.
I will post a Class A version with +/-25 Volt for you
I would be happy if someone tried my circcuit in a real project.
Thanks for your interest.
Of course we can run it in 2A or 1.5A.
I suuggest lower supply to +/-25 Volt, with one 2x18VAC transformer.
And increase bias to 1.5A.
This will cost like 75 Watt to dissipate at heatsink.
I would say we keep Q1.
Because it is, I think, more simply.
Otherwise, if we do not use zener, there will be plenty of diodes and LED and trimpot to replace it.
I will post a Class A version with +/-25 Volt for you
I am sure he means the last diagram.
It is also quite a bit different from previous.
I would like to get me the spice models of BUZ900 and complementary.
To use 2SK1058/2SJ162 if people will have to replace is not interesting to me.
And you say there are laterals to find.
Good if this is so.
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