Lateral MOSFET = 'Audio Application MOSFET'
Vertical MOSFET = 'Industrial MOSFET'.
The main benefit of Audio Application MOSFET is a simpler BIAS circuit, because no temperature compensation and almost no Gate DC offset is required.
These two factors have to be contemplated when using industrial MOSFET. On the other hand the industrial MOSFET's have many benefits compared to Audio Application ones. Higher power, lower price, better availability etc.
The Audio Application MOSFET's generally cost 2-3 times more than industrial type ones, and have less power handling capability. Since the problems associated with using industrial MOSFET's are adressed and solved in the ZETA design, there is no reason to consider Audio Application MOSFET's for this amplifier. 🙂
BUZ902DP USD 14.30 ea (@100) 16A 250W (lateral)
IRFP260N USD 1.5 ea (@100) 49A 300W (vertical)
😎
Vertical MOSFET = 'Industrial MOSFET'.
The main benefit of Audio Application MOSFET is a simpler BIAS circuit, because no temperature compensation and almost no Gate DC offset is required.
These two factors have to be contemplated when using industrial MOSFET. On the other hand the industrial MOSFET's have many benefits compared to Audio Application ones. Higher power, lower price, better availability etc.
The Audio Application MOSFET's generally cost 2-3 times more than industrial type ones, and have less power handling capability. Since the problems associated with using industrial MOSFET's are adressed and solved in the ZETA design, there is no reason to consider Audio Application MOSFET's for this amplifier. 🙂
BUZ902DP USD 14.30 ea (@100) 16A 250W (lateral)
IRFP260N USD 1.5 ea (@100) 49A 300W (vertical)
😎
When MOSFETs first came out, there were all of lateral types because that was the prevailing technology back then. Because of the shallow channel, they couldn't handle much current.
Today, most people have moved away from lateral types to vertical types. And audio use of MOSFET is getting rare.
As such, Verticals benefit from economy of scale.
In this case, prices do not correlate well with quality.
I use all vertical types and haven't had any problem so far.
As to negative temp co., I do not believe there is any inherent reason that verticals cannot be made to switch temp co at low current. It is just that for their applications (high current switching), such a "merit" may not be desirable.
Today, most people have moved away from lateral types to vertical types. And audio use of MOSFET is getting rare.
As such, Verticals benefit from economy of scale.
In this case, prices do not correlate well with quality.
I use all vertical types and haven't had any problem so far.
As to negative temp co., I do not believe there is any inherent reason that verticals cannot be made to switch temp co at low current. It is just that for their applications (high current switching), such a "merit" may not be desirable.
Hi,
a bit too simplistic but consider a vertical mosfet as a very Hi impedance, very Hi bias requirment, Hi speed version of a BJT with a larger capacitor across the input.
Then it works or can be made to work in most designs.
The down side is trying to find a complementary matching pair.
a bit too simplistic but consider a vertical mosfet as a very Hi impedance, very Hi bias requirment, Hi speed version of a BJT with a larger capacitor across the input.
Then it works or can be made to work in most designs.
The down side is trying to find a complementary matching pair.
Lars,
I still want to make the 800 to1000w 4 ohm version of the ZETA with 10pairs of IRFP250s will you HELP me ?
I am impressed by your design and the low price , specks and easy availibility of the IRFP250 here
The amp will be useful for my small touring sound system here .
I still want to make the 800 to1000w 4 ohm version of the ZETA with 10pairs of IRFP250s will you HELP me ?
I am impressed by your design and the low price , specks and easy availibility of the IRFP250 here
The amp will be useful for my small touring sound system here .
Lars..........................
Any update on the ZETA 320 yet..................schems for web site?????
Any update on the ZETA 320 yet..................schems for web site?????
ZETA PCB's.........?????????
I am interested in the ZETA 320 PCB's that have been disscussed. Any word yet?
Gav
I am interested in the ZETA 320 PCB's that have been disscussed. Any word yet?
Gav
ZETA...320
I´m been lurking around on diyaudio for some time now and I think that many DIY:ers is eager to see the schematics and maybe the layout of the ZETA 320.. A small (footprint) and not so costly but powerful amp is what i´ve been looking for a long time. I´m not an EE and trial and error is my way but i´ve lerned a lot from this forum alone and the ZETA sounds viable and affordable to me..
Really looking forward for an update of oliveaudio.com and the ZETA 320
/Martin Sahlin.
I´m been lurking around on diyaudio for some time now and I think that many DIY:ers is eager to see the schematics and maybe the layout of the ZETA 320.. A small (footprint) and not so costly but powerful amp is what i´ve been looking for a long time. I´m not an EE and trial and error is my way but i´ve lerned a lot from this forum alone and the ZETA sounds viable and affordable to me..
Really looking forward for an update of oliveaudio.com and the ZETA 320
/Martin Sahlin.
I'm just a newb, but the schematic is very simple. Why should it be a big problem not using a PCB for this, but to just wire the amp?
keeping the leads short can't be so hard!
keeping the leads short can't be so hard!
Lars Clausen said:
Is this distinction really due to some inherent differences between the two types of devices or it is mostly due to history as the lateral types were the ones first available ("older technology")?
My recollection is that MOSFETs (lateral types back then) were quite popular when they first came out but people gradually realized problems using those devices and started to cool off. Then vertical types were invented at that time.
Had vertical types were first to the market, we might be calling them "audio application MOSFETs".
I'll try to get someone to help with designing a board for the 1000W version 
Well as said, only fans are practical for the high power version. what would be an ideal distance between MOSFETs?
Well as said, only fans are practical for the high power version. what would be an ideal distance between MOSFETs?
Hi´Lars, when can we expect, the schematic for the single transistor pair version, to be ready?
Someone please post the updated schematic...I will design PCB..have opinions...redesign...finalise...:
I think mr. Lars Clausen is too busy in some new designing thats why he doesn't pays much attention on high powered version of Zeta , because it would not earn him the lovely Euros.....simply the wastage of his precious time...
Just wait, he said he will post it and i think he is going to as soon as he will have time..
Im waiting for it too, but im sure everyone wants to do his work first before free time stuff.
Im waiting for it too, but im sure everyone wants to do his work first before free time stuff.
The THD of the ZETA is inversly proportional to the bias current, as a result of the low feedback factor.
At 120 mA you cross the 0.1% THD line, this is measured with 300 mA BIAS.
So i guess for other than bass use, you should run it at fairly high BIAS.
At 120 mA you cross the 0.1% THD line, this is measured with 300 mA BIAS.
An externally hosted image should be here but it was not working when we last tested it.
So i guess for other than bass use, you should run it at fairly high BIAS.
THD without load and the associated Vgs curve in the signal path.
Around 0.003%
Around 0.003%
An externally hosted image should be here but it was not working when we last tested it.
Lars,
This is to be my first audio amplifier projects, So please help for...
I am very much interested in making ZETA, with IRF250N X 4 for use in Midrange of Active System. As this amp has a good flare in Mids.
Can i use MPSA42 & MPSA92 in place of 2n4501 & 2n5550, as i dont know the hfe for MPSA Transistors.
How to set the bias, ie. 40-80ma to be checked at the source resistors.
Rajeev,
I would be very thanful if you can mail me the PCB layout, as i don't wanna run into problems associated wiyh oscillations due to improper PCB Layout.
This is to be my first audio amplifier projects, So please help for...
I am very much interested in making ZETA, with IRF250N X 4 for use in Midrange of Active System. As this amp has a good flare in Mids.
Can i use MPSA42 & MPSA92 in place of 2n4501 & 2n5550, as i dont know the hfe for MPSA Transistors.
How to set the bias, ie. 40-80ma to be checked at the source resistors.
Rajeev,
I would be very thanful if you can mail me the PCB layout, as i don't wanna run into problems associated wiyh oscillations due to improper PCB Layout.