Why so? You want it a classic or mosfets shake your cage more nowadays ?
I’m in the middle of the battle with the output fets. Still a long way to go to decide what I like most in my boo.
The pucks having a higher transconductance means they will give a lower output impedance, correct?
as I wrote, not so cryptic - main role of specimen amp is to involve salivating and solvent peeing from target group
target group is, in most cases, bunch of mindless idiots with common general character flaw of more thinking about sound than foot tapping/enjoying in music
most important decisive factor is type of speakers they're using , and full mos is able to make nail singing
as i said several times - I'm personally blessed - equally enjoying diametrically different amps - those being THD generator and those having minuscule THD ....... under condition that 2nd is dominant
I share your appreciation of both types of amp ZM; the 2nd harmonic dominant profile certainly seems to contribute something that a lot of people like. In a similar way vinyl seems to add something (don’t know exactly what) that a lot of people find engaging despite its limitations vs digital. Re the other type of amp, I also have some Neurochrome amps that have so vanishingly small amounts of distortion that I doubt you can hear it at all, and that has its own appeal as it produces an open window effect that makes everything sound, well, realistic. It’s for that reason that a Wolverine is also in my future.
when you have combined N channel MOS with P channel MOS in output, these are so-so very similar devices, and their contribution to output signal is pretty much the same
(some luck we have, N channel and P channel IXYS pucks are not having equal xconductance, so we end up with some asymmetry of their action, resulting in mild dominant 2nd, in OS itself)
heck, everyone is craving to/about symmetry
when you combine two dissimilar parts in output, they have unequal contribution to output signal, thus THD is rising
and , combining SIT with MOS is special case of inequality - as proven before, SIT is actually working antiphase/against MOS, and speaker is getting not sum of their currents, but difference
that's why I called DEFiSIT (Papa's Papa of Them All) and all my derivatives of it - ∀ Class amp
and yes, besides SIT, only Schaded Mosfet is showing same behavior, when combined with straight mos
Schaded mosfet - tricky to drive (as is in general, penalty paid in HF), when applied in quasi DEF arrangement, is getting significant drive though source, sorta grounded gate; fact is that we are driving gate of P channel mosfet, while source of mos is directly driving source of Schaded part......... and gate of same is practically bolted (through cap DC charge) to mosfet gate
huh
Ouroboros, someone?
(some luck we have, N channel and P channel IXYS pucks are not having equal xconductance, so we end up with some asymmetry of their action, resulting in mild dominant 2nd, in OS itself)
heck, everyone is craving to/about symmetry
when you combine two dissimilar parts in output, they have unequal contribution to output signal, thus THD is rising
and , combining SIT with MOS is special case of inequality - as proven before, SIT is actually working antiphase/against MOS, and speaker is getting not sum of their currents, but difference
that's why I called DEFiSIT (Papa's Papa of Them All) and all my derivatives of it - ∀ Class amp
and yes, besides SIT, only Schaded Mosfet is showing same behavior, when combined with straight mos
Schaded mosfet - tricky to drive (as is in general, penalty paid in HF), when applied in quasi DEF arrangement, is getting significant drive though source, sorta grounded gate; fact is that we are driving gate of P channel mosfet, while source of mos is directly driving source of Schaded part......... and gate of same is practically bolted (through cap DC charge) to mosfet gate
huh
Ouroboros, someone?
Did I said ?
All Ouroborosessss are equal, just some Ouroborosesss are more equal.........
All Ouroborosessss are equal, just some Ouroborosesss are more equal.........
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Interesting, so if we had a bunch of Sony and Yamaha VFETs lying around, we could probably find a driver that is more closely aligned to the Tokins in its parameters and end up with a low THD amp?
I.e., the Tokins themselves aren't inherently sugary, we just have a small grocery store with limited selection of ingredients..?
🙂
I.e., the Tokins themselves aren't inherently sugary, we just have a small grocery store with limited selection of ingredients..?
🙂
Babelfish XA252 SIT isn't enough low THD amp?
and no, I have no intention to further complicate my complicated (even if great and interesting and fully hedonistic) life with quasi complementary SIT OS amp
if going to symmetry, there are many cheaper, more equal parts on disposal
and having SIT(s) in amp just to say it's in, ZM No Habla Audiophoolery that good
and no, I have no intention to further complicate my complicated (even if great and interesting and fully hedonistic) life with quasi complementary SIT OS amp
if going to symmetry, there are many cheaper, more equal parts on disposal
and having SIT(s) in amp just to say it's in, ZM No Habla Audiophoolery that good
Oh, don't get me wrong. I'm not bothered by THD -- I mean, I use the SissySIT as my primary music enjoyer. 🙂
I intend to build the XA252 as a complement.
I'm moreso curious just how much of an amp's THD profile arises from the output device itself. Sounds like its probably like 99% based on implementation as opposed to output devices?
I intend to build the XA252 as a complement.
I'm moreso curious just how much of an amp's THD profile arises from the output device itself. Sounds like its probably like 99% based on implementation as opposed to output devices?
well, everything counts .....
I mean , major thing in each amp is nothing else than starting idea, concept, mental image combined with ntended level of not just sense of achievement but also sense of achievement
as I wrote before (somewhere on first page of this thread)...... ha, shortest is just to quote Mighty ZM itself:
I had everything, but intended level of sense of achievement wasn't fulfilled
that was the reason why first one was abandoned, and that was the reason why this one happened afterwards
as in many human activities, this one ( which isn't Dialysis, as we know) is practically clogged with generalizations, some of them being true, some of them being less true (depending of context) and some of them being never true
now, if you take any of well known books about amps or audio electronic in general, great possibility is that you took one written by clever and smart guy; any of them is already having covered anything I could just try to explain ( with my level of knowledge and lack of any formal education in the field) but you can be also sure in few important facts:
so, moral of the story, if making amps isn't your daily job, take it as fun; learn simple things, combine them, you'll able to grasp bigger things then to combine them, engrossing the pool of things/blocks/ideas familiar to you ..... after some time, having an amp and using it isn't main goal anymore ( from the moment when you already have at least one, to listen to), but main thing becomes working on something with your brain
or you can simply embrace my approach to construction :
I mean , major thing in each amp is nothing else than starting idea, concept, mental image combined with ntended level of not just sense of achievement but also sense of achievement
as I wrote before (somewhere on first page of this thread)...... ha, shortest is just to quote Mighty ZM itself:
Few years ago, we had enormous fun in funny named thread : F4 Beast Builders
Well, you can call it Group of Hysteric Housewives Brainstorming
Result of that was that I had myriad of back of napkin sketches, and after these I started simulating ...... and simulating ... and simulating
After myriad of sims ( out of sheer enthusiasm I even made pcb files for some of iterations), I finally had made nice smallish channel pcbs, containing OS having different-ish approach to biasing than Papa's original XA25, while FE was in principle same as Papa's, but with few beautiful quirks, of which I was damn proud (yup, Mighty ZM reinventing Da Wheel, time and time again)
And they were sitting, populated, on my shelf ........ always being pushed to bottom of list; I knew they would work, but somehow I wasn't content with overall picture
I had everything, but intended level of sense of achievement wasn't fulfilled
that was the reason why first one was abandoned, and that was the reason why this one happened afterwards
as in many human activities, this one ( which isn't Dialysis, as we know) is practically clogged with generalizations, some of them being true, some of them being less true (depending of context) and some of them being never true
now, if you take any of well known books about amps or audio electronic in general, great possibility is that you took one written by clever and smart guy; any of them is already having covered anything I could just try to explain ( with my level of knowledge and lack of any formal education in the field) but you can be also sure in few important facts:
- no book written having covered it all
- every author is writing from his point of view and by his intellectual agenda
so, moral of the story, if making amps isn't your daily job, take it as fun; learn simple things, combine them, you'll able to grasp bigger things then to combine them, engrossing the pool of things/blocks/ideas familiar to you ..... after some time, having an amp and using it isn't main goal anymore ( from the moment when you already have at least one, to listen to), but main thing becomes working on something with your brain
or you can simply embrace my approach to construction :
I said "before" retirement ha ha. If I'm on my feet I will be building something! But not be as often
Oh, but this is dangerous. >:]
First, to try and figure out how to complete this bridge across both peaks at Mt. Kilimanjaro...
Appreciate the shop talk, ZM.
I just needed to solder the green LED since mid December to finish the board but had a few other problems to deal with. I got round to it today and powered up the board. A green light and no magic smoke 😊 I will set the bias and 0v tomorrow.
I see you implemented TO247 pads, just in case
with those, you practically have Plethora of Pinjatas amp
They were for testing but went for the big guns. Would I need to change much to use irfp150’s?
well, IRFP240 (or IRFP150, if you want to play with THD Spectra) up, IRFP9140 down
no other change than rails down to 24Vdc, Iq no more than 1A8
everything as explained in link above
no other change than rails down to 24Vdc, Iq no more than 1A8
everything as explained in link above