Srajans review is finished now....
blue moon award
https://6moons.com/audioreview_articles/firstwatt-sit5/5/
blue moon award
https://6moons.com/audioreview_articles/firstwatt-sit5/5/
like Playboy magazine the only thing interesting in it is the Pictures
This is what Srajan writes ( I couldn't cut and paste his text.. I had to take a "picture". You tell me what it means.... (*)
Is the SIT5 then operating some kind of a high bit rate or is it sort of like the FET is filling it's holes one at a time and thus creating a voltage quantum gradient energy flow copacetic with the FE so that the Tokin steps in to fill in like the City Hall workers used to fix potholes in the Windy City in the Days Of Daly?
Has Nelson Pass perhaps managed to undo Leibniz's "natura non facit saltus" claim? Has Nelson invented a new "electronic calculus" that combines macro-quantum ion flow with a negative continuous rate of energy dispersion? Maybe Nelson has a bunch of French knives in his closet and he went "chop chop" happy one saturday evening and.. lo and behold... the sound of F5... Does the Iron Chef own a pair of F5s?
Honestly, I got no clue what Srajan writes about anymore.
God forbid he starts using a Japanese knife.... like a Santoku.. Will that make it so because Tokin is a Japanese device? Or maybe he's saying that the F5 mushes the potatoes instead of making hash browns... ?
Must be the fine Irish whiskey, I reckon.
Anyhow, I just wish the F5 weren't so expensive.... hmmm..... Maybe if I create my own Audio Review Site.... Zon Of Zenaudio... I might get some F5s from FW for an extended review. I'm sure I can come up with all kinds of uptown purty words too.. I got a theasurus somewhere... maybe use some Audio Reviewer AI machine...
(*) Mind you, trained as a physicist, I usually can successfully straddle the worlds of philosophy and engineering... but as Srajan gets older, he's become a bit more obtuse. He's gone into the realm of science fiction prose like Bradbury.
Is the SIT5 then operating some kind of a high bit rate or is it sort of like the FET is filling it's holes one at a time and thus creating a voltage quantum gradient energy flow copacetic with the FE so that the Tokin steps in to fill in like the City Hall workers used to fix potholes in the Windy City in the Days Of Daly?
Has Nelson Pass perhaps managed to undo Leibniz's "natura non facit saltus" claim? Has Nelson invented a new "electronic calculus" that combines macro-quantum ion flow with a negative continuous rate of energy dispersion? Maybe Nelson has a bunch of French knives in his closet and he went "chop chop" happy one saturday evening and.. lo and behold... the sound of F5... Does the Iron Chef own a pair of F5s?
Honestly, I got no clue what Srajan writes about anymore.
God forbid he starts using a Japanese knife.... like a Santoku.. Will that make it so because Tokin is a Japanese device? Or maybe he's saying that the F5 mushes the potatoes instead of making hash browns... ?
Must be the fine Irish whiskey, I reckon.
Anyhow, I just wish the F5 weren't so expensive.... hmmm..... Maybe if I create my own Audio Review Site.... Zon Of Zenaudio... I might get some F5s from FW for an extended review. I'm sure I can come up with all kinds of uptown purty words too.. I got a theasurus somewhere... maybe use some Audio Reviewer AI machine...
(*) Mind you, trained as a physicist, I usually can successfully straddle the worlds of philosophy and engineering... but as Srajan gets older, he's become a bit more obtuse. He's gone into the realm of science fiction prose like Bradbury.
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do not put Bradbury's name in same sentence with any FiFi periodics
He was honest man, SciFi writer, with not much redundant words.
anyhow, regarding sound report and everything, choose what you like more ........ either 42 or Papa's sentence "How it sounds ? Darn good."
He was honest man, SciFi writer, with not much redundant words.
anyhow, regarding sound report and everything, choose what you like more ........ either 42 or Papa's sentence "How it sounds ? Darn good."
What is 42?
Yeah, I trust Pass' ears. If he says it sounds "darn good" I figure it does. Most of us in these forums like that kind of sound.
Funny eh? One says "darn good", the other goes off about kitchen knives...
Bradury's prose did not have many redundant words... but his prose was flowery and convoluted -in a nice way. He painted things in the mind of the reader.
It took Bradbury a page to describe something while Asimov or China Miéville take half a paragraph to do the same thing.
I wonder how manufacturers deal with audio reviewers... the old StereReviewPhile crew was reasonable, they always mixed the words with the measurements... but others went off the rails.
Yeah, I trust Pass' ears. If he says it sounds "darn good" I figure it does. Most of us in these forums like that kind of sound.
Funny eh? One says "darn good", the other goes off about kitchen knives...
Bradury's prose did not have many redundant words... but his prose was flowery and convoluted -in a nice way. He painted things in the mind of the reader.
It took Bradbury a page to describe something while Asimov or China Miéville take half a paragraph to do the same thing.
I wonder how manufacturers deal with audio reviewers... the old StereReviewPhile crew was reasonable, they always mixed the words with the measurements... but others went off the rails.
I'm biased here
As long their writing contributes to Papa's stash of greenies, I'm good
Happy Pa, happy Greedy Boyz
though, I'm Wee Boy, looking at pics, no reading
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Hey, there is nothing wrong with the F5 amp... Certainly always worth a mention even if by accident... However, the SIT amps have this wonderful ease and naturalness to them that is so precious. Engineers have worked so hard to achieve the type of sound that the SIT comes by so intrinsically.
Update:
Here is my current schematic. It's still changing as I listen and experiment.
Here are my thoughts on adjusting the source to source resistor and series output. I played with 2 ohms source to source which reduced the gain. I didn't need more than 1.5v there so I just went with 1 Ohm and I like the sound.
I'm trying to keep the harmonics the same for 4 and 8 ohms with even spacing. Here are some examples .55 ohms, .7 ohms, 1.1 ohms and 1.65 ohms. I'm currently at .84 ohms.
The 1.65 ohms is close to the 20% but i don't care for the sound. Maybe I'm not measuring it correctly. Also as I'm running the 1.65 ohm tests I can see the H2 drop below the H3. crossing to the other side of the load line.
The sound is quite nice, different from my Tokin choke loaded or MU followers.
Here is my current schematic. It's still changing as I listen and experiment.
Here are my thoughts on adjusting the source to source resistor and series output. I played with 2 ohms source to source which reduced the gain. I didn't need more than 1.5v there so I just went with 1 Ohm and I like the sound.
I'm trying to keep the harmonics the same for 4 and 8 ohms with even spacing. Here are some examples .55 ohms, .7 ohms, 1.1 ohms and 1.65 ohms. I'm currently at .84 ohms.
The 1.65 ohms is close to the 20% but i don't care for the sound. Maybe I'm not measuring it correctly. Also as I'm running the 1.65 ohm tests I can see the H2 drop below the H3. crossing to the other side of the load line.
The sound is quite nice, different from my Tokin choke loaded or MU followers.
I made an affirmation in the past when Generg asked how to measure, the affirmation was wrong.
To calculate the contribution of mosfet you need to look at the current at its source pin.
This current is the sum of the current that runs through the resistors that are between the sources and also the resistors that are in series with the cap.
Also to mention that those groups of resistors is in parallel one with the other and for the resistor values that you have in your schematic total R is ~0.46r. It could be that you go class ab with such a low value and only 1.5a bias. You can monitor the voltage drop on the power resistor in the rc filter of the ps and see if it changes and how much.
It is good to adjust the vds of sit at the highest power that you target into both 4r and 8r and try to keep the higher harmonics as low as possible. Then see if you like what you get at 1w 🙂)
I have been playing with an output stage in LTSpice and I have been looking at the current through the two output capacitors as a way of checking the contribution of the SIT and mosfet to the output.
According to the output plot, the current through C4 (SIT) was 363mA peak, through C7 (mosfet contribution) was 147mA peak. Total current was 510mA so the mosfet contributed 29% in this example. I hope that this is the correct interpretation.
According to the output plot, the current through C4 (SIT) was 363mA peak, through C7 (mosfet contribution) was 147mA peak. Total current was 510mA so the mosfet contributed 29% in this example. I hope that this is the correct interpretation.
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Before someone tells me that the voltage regulator in the simulation is not working, I know it isn't. This sim originally had a 63V power supply. When I changed the supply to 44V, I did not change the zener string accordingly. 🤓
Ben.. at U1S you have a summing node, the signal from U1 and also the signal from M1 so C4 will pass the sum.
Check also at the sources to see what is happening and compare.
Check also at the sources to see what is happening and compare.
This plot shows peak to peak currents that I extracted.
The speaker (R8) was 1019mA. C4 was 719mA and C7 was 299mA, for a total of 1018mA.
At U1 (SIT) source it was 274mA, and at M1 (Mosfet) source it was 750mA.
The speaker (R8) was 1019mA. C4 was 719mA and C7 was 299mA, for a total of 1018mA.
At U1 (SIT) source it was 274mA, and at M1 (Mosfet) source it was 750mA.