I'm not the brightest bulb here, but I've seen the "Sanken cheating at 10...12V" argument before.
Even without the measurements showing that Sanken was better even at 5 V, it's the second time I'm telling why Sanken is not cheating.The FT measurements should actually be done around 50...100V to be really relevant because these transistors are supposed to work at high VCE and the sinus signal slew rate is maximum when crossing zero point , being minimum at VCE=5V.
Stability or minimum phase shift is required around crossover point where the VCE and slew rate are at their maximum values.
I wonder what would people would have said if they'd show the FT at VCE=80 V...
Actually I have no ideea why they'd show those measurement at such voltages unless they'd aim these transistors for class D amps or pwm switching circuits or class C short wave RF amplifiers which I believe was a more relevant field of application for these transistors than audio amplifiers.In that case I'd say they made the measurements where it really counts.12 V is usually the car's inverter's and long distance car or stationary radio stations usual voltage .
Thus...aren't we actually talking about rebranded switching transistors for audio? Something like ths6012 vs tpa6120 datasheet...
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You may fall foul of trade restrictions or sanctions either in trade or payment. Now if you bought them from a non-sanctioned reseller that is reselling their own stock that's different. I'm noticing a large amount of Chinese originating stock disappearing from resellers that is marked "restricted availability" and hence can't be shipped to the UK.
EF80 supposedly manages 100MHz with ~5pF of capacitance.. that Russian mosfet is 470pF collector capacitance but doesn't list gate characteristics. So perhaps as common gate it may work at 100MHz.. but perhaps not for all forms of amp?
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Datasheet says it's bipolar transistor...
Nope. The amplifier must be stable at the worst case operating point of output devices. That's low Vce and high current. This worst case point determines what the open loop unity gain frequency and compensation will be. If you compensate an amplifier only according to the output devices operating point at 0V output and no current, then ULGF will be too high, and it may oscillate near clipping.
Sorry been staring at mosfets data sheets and SOA diagrams for the last three days. Think I need a sanity check.
Which makes my point of these measurements being aimed at class d or switching circuits cause any good amplifier should be provided with antisaturation circuits so that you won't get into hard clipping.
If Sanken was aiming audio amplifier market yet it still had the best transistors(for which measurements I'm thankful too) at 5V then why would they specify for 12 volts?
On the other hand at the peak of a sinus waveform the slew rate is next to zero so bandwith requirements seem to be ridiculously overrated next to saturation region and actually slower transistors may get gradually slower into hard clipping making it a soft knee , but still 200kHz FT for some of the slower germanium transistors is 10 times more than 20khz.
Ch2 is dc coupled and triggered in the zcd area.You have the symbols describing that in the image.
I'm not talking about clipping, but what happens before clipping. If your supply voltage is 35V and it's outputting 30V, then Vce will be 5V.
No idea.
Stability of the amplifier is a property of the amplifier, not a property of the signal being amplified. If the amp is compensated taking only into account the speed of output transistors in the best case (high Vce) then it will oscillate when the transistors get slower at low Vce (high output voltage/current). An amplifier that is only stable with some input signals is not a stable amplifier.
It's the residual from a distortion analyzer, with the input fundamental removed.
Maybe it's not about a 5 V VCE applied on a linear amplifying transistor, but about a 12...24 V switching inverter operation...Most of Sanken production was aimed at inverters and switchers so I think they just used same setups for measurements for all of their production.Usually high power transistors (400...30 000V/100...100mA) are slower and are done with different processing so maybe these transistors were just made in the low voltage transistors manufacturing facilites where they usually make the high speed switching transistors so they wouldn't care about making different measurements than for let's say 30 V 100 amps transistors.Seeing an old Sony car amp using 100Mhz npn high power transistors in the inverter section and complementary 60 (pnp)and 70 mhz (npn)sanken trz in the audio section made me think if actually the audio 70 mhz npn trz were chosen from a 100mhz switching trz batch that disn't pass all the tests.The slower the trz the higher the max VCE can be , the faster rf trz having max Ft has also the lowest VCE. Now we all know RF amps and inverters very rarely exceed 48V supply...
Those VL035DP and VL035DN transistors can be bought from one seller for 1000 ₽ for a complementary pair, but buyers beware!
The more interesting part is the info text claiming these transistors to be Ring Emitter Transistors (RET), or more exactly Siemens RET as they put it, but I can't find much related to Siemens, Fujitsu at least have manufactured RET's.
https://market.yandex.ru/product--tranzistory-vl035dp-i-vl035dn-para/1766082442
These transistors are also discussed here where RET is mentioned again:
https://rcl-electro.ru/threads/siret-транзисторы-Новые-Русские.32/
The more interesting part is the info text claiming these transistors to be Ring Emitter Transistors (RET), or more exactly Siemens RET as they put it, but I can't find much related to Siemens, Fujitsu at least have manufactured RET's.
https://market.yandex.ru/product--tranzistory-vl035dp-i-vl035dn-para/1766082442
These transistors are also discussed here where RET is mentioned again:
https://rcl-electro.ru/threads/siret-транзисторы-Новые-Русские.32/
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Tta1943 ttc5200 are quite fast 30mhz . With good gain . Highly recommended for audio
hah you are right, actually I got the robot challenge pop-up when I reload the web page, but on Firefox I only had to tick the box left to the Я не робот and it let me by, on Brave it would in addition ask for typing in Cyrillic, I have installed Cyrillic on my Linux machine but it never worked in the past... until now I just discovered it actually works.
But for the rest, you can copy and paste one by one the corresponding Cyrillic character.
:DА Б В Г Д Е Ё Ж З И Й К Л М Н О П Р С Т У Ф Х Ц Ч Ш Щ Ъ Ы Ь Э Ю Я
а б в г д е ё ж з и й к л м н о п р с т у ф х ц ч ш щ ъ ы ь э ю я
алмаз широком )
To see the images in Post #46 you need to look at the distortion output of a Distortion Analyzer, such as Sound Technology 1700B or similar. Channel 1 is the amplified signal and Channel 2 is the crap that isn't supposed to be there.
Craig
Craig
Or you might look into Silicon Carbide Mosfets, they have very low gate capacitance and low On resistance so should be very fast in switching. And they can handle a lot of heat and current.
On second thought, I'm not going to try them. fT at high current drops too much.
About SiC MOSFETs: there is no P channel, gm is low, and Rth is high.
peufeu, I had to look a second time where the gain bandwidth ft curves you mentioned are because they are not visible in my version of the datasheet dated 2022-07-25, then I see in post #7 a slight difference for only the VL035DN datasheet which has a ft curve, yes I agree, being a 150 Watt device it falls earlier at higher currents comparison to some other, but I see those other transistor ft curves you added in an earlier post #26 are on the other hand "very poor" in comparison at very low currents, at 100 mA they are down to some 20 MHz, while these specialties are still hovering around some respectable 90 MHz, at least the NPN version for now as the PNP datasheet says nothing except for the fixed data at Vce 10, Ic 1A, a difference to keep in mind too.
I am thinking like Mr Pass, the first Watt is what counts, then if an amplifier from there on degrades at higher wattage is less important (maybe I'm making wrong assumption here?) as listening to high sound pressure the fidelity of the music is anyway becoming naturally distorted/altered by other factors such as our ears due to its involuntary muscle contraption that start to tense on the ear drum and change the perception etc., and not the least it's also unpleasant too.
Well, one can argue for and against which is more preferable, having high ft down to the lowest currents (which may be important for lower crossover distortion?), or at the other side of the spectrum, for what it's worth these mysterious transistors (NPN) are pushing well enough up to at least couple and a half of Amps which should be good for some 50 Watts output which is plenty for many listeners.
I am thinking like Mr Pass, the first Watt is what counts, then if an amplifier from there on degrades at higher wattage is less important (maybe I'm making wrong assumption here?) as listening to high sound pressure the fidelity of the music is anyway becoming naturally distorted/altered by other factors such as our ears due to its involuntary muscle contraption that start to tense on the ear drum and change the perception etc., and not the least it's also unpleasant too.
:)Well, one can argue for and against which is more preferable, having high ft down to the lowest currents (which may be important for lower crossover distortion?), or at the other side of the spectrum, for what it's worth these mysterious transistors (NPN) are pushing well enough up to at least couple and a half of Amps which should be good for some 50 Watts output which is plenty for many listeners.