I would appreciate it if anyone can lay out, in layman's terms, the advantage of using these devices or their drawbacks. I am curious as to why they are good or why they suck and can think of no better place than here to receive proper edification.
Profuse thanks in advance to all respondents!
speaker
Profuse thanks in advance to all respondents!
speaker
Sanken's 2SA1216, and its counterpart , the 2SC2922, are ring-emitter transistors.
They also used to be called multi-emitter devices.
Sanken also produces the 2SA1215 and 2SC2921, 150 watt versions.
Nowadays the planar epitaxial technique is solely connected to Sanken.
Sanken produces a great number of other planar epitaxial devices in MT200, e.g. the 2SA1494/2SC3858.
Toshiba produced ring-emitter devices for a relative short period: the 2SA1095 and 2SC2565.
Simply put, a ring-emitter device consists of a great number of transistors on 1 die.
Which translates in a large SOA with an unusual curving, and a very high bandwidth.
The 1216/2922 have a 40 MHz bandwidth, the 1215/2921 do 50 MHZ.
Toshiba's 150 watt 2SA1095/2SC2565 devices even higher at 60 MHz.
High bandwidth translates in high speed, in return this requires less feedback correction.
Less feedback is favorable for low TIM distortion.
Ring-emitter's have a high Hfe, which reduces the current capability of the driver devices, and consequently less current gain from the front end of the amplifier.
These devices are considered the best BJT's.
Besides many Japanese companies, a great many other audio companies have used the ring-emitter's for output stages.
Nelson Pass for a short period on Forte Audio models, Per Abrahamsen in Electrocompaniet power amps.
In Germany companies as Dieter Burmester in his Burmester 828, Reinhard Wachoviak in the Audiolabor Stark.
Here in Holland Johan Ketelaar on his 80's Active I and II, now in his prestige amp.
Best known now in the Zap modules.
Up till a number of years ago ring-emitter's and Sanken 2SA1216/2SC2922 were hard to get and price level was in accordance.
Audio designer/manufacturer Johan Ketelaar told me in the 80s he could only order large quantities of the Sanken's he used in his amps.
Currently prices for Sanken's are very low, seems to me that transistor price level is at the same level as 15 years ago.
http://www.jkacoustics.nl/AmpPrestigePowerAmp.htm
They also used to be called multi-emitter devices.
Sanken also produces the 2SA1215 and 2SC2921, 150 watt versions.
Nowadays the planar epitaxial technique is solely connected to Sanken.
Sanken produces a great number of other planar epitaxial devices in MT200, e.g. the 2SA1494/2SC3858.
Toshiba produced ring-emitter devices for a relative short period: the 2SA1095 and 2SC2565.
Simply put, a ring-emitter device consists of a great number of transistors on 1 die.
Which translates in a large SOA with an unusual curving, and a very high bandwidth.
The 1216/2922 have a 40 MHz bandwidth, the 1215/2921 do 50 MHZ.
Toshiba's 150 watt 2SA1095/2SC2565 devices even higher at 60 MHz.
High bandwidth translates in high speed, in return this requires less feedback correction.
Less feedback is favorable for low TIM distortion.
Ring-emitter's have a high Hfe, which reduces the current capability of the driver devices, and consequently less current gain from the front end of the amplifier.
These devices are considered the best BJT's.
Besides many Japanese companies, a great many other audio companies have used the ring-emitter's for output stages.
Nelson Pass for a short period on Forte Audio models, Per Abrahamsen in Electrocompaniet power amps.
In Germany companies as Dieter Burmester in his Burmester 828, Reinhard Wachoviak in the Audiolabor Stark.
Here in Holland Johan Ketelaar on his 80's Active I and II, now in his prestige amp.
Best known now in the Zap modules.
Up till a number of years ago ring-emitter's and Sanken 2SA1216/2SC2922 were hard to get and price level was in accordance.
Audio designer/manufacturer Johan Ketelaar told me in the 80s he could only order large quantities of the Sanken's he used in his amps.
Currently prices for Sanken's are very low, seems to me that transistor price level is at the same level as 15 years ago.
http://www.jkacoustics.nl/AmpPrestigePowerAmp.htm
Advantage in practice:
- quite rugged devices, confirmed by Eva here.
- high current capability.
- Sanken produces even higher voltage models.
- large sink area, low thermal resistance from case to heatsink.
- double mounting holes, which ensures mounting the device flat to the heatsink.
Downside:
- Mica insulators for MT200 are hard to get and very pricy.
- Up till now i have not seen AL2O3 or Kapton insulators for MT 200 casings.
- quite rugged devices, confirmed by Eva here.
- high current capability.
- Sanken produces even higher voltage models.
- large sink area, low thermal resistance from case to heatsink.
- double mounting holes, which ensures mounting the device flat to the heatsink.
Downside:
- Mica insulators for MT200 are hard to get and very pricy.
- Up till now i have not seen AL2O3 or Kapton insulators for MT 200 casings.
I am currently building the extended leach of Jens Rasmussen with 10 Toshiba 2SA1302/2SC3281 in the output section.
If Jens goes through with redesigning the Super Leach for flatpacks i am doing that one too, trying it both with Toshiba 2SA1095/2SC2565 and with Sanken 2SA1216/2SC2922 in the output.
The front end boards probably will be exactly the same as for the "regular" extended Leach.
The chassis i am building will accept all three version device boards mounted on a separate heatsink as removable modules.
Besides the higher voltage there should not be any difference between the three except the voltage level and the number of output devices.
There seems to be an agreement here that the original Toshiba 2SA1302/2SC3281 that i am using are as good or better as the MJL1302/3281A versions or the Toshiba SA1943/SC5200 .
Reads as those are very popular ones.
To me, the 2SC2922 looks much more linear on its datasheet than the 2SC5200.
On the link i posted you can read the stats on the JK Ultimate amp.
I had the chance to 'hear' those amplifiers, 200 watts in class A on 14 Sanken's per channel, +350 in AB, tremendous current ability.
Nice amps, for a tadd over $20.000(in Holland).
But then, Johan really is a nice guy, so i am not going to put him down.
If you check the Metaxas site you can read that they still use extrem high bandwidth devices.
Same goes for the amplifiers John Curl designs, a few days ago i posted on his JC1 Halo, would not surprise me if the JC1 uses ring-emitters.
Maybe Mr Curl will be kind enough to tell a bit more of his designs some day. He is not going to write a book, he said.
If Jens goes through with redesigning the Super Leach for flatpacks i am doing that one too, trying it both with Toshiba 2SA1095/2SC2565 and with Sanken 2SA1216/2SC2922 in the output.
The front end boards probably will be exactly the same as for the "regular" extended Leach.
The chassis i am building will accept all three version device boards mounted on a separate heatsink as removable modules.
Besides the higher voltage there should not be any difference between the three except the voltage level and the number of output devices.
There seems to be an agreement here that the original Toshiba 2SA1302/2SC3281 that i am using are as good or better as the MJL1302/3281A versions or the Toshiba SA1943/SC5200 .
Reads as those are very popular ones.
To me, the 2SC2922 looks much more linear on its datasheet than the 2SC5200.
On the link i posted you can read the stats on the JK Ultimate amp.
I had the chance to 'hear' those amplifiers, 200 watts in class A on 14 Sanken's per channel, +350 in AB, tremendous current ability.
Nice amps, for a tadd over $20.000(in Holland).
But then, Johan really is a nice guy, so i am not going to put him down.
If you check the Metaxas site you can read that they still use extrem high bandwidth devices.
Same goes for the amplifiers John Curl designs, a few days ago i posted on his JC1 Halo, would not surprise me if the JC1 uses ring-emitters.
Maybe Mr Curl will be kind enough to tell a bit more of his designs some day. He is not going to write a book, he said.
...batches...
I tried to buy the really good sanken parts (2sa1216 etc) about 6 years ago, at that time I was told they were only available 'anytime' as samples and that larger quantity required a bulk purchase (5000+ pairs) or to wait for the next production run, then about every 4 months...a major pain in the derriere for small shops...plus no second source I could find...
my 2c
Stuart
I tried to buy the really good sanken parts (2sa1216 etc) about 6 years ago, at that time I was told they were only available 'anytime' as samples and that larger quantity required a bulk purchase (5000+ pairs) or to wait for the next production run, then about every 4 months...a major pain in the derriere for small shops...plus no second source I could find...
my 2c
Stuart
I can come up with at least 20 brand model names, with proper cerebral massaging.
Quicky:
Rotel RHB10
The poweramp model with the Japan Red wooden sidepanels and closed chimney heatsinks.
200W/8 - 330W/4
Used 8 Sanken's per channel, two 1000VA toroids.
In Germany the Berendsen, Linear Acoustics, and Brinkman power amplifiers.
Islem in France.
btw:
Elektor did a 200 watt car amplifier design several years ago, with the 2SA1216/2SC2922 for outputs.
Including a very powerfull smps.
Quicky:
Rotel RHB10
The poweramp model with the Japan Red wooden sidepanels and closed chimney heatsinks.
200W/8 - 330W/4
Used 8 Sanken's per channel, two 1000VA toroids.
In Germany the Berendsen, Linear Acoustics, and Brinkman power amplifiers.
Islem in France.
btw:
Elektor did a 200 watt car amplifier design several years ago, with the 2SA1216/2SC2922 for outputs.
Including a very powerfull smps.
No real disadvantages circuit-wise except maybe an elevated input capacitance, but still well below that of common MOSFETs.
Other practical disadvantages apply - the transistors are difficult to find and expensive to begin with (although since Allegro has merged with Sanken they can be found through European distributors), which means they are often falsified. Firtunately the case does not lend itself to easy falsification and so far the knock-offs were not extremely difficult to spot, but who knows, things may change...
Other practical disadvantages apply - the transistors are difficult to find and expensive to begin with (although since Allegro has merged with Sanken they can be found through European distributors), which means they are often falsified. Firtunately the case does not lend itself to easy falsification and so far the knock-offs were not extremely difficult to spot, but who knows, things may change...
Here is a picture of the first Nelson Pass amp i owned, the Model 1 Forte Audio.
The amplifier did a great job at my ESL63's, only had a thermal sensor you can see on the left heatsink.
Non-inverting complementary, constant current source differential input, no Zobel
(first sanded alloy front plate amp i had, bit thin maybe )
The amplifier did a great job at my ESL63's, only had a thermal sensor you can see on the left heatsink.
Non-inverting complementary, constant current source differential input, no Zobel
(first sanded alloy front plate amp i had, bit thin maybe
)Attachments
Re: ...oh and...
I owned a Forte Model 4. 200w class-AB. Used the 1302/3281's.
I have seen the Sankens used in higher end Onkyo's, Kenwoods and all of the Denon POA power amps. Very nice sounding, Oh and yes, the Luxman power amps e.g. M-117 of which I own 2 ;-).
Very nice and smooth amp, uses Elna cerafines all over when made in 1987.
Stuart Easson said:
jacco vermeulen said:Here is a picture of the first Nelson Pass amp i owned, the Model 1 Forte Audio.
The amplifier did a great job at my ESL63's, only had a thermal sensor you can see on the left heatsink.
Non-inverting complementary, constant current source differential input, no Zobel
(first sanded alloy front plate amp i had, bit thin maybe
I owned a Forte Model 4. 200w class-AB. Used the 1302/3281's.
I have seen the Sankens used in higher end Onkyo's, Kenwoods and all of the Denon POA power amps. Very nice sounding, Oh and yes, the Luxman power amps e.g. M-117 of which I own 2 ;-).
Very nice and smooth amp, uses Elna cerafines all over when made in 1987.
Hi!
And they were (are) being used by LCAudio of Denmark, in their "The End Millenium" and "Zap" (not the "Zap Pulse") amplifiers, namely the 2SC2922/2SA1216, combined with japanese driver transistors D1763A and B1186A.
Since I own a pair of End Milleniums, and only use one of them as a sub amp, I also tried those devices in a head-to-head comparison in my P3A Stereo amp, compared to MJ15003/MJ15004 (with BJ139/BJ140 as drivers), and to OnSemi MJL4302A/MJL4281A.
I have to admit that I did not hear any differences, apart from the MJL On devices getting hotter than the TO3 MJ15003/15004 or the Sankens, and since R. Elliot recommends the new OnSemi devices, I now stick to them.
Well, and the "End Millenium" design shows, that the Sankens are quite capable of handling more power (higher supply voltage / output power) than the "classic" MJ15003/15004.
But also beware of fakes, yes, there are fake Sankens out there (again, take a look on ESP to see what I mean).
Bye,
Arndt
And they were (are) being used by LCAudio of Denmark, in their "The End Millenium" and "Zap" (not the "Zap Pulse") amplifiers, namely the 2SC2922/2SA1216, combined with japanese driver transistors D1763A and B1186A.
Since I own a pair of End Milleniums, and only use one of them as a sub amp, I also tried those devices in a head-to-head comparison in my P3A Stereo amp, compared to MJ15003/MJ15004 (with BJ139/BJ140 as drivers), and to OnSemi MJL4302A/MJL4281A.
I have to admit that I did not hear any differences, apart from the MJL On devices getting hotter than the TO3 MJ15003/15004 or the Sankens, and since R. Elliot recommends the new OnSemi devices, I now stick to them.
Well, and the "End Millenium" design shows, that the Sankens are quite capable of handling more power (higher supply voltage / output power) than the "classic" MJ15003/15004.
But also beware of fakes, yes, there are fake Sankens out there (again, take a look on ESP to see what I mean).
Bye,
Arndt
Cradle22 said:
With the same circuit parameters i dont think you will hear much of a difference.
imo, high speed output devices enable to design a circuit with a higher closedloop bandwidth.
That does influence sound quality.
Marshall Leach's amplifier originally had a higher bandwidth.
The product of open-loop bandwidth and closed-loop voltage gain is the closed-loop bandwidth.
With the 40 MHz Sanken and 50/60 MHz Toshiba ring-emitter devices in the output of the Leach amplifier i am going to alter the open-loop bandwidth of the circuit and/or the voltage gain.
In full class A with higher bandwidth there should be a difference in sound quality.
Me thinks of a Spectral amplifier in class A.
Going to build the chassis with side/top/back panels in 0.4" Trespa plating, copper foil glued on the inside for shielding.
1" marble for the front plates, copper foil shielding too.
I wonder if anyone here on diy ever used Trespa for chassis building ?
POA2200, POA4400, POA6600 ?
jacco vermeulen said:
Have seen them in the POA 2200, 2400, 2400a (In the 2400a they were the MT200 ones c3858?) and 2800. I am sure they were used in others but these I know for a fact.
the c2922? or c3856 or 58 (MT200) were used in the Luxman M-117 and M-03. 2 pairs in the denons, 3 pairs (MT-200) in the Luxman. All 200wpc amps.
Note :
i am not an audio designer, and this place is filled with megastar Pro's.
I am a ship designer and know a bit or two of the same theories that apply for electronics.
I am currently building the Leach amplifier with Jens Rasmussen's boards, and using the partslist Jens made on Delta-Audio.
Those boards will have 10 Toshiba 2sa1302/2sc3281.
The Super Leach boards will have the ring-emitter output devices.
The mje15032/15033 drivers are ok.
The mje340/350 in the extended Leach design will go for 100MHz 2SA968B/2SC2238B 200volt models. I still have a lot of those.
The MPSA42/92 devices in the front end can stay, these are planar epitaxials also !!!!
If you put 1 mA on the input and trace it down the circuit it will show the open-loop voltage gain.
By changing the collector resistors in the voltage gain stages the open-loop gain changes, in Jens's Leach circuit R2/R21 in the first gain stage, R24+R25/R33+R35 in the second gain stage.
By altering the gain of one of the voltage gain stages bandwidth changes, as bandwidth is total gain times open-loop bandwidth.
Most of the distortion in an amplifier is formed in the driver-output section, because high output devices behave less linear, and because Hfe reduces at higher frequencies.
Feedback reduces the distortion level to an acceptable level.
With high Ft drivers and output transistors open-loop distortion is much lower and reduces the need for feedback, so the feedback numbers can be altered.
Besides Lag correction to limit the slewrate and open-loop bandwidth the Leach circuit has a Lead correction, that raises local gain, in effect raises bandwidth.
The Leach also has somewhat FeedForward, from driver output to power device output.
The feedback in the Leach is partially from the driver section, R8 and C5 in Jens's layout, partially from the output ; R12/R13/R16C12/C13/C9.
With the Sanken and Toshiba devices i mentioned i am altering the values of the sections described above.
For obtaining the open-loop bandwidth you need to read the bandwidth at specific current level on the datasheets of the devices in the circuit.
Me thinks you can read some of the stuff about voltage gain, bandwidth, frequency correction and distortion on Prof. Marshall Leach's homepage.
You can compare the current circuit with earlier versions that had different open-loop figures.
Schmeets in Germany did a couple of lowfeedback and feedforward designs for Elektor, of which i constructed 2, some of the theory for lowtim amps and high speed output devices is explained in those articles.
imo, the Leach and Super Leach are ideal for using high Ft planar epitaxials.
But i am not advertising someone here to do the same for the above mentioned reason.
That is why i did not suggest alterations when Jens did the Extended Leach design thread.
i am not an audio designer, and this place is filled with megastar Pro's.
I am a ship designer and know a bit or two of the same theories that apply for electronics.
I am currently building the Leach amplifier with Jens Rasmussen's boards, and using the partslist Jens made on Delta-Audio.
Those boards will have 10 Toshiba 2sa1302/2sc3281.
The Super Leach boards will have the ring-emitter output devices.
The mje15032/15033 drivers are ok.
The mje340/350 in the extended Leach design will go for 100MHz 2SA968B/2SC2238B 200volt models. I still have a lot of those.
The MPSA42/92 devices in the front end can stay, these are planar epitaxials also !!!!
If you put 1 mA on the input and trace it down the circuit it will show the open-loop voltage gain.
By changing the collector resistors in the voltage gain stages the open-loop gain changes, in Jens's Leach circuit R2/R21 in the first gain stage, R24+R25/R33+R35 in the second gain stage.
By altering the gain of one of the voltage gain stages bandwidth changes, as bandwidth is total gain times open-loop bandwidth.
Most of the distortion in an amplifier is formed in the driver-output section, because high output devices behave less linear, and because Hfe reduces at higher frequencies.
Feedback reduces the distortion level to an acceptable level.
With high Ft drivers and output transistors open-loop distortion is much lower and reduces the need for feedback, so the feedback numbers can be altered.
Besides Lag correction to limit the slewrate and open-loop bandwidth the Leach circuit has a Lead correction, that raises local gain, in effect raises bandwidth.
The Leach also has somewhat FeedForward, from driver output to power device output.
The feedback in the Leach is partially from the driver section, R8 and C5 in Jens's layout, partially from the output ; R12/R13/R16C12/C13/C9.
With the Sanken and Toshiba devices i mentioned i am altering the values of the sections described above.
For obtaining the open-loop bandwidth you need to read the bandwidth at specific current level on the datasheets of the devices in the circuit.
Me thinks you can read some of the stuff about voltage gain, bandwidth, frequency correction and distortion on Prof. Marshall Leach's homepage.
You can compare the current circuit with earlier versions that had different open-loop figures.
Schmeets in Germany did a couple of lowfeedback and feedforward designs for Elektor, of which i constructed 2, some of the theory for lowtim amps and high speed output devices is explained in those articles.
imo, the Leach and Super Leach are ideal for using high Ft planar epitaxials.
But i am not advertising someone here to do the same for the above mentioned reason.
That is why i did not suggest alterations when Jens did the Extended Leach design thread.
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