What do you guys think is the best BJT's for use in output stages where rails approach 90v? I'd prefer responses limited to flatpak types i.e. not TO-3's but instead to TO-3P's , TO-3PL's, MT-200's etc.
Here are some devices I researched and will welcome responses from anyone with experience with these.
• PS Audio AC Generators have rails of 105vdc and use MJL21193/94.
• Toshiba has the 150 watt replacement for the Ubiquitous 2sc3281/A1302 that many in the Industry used, i.e. Mr. Pass in the Forte amps, Bob carver in his Sunfire’s etc. These are higher volt (Vce=230) and are 2sc5200/2sa1943.
• Toshiba’s own 180 watt version of the above (also Vce=230) the 2sc5359/2sa1987.
• Kenwood used custom Sanken Devices in their M2/M2a (and their other DLD class-G amps) and were 15Amp 210vce devices called DAT1521N/P
• Sanken’s well known 2sa1295/2sc3264 pair. 200w 17A and 230vce.
• Any other devices?
• What does Krell use? Is it a variant of the old MJ15024/25 that is now upgraded as the MJ21195/96?
Thanks!!
Here are some devices I researched and will welcome responses from anyone with experience with these.
• PS Audio AC Generators have rails of 105vdc and use MJL21193/94.
• Toshiba has the 150 watt replacement for the Ubiquitous 2sc3281/A1302 that many in the Industry used, i.e. Mr. Pass in the Forte amps, Bob carver in his Sunfire’s etc. These are higher volt (Vce=230) and are 2sc5200/2sa1943.
• Toshiba’s own 180 watt version of the above (also Vce=230) the 2sc5359/2sa1987.
• Kenwood used custom Sanken Devices in their M2/M2a (and their other DLD class-G amps) and were 15Amp 210vce devices called DAT1521N/P
• Sanken’s well known 2sa1295/2sc3264 pair. 200w 17A and 230vce.
• Any other devices?
• What does Krell use? Is it a variant of the old MJ15024/25 that is now upgraded as the MJ21195/96?
Thanks!!
Needing such a high output power, have you considered using class-G?
I've ripped some waveforms from audio CDs and simulated power dissipation of a standard class AB circuit driving a resistive load and being feed by these waveforms
Results were outstanding, with +-120V supply and at clipping threshold, power efficiency was about 30% while with +120V,+80V,+40V,-40V-80V,-120V it approached 80-90%
In practice Class-G with music waveforms has power efficiencies comparable to class-D and class-B or AB linearity [It could also be implemented in class-A, anybody tried this?]
Also, when driving reactive loads it's useful to let the positive rail drop under 0V and the negative rail to rise over 0V since this reduces dissipation, improves reliability [SOA] and allows the reactive load to actually return some energy back to the power supply instead of being fully transformed into heat in the output devices
As output devices I prefer Sanken or Toshiba since the rugged style of Motorola usually means using very big dies and making slower devices with huge B-E and C-E capacitances, with large turn-on delays and turn-off current tails that need lots of frequency compensation to lower the frequency-bandwith product of the amplifier and get decent phase margin and little oscillation when recovering from clipping or at zero-crossing with high slew rates [testing the circuit fulll power at 20Khz with some clipping reveals all these things]
Capacitances can be easily measured and compared
Tip: false devices appear to have 15% to 50% of the capacitance found in the original devices and opening them you can see the smaller die size used [I bought some false Sanken 2SC3264 and Toshiba 2SC3281 & 2SA1302 some time ago, false devices marked as Toshiba or Sanken appear to be common those days]
I've ripped some waveforms from audio CDs and simulated power dissipation of a standard class AB circuit driving a resistive load and being feed by these waveforms
Results were outstanding, with +-120V supply and at clipping threshold, power efficiency was about 30% while with +120V,+80V,+40V,-40V-80V,-120V it approached 80-90%
In practice Class-G with music waveforms has power efficiencies comparable to class-D and class-B or AB linearity [It could also be implemented in class-A, anybody tried this?]
Also, when driving reactive loads it's useful to let the positive rail drop under 0V and the negative rail to rise over 0V since this reduces dissipation, improves reliability [SOA] and allows the reactive load to actually return some energy back to the power supply instead of being fully transformed into heat in the output devices
As output devices I prefer Sanken or Toshiba since the rugged style of Motorola usually means using very big dies and making slower devices with huge B-E and C-E capacitances, with large turn-on delays and turn-off current tails that need lots of frequency compensation to lower the frequency-bandwith product of the amplifier and get decent phase margin and little oscillation when recovering from clipping or at zero-crossing with high slew rates [testing the circuit fulll power at 20Khz with some clipping reveals all these things]
Capacitances can be easily measured and compared
Tip: false devices appear to have 15% to 50% of the capacitance found in the original devices and opening them you can see the smaller die size used [I bought some false Sanken 2SC3264 and Toshiba 2SC3281 & 2SA1302 some time ago, false devices marked as Toshiba or Sanken appear to be common those days]
Nice,
I have never seen 350vce BJT's for Audio use. Looking at the part numbers, they seem eerily similar to 1302/3281
It is also a 35MHz part. One of the few power devices that go that high... I have heard that the Custom parts Dan D'Agostino ordered from Motorola were 35Mhz parts. These may be downstream products out of that product developement... i am just guessing but this is a nice find!
thanks Dine1967!
I have never seen 350vce BJT's for Audio use. Looking at the part numbers, they seem eerily similar to 1302/3281
It is also a 35MHz part. One of the few power devices that go that high... I have heard that the Custom parts Dan D'Agostino ordered from Motorola were 35Mhz parts. These may be downstream products out of that product developement... i am just guessing but this is a nice find!
thanks Dine1967!
Joan2,
One of the best selling Class-G amps (in Absolute volume) are the Kenwood DLD amps. This includes the following integrateds:
KA-770D
KA-880
KA-1100
KA-2200
KA-3300
And power amps
M1/M2 series.
and ofcourse one of the most sought after Japanese integrated (Actually its not integrated because the PSU unit is separate) is the Kenwood L-02a (1983 circa) they still go over $1000 on eBay if you see one.
The M2's are 220watts into 8 ohms and are great for experimenting, you can get these as low as $200 on ebay and play around. They feature medium NFB and a high damping factor of 1000. For the money, they make great subwoofer amps on a eer budget.
One of the best selling Class-G amps (in Absolute volume) are the Kenwood DLD amps. This includes the following integrateds:
KA-770D
KA-880
KA-1100
KA-2200
KA-3300
And power amps
M1/M2 series.
and ofcourse one of the most sought after Japanese integrated (Actually its not integrated because the PSU unit is separate) is the Kenwood L-02a (1983 circa) they still go over $1000 on eBay if you see one.
The M2's are 220watts into 8 ohms and are great for experimenting, you can get these as low as $200 on ebay and play around. They feature medium NFB and a high damping factor of 1000. For the money, they make great subwoofer amps on a eer budget.
I guess I should have made it more clear.. what I should have said was that I have not seen any class-G DIY designs for guys like us, but I have has good success modding those Kenwood amps.
They are weak in the PSU section and that can be improved up etc. Just by making the M2 PSU more beefy i.e. 1.5kVa will increase the power from 220wpc to over 350 wpc into 8E.
Peace!
They are weak in the PSU section and that can be improved up etc. Just by making the M2 PSU more beefy i.e. 1.5kVa will increase the power from 220wpc to over 350 wpc into 8E.
Peace!
I guess Bridge Amps cannot be used as common ground amp. E.g. with the Polk SDA-SRS 1.2TL speakers I have.
Also the damping is half of a regular stereo amp (if it matters.)
Lastly distortion is slightly more than regular amps for the same power.
However in the defense of bridge amps, I think the sound is less grainy.
Also the damping is half of a regular stereo amp (if it matters.)
Lastly distortion is slightly more than regular amps for the same power.
However in the defense of bridge amps, I think the sound is less grainy.
K-amps
In my opinion, the right amps bridged are just better than a single amp....
Maybe damping factor is lower in bridge amps, however using bridged amps with each 700-1000 in damping factor, the factor is still good and you benefit of the doubbled raise time V/uS
Also if you build your own bridged amplifier you can benefit of the lower costs for PSU, as you use thge power of both the negative and the positive rail at the same time (and not only one at a time)
In my opinion, the right amps bridged are just better than a single amp....
Maybe damping factor is lower in bridge amps, however using bridged amps with each 700-1000 in damping factor, the factor is still good and you benefit of the doubbled raise time V/uS
Also if you build your own bridged amplifier you can benefit of the lower costs for PSU, as you use thge power of both the negative and the positive rail at the same time (and not only one at a time)
Damping factor
Jan, in bridge mode is output impedance twice bigger. If you hear diferences, it is not about output impedance, but about analyse of harmonic distortion, which is in this case different. Better than bridge mode ( by my experiences ) is biamping, 'cos give lower intermodulation distortion and human ear is much more sensitive for this.
Jan, in bridge mode is output impedance twice bigger. If you hear diferences, it is not about output impedance, but about analyse of harmonic distortion, which is in this case different. Better than bridge mode ( by my experiences ) is biamping, 'cos give lower intermodulation distortion and human ear is much more sensitive for this.
By the way guys check this news bulletin:
Big gains for audio-output transistors
A new family of audio bipolar transistors boasts the highest voltages available in the industry.
The MJL4281A (NPN) and MJL4302A (PNP) audio-output transistors provide the maximum amplification of an input signal currently available from a single transistor.
These devices were designed with the high power demands required in high-end audio applications, including professional audio amplifiers, theatre and stadium sound systems, and public address systems (PAs).
The MJL4281A (NPN) and MJL4302A (PNP) are 15A, 230W PowerBase power transistors that feature 350V collector-emitter sustained voltage.
Competitive devices available for these applications are only available up to 230V.
The devices deliver high bandwidth and high-gain linearity.
The devices feature an excellent safe operating area (SOA) allowing 1.2A collector current and 100V at 1s enabling high bandwidth and clean, low-distortion output.
With uniform linearity from 0.1 to 5A the devices deliver accurate reproduction of input signal.
High gain (80 to 250) results in greater amplification of output signal.
The MJL4281A and MJL4302A amplifiers are offered in the TO-264 package and priced at $1.85 per unit in 10,000-unit quantities.
Drivers to complement these high voltage output transistors also have been released.
The MJE15034 and MJE15035 are available in TO-220 packages priced at $0.36 per unit in 10,000-unit quantities.
Big gains for audio-output transistors
A new family of audio bipolar transistors boasts the highest voltages available in the industry.
The MJL4281A (NPN) and MJL4302A (PNP) audio-output transistors provide the maximum amplification of an input signal currently available from a single transistor.
These devices were designed with the high power demands required in high-end audio applications, including professional audio amplifiers, theatre and stadium sound systems, and public address systems (PAs).
The MJL4281A (NPN) and MJL4302A (PNP) are 15A, 230W PowerBase power transistors that feature 350V collector-emitter sustained voltage.
Competitive devices available for these applications are only available up to 230V.
The devices deliver high bandwidth and high-gain linearity.
The devices feature an excellent safe operating area (SOA) allowing 1.2A collector current and 100V at 1s enabling high bandwidth and clean, low-distortion output.
With uniform linearity from 0.1 to 5A the devices deliver accurate reproduction of input signal.
High gain (80 to 250) results in greater amplification of output signal.
The MJL4281A and MJL4302A amplifiers are offered in the TO-264 package and priced at $1.85 per unit in 10,000-unit quantities.
Drivers to complement these high voltage output transistors also have been released.
The MJE15034 and MJE15035 are available in TO-220 packages priced at $0.36 per unit in 10,000-unit quantities.
Oh boy they are lower:
2sc5200 =$1.54
2sa1943= $1.68
www.matchakbob.com
they have the best prices i have seen for semi-conductors, forget MCM and Digikey...
have fun!
2sc5200 =$1.54
2sa1943= $1.68
www.matchakbob.com
they have the best prices i have seen for semi-conductors, forget MCM and Digikey...
have fun!
Hi K-amps,
can you send me some of you your ADCOM and Kenwood power amps schematics please...thanks...my email: tonytecson@yahoo.com
can you send me some of you your ADCOM and Kenwood power amps schematics please...thanks...my email: tonytecson@yahoo.com
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