according to website designed for amplifiers , anyone used them and do they sound
Any good, which ones for use in Pass amps F6, alpha j or F5.
Any good, which ones for use in Pass amps F6, alpha j or F5.
They sound fantastic. They are also very easy to use because the bias current can be set using a resistor and a pot, i.e., there isn’t a thermal runaway. It remains stable.
They have lower gain than verticals so they cannot be just dropped into designs where there is gain (F5) without other changes. But they could be used in follower output stages. They don’t even need source resistors.
I have been using them in a Mofo style amp with success. I’m calling it Elmo, as in L-Mo or Lateral Mofo 🙂 . Hope to post something on it soon.
They have lower gain than verticals so they cannot be just dropped into designs where there is gain (F5) without other changes. But they could be used in follower output stages. They don’t even need source resistors.
I have been using them in a Mofo style amp with success. I’m calling it Elmo, as in L-Mo or Lateral Mofo 🙂 . Hope to post something on it soon.
As ZM said, not suitable for use in most PASS amps except for F7. They can't be dropped in anyway, since the have a different pinout.
One big drawback is the drive requirement. It needs a beefy driver with low output impedance, otherwise it can sound tinny.
There is still 2sk2013/2sj313 around swap meet (@tamra reliable source), true beast to drive these 😁 Smaller numbers though... And also obsolete, fqp3n30/3p20 probably in more quantities. And still very obtainable IRF610 / 9610.
I think pops wrote somewhere he had designed an f5 version for these lats.
I think pops wrote somewhere he had designed an f5 version for these lats.
I use [Toshiba] laterals in my F5, even without a source resistor. Three in parallel.
I used them in my "Mirror Magic" amp, which sounded pretty good at Burning Amp 2019.
The thread is here - the actual "Mirror Magic " part is near the end of the "Le Mutant" thread.
The "Mirror Magic" part of the "Le Mutant" post is from post 50 onward...
The thread is here - the actual "Mirror Magic " part is near the end of the "Le Mutant" thread.
The "Mirror Magic" part of the "Le Mutant" post is from post 50 onward...
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I used complementary BJT followers to drive the lateral outputs of my "Mirror Magic" amplifier. You can see the followers on post #54 of the "Le Mutant" thread, which is here:
Having said that, I never got around to implementing the boost supply. One channel of the amplifier is out currently, possibly due to an open input cable. The channel started out intermittent, then cut off entirely. When I get around to it, I'll cobble a new input cable together and see if it fixes the problem.
Having said that, I never got around to implementing the boost supply. One channel of the amplifier is out currently, possibly due to an open input cable. The channel started out intermittent, then cut off entirely. When I get around to it, I'll cobble a new input cable together and see if it fixes the problem.
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Check out Erno Borbeley’s old articles on power mosfet amps. He drove the laterals with PP BJT or mosfet followers. I recall about 30 mA of drive current in the follower stage preceding the laterals for getting 100W output. That might be a good number to shoot for, though it probably varies with the specific devices. Erno also provides the method for calculating the drive requirement, using slew rate needed at 20 kHz, given the input capacitance of the lateral. I’ve gotten decent sound with 10-20 mA with a follower driving a single lateral with choke load. @kevinkr has been playing with them and may have more specific recommendations.
Recommend looking at FAB's USSA 3 , 3.2 and 5 .
He used dual die Exicon's , ECW20n20 and ECW20p20 's so output MOSFET's are matched .
The transconductance is relatively low on these , so he's used driver MOSFET's to increase this .
... and they sound amazing .
Go with a dual power supply with 2 x 300 VA transformers with a minimum of 2 x 120,000 uF .
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