Hi Jwilhelm, can you also share the 5P OPS BOM? Somebody already posted before but can't find it.
Thanks,
Fred
Thanks,
Fred
Here's a BOM and schematic for the output board. Follow the charts on the bottom of the schematic for different output device options. The 1 watt resistors listed should be 3 Watt.
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thanks jwilhelm
now as winter is coming and more time spent indoors, slewmonster building back on.
now as winter is coming and more time spent indoors, slewmonster building back on.
Hello gentlemen
here are some image of the build of Wolverine and SlewMaster Mini sounds is amazing
I also put in together the SlewMonster 5P for later on 😉
here are some image of the build of Wolverine and SlewMaster Mini sounds is amazing
I also put in together the SlewMonster 5P for later on 😉Attachments
Hey Juan,
That's great. I knew that Slewmaster mini would surprise you. That Wolverine is a beautiful IPS too. Very similar to the Badger which of course is becoming a cult classic do in part to the diy audio store. Nice build!
Blessings, Terry
That's great. I knew that Slewmaster mini would surprise you. That Wolverine is a beautiful IPS too. Very similar to the Badger which of course is becoming a cult classic do in part to the diy audio store. Nice build!
Blessings, Terry
thanks Terry hey sorry to ask too much what would be the maximum rail voltage for the SlewMaster Mini ? I have a 330VA toroid that give me about 53V DC after rectification and filtering 🙂
Hey Juan,
I'd suggest keeping the supply voltage to a maximum of 50V if possible. You might get away with your unloaded 53V rails so long as you don't have a demanding or 'difficult' load (speakers with a wild impedance curve). Amything over 45V should not be used with a 4R load. Hope that helps.
thanks Jason 🙂
then I'm gonna use only lower load only 8 ohms as it right now the rail voltage is on 42V DC and responds really nice
Best Regards
Juan
I would stay with the 42v supply. That is perfect for the mini. 4ohm is no problem. The difference between 42v and 53v is not noticeable unless you are playing very loud you might notice earlier clipping but if you need that much power you really should be using the monster ops anyway.
I'm putting together a Slewmaster with a single 2SC3264 and 2SA1295 MT200 per channel, 72v rails. What would be the best transistors for the other positions.
I'm looking at NJW0281/NJW0302 and KSA916/KSC2316. Will these be good? Thanks!!!
I'm looking at NJW0281/NJW0302 and KSA916/KSC2316. Will these be good? Thanks!!!
72V is too much for a single pair of outputs. You should probably have 3 pairs at least. NJW0281/0302 would work for drivers. The rest of the devices are TO218, not TO92. MJE340 is the best match for the bias spreader.
I was thinking the big dog Sanken MT-200 could handle 72V. Back to trying to wrap my head around this. Thanks!!
I might have to build another slew. Before I built the first one I bought some second hand transformers with wrong voltage. Getting inpatient I bought two new 2x55v 625va trannies to use in the amp.
After I finished the amp I got an email from the seller of the first transformers that he have sent me 2x 800va 2x55V transformers to replace those with too low voltage.
Is there anything to gain by installing these instead of the 625va trannies in my 5p njw0302/0281?
Anyway I'm sitting here with two extra transformers, two extra 5p OPS PCBs and most of the parts to populate them. Is there any reason not to buy some Sankens and try to build something more powerfull? 😛
Can I use NJW0302/0281 as predrivers for sanken outputs?
After I finished the amp I got an email from the seller of the first transformers that he have sent me 2x 800va 2x55V transformers to replace those with too low voltage.
Is there anything to gain by installing these instead of the 625va trannies in my 5p njw0302/0281?
Anyway I'm sitting here with two extra transformers, two extra 5p OPS PCBs and most of the parts to populate them. Is there any reason not to buy some Sankens and try to build something more powerfull? 😛
Can I use NJW0302/0281 as predrivers for sanken outputs?
Njw0302/0281 will work for drivers, but Sanken has some high speed TO3ps that will drop right in too. It's not necessary, but fast is good for drivers.
Sanken MT200 are 250 watt I think. 72 volt rails with make the output of the amplifier in the 300 watt range. To calculate the output device wattage required, add the total of all the devices and divide by 5 ( some divide by 4, but 5 gives you more room for abuse).
3 pairs of MT200 would total 1500 watts. Divide by 5 would equal 300 watts which would be perfect.
For those that want maximum reliability, Ostripper has noticed they run considerably cooler below 65V. This is where I am running mine and the heat sink stays around 35C in normal operation.
Sanken MT200 are 250 watt I think. 72 volt rails with make the output of the amplifier in the 300 watt range. To calculate the output device wattage required, add the total of all the devices and divide by 5 ( some divide by 4, but 5 gives you more room for abuse).
3 pairs of MT200 would total 1500 watts. Divide by 5 would equal 300 watts which would be perfect.
For those that want maximum reliability, Ostripper has noticed they run considerably cooler below 65V. This is where I am running mine and the heat sink stays around 35C in normal operation.
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Actually none are 250W, well at least these from digikey. Have to check sanken site to see if any at all.
Transistors (BJT) - Single | Discrete Semiconductor Products | DigiKey
I know Semelab make a 300 & 400W in a TO-264
You're right. They are actually rated for 200W, but the SOA lets them far exceed the power of normal 200W transistors safely.
So I check Sanken 2sc3264 against Semelab MG6330(200W), hardly a diff in SOA.
Then I check against MG6331(300W), big improvement.
As advertised in the spec
"Highest Current audio bipolar available on the market with widest Safe Operating Area in TO-3P package"
Then I check against MG6331(300W), big improvement.
As advertised in the spec
"Highest Current audio bipolar available on the market with widest Safe Operating Area in TO-3P package"
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So are you going to build a 5 pair Semelab slewmaster? Should be good with 100V rails. That would likely be the king of the Slewmasters.