Jason and Valery,
So given a choice would you rather use the three pairs of mosfet or hexfet devices over the five pairs as originally designed? I do remember you guys working out the bias scheme and was wondering if you compared the original design to this other option you both built. If not for the power differences in output and SOA is there any real difference in the sound of the final implementations? Thanks for the responses in advance.
So given a choice would you rather use the three pairs of mosfet or hexfet devices over the five pairs as originally designed? I do remember you guys working out the bias scheme and was wondering if you compared the original design to this other option you both built. If not for the power differences in output and SOA is there any real difference in the sound of the final implementations? Thanks for the responses in advance.
Hi Kindhornman, my personal opinion - there may be different ones - IRFP option sounds better in low loop gain configurations. For example, I've got a tube-based front-end, assuming no global feedback loop at all. In this case you hear all distortion products of the output stage "as-is". MOSFET option sounds better here, having somewhat "softer", less noticeable, crossover distortion.
In high loop gain designs, you will most likely not distingwish between BJT and MOSFET output stages in A/B test. IRFPs have got relatively high non-linear input capacitance, but being driven from a powerful enough EF driver stage, it does not hurt at all.
The other advantage of IRFPs - they are extremely rugged, robust devices. I used this OPS in "dangerous" experiments, with violent oscillations, having the output shorted to the rail with DMM lead (with certain damage to the lead
) - those tough guys survived. So, they are always welcome to my test bench
Cheers,
Valery
In high loop gain designs, you will most likely not distingwish between BJT and MOSFET output stages in A/B test. IRFPs have got relatively high non-linear input capacitance, but being driven from a powerful enough EF driver stage, it does not hurt at all.
The other advantage of IRFPs - they are extremely rugged, robust devices. I used this OPS in "dangerous" experiments, with violent oscillations, having the output shorted to the rail with DMM lead (with certain damage to the lead
) - those tough guys survived. So, they are always welcome to my test bench Cheers,
Valery
thank you for this
i as well as other newbie's need this kind of info. this build is a daunting task for me. knowing nothing of the terms used or ability to read schematic's or even when others state testing items they call them . wow a lot to take in .
the building of this amp board really should have a instruction wrote up .
the people who will turn away from a build due to fear of it's complexity are great.
i'm there as well but one differance, nobody on this planet is going to stop me from having a pair of killer 10 times over built high power mono blocks, period.
i got some bad news today my order for the 2 toroid's has been lost.
tracking as we speak
guys my boards arrived today and i have goose bumps holding them. they are the best quality i have ever seen. i had no idea they would be audio gold. who ever made these boards should have a website setup for selling of these . i mean guys any of you just watching, this jump in, you will not be expecting the quality of these boards.
i'm very excited now to get this going.
thank you terry from the bottom of my heart.
http://[URL=http://s400.photobucket.com/user/91owner/media/Slew%20Monster%20Amp%20Build/slew%20monster%20amp%201.jpg.html]
http://[URL=http://s400.photobucket.com/user/91owner/media/Slew%20Monster%20Amp%20Build/slew%20monster%20amp%202.jpg.html]
i'm very excited now to get this going.
thank you terry from the bottom of my heart.
http://[URL=http://s400.photobucket.com/user/91owner/media/Slew%20Monster%20Amp%20Build/slew%20monster%20amp%201.jpg.html]
An externally hosted image should be here but it was not working when we last tested it.
[/URL]http://[URL=http://s400.photobucket.com/user/91owner/media/Slew%20Monster%20Amp%20Build/slew%20monster%20amp%202.jpg.html]
An externally hosted image should be here but it was not working when we last tested it.
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I re-drew the art work and I also put a pile of boards in the hands of builders. The boards you have came from one of the members here who used my files to have them made. The designs are Ostrippers; those boards are just my spin on the layout. I have posted the files needed to have boards made but I'm not currently distributing the boards myself.
well then let me say thank you.
these came from still4given/ terry
he was great gentleman very helpful
how do i find a list of parts?
still4given (Terry) is very much a kind soul and very prolific builder on this here forum.
There hasn't been any real BOM for these boards. Most items are pretty generic and that means you can just build off the schematic.
Most resistors can be 1/4W unless you see a larger footprint on the board, in which case you need a larger unit. The semiconductors on the schematics are usually the recommended ones, though substitutions are possible. Just mind the pin-out of the devices.
Should there be questions, don't hesitate to ask. I prefer to do a little hand-holding and assist in a slow but successful build than have to do a bunch of remote diagnostics and troubleshooting on a rushed build. There's a number of us who have built the OPS and different IPSs, so genuine help is available.
Here's wishing you the best in your build!
Some resources >HERE<
Also check ostripper's signature link as I believe he has archived the 'final' versions of his designs and his toner transfer PCB artwork.
Just a note. I checked ostripper's archive and he has put the CFA-X v1.2 there but not the CFA-XH v1.3 which is the version of the schematic you need to reference for the boards you have, linked above.
Also check ostripper's signature link as I believe he has archived the 'final' versions of his designs and his toner transfer PCB artwork.
Just a note. I checked ostripper's archive and he has put the CFA-X v1.2 there but not the CFA-XH v1.3 which is the version of the schematic you need to reference for the boards you have, linked above.
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Hi Gordie,
You need to poke around the threads related to the project a little, there's lots of information that is already posted. I know the main thread is pretty big one but that is where you will get the lion's share of the information and will be worth some of your time picking through it. You will see the progression that will help you see why certain choices were made in the various designs.
The SlewMaster is a DIY effort at it's finest but it is not at this point documented fully in one neat concise package. You have to do a little digging for the information, though there's nothing too difficult about it overall. It looks tougher than it really is.
Ostripper's site is linked in his profile signature, but for convenience you can find it >HERE<.
As already pointed out, the SlewMonster is just the biggest of the OPS boards. We just like to have some fun with playful names
.
ok thanks guysHi Gordie,
You need to poke around the threads related to the project a little, there's lots of information that is already posted. I know the main thread is pretty big one but that is where you will get the lion's share of the information and will be worth some of your time picking through it. You will see the progression that will help you see why certain choices were made in the various designs.
The SlewMaster is a DIY effort at it's finest but it is not at this point documented fully in one neat concise package. You have to do a little digging for the information, though there's nothing too difficult about it overall. It looks tougher than it really is.
Ostripper's site is linked in his profile signature, but for convenience you can find it >HERE<.
As already pointed out, the SlewMonster is just the biggest of the OPS boards. We just like to have some fun with playful names
but see im 52 and have been at a audio mind blown state since 8 years old .
but i'm as new as a teen age boy here with this. when i read through the post it's over my head.
you guys are miles ahead of me on this subject.i have no idea what os talks about. he may as well be talking another language .
i am a so new person to slew. about 1 month ago , i opened up the site and looked at solid state for the first time, i don't know why but looked at the build page and saw jwilhelm amp.it was love at first site. with his use of air plane scrap aluminum. instantly i was taken with this stunning sexy chassis.
this image will be in my mind till i have no more days.
so back up a bit, before i saw this i was in the final stages of a pair of 300b dual set mono blocks build. tube has been my focus for 10 years.
a solid state amp build was farthest from my mind.
so that kind of new. not knowing enough even to know what questions to ask.
i 'm so overwhelmed looking at all this it's scary.
but all i need too see is these boards to know the blood , sweat and tears that went into this design. this is serious and not a toy.
how do you guys know what values of caps and resistors to order?
i have the heatsinks ordered and the 625va toroid if they ever are found.
12 10000uf 100v caps and hexfets. so well on the way.
sorry to be so green
gordie
Gordie,
If you aren't afraid to work with the voltages of a 300B amplifier this should be a cake walk. There have been many different combinations put together with these boards and except for one input section there have been no real problems at all. The values for the components are on the schematic, just follow that and you should be good to go. If you can't find a particular part just ask and someone will give you alternative part number that will work just as well. This is a first class amplifier and you would have to spend thousands of dollars to match this quality if they are even this good. Just think of it as a modern day high tech HeathKit project.
Steven
If you aren't afraid to work with the voltages of a 300B amplifier this should be a cake walk. There have been many different combinations put together with these boards and except for one input section there have been no real problems at all. The values for the components are on the schematic, just follow that and you should be good to go. If you can't find a particular part just ask and someone will give you alternative part number that will work just as well. This is a first class amplifier and you would have to spend thousands of dollars to match this quality if they are even this good. Just think of it as a modern day high tech HeathKit project.
Steven