All I really need now is some serious electronics to go with the speaker development. That is why this thread has caught my eye, you have done what I can't do, I could have had a simple monolithic amp done long ago but wasn't satisfied with that approach. I have plenty of 3886 chips but never found a way to make them work well enough and Bridged 3886 was the idea but nobody seems to be happy with that approach. If you look carefully you will see a usb connector on the back. I was thinking of adding an internal dsp so you could play directly from any source, also looked at some CSR Bluetooth technology but may save all that for a follow up model.
ps. Now, Back to work on a lens I am designing for a lighting application. A tessellated lens combined with a divergent lens. A real pain to draw in my cad system.
pps. Now you can understand why I wanted to give you some sort of royalty for your input and anyone else who has helped to get this thing to market. I do plan on selling a lot of these and want them to be the best I can do and at a price that the average man can afford. Not cheap definitely but not going to put an audiophile price on these speakers.
ps. Now, Back to work on a lens I am designing for a lighting application. A tessellated lens combined with a divergent lens. A real pain to draw in my cad system.
pps. Now you can understand why I wanted to give you some sort of royalty for your input and anyone else who has helped to get this thing to market. I do plan on selling a lot of these and want them to be the best I can do and at a price that the average man can afford. Not cheap definitely but not going to put an audiophile price on these speakers.
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thanks os
my speakers are diy 3 ways 4 6.5 woofers focal 4" utopia mid and dynaudio d28 tweeter in each . these are sitting at nominal 10.8 ohm so it does take a little lift in power to use .
now i don't ever use 250 watt or 300 watt but these amps are going for the highest rms output safely.
i don't care about the irfp if they are not the best solution .
i just want a schematic that fits the board i have and use the mosfet it was designed for period.
i don't want to change or alter or modify any part. board has 5 positions and 5 positions it will have
thanks guys
gordie
Hi Gordie,
I built two pair of the OPS with five pair MJL3281/1303, one pair with 5 pair MJL4281/4302 and one pair IRFP240/9240. I can hear no difference between them. Any of them will give you more power than you will ever need for your speakers. The easiest path is with the BJT devices. That is what the boards were designed for so there are no modifications necessary and they have been proved many times over. OS did his homework on these.
I built two pair of the OPS with five pair MJL3281/1303, one pair with 5 pair MJL4281/4302 and one pair IRFP240/9240. I can hear no difference between them. Any of them will give you more power than you will ever need for your speakers. The easiest path is with the BJT devices. That is what the boards were designed for so there are no modifications necessary and they have been proved many times over. OS did his homework on these.
GKF,
If you are going to use the mosfets you have to make changes. The boards are meant for bjt transistors. If you don't care about not using what you already ordered then go with the bjt's and order the parts that are listed on the boards. this was the original intent. The mosfet versions were just a modification that was done by a couple people while we waited for OS to come back on line for a couple of months.
If you are going to use the mosfets you have to make changes. The boards are meant for bjt transistors. If you don't care about not using what you already ordered then go with the bjt's and order the parts that are listed on the boards. this was the original intent. The mosfet versions were just a modification that was done by a couple people while we waited for OS to come back on line for a couple of months.
Yes , that one is 99% correct.
When I actually built them (and others did) , we found that R113 -68R
is best at 120-150R - keeps the drivers cooler.
It would run as posted - just a tad hot (drivers).
And the main Vbe adjustment limiter (R107) , I used 390R - which
made a stock trimmer (R106) , without adjustment ... a perfect
0 mv when I first powered up the output stage.
On all 4 of my OPS's , I just ran the drivers first with two 68R's
feeding the NFB on my "wolverine" input stage.
All 4 worked first time - I have 3 different combinations of semis
on these output stages , but they all worked perfect/flawless.
Then after setting my voltage across the drivers to 1.1V , all
the main output trannies were populated - again , flawless.
OS
Output transistors
Here is a list of usable transistors that are not obsolete, however some may not be stocked by most distributors.
I am also sticking to only listing Bipolar transistors for the time being, even though several builders have had success modifying the design to use MOSFETS.
Please let me know if there are any additions to be added, or if there are any mistakes.
I have removed MJL21193/4, for being too slow for the SlewMaster. They can still be used, but more compensation is needed.
Sanken MT-200 packages are extra wide (37mm) and will require skipping outputs on the 5 or 3 pair boards to be usable.
I have put in bold outputs that have been successfully used in at least one SlewMaster build. The Sanken and Semelab parts look to have the best specs, but can be hard to find. On semi MJL4281/MJL4302 are the next best thing, and almost all suppliers stock them.
Toshiba: (avalable from Mouser and Digikey)
2SC5200/2SA1943 230V 150W 30MHz TO-264
2SC5242/2SA1962 230V 130W 30MHz TO-3P
Fairchild: (avaliable from Mouser and Digikey)
FJL4315/FJL4215 Toshiba 2SC5200/2SA1943 clone
FJA4313/FJA4213 Toshiba 2SC5242/2SA1962 clone
On Semi: (avalible from Mouser, Digikey, and Newark/Farnell)
NJW0281/NJW0302 250V 150W 30MHz TO-247
NJW3281/NJW1302 250V 200W 30MHz TO-247
MJL3281/MJL1302 250V 200W 30MHz TO-264
MJL4281/MJL4302 350V 230W 35MHz TO-264
Semelab: (avalible from Profusion and Newark/Farnell)
MG6330/MG9410 230V 200W 35MHz TO-3P
MG6330-R/MG9410-R 260V 200W 35MHz TO-3P
MG6331/MG9411 230V 300W 35MHz TO-3P
MG6331-R/MG9411-R 260V 300W 35MHz TO-3P
MAG6332/MAG9412 230V 400W 35MHz TO-264
MG6333-R/MG9413-R 260V 400W 35MHz TO-264
Sanken: (available from Digikey, Profusion, and Newark/Farnell)
2SC6145A/2SA2223A 260V 160W 35MHz MT-100/TO-3
2SC3263/2SA1294 230V 130W 35MHz MT-100/TO-3P
2SC3264/2SA1295 230V 200W 35MHz MT-200
2SC3519/2SA1386 160V 130W 40MHz MT-100/TO-3P (70V rails max)
2SC2922/2SA1216 160V 200W 40MHz MT-200 (70V rails max)
2SC2921/2SA1215 160V 150W 50MHz MT-200 (70V rails max)
2SC3284/2SA1303 150V 125W 50MHz MT-100/TO-3P (60V rails max)
Here is a list of usable transistors that are not obsolete, however some may not be stocked by most distributors.
I am also sticking to only listing Bipolar transistors for the time being, even though several builders have had success modifying the design to use MOSFETS.
Please let me know if there are any additions to be added, or if there are any mistakes.
I have removed MJL21193/4, for being too slow for the SlewMaster. They can still be used, but more compensation is needed.
Sanken MT-200 packages are extra wide (37mm) and will require skipping outputs on the 5 or 3 pair boards to be usable.
I have put in bold outputs that have been successfully used in at least one SlewMaster build. The Sanken and Semelab parts look to have the best specs, but can be hard to find. On semi MJL4281/MJL4302 are the next best thing, and almost all suppliers stock them.
Toshiba: (avalable from Mouser and Digikey)
2SC5200/2SA1943 230V 150W 30MHz TO-264
2SC5242/2SA1962 230V 130W 30MHz TO-3P
Fairchild: (avaliable from Mouser and Digikey)
FJL4315/FJL4215 Toshiba 2SC5200/2SA1943 clone
FJA4313/FJA4213 Toshiba 2SC5242/2SA1962 clone
On Semi: (avalible from Mouser, Digikey, and Newark/Farnell)
NJW0281/NJW0302 250V 150W 30MHz TO-247
NJW3281/NJW1302 250V 200W 30MHz TO-247
MJL3281/MJL1302 250V 200W 30MHz TO-264
MJL4281/MJL4302 350V 230W 35MHz TO-264
Semelab: (avalible from Profusion and Newark/Farnell)
MG6330/MG9410 230V 200W 35MHz TO-3P
MG6330-R/MG9410-R 260V 200W 35MHz TO-3P
MG6331/MG9411 230V 300W 35MHz TO-3P
MG6331-R/MG9411-R 260V 300W 35MHz TO-3P
MAG6332/MAG9412 230V 400W 35MHz TO-264
MG6333-R/MG9413-R 260V 400W 35MHz TO-264
Sanken: (available from Digikey, Profusion, and Newark/Farnell)
2SC6145A/2SA2223A 260V 160W 35MHz MT-100/TO-3
2SC3263/2SA1294 230V 130W 35MHz MT-100/TO-3P
2SC3264/2SA1295 230V 200W 35MHz MT-200
2SC3519/2SA1386 160V 130W 40MHz MT-100/TO-3P (70V rails max)
2SC2922/2SA1216 160V 200W 40MHz MT-200 (70V rails max)
2SC2921/2SA1215 160V 150W 50MHz MT-200 (70V rails max)
2SC3284/2SA1303 150V 125W 50MHz MT-100/TO-3P (60V rails max)
On the comment just made about only being able to use three of the five positions for the Sanken MT-200 package I have a theoretical question. If you offset the mt-200 device so that they all weren't on the same plane, so that you could install all five pairs, and you used a block of aluminum between the two offset pairs so that they could attach to the same heat sink as the other three pairs would the difference in the path length of the heat path to the main finned heat sinks cause serious problems with matching the bias settings of the devices? Would it matter or would the slight difference in path length to cool the devices be inconsequential. Again, this is just a theoretical question.
There's too muc heat to dump with them that close together. 1.8" centers are likely the limit. The center device runs warmer at that distance.
Me either. I went to the MT200S because Newark had them on sale rediculously cheap. Three of them aren't really working with a 4 ohm dummy load.
that is great news guys
now i can feel good about going forward with mjl bjt's
ordered the 20 mjl today as well as all related parts for all 4 boards.
terry thank you in case i didn't say it before for the cfa schematic .
that one easy as pie to get a list.
now if my lost toroid's ever show up.
thanks brother
you got me started here with this build and i wish to thank you.
while i'm at it thank all of you for having patience with my lack of knowledge.
you all have assisted me more then you know.
can any of you tell me what 2 marked holes are? has me wondering g2 at both ends.
Hi Gents,
I posted on the other thread yesterday and was directed here.
I'm wanting to do some of this stuff too. Like GKF I am a tube
guy, tube head, tuby, what have you...and I"m interested in building
this stuff and listening to it.
I've been gathering some modest test gear, some old and some new
not bad stuff. Distortion Analyzers, Frequency Generators, Power Supplys
that kind of stuff and some newer budget stuff, FFTs etc for making plots,
LCR meter, etc, that is just gets the job done for the money spent.
Some pretty good stuff for what we are working on. Most all of it
I've repaired with a lot of help from the good folks at other forums
on DIY.
It's old and new, modernized, it as best as I can, or got it working
when it hasn't been working. I probably have a bit more to do on some pieces
but what the heck.
Most of the Hi-Fi gear that is tube gear I have works fine. It's old but
quality stuff.
Most of the Hi-Fi gear that I have that doesn't work fine, or doesn't work
is solid state stuff. Some of it is old and quality stuff, some of it is new
shitty stuff, it is what it is.
Most of the Music Instrument stuff I have it tube gear and its about
1/2 and 1/2 working or non working....it's quality stuff.
I'm trying to let you know where I'm coming from with this, not to be a gear slut,
but just so you understand better what I've got and my experience.
With that being said I'm interested in helping others and contributing,
learning, and building. I'm older, but have a little 23 month old little
girl. At least before she goes to school I am at time limited to what
I can do and my attention is diverted.
It's just life.
Any way I don't want to reinvent the wheel here, I can help document
some BOMs etc, or other stuff that no one seems to have one entire
build etc.
I can also help you guys with test and measurement of some of your
boards so we might be able to see what's going on as we build or
mod this stuff.
That might already have been done as I've not gone through the two
forums yet.
AND
If we don't measure properly some guys who talk softly and carry
big sticks will thump me like used to happen when I was a Marine,
and given enough thumping, I'll figure it out, or lose what ever
thinking I have left.
Also, if folks are building chassis, make more than one when you do.
Or, Identify what to get finding them from broken stuff
and remaking them usable, I'd like to go those routes rather then
start from scratch.
I've already have a suggestion when I order boards, to buy 10
or more for the price break and save the rest for DIYer who might
need them. That might work okay for me.
I'm jumping around here trying to figure out what I'll need to do
and what parts I'll need. I"m starting from square one.
Cheers for now, as I'm still trying to figure everything out
and read the threads and posts.
I posted on the other thread yesterday and was directed here.
I'm wanting to do some of this stuff too. Like GKF I am a tube
guy, tube head, tuby, what have you...and I"m interested in building
this stuff and listening to it.
I've been gathering some modest test gear, some old and some new
not bad stuff. Distortion Analyzers, Frequency Generators, Power Supplys
that kind of stuff and some newer budget stuff, FFTs etc for making plots,
LCR meter, etc, that is just gets the job done for the money spent.
Some pretty good stuff for what we are working on. Most all of it
I've repaired with a lot of help from the good folks at other forums
on DIY.
It's old and new, modernized, it as best as I can, or got it working
when it hasn't been working. I probably have a bit more to do on some pieces
but what the heck.
Most of the Hi-Fi gear that is tube gear I have works fine. It's old but
quality stuff.
Most of the Hi-Fi gear that I have that doesn't work fine, or doesn't work
is solid state stuff. Some of it is old and quality stuff, some of it is new
shitty stuff, it is what it is.
Most of the Music Instrument stuff I have it tube gear and its about
1/2 and 1/2 working or non working....it's quality stuff.
I'm trying to let you know where I'm coming from with this, not to be a gear slut,
but just so you understand better what I've got and my experience.
With that being said I'm interested in helping others and contributing,
learning, and building. I'm older, but have a little 23 month old little
girl. At least before she goes to school I am at time limited to what
I can do and my attention is diverted.
It's just life.
Any way I don't want to reinvent the wheel here, I can help document
some BOMs etc, or other stuff that no one seems to have one entire
build etc.
I can also help you guys with test and measurement of some of your
boards so we might be able to see what's going on as we build or
mod this stuff.
That might already have been done as I've not gone through the two
forums yet.
AND
If we don't measure properly some guys who talk softly and carry
big sticks will thump me like used to happen when I was a Marine,
and given enough thumping, I'll figure it out, or lose what ever
thinking I have left.
Also, if folks are building chassis, make more than one when you do.
Or, Identify what to get finding them from broken stuff
and remaking them usable, I'd like to go those routes rather then
start from scratch.
I've already have a suggestion when I order boards, to buy 10
or more for the price break and save the rest for DIYer who might
need them. That might work okay for me.
I'm jumping around here trying to figure out what I'll need to do
and what parts I'll need. I"m starting from square one.
Cheers for now, as I'm still trying to figure everything out
and read the threads and posts.
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