yes the fans i hate on a amp in my attic built listening room thats dead silent. my pc i use for flac and dsd has been worked on with a 6" fan on a speed control to slow to a silent level. i was hoping to use another zallman set up like this on the amps.
the p101 are running now when i am here online for 4 to 5 hours a night when i can and they don't even get warm only in summer heat. these have no fan at all. that is how little power i use.
i have a adcom gfa 5400 modded and rebiased it as well as the p101 played at low levels sound cramped. open them up and the sound open.
this is the thing i'm after no compression at low volume.
when the 2 slews are done i plan on selling both the adcom and the 2 p101
the p101 are running now when i am here online for 4 to 5 hours a night when i can and they don't even get warm only in summer heat. these have no fan at all. that is how little power i use.
i have a adcom gfa 5400 modded and rebiased it as well as the p101 played at low levels sound cramped. open them up and the sound open.
this is the thing i'm after no compression at low volume.
when the 2 slews are done i plan on selling both the adcom and the 2 p101
My amp only runs around 110F degrees playing normally. Most of the heat is generated from bias current. It will get hot playing into a dummy resistor though. The big heat sinks are really only needed for testing and showing your buddies what it can do.
guys the last few days i have been looking for a soft start system for the 2 slew's and this has got me confused .
i see some are operated by a 12v source, so i would guess that another transformer is needed. on the new chassis i want to add a round push on and off led blue switch.
led needs 12 v to light so is the switch turning the soft start on which in turn switches on the main power?
i'm thinking it works kinda like a relay, low power to switch high power.
am i right?
i see some are operated by a 12v source, so i would guess that another transformer is needed. on the new chassis i want to add a round push on and off led blue switch.
led needs 12 v to light so is the switch turning the soft start on which in turn switches on the main power?
i'm thinking it works kinda like a relay, low power to switch high power.
am i right?
Here's what I use for softstart and protection.http://www.diyaudio.com/forums/soli...-st-century-protection-board.html#post4110406 It runs from a separate 12V transformer and can work with the switch you are talking about. Your switch LED can operate as your protection indicator too.
I use a good OPS, based on Slewmaster boards, with IRFP240/9240 Hex-FETs.
Exicon ones are Laterals - rather different technology.
Exicon ones are Laterals - rather different technology.
i'm getting a bad feeling about this .
searched the irfp240 and can't seem to find a on line supplier digikey have the n but not the p.
and if the sanken brand are too wide .
back to square one
searched the irfp240 and can't seem to find a on line supplier digikey have the n but not the p.
and if the sanken brand are too wide .
back to square one
IRFP9240PBF Vishay Siliconix | IRFP9240PBF-ND | DigiKey is the P channel. Everybody has these.IRFP9240PBF VISHAY SILICONIX Transistors - MOSFET | 63J6898 | Newark element14 Canada Newark has them on sale. 3 pairs of the MT-200 Sankens will fit in a 5 pair board. With the high SOA of these devices three pairs will handle more power than 5 pairs of TO3P devices.
thanks guys for your patience with me. i don't really like this part of diy. to be honest searching for some of the needed parts makes my blood boil. it's frustrating when i don't know.
i understand now at first i thought irfp240/9240 was one number. that is why no search results.
why are these so cheap ?
isn't there any better top end ones to use?
maybe they are fine i don't know. i would just guess that there must be better quality that cost more somewhere.
these exicon version in the p101 were like $23 each so the irfp at $3.10 seems cheap
i understand now at first i thought irfp240/9240 was one number. that is why no search results.
why are these so cheap ?
isn't there any better top end ones to use?
maybe they are fine i don't know. i would just guess that there must be better quality that cost more somewhere.
these exicon version in the p101 were like $23 each so the irfp at $3.10 seems cheap
They are completely different technology inside. Laterals are always much more expensive than Hex-FETs. Both have got certain advantages and disadvantages, requiring different approaches in output stage design.
See my recent CFA design here (live measurements):
>With Laterals<
>With Hex-FETs<
Both are very high-performance. There are minor differences, if you look carefully, but they are insignificant. The fact IRFPs are cheaper doesn't mean anything. They are excellent output devices if used properly.
Cheers,
Valery
P.S. OPS schematics are not shown there, but I can drop you the links, if you are interested 😉
See my recent CFA design here (live measurements):
>With Laterals<
>With Hex-FETs<
Both are very high-performance. There are minor differences, if you look carefully, but they are insignificant. The fact IRFPs are cheaper doesn't mean anything. They are excellent output devices if used properly.
Cheers,
Valery
P.S. OPS schematics are not shown there, but I can drop you the links, if you are interested 😉
Electronic parts get cheaper as they become more popular. These devices have been around forever and are very popular because they are such a good device. Selecting parts gets easier fast. It's a little intimidating at first. One characteristic of a device you won't find on paper is how well they stand up to a slipped test probe or shorted speaker lead. hexfets stand up very well to that.
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Yep. Excellent BC550/560 (for the input stage) costs around $0.3 per piece ($0.03 if you buy a 4000-pieces reel 😉), being excellent regardless the fact it costs "nothing" 🙂
thanks guys
i just want to be sure i do this right
ordered 10 240's and 10 9240's
we will see how it goes
you all have made me feel better with your knowledge
i just want to be sure i do this right
ordered 10 240's and 10 9240's
we will see how it goes
you all have made me feel better with your knowledge
I have two slewmaster 5 pair sets one with 240/9240 and a set with bjts 3281/1302 on semi. They are both excellent. Build with parts easily available from the big suppliers and you won't be disappointed. For a stereo pair some extra output devices to allow some matching would be nice.