[CrusherW9]

I've been looking at amps for my KEF Q100s and I stumbled upon the Behringer KM750. Spec wise it seems similar, actually, slightly better than the A500, but with more power (it has a fan though) and $50 cheaper. I've searched but haven't found anything about the KM750. Since they're both AB amps and have similar specs, is it possible this is some sort of remake/new version of the A500? Does anyone know anything about the KM750?

A500 Manual (Contains spec page):
https://media.music-group.com/media/PLM/data/docs/P0217/A500_P0217_M_EN.pdf

A500 on Amazon:
https://smile.amazon.com/dp/B000CZ0RL0/_encoding=UTF8?coliid=IUZDJSXKZU4E4&colid=3VF9Z8K0VMSWQ&psc=0

KM750 Manual:
https://media.music-group.com/media/PLM/data/docs/P0BRJ/KM1700_KM750_QSG_WW.pdf

KM750 on Amazon:
https://smile.amazon.com/Behringer-KM750-BEHRINGER/dp/B01M3RHY5K/ref=cm_cr_arp_d_product_top?ie=UTF8

 

[CrusherW9]

When I made the thread I only had 4 posts but you need 5 to post links. Since I now have 5 posts, here's what I was going to include .

Here's a video that shows the internals of the KM750, though I really don't know what I'm looking at.
https://youtu.be/SnDOkku1FSo?t=52s

Picture of the A500 internals
https://forums.audioholics.com/forums/attachments/inside1-jpg.3415/

 

[Squirrel!]

Old thread I know, but I just bought one of these amps. What you are looking at are 2 main differences, the 1st, no fan on the A500, instead, the cooling fins are external, and secondly, the torroidal transformer looks to be twice the size of the KM750 torroidal. Those are 2 highly desired features.

I opted for the KM750 is based on the desired use, to replace 2 Dayton Audio SPA500 plate amps. I am only looking for the same quality of audio, reasonably priced, not something to blow the doors off their hinges. Just something to replace what I already have/had. I think this amp should fill the need nicely.

Now, my only concern is where to place it so 1] I don't hear the fans and 2] it gets enough ventilation, which is likely what killed my SPA500, or lack thereof, anyway. Real estate in my living room is at a premium as well, making it that much more difficult to place than it needs to be.

Anyone here how loud the fan is? Can you compare it with something? Can't find any videos of the fan noise.

 

[StevenC56]

Old thread I know, but I just bought one of these amps. What you are looking at are 2 main differences, the 1st, no fan on the A500, instead, the cooling fins are external, and secondly, the torroidal transformer looks to be twice the size of the KM750 torroidal. Those are 2 highly desired features.

I opted for the KM750 is based on the desired use, to replace 2 Dayton Audio SPA500 plate amps. I am only looking for the same quality of audio, reasonably priced, not something to blow the doors off their hinges. Just something to replace what I already have/had. I think this amp should fill the need nicely.

Now, my only concern is where to place it so 1] I don't hear the fans and 2] it gets enough ventilation, which is likely what killed my SPA500, or lack thereof, anyway. Real estate in my living room is at a premium as well, making it that much more difficult to place than it needs to be.

Anyone here how loud the fan is? Can you compare it with something? Can't find any videos of the fan noise.

Which one are you saying has a larger transformer, the SPA500 or the KM750?

 

[Squirrel!]

Which one are you saying has a larger transformer, the SPA500 or the KM750?

The SPA, easily.

 

[jbjbjbjb]

Old thread I know, but I just bought one of these amps. What you are looking at are 2 main differences, the 1st, no fan on the A500, instead, the cooling fins are external, and secondly, the torroidal transformer looks to be twice the size of the KM750 torroidal. Those are 2 highly desired features.

I opted for the KM750 is based on the desired use, to replace 2 Dayton Audio SPA500 plate amps. I am only looking for the same quality of audio, reasonably priced, not something to blow the doors off their hinges. Just something to replace what I already have/had. I think this amp should fill the need nicely.

Now, my only concern is where to place it so 1] I don't hear the fans and 2] it gets enough ventilation, which is likely what killed my SPA500, or lack thereof, anyway. Real estate in my living room is at a premium as well, making it that much more difficult to place than it needs to be.

Anyone here how loud the fan is? Can you compare it with something? Can't find any videos of the fan noise.

I use the KM750 for my rear surrounds. The fan is almost silent.

 

[Squirrel!]

I use the KM750 for my rear surrounds. The fan is almost silent.

Thankyou for the insight!

 

[Squirrel!]

I use the KM750 for my rear surrounds. The fan is almost silent.

LOL! Got mine. Fan sounds like a dang jet! I presume you have your mounted away somewhere so you can't hear the fan. I realize this piece was designed to be used in a music venue and not home theater duties so fan noise is really inconsequential in the right environment. I will be doing several tests as to what the appropriate 'fix' is and will report my findings here.

As for my venue, my living room, it won't be pushed hard except occasionally with some good action movies and music of course. The music is what gets cranked more than the movies, and is how I destroyed my SPA500 plate amp in one of my subs. So I am looking at 1 of 3 options:

1] No fan...just plain disconnect and be done with it.

2] Add a resistor to slow down the existing fan speed which in turn will be quieter

3] New Fan...go to a thinner fan blade - drawback is there will still be noise


Option 1 obviously is the 1st test. See how hot it gets.

 

[Squirrel!]

Went with option #1 . Ran hard for an entire movie and warmest it got [no fan] was 141 degrees. Temp after extended 'normal' tv viewing [SNF] was 83 degrees. It'll be fine with no fan.

 

[FlavioWolff]

Went with option #1 . Ran hard for an entire movie and warmest it got [no fan] was 141 degrees. Temp after extended 'normal' tv viewing [SNF] was 83 degrees. It'll be fine with no fan.

Is 141 really safe?

 

[Squirrel!]

Is 141 really safe?

I think so. If it were constant, then I might have a different opinion, but for 1 movie a week cranked up, it's fine. I don't have the time to sit around watching movies so sometimes it isn't even once a week.