I’m guessing 10-32? I don’t have a set in front of me so really a guess based on memory. I can check later.
Hi jimk04,
Not sure what you need, maybe this will be of help. I could not find clips to attach my fans to the cooler HS, so I bought some small diameter rods 2mm,56 tpi (2-56) from du-bro and some nuts from amazon. I am going to cut the rods to length to go thru the fan holes and HS and are coupled by nuts on each end of the rod. Fans on bottom of chassis plate, 92mm diameter hole, and HS on chassis plate top. Should work pretty slick and hold things solid. This rod is also sold by model aircraft stores. See pics below. My HS are shown in post#2734.
MM
Not sure what you need, maybe this will be of help. I could not find clips to attach my fans to the cooler HS, so I bought some small diameter rods 2mm,56 tpi (2-56) from du-bro and some nuts from amazon. I am going to cut the rods to length to go thru the fan holes and HS and are coupled by nuts on each end of the rod. Fans on bottom of chassis plate, 92mm diameter hole, and HS on chassis plate top. Should work pretty slick and hold things solid. This rod is also sold by model aircraft stores. See pics below. My HS are shown in post#2734.
MM
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While I am here, I am redesigning my AN39 to be more like the amp that X built. With the price of things these days, I have had to limit my expenditures a little. So I am going with:
Antek 5224 transformer
1 dual rail SLB. I have built 2, will save one for later.
2 cpu cooler HS
2 SSR protection modules
1 SFP module
Will post pics as I go along. This will be fun.
MM
Antek 5224 transformer
1 dual rail SLB. I have built 2, will save one for later.
2 cpu cooler HS
2 SSR protection modules
1 SFP module
Will post pics as I go along. This will be fun.
MM
Sorry if any confusion but these are the spring loaded fixings for the CPU, not the fan. So I intend to use them to hold down the MOSFETs !
sussed out the sprung fixings. I found some I removed from some other coolers and they are M3, so that opens up all my stash of brass standoffs etc, result.
These 120mm Noctuas fit a treat aswell depsite the cooler being designed for 80mm
Also I looked over my crossovers and realised id read some time ago about trying an 8r across the amp outputs, to smoothen the impedance or something. it was smoothing it but also lowering it. Ive removed it now and this is the new sweep, much more 8R AN39 friendly i think.
These 120mm Noctuas fit a treat aswell depsite the cooler being designed for 80mm
Also I looked over my crossovers and realised id read some time ago about trying an 8r across the amp outputs, to smoothen the impedance or something. it was smoothing it but also lowering it. Ive removed it now and this is the new sweep, much more 8R AN39 friendly i think.
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Out of interest, I've recently dismantled my Aleph 30 to improve the initial test chassis. When I removed the amp boards, a lot of the ceramic insulation pads disintegrated. Dont know if that ls excess heat, fastener torque, if the thermal compound has eaten them or whether it's just the norm!
No I swapped out the unidentified imperial....couldn't find nuts to fit so these M3 fixings came out of some other coolers. Hopefully test the PSU tomorrow!
If you "put a resistor across the amp terminals, to smooth out the driver's impedance" ... it needs to be a resistor in series with a capacitor - not just a resistor! There's a name for this tweak ... I just happen to forget it. 🙁
All the 8ohm resistor by itself will do ... is parallel the (nominal) 8 ohms of the spkr, to turn it into a 4 ohm spkr - so not a good idea, at all! 👎
I would think the extremely high impedance peak @ 50Hz may well be problematic for an 8R AN.
The only alumina ceramic insulator that cracked on me was used with TO3 metal can devices. The mounting "ears" were slightly curved and when the second fastener was torqued it cracked.
Simple maths!
If the amp clips at 39w into 8 ohms ... it will only be able to deliver 39 x 8 / 21 at 50Hz. This is 15w.
So a loud transient at 50Hz will cause the amp to clip.
Need to make a slight amendment to my post above - as follows:
If the amp clips at 39w into 8 ohms ... it will only be able to deliver 39 x 8 / 21 at 50Hz, into 21 ohms. This is 15w.
So a loud transient at 50Hz may cause the amp to clip.
If the amp clips at 39w into 8 ohms ... it will only be able to deliver 39 x 8 / 21 at 50Hz, into 21 ohms. This is 15w.
So a loud transient at 50Hz may cause the amp to clip.
Thanks for the explanation. Surely a lot of speakers have these LF impedance peaks due to Fs and BR tuning etc. Don't we just accept this as one of the compromises of this whole game?
Sure, Jim - which is why so very many people never get to hear what their spkrs are capable of sounding like ... as their spkrs drop to low impedances and they use amps which can't put out sufficient current into a low impedance load. 🙁
This is one reason - IMO - active spkrs generally sound better than their passive equivalents; when the amps are directly connected to the drivers, the amps don't experience the same impedance swings as when the drivers are mixed up with passive XO components - so the amps have an easier job of making the drivers "sing". 🙂
Your spkrs don't suffer from a low-impedance problem - exactly the reverse! But that means there's not much power available to the spkr (from an AN 8R) at that 'peak-impedance frequency'. And 50Hz is well within bass guitar range! I would suggest such a spkr is best driven by an amp which has at least 100w available into 8 ohms (38w into 21 ohms). Like Hugh's "Titan" or "Maya" amps. (Whilst these are generally fully-built amps ... if you are DIY-inclined, you can just buy the amp modules and wire them up in your own cases.)
This is one reason - IMO - active spkrs generally sound better than their passive equivalents; when the amps are directly connected to the drivers, the amps don't experience the same impedance swings as when the drivers are mixed up with passive XO components - so the amps have an easier job of making the drivers "sing". 🙂
Your spkrs don't suffer from a low-impedance problem - exactly the reverse! But that means there's not much power available to the spkr (from an AN 8R) at that 'peak-impedance frequency'. And 50Hz is well within bass guitar range! I would suggest such a spkr is best driven by an amp which has at least 100w available into 8 ohms (38w into 21 ohms). Like Hugh's "Titan" or "Maya" amps. (Whilst these are generally fully-built amps ... if you are DIY-inclined, you can just buy the amp modules and wire them up in your own cases.)
Thanks Andy that's all very interesting. I suppose I hadn't looked at it that way. I have a NP 6-24 active XO on my 'bench' so I think I'll just build the 8r AN for now to test and get running, and then when I go active I'll use the AN on the bass (8ohm) and should be able to sort the impedance better then.
Sorry, I'm not familiar with the "NP 6-24 active XO" ... but it sounds like it's a stereo, 3-way active XO, using 24dB slopes?
Which will be a great thing to use (I use a 3-way miniDSP active) but ... I would suggest the beautiful sound of the AN 8R is not appropriate for the bass drivers and should be used on the upper frequencies. Better to use a much more powerful Class AB - or even D - on the bass drivers.
Which will be a great thing to use (I use a 3-way miniDSP active) but ... I would suggest the beautiful sound of the AN 8R is not appropriate for the bass drivers and should be used on the upper frequencies. Better to use a much more powerful Class AB - or even D - on the bass drivers.