Dual/Stereo mnats 1176 hum [SOLVED]

abechap024 said:

ferrochrome said:

. If I decide to replace with a lm1085 would I need to modify the circuit otherwise or just replace regulator and adjust to 30V?

Click to expand...

http://www.ti.com/lit/ds/symlink/lm1085.pdf
They just drop right in.

Have fun tracking

Click to expand...

Now that's nice to know! even an easy option!. Any way, I did some tracking and it really sounds great right now. In nuke/slam/all button mode with agressive input it does somthing really cool to my bassdrum, I don't think it used to be agressive like that! So again thanks for all you diy'ers help!

By the way Abe, your clx-vu would be nice to solder up and rack, how much approxiomately would it cost to build a stereo unit incl the parts in the BOM (+That/hairball parts/collective case)?

ferrochrome said:

By the way Abe, your clx-vu would be nice to solder up and rack, how much approxiomately would it cost to build a stereo unit incl the parts in the BOM (+That/hairball parts/collective case)?

Click to expand...

Glad its sounding good It all depends on what parts you want to source. But I would say roughly 400-500$ for a stereo unit you could do it for less, you could easily do it for more. I'm doing a pre-order in the white market with parts kits if you want to get on it.

Best,
Abe

Maybe sum it up in the first post to help to others in the future ,
anyway good to hear , [ you probably know more about grounding now as well ]

abechap024 said:

ferrochrome said:

By the way Abe, your clx-vu would be nice to solder up and rack, how much approxiomately would it cost to build a stereo unit incl the parts in the BOM (+That/hairball parts/collective case)?

Click to expand...

Glad its sounding good It all depends on what parts you want to source. But I would say roughly 400-500$ for a stereo unit you could do it for less, you could easily do it for more. I'm doing a pre-order in the white market with parts kits if you want to get on it.

Best,
Abe

Click to expand...

-Well now thats something to consider, I'm sending you a post regarding that abe!

-Good idea okgb, I've edited the first post!

The lower headroom after setting the 30V rail to 28V makes the compressors far from versatile, its impossible to get proper GR without distortion on higher ratios.

One thing I found while checking out the LM1085adj datasheet is that Voltage-in max is 29V. Can I really use the LM1085 in this application? Just hoping to get this confirmed before swapping the LM317.

ferrochrome said:

The lower headroom after setting the 30V rail to 28V makes the compressors far from versatile, its impossible to get proper GR without distortion on higher ratios.

One thing I found while checking out the LM1085adj datasheet is that Voltage-in max is 29V. Can I really use the LM1085 in this application? Just hoping to get this confirmed before swapping the LM317.

Click to expand...

Voltage-in and -out doesn't seem to confirm to my application : http://www.digikey.no/product-detail/en/LM1085IT-ADJ/LM1085IT-ADJ-ND/3701308

ferrochrome said:

ferrochrome said:

The lower headroom after setting the 30V rail to 28V makes the compressors far from versatile, its impossible to get proper GR without distortion on higher ratios.

One thing I found while checking out the LM1085adj datasheet is that Voltage-in max is 29V. Can I really use the LM1085 in this application? Just hoping to get this confirmed before swapping the LM317.

Click to expand...

Voltage-in and -out doesn't seem to confirm to my application : http://www.digikey.no/product-detail/en/LM1085IT-ADJ/LM1085IT-ADJ-ND/3701308

Click to expand...

'Maximum Input to Output Differential' must not exceed 29V. Your raw-DC input is about 32V, your wanted output is 30V, giving a I-O differential of 2V. Just make sure you don't short the output to 0V reference voltage, that might cause a 32V differential (probably a lot less with this imaginary 0 ohm load/short).

Thank you Harpo, for making that clear for me!

Maybe you don't need 3A current output, the LM1086 is ok (1.5A like LM317) also a little cheaper

http://www.digikey.no/product-detail/en/LM1086CT-ADJ%2FNOPB/LM1086CT-ADJ%2FNOPB-ND/363573

But I didn't know you will experience so much difference in compression use, going from 30V to 28V with 1176 circuit

I found this thread while searching if other people were having the same problem as me. I have the same hum problem with my 2-1176 using Mnats separate PSU board -

with the LM317 in I lowered the voltage down to 28V - the hum was reduced significantly but still didnt go away completely.

So I decided to  replace the LM317 with the suggested LM1086 regulator, adjusted the PSU back to 30v but the hum is back unless I reduce the voltage down - I can get it to about 28.8V until the major hum comes back. Am I missing something? Or is this how it should be?

http://mouser.com/Search/ProductDetail.aspx?R=LM1086CT-ADJ%2fNOPBvirtualkey59500000virtualkey926-LM1086CT-ADJNOPB

I have attached two images of the frequency analyzer - one shows the unit at 30V with the major hum, and the other shows it with the least amount of hum I am able to achieve as close to 30v as possible, which is at 28.8V. I was also wondering whether the level at reduced noise/hum shown at the lower amount is still shows a problem or if this is an acceptable level? I am wondering about that bump at 47Hz too?

Any insights would be much appreciated. Thank you

28.8V

Hi guys.
I have related (but different) question..

I want to power two MNATS 1176 RevJ boards from one mains toroidal, but using both of the individual onboard regulator circuits (rather than the optional shared one).

Is it fine to do this?

My understanding is that I would just run the 24-0-24 from the secondary of the (Hairball) mains toroidal across to the 24-0-24 points on both the 1176 boards.

Did I miss anything?
Cheers
Evan

that board can power both comps just fine.
however you can use separate psu per comp no prob.
but i dont think you will fix all issues.

make sure you got all grounds well connected and have a starground.
i