DIY Ground Loop Isolator 1:1, help

[orfeous]

Thinking of building my own HiFi RCA stereo ground loop isolator with 1:1 ratio for transformers.

Trying to mimic Supra AGS-10k
Frequence intervall: 15 Hz - 22 kHz
In- and Out Impedance: 10 kOhm
Ratio: 1:1

Any suggesstions for this DIY project?

That Supra AGS-10k costs around 60 euro so if i can build a similiar cheaper im happy. If not im buying it.

Use for reciever sub preamp and subwoofer amp.
Having issues with noises from PC via HDMI and antenna cable tv to antenna socket/wall. Humming in subwoofer.

 

[simon7000]

Triad TY141. Goes much lower than the data sheet spec at lower power. So at 1VRMS reasonably flat to 20 hertz.

 

[PRR]

I have, in a pinch, used a car-audio transformer for mastering with excellent result. This depends on giving it a low source impedance ("600r" mixer) and not trying for +22dBV levels at low frequency.

Amazon.com: InstallGear Ground Loop Isolator Amp Noise Filter: Car Electronics
https://images-na.ssl-images-amazon.com/images/I/61vq9B+QbnL._AC_SL1300_.jpg

Yes, ten bucks (I paid $17 locally).

 

[Galu]

It's one of those cases where buying the finished product can prove cheaper than buying the necessary components. This HQ one only costs £16.50:

Monacor FGA-40HQ High-End Ground Loop Isolator - Monacor from Inta Audio UK

MONACOR: FGA-40HQ

And it's surprising how little these inexpensive ground loop isolators audibly affect the bass response.

 

[orfeous]

Thank you for all the suggestions.
I know that there allready are built working products.
But what is the fun with that to not DIY?

That Monacor looks premium and seems to have "premium" specs on the paper too.
It differce a little in the frequency range but.. i dont know.

My main usage of this ground loop isolator is to eliminate my audible noise when using my computer. HDMI and RCA seems to pick it up.

Signal path: Onkyo TX-NR818->Subwoofer PREOUT RCA (mono)->RCA single end with Y-split->Ground loop isolator->Left&Right RCA stereo RCA cable -> Left&Right RCA input.

I hope i declared myself correct or somewhat understandable.

XLR-RCA is also an option. To use XLR input on subwoofer amp and single ended RCA to receiver subwoofer preout.

Supra/Jenving are using Toroidal-transformers for low distorsion and wide frequency range.
@simon7000 suggessted Triad TY141. If i want to try and build my own i will need two of those then and 4 RCA female input connectors? Maybe some kind of test board or something to solder everything in or something similiar.

 

[orfeous]

Seems that subwoofer humming/buzzing noises are gone now. Ive fixed it.
Did some changing of power cord to computer and connected it to my other power brick.

 

[kodabmx]

I made a board for two TY250P transformers.

Driven from a low Z circuit, and with a zobel on the secondary consisting of a 1000pF cap in series with 1k5, it makes clean 20kHz square waves.

I have a some left.

2$ each plus postage if you're interested.

 

[Gill.T]

I made a board for two TY250P transformers.

Driven from a low Z circuit, and with a zobel on the secondary consisting of a 1000pF cap in series with 1k5, it makes clean 20kHz square waves.

I have a some left.

2$ each plus postage if you're interested.

You still have those PCBs?

 

[kodabmx]

Yes. I have five of them left.