DC Blocker

[Cathode Ray]

Looking for a schematic for a DC Blocker - a device that will clean any DC and noise from the mains coming into an amp.

Want to build something in a small enclosure that I can plug into the wall outlet, then plug amp into the DC Blocker.

Goal is to quiet down hiss/hum when running high gain.

[sluckey]

Here's a nice line filter...

https://www.amazon.com/Suppressor-Singl ... 073MCGBP5/

Don't need any DC blocking since DC cannot pass through the amp's PT.

[Cathode Ray]

Here's a nice line filter...

https://www.amazon.com/Suppressor-Singl ... 073MCGBP5/

Don't need any DC blocking since DC cannot pass through the amp's PT.

Thanks !

Getting lots of conflicting answers on this one (from different sources).

Got interested in this when I saw an amp builder using the AudioLabs DC Blocker between an amp and the wall outlet to quiet noise.

Showed him a schematic to ask about a design to build one, and he told me "using polarized electrolytic caps is such a device would be a bomb".

Found a YouTube video showing the inside of an AudioLabs DC Blocker.. guess what's in there ?

[TUBEDUDE]

You need ClassX caps to insure the failure mode is open rather than shorted.
And won't D.C. on the line potentially saturate the power tranny?

[Cathode Ray]

You need ClassX caps to insure the failure mode is open rather than shorted.
And won't D.C. on the line potentially saturate the power tranny?

The schematics I found note using "low ESR types" for the polarized electrolytics.

Looking back at the post that got me interested in this in the first place, I think Sluckey is correct about the part he recommended.

[Cathode Ray]

Going off Sluckey's recommendation, I guess what I'm really looking for is a Power Entry Module/EMI filter.

[gktamps]

DC blockers are sometimes used with audio gear, most often when powered with toroidal transformers, as they can tend to hum more than EI transformers when there is DC on the AC line. If the problem is RFI, the filter shown previously is appropriate.

Here is a PCB I have for this purpose. Circuit design by Rod Elliot, board design by someone else, made public for diy.

ElliotDCBlocker.jpg

[Cathode Ray]

DC blockers are sometimes used with audio gear, most often when powered with toroidal transformers, as they can tend to hum more than EI transformers when there is DC on the AC line. If the problem is RFI, the filter shown previously is appropriate.

Here is a PCB I have for this purpose. Circuit design by Rod Elliot, board design by someone else, made public for diy.


ElliotDCBlocker.jpg

That looks right along the lines of what I was coming up with.. couple of polarized electrolytics, bridge rectifier..

[Reeltarded]

A great idea is a specialist electrician's description of how to know if your lines are balanced and clean. Hundreds of videos and articles.

If you do a line test and find tiny DC it's not the hugest deal. If your circuit box was assembled by a madman or additions took the load off balance even for motor run spikes, it can be an awful mess.

[pdf64]

You need ClassX caps to insure the failure mode is open rather than shorted.
…

I think ‘fail open’ is class Y, class X being ‘fail short’.

[Cathode Ray]

Found a "drop-in" replacement for the power entry module on my amp:

https://www.amazon.com/gp/product/B09BN ... UTF8&psc=1

[sluckey]

Found a "drop-in" replacement for the power entry module on my amp:

That looks like a great idea. I still don't get the dc blocker, but I guess somewhere you may encounter dc on the mains. Not in my part of the world though.

[Cathode Ray]

Found a "drop-in" replacement for the power entry module on my amp:

That looks like a great idea. I still don't get the dc blocker, but I guess somewhere you may encounter dc on the mains. Not in my part of the world though.

Yeah, I saw it in a amp builder's post and he was using it and talking it up..

Looked into it and saw the device cost $160, but once I found a schematic and component list I realized I could build it for about $35.

In the end, I think you are correct in saying a DC Blocker is not what I need.

[TUBEDUDE]

Deleted

[WhopperPlate]

I just want a kikisui pcm4000m