diyAudio (
-   Headphone Systems (
-   -   Background noise - tube amp (

Torstensson 10th December 2012 12:57 PM

Background noise - tube amp
As a newbie I ordered this tube amp kit: Under $25 00 DIY 12AU7 Valve Cmoy Hi Fi Headphone Amplifier Kit Guaranteed | eBay

I've finished it and it's working but there is a lot of background noise.
From what I've found here in the forum it could be the AC-adapter.
It's a regulated 12V / 1A adapter but i still making lot's of background noise.
Tried 2 different ac-adapters I had at home, one from Netgear and one from Yamaha.

Could it be something else or is it most likely the ac-adapter?
Can I build some sort of filter?
Can run it from two 9V batterier in series instead?

I haven't fitted the pcb in a case yet but would this do any difference?

Thanks in advance!

merlin el mago 10th December 2012 03:46 PM

Why you don't make a linear PSU for it?

jerluwoo 10th December 2012 04:17 PM

Since this has a lm317 regulator on the board already, changing ac adapters will have no real effect. What is said about the ac adapter being regulated is misleading as very few actually are. I would think it is meant that the adapter rating is 12v 1a, its not necessary for it to be regulated with a regulator already a part of the circuit.
A schematic would be very helpful in finding ways to make it quieter.

Torstensson 11th December 2012 07:19 AM

How would I make linear PSU?
I will scan the schematic and post it later, no scanner at home.

All times are GMT. The time now is 01:11 PM.

Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 18.75%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio