Chinese hv1 eBay diy kit relay problem

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Just put together this kit and it sounds awesome with my akg k712s.

the problem is after 10min of play the protection relay clicks off on repetetly.
The spec sheet says this is dual 12-15v 30va amp. I had a spare toroidal transformer lying around rated at x2 15v and 100va.

The voltage reading is 18v off load and 17.5v when amp is powered. The amp is using 0.25amp per 15v load.

When blowing on the transistor heatsinks the relay stops clicking.
also when plugging in my ipod the relay cuts the headphones off when upping the volume past a quarter turn this is not the case when connected to my pc soundcard

So my question is should I upgrade the heatsink or downgrade the transformer to a 12v 30va or could there be another issue. All components are fitted correctly.
kit is based on A1


Video of the problem

YouTube
 
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Sellers Discription:

Main materials:

Original ST33078N dual op amp, STDB139-140 power transistor.

Panasonic FK Series main smoothing capacitor

1/4W 1% precision metal film resistors

AUDIOPHILE MKP 4U7 400V 3% precision tinfoil capacitance

Omron G2R - 2 12V Relay 700MV Protection circuit,7 seconds delay connect function.
 
Transformer setup

pcb.png
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.