u/Demitriicuz

I am working on a Sony TA-FE370 integrated amplifier that I recently purchased at a local pawn shop and I am trying to troubleshoot a channel imbalance problem.

At the time when the unit is cold, the two channels are perfectly balanced with clean output. About 10-15 minutes into operation the right channel becomes quieter. It begins quite subtly, but it becomes quite evident in the course of additional warming up

….I have eliminated speakers, cables, and sources of inputs by changing all of them. The problem is on the same channel irrespective of what I am connecting.

The amp had a small Trimmer Potentiometer on the board inside the amp, probably to adjust the bias or DC offset. A minor adjustment helped to stabilize the balance temporarily, but the unit began to heat up again, and the drift reappeared. The Trimmer Potentiometer is also rather scratchy and not very stable to adjust, and that makes me think that it might not be retaining its setting correctly…

I had checked the replacements and found some cheap ones on alibaba before deciding to replace it, but I am not convinced of the consistency and reliability of small parts such as this in an audio repair.

Prior to desoldering anything, does this behavior indicate more of a failing Trimmer Potentiometer, or could it still be due to another element such as a transistor drifting with temperature?

Thrifted last weekend in a local charity shop in Manchester and was not anticipating much. The rails have recently been scavenged or simply stocked with over-priced fast fashion items attempting to be vintage.

….After that i happened upon a very heavy winter coat, a men’s parka that quite literally seems like it might be able to deal with a real UK winter. Solid weight, thick lining, and clean stitching feel good, even the zip. It cost me £12 hence i did not think too much before picking it up.

Got it home, and put it on right, and it fits almost too well. That was when i began to see details such as the branding being not so sharp and the inside tags being really plain and nothing that makes a real impression and a story.

…Nevertheless, it is hot, cozy, and all is well following a shower. I have heard that sometimes stores will source excess or bulk products elsewhere on the internet, such as on sites like alibaba, however, i am not certain that this is the case here or otherwise.

I only wonder whether any other person had also encountered thrift discoveries such as these that are comfortable but leave one a little puzzled as to the origin of such items.