trainbuftony
Electron Herder
In a previous thread, an AKer was trying to diagnose and get working a custom built amplifier by a gentleman named Lance Cochrane. He was not able to achieve musical bliss with it, so he returned it. During the course of that thread I offered to have a look at it. The OP decided to simply send it back for a refund. After he did so, Lance chimed in on the thread.
That's neither here nor there. Another AKer took me up on the offer to have a look at his Lance Cochrane amp which he believes has similar symptoms.
The symptoms: amplifier sounds OK at low volume but at listening volume, it's unlistenable due to massive distortion.
Aker @eiraved sent me this unit, with tubes, and it arrived unscathed. The story is that the last person to open it up was the builder Lance Cochrane. The business card I found inside suggests that is the case. The owner would like for it to work correctly and I agreed to help achieve that end, under the condition that I would post a thread and share my thoughts and findings. So far I'm not impressed.
Paint and finish:
This is clearly a repurposed amplifier. I think it came out of a juke box but I really don't know. The offset transformers and tube sockets suggest it was originally designed to be hidden out of sight. Several holes in the chassis have been plugged. The paint is raised up and cracking, not like a wrinkle paint but like way too much rattle can, in thick coats without sufficient drying time. The mounting ears of the transformers, tube sockets and wiring all have overspray on them. The whole amp is screwed to a cutting board, with rubber feet. I'm not in love with the style.
Construction:
The amp appears to have been stripped and totally repurpurposed into its current configuration which at first glance is a push pull cathode biased output stage. Bottom side leaves a lot to be desired as well. There's flying connections and the whole thing has no order to the design or layout. The terminal strip which originally connected to the speakers is painted over. Jumpers beneath connect to 5 way banana posts. As someone who builds amplifiers i feel it's worth noting that a clean chassis direct from hammond comes in a variety of size options at the ~$20 price point. It doesn't make a whole lot of sense from my perspective to try and salvage stuff like this chassis. The output transformers however look viable. If I had to guess this thing should make a clean 20 watts. The owner says it doesn't even come close.
Next: we plug it in!
That's neither here nor there. Another AKer took me up on the offer to have a look at his Lance Cochrane amp which he believes has similar symptoms.
The symptoms: amplifier sounds OK at low volume but at listening volume, it's unlistenable due to massive distortion.
Aker @eiraved sent me this unit, with tubes, and it arrived unscathed. The story is that the last person to open it up was the builder Lance Cochrane. The business card I found inside suggests that is the case. The owner would like for it to work correctly and I agreed to help achieve that end, under the condition that I would post a thread and share my thoughts and findings. So far I'm not impressed.
Paint and finish:
This is clearly a repurposed amplifier. I think it came out of a juke box but I really don't know. The offset transformers and tube sockets suggest it was originally designed to be hidden out of sight. Several holes in the chassis have been plugged. The paint is raised up and cracking, not like a wrinkle paint but like way too much rattle can, in thick coats without sufficient drying time. The mounting ears of the transformers, tube sockets and wiring all have overspray on them. The whole amp is screwed to a cutting board, with rubber feet. I'm not in love with the style.
Construction:
The amp appears to have been stripped and totally repurpurposed into its current configuration which at first glance is a push pull cathode biased output stage. Bottom side leaves a lot to be desired as well. There's flying connections and the whole thing has no order to the design or layout. The terminal strip which originally connected to the speakers is painted over. Jumpers beneath connect to 5 way banana posts. As someone who builds amplifiers i feel it's worth noting that a clean chassis direct from hammond comes in a variety of size options at the ~$20 price point. It doesn't make a whole lot of sense from my perspective to try and salvage stuff like this chassis. The output transformers however look viable. If I had to guess this thing should make a clean 20 watts. The owner says it doesn't even come close.
Next: we plug it in!
I'm curious about the feedback strategy, both local and global.
