17 October 2020

"Fixing" a Broken Peavey Vypyr Input Jack - Updated

 I just bought a Peavey Vypyr VIP-1 (Fig. 1) with an "input that needs to be tightened or replaced" (per the listing) for a practice amp. Turns out the threads were stripped (I forgot to take a before pic, but you can kind of see them in Fig. 2) so it needed to be replaced. Fair play – I offered $10 less than the asking price and the seller accepted, so no complaints at all.

Fig. 1 Peavey Vypyr VIP-1 with stripped input jack and missing knob

Fig. 2 Stripped threads on the original input jack (pictured here after the 'fix')

When I removed the chassis, I saw that the jack is mounted to a PCB and connected to another PCB by a ribbon cable, which was pretty tightly coiled, presumably from the seller trying to tighten the nut onto the jack but just spinning the whole jack/PCB assembly inside. Past experience tells me that sometimes it's best to leave wires as is if they're not hurting anything (unbending wire can sometimes break it), so I uncoiled it a little bit, but not too much.

I found what I think is the right jack in a few places, all of which cost $8 to $10 or so with shipping. But I don't know much about these kind of jacks with the additional NC contact (that power down the amp when you remove the guitar cable). I didn't want to spend the $10 on what might be the wrong jack, or in a more likely and worse scenario, I didn't want to risk frying any of the tiny surface mounted components on the jack's PCB in the process of desoldering the five solder points.

Instead, I removed one end of a short effects pedal cable (Fig. 3), soldered that end to a new mono input jack and left the other end plugged into the original jack inside the chassis. I used a couple of zip ties to keep it from wiggling around and possibly touching something it shouldn't (Fig. 4). Update: Due to unwanted vibration and rattling on some notes, I had to open up the amp again and put foam tape under the input jack and metal part of the cable.

Fig. 3. Repurposed effects pedal cable with 1/4" mono jack

Like many of my hack jobs, it's not pretty, but it works. And with the amp back together, you can't tell the difference anyway, other than the input jack looking nicer than the original (Fig. 5).

Fig. 4 Original jack and cable zip-tied in place

Fig. 5. New input jack