Peavey session 500 adjustments

Jack Stoner · Post by **Jack Stoner** » 28 Aug 2014 2:28 am

I had a NV400 that had an intermittent hum (mostly hum) in the reverb. The amp blew up under warranty so I sent it back to Peavey for repair. When it came back they fixed the "blow up" problems but it still had the reverb hum. It was sent back again and they couldn't find any problem.

I fought it for about a year and kept messing with the troublesome Molex connector until I finally figured out the problem was in the chassis and not the connector. As it turned out there was a hairline crack in the trace for one of the chassis Molex pins. After soldering that, no more problems.

Lee Dassow · Post by **Lee Dassow** » 28 Aug 2014 9:10 am

Jack, When you say the molex connector are you referring to the IC's or something else? T.L.

Jack Stoner · Post by **Jack Stoner** » 28 Aug 2014 9:51 am

Molex is a brand name. The "Molex Connector" I was referring to connects the reverb tank to the amp chassis. Its a white/cream colored connector. There have been many intermittent and hum problems related to that connector.

Its generally the same size as the IDE power connector that is used in PC's, which is also a Molex brand (or clone).

Molex connectors were originally designed for power, not low level audio signals. They are an inexpensive connector so they are used in many applications. Peavey wised up and changed to a different connector for the Nashville 1000 and 112 amps.

Lane Gray · Post by **Lane Gray** » 28 Aug 2014 11:59 am

Your 500 has several Molex connectors, they connect the bottom board to top board and also one going from top board to the reverb tank.

Lee Dassow · Post by **Lee Dassow** » 28 Aug 2014 4:35 pm

Jack and Lane, That's the connector that the amp tech Soldered The wire back in when He came out to my house. Thanks for clarifying that. T.L.

Lee Dassow · Post by **Lee Dassow** » 24 Nov 2014 3:01 pm

Well more problems with the Peavey session 500.
Me and some of the local musicians got together last
Wednesday. Soon as I turned the amp on, instant fuzz
tone! Both effects knobs are shut off. I'm going
to have to call the amp tech who worked on it, but
he hasn't been returning my calls. I may have to find a new peavey tech. in this neck of the woods.
Maybe somebody knows one? Anyhow I bought a session 400 cause I heard so many good things about them. T.L.

Scott Jenkins · Post by **Scott Jenkins** » 22 Sep 2025 11:20 am

Lane Gray wrote: 26 Aug 2014 3:08 am Lee, if your tone is muddy, I'd try a Lil' Izzy. Cleans up amazingly well.

The Steel Guitar Forum

Peavey session 500 adjustments

Lil’Izzy. That’s old school for sure 👍