Noisy reverb - Nashville 112

Ron Pruter · Post by **Ron Pruter** » 21 May 2023 11:18 am

I seldom go beyond 12 o-clock setting but at 12 the ground hum becomes unacceptable. Pertinent facts-- Pre vol @9 oclock, post vol. @ 12.
Also, the hum is variable by turning post vol. Up or down. I'm sure this is not normal. I don't see any problems. With reverb off, no hum at all. Please help. Thx. Ron

Pat Chong · Post by **Pat Chong** » 21 May 2023 6:55 pm

Hi Ron,
It would be a ground problem in the reverb circuit, shown by the effect the post and reverb controles have on the hum.

There is a molex connector with the reverb circuit:

1. Pull it off and reconnect it a few times, see if that helps, and check that none of the molex connector wires are loose.
2. While there is sound, wiggle the molex connector to check for good connrctions. (Be careful of the volume you are checking this at...)
3. Check if the reverb tank is grounded.

Let us know if this helped, or not.....Pat.

Bill Ferguson · Post by **Bill Ferguson** » 22 May 2023 6:39 am

The hum in the reverb circuit of the NV112 is pretty much normal.
I've had at least 10 of these amps and every one hummed (did not know the words, ha) when the reverb was turned up past 4.

It has been discussed many times and I have talked to the engineers at Peavey. Seems it was something in the design, but it is not considered a defect.
Unless you are playing alone, it is surely not noticable on stage.

Most players do not use the internal reverb in a recording studio, where it could cause a problem.

Hope this helps

Ron Pruter · Post by **Ron Pruter** » 22 May 2023 7:10 pm

Thanks guys. Ron

Pat Chong · Post by **Pat Chong** » 23 May 2023 8:25 am

Hi Ron, hope it helps.
Hi Bill,

Interesting input, from you and Peavey, themselves.

What you said would more likely be so, as I was going off of my Nv400, so what I said may not apply to the Nv112. However:

Your responce may explain a circuit in the Nv400 schematic, where, with IC u4, 1 "+" input is audio-grounded, but the other "+" input is grounded through a 22 ohm resistor going to audio ground, and a 15 ohm resistor going to chassis ground. I believe that would be a "hum cancelling" circuit, even though the schematic says that the 2 grounds are directly connected together at the instrument inputs.

I have tried to locate the same kind of circuit in Nv112 schematics, to test my theory, but every Nv112 schematic I pulled up (so far) had a note that it was the Nv1000 pre amp circuit, instead.

Interesting situation............Pat

Bill Ferguson · Post by **Bill Ferguson** » 23 May 2023 8:50 am

The PreAmp circuit of the NV1000 and NV112 are the same.

Different power amps, speaker and cabinet size.

Pat Chong · Post by **Pat Chong** » 23 May 2023 9:19 am

Hi Bill,

Yes, that had occured to me, too.

Anyway, thanks Bill, this is was interesting......Pat

Clyde Mattocks · Post by **Clyde Mattocks** » 24 May 2023 10:27 pm

All my NV 112s do that. I have to use outboard reverbs. Peavey has lost their way on reverbs. Remember how great the reverb was on the old Session 400s. Sounded like the reverbs on the old Sho Bud amps like Leon Rhodes'.

John Talbott · Post by **John Talbott** » 30 Jul 2023 4:49 pm

I think my NV-112 reverb is exhibiting anomalous behavior. Works well and has no hum no matter where I set it.

Mark Hepler · Post by **Mark Hepler** » 7 Aug 2023 5:08 am

When I upgraded my spring unit I noticed that its placement caused issues: it's right under the power transformer.

Different locations/angles etc. can make a slight improvement.

Stephen Cowell · Post by **Stephen Cowell** » 7 Aug 2023 7:04 am

Mark Hepler wrote:When I upgraded my spring unit I noticed that its placement caused issues: it's right under the power transformer.

Different locations/angles etc. can make a slight improvement.

The pickup end is the sensitive one... put the reverb tank in so that the pickup end is far from the power transformer.

You can tell the pickup end because when you unplug the RCA and touch the tip it hums.

If the PT is in the middle all bets are off!

Ron Pruter · Post by **Ron Pruter** » 9 Aug 2023 12:01 pm

Sure seems like better shielding would solve this. Maybe a hack like wrapping the wires and pan in aluminum foil and grounding it??? Ron

Tony Glassman · Post by **Tony Glassman** » 9 Aug 2023 12:49 pm

Clyde Mattocks wrote:All my NV 112s do that. I have to use outboard reverbs. Peavey has lost their way on reverbs. Remember how great the reverb was on the old Session 400s. Sounded like the reverbs on the old Sho Bud amps like Leon Rhodes'.

I never liked the Session 400 reverb. It sounded to clangy & metallic compared to the Webb 6-14 verb.

Since then I’ve played through N-400s and 112s, albeit using outboard reverb pedals.

Tony Glassman · Post by **Tony Glassman** » 9 Aug 2023 1:38 pm

Clyde Mattocks wrote:All my NV 112s do that. I have to use outboard reverbs. Peavey has lost their way on reverbs. Remember how great the reverb was on the old Session 400s. Sounded like the reverbs on the old Sho Bud amps like Leon Rhodes'.

I never liked the Session 400 reverb. It sounded to clangy & metallic compared to the Webb 6-14 verb.

Since then I’ve played through N-400s and 112s, albeit using outboard reverb pedals.

Karl Paulsen · Post by **Karl Paulsen** » 11 Aug 2023 3:56 am

Tony Glassman wrote:
Clyde Mattocks wrote:All my NV 112s do that. I have to use outboard reverbs. Peavey has lost their way on reverbs. Remember how great the reverb was on the old Session 400s. Sounded like the reverbs on the old Sho Bud amps like Leon Rhodes'.
I never liked the Session 400 reverb. It sounded to clangy & metallic compared to the Webb 6-14 verb.

Since then I’ve played through N-400s and 112s, albeit using outboard reverb pedals.

What's your recommendation for outboard Reverb pedals?

The Steel Guitar Forum

Noisy reverb - Nashville 112

Noisy reverb - Nashville 112

Unit's orientation doesn't help.

Re: Unit's orientation doesn't help.