Mesa Subway D-350!

[BlueTalon]

Agedhorse, this is directed at you, but I appreciate input from anyone. I love my D-350 with my active Stingray Specials but recently I picked up a new Fender Pro 2 precision bass (passive) and I get an annoying hum. When I use one of those orange colored plug in adapters the hum is gone. If however I use the active Stingray along with the orange adapter I get the same hum whereas before no hum without the adapter.

By "orange colored plug in adapter" do you mean a 3-prong-to-2-prong adapter? One that removes the ground connection?

 

[Moonskunk]

It's a 2 prong. Yes, 3 prong into a 2 prong.

 

[Moonskunk]

To be clear, this thing.

 

[wblaze]

I love my D-350 with my active Stingray Specials but recently I picked up a new Fender Pro 2 precision bass (passive) and I get an annoying hum.

I had the same problem with a B-stock or "open box" model D350 I purchased and eventually returned. The hum happened with a passive Precision, and with my Stingray wasn't as noticable. I figured it was a problem with the particular open box unit. The hum didn't occur with a Genzler 350 or Ampeg combo plugged into the same socket.

 

[BlueTalon]

It's a 2 prong. Yes, 3 prong into a 2 prong.

To be clear, this thing.
View attachment 5434944 View attachment 5434943

I was afraid of that. That ground connection is there for your safety. There are other ways of making basses silent that don't involve risking your life. Yes, I'm being dramatic, but it's like playing on stage barefoot -- most of the time, nothing's probably going to happen, but it only takes one time to make you regret your choices.

 

[Moonskunk]

I was afraid of that. That ground connection is there for your safety. There are other ways of making basses silent that don't involve risking your life. Yes, I'm being dramatic, but it's like playing on stage barefoot -- most of the time, nothing's probably going to happen, but it only takes one time to make you regret your choices.

Ok thanks, I guess I won't be using the adapter anymore. I'll wait and see what Agedhorse has to say. I like that the D350 has no fan so no noise in that regard, but this is way more annoying than any fan.

 

[agedhorse]

Ok thanks, I guess I won't be using the adapter anymore. I'll wait and see what Agedhorse has to say. I like that the D350 has no fan so no noise in that regard, but this is way more annoying than any fan.

Are you using the amp in conjunction with any other gear like pedals, the DI into a mixer or interface, etc?

 

[Moonskunk]

Are you using the amp in conjunction with any other gear like pedals, the DI into a mixer or interface, etc?

No, none of that.

 

[Moonskunk]

As stated I don't get the hum with either a WD 800 or TH -350.

 

[agedhorse]

Does the hum change with gain and volume controls on the bass?

 

[agedhorse]

As stated I don't get the hum with either a WD 800 or TH -350.

Each of these amps has a different architecture.

 

[Moonskunk]

Does the hum change with gain and volume controls on the bass?

I'm going to hook it up now so I can give an accurate answer to that, I'll get back right afterwards.

 

[Moonskunk]

As I turn the volume up on the P bass the hum gets progressively louder until the last 3% until max when it gets a bit quieter but still annoying.

 

[MOSCOWBASS]

As I turn the volume up on the P bass the hum gets progressively louder until the last 3% until max when it gets a bit quieter but still annoying.

That's what mine has been doing since I got it. The amp was replaced and the new one does the same. It's only with passive basses, it works fine with my active basses. What country are you in, are you 230 volts?

 

[Moonskunk]

That's what mine has been doing since I got it. The amp was replaced and the new one does the same. It's only with passive basses, it works fine with my active basses. What country are you in, are you 230 volts?

USA. I only have one passive bass so does it do it with all passive basses, I don't know. However I did have another Fender Pro 2 two weeks ago and it did the same thing.

 

[agedhorse]

As I turn the volume up on the P bass the hum gets progressively louder until the last 3% until max when it gets a bit quieter but still annoying.

Ok, this is the indication that the noise is entering through the bass before the amp. When you use the ground lift adapter, there may be some noise present in the amp that's not present without the adapter that is canceling with the noise that's being picked up by your bass.

When dealing with quirky noise issues like this, each amp's architecture can have a positive or negative impact on the noise. An architecture that works perfectly with one bass may be noisier with another bass, yet the first bass may be noisier with another architecture.

Something things that might be worth looking into are shielding of the pickup and controls cavity, insuring that your (presumably stock) pickups are correctly wired so that the split pickups are actually hum canceling and not hum reinforcing, and that there are no strong electro-magnetic fields in the environment being picked up by the pickups.

 

[MOSCOWBASS]

USA. I only have one passive bass so does it do it with all passive basses, I don't know. However I did have another Fender Pro 2 two weeks ago and it did the same thing.

Mine does it with all passive basses and guitars I've tried. It's fine with my 2 Sadowskys in active, but if I switch them to passive, I get hum when I back the bass volume off just as you describe.Same with my Xotic jazz, ok in active, hum with volume backed off in passive.
Ive used mine in many venues in the UK for past 2 years and it does it in all venues, so its not a specific location with bad mains supply.
I have a D800, it doesn't have this problem. I also have a D800 preamp pedal, it doesn't happen with that either, even when the pedal is plugged into the aux in on the D350

 

[agedhorse]

That's what mine has been doing since I got it. The amp was replaced and the new one does the same. It's only with passive basses, it works fine with my active basses. What country are you in, are you 230 volts?

USA. I only have one passive bass so does it do it with all passive basses, I don't know. However I did have another Fender Pro 2 two weeks ago and it did the same thing.

I don't think any of this is actually amp related. Passive basses are generally more sensitive to EMF pickup, especially in higher EMF environments, than active pickup basses.

What happens when you change the position of the bass? Does the noise change at all? Does the noise change as you move away from the amp?

I have confirmed that it's unrelated to 120 versus 230/240V, and that there are maybe a thousand of these amps out there with only a very few issues.

Another issue with split coil pickups is if the coil balance is incorrect. The positive and negative wound coils must match for the common mode noise cancellation to work well. Are these stock pickups?

 

[Moonskunk]

So am I putting my life in danger by using the adapter? I have been using my P bass and D-350 with the adapter but if it's too risky I'll save the D-350 for my active Stingrays. I believe my P bass is wired correctly judging from the fact that another identical bass I used last week did the same thing. Fender QC is pretty bad these days but what are the chances of 2 of their current pro basses being wired wrong. Ok 5%

 

[Moonskunk]

Yes, everything is stock. Its a brand new Fender Pro 2 P.
This one.