GR Bass 350 DI noise

[Envincibal]

I just purchased this bass head on Reverb, so I know I can return this (just arrived yesterday, and no issues were listed by the seller).

The amp works as it should when connected to a speaker, but when I tried the DI, I have this whinny sound going from the DI. The noise it creates is affected by the DI volume control, and when at extremes (max counter clockwise and max clockwise) there is no noise.

I tried my other bass heads (Berg Forte HP, Mesa WD800, and a GR Bass 1400 single), and no noise on any of them. To further troubleshoot the DI noise, I did try a different outlet, different XLR cable, with and without a 4ohm speaker connected, and the results were always the same - noise in the DI.

Another thing to note, is that even when the mute button was engaged, the noise was still present, which tells me its probably happening on the DI path. I also did check that the grounding button was set for grounded (changing to lift did not make the noise go away). No changes I made to the amp stopped the noise (there was nothing using the 9 volt supply on the back of the head either). No difference either if I selected Pre or Post Eq.

The file attached is a direct recording of the DI as I cycle through the DI volume; from 0 to max, then some variation rotating the knob. Recorded directly into Reaper via scarlet (no filters, no changes to input or output levels).

Any ideas what is causing this? What's involved in getting this corrected, or should I just send it back?

thanks!
Jon

 

[tubedude]

Might be an ultrasonic oscillation. Call tech support or take it to a tech.

 

[Envincibal]

Might be an ultrasonic oscillation. Call tech support or take it to a tech.

Since I didn't buy it new, I don't want to put any additional money into it.

 

[agedhorse]

If it’s not new, but I g it becomes your problem. IMO, you are probably better off returning it.

 

[Envincibal]

Just adding a little more info (though I will start the return process)...
the DI does send the bass signal out as well (I should have given more info on that), along with the noise captured in the clip above.

 

[DJ Bebop]

I just purchased this bass head on Reverb, so I know I can return this (just arrived yesterday, and no issues were listed by the seller).

The amp works as it should when connected to a speaker, but when I tried the DI, I have this whinny sound going from the DI. The noise it creates is affected by the DI volume control, and when at extremes (max counter clockwise and max clockwise) there is no noise.

I tried my other bass heads (Berg Forte HP, Mesa WD800, and a GR Bass 1400 single), and no noise on any of them. To further troubleshoot the DI noise, I did try a different outlet, different XLR cable, with and without a 4ohm speaker connected, and the results were always the same - noise in the DI.

Another thing to note, is that even when the mute button was engaged, the noise was still present, which tells me its probably happening on the DI path. I also did check that the grounding button was set for grounded (changing to lift did not make the noise go away). No changes I made to the amp stopped the noise (there was nothing using the 9 volt supply on the back of the head either). No difference either if I selected Pre or Post Eq.

The file attached is a direct recording of the DI as I cycle through the DI volume; from 0 to max, then some variation rotating the knob. Recorded directly into Reaper via scarlet (no filters, no changes to input or output levels).

Any ideas what is causing this? What's involved in getting this corrected, or should I just send it back?

thanks!
Jon

Reminds me of…

 

[logdrum]

Your other amps are terrorizing it and that is it whimpering, Also the GAS spirits think you have too many amps already.

You have done thorough troubleshooting and the last step was to ask TB and the experts have spoken. Send it back.

 

[Ben Clarke]

Sounds like (from your description and the audio clip) that the issue lies in the DI level control circuit.

Definitely not normal. I'd return it or get an unreasonably large discount to take the risk of repairing it.

 

[agedhorse]

Sounds like (from your description and the audio clip) that the issue lies in the DI level control circuit.

Definitely not normal. I'd return it or get an unreasonably large discount to take the risk of repairing it.

Maybe, maybe not. This is just guessing at this point.

 

[Ben Clarke]

Maybe, maybe not. This is just guessing at this point.

Yes, I'm guessing. Jeesh.

Is there something irresponsible that I said to the OP?

I get and agree with your general POV and encouragement to not poke into things we don't understand and that can cost us a lot of money. I am grateful for the knowledge that I've acquired at little cost to me, too. There have been at least several times over the decades where your posts have taught me something new.

But come on man, I said it seems like, and is it not a reasonable statement to say that is seems like what I think it seems like?

Does every sentence that lives on FB have to be 100% defensible in a court of semantics and seven independently audited test benches?

"It sounds like" = "maybe, maybe not" to most people.

You can stand down, soldier, I'm not invading your homeland.

 

[agedhorse]

Yes, I'm guessing. Jeesh.

Is there something irresponsible that I said to the OP?

I get and agree with your general POV and encouragement to not poke into things we don't understand and that can cost us a lot of money. I am grateful for the knowledge that I've acquired at little cost to me, too. There have been at least several times over the decades where your posts have taught me something new.

But come on man, I said it seems like, and is it not a reasonable statement to say that is seems like what I think it seems like?

Does every sentence that lives on FB have to be 100% defensible in a court of semantics and seven independently audited test benches?

"It seems like" = "maybe, maybe not" to most people.

You can stand down, soldier, I'm not invading your homeland.

Really? What did I do to you to deserve this disrespectful response?

It could be a whole lot of other things, especially since this amp has a switchmode power supply, which can generate high frequency noise that must be accounted for in the design. If there is a failure in these noise current steering circuits, this can be the result. There are other possible causes too, most of them anything but obvious, and not necessarily in the DI circuit though that’s where the symptoms present themselves.

 

[Envincibal]

I just want to say thank you to all who contributed (one of the many things that makes this community so great).

I did reach out to the seller, and he says they're is nothing wrong with the DI and that it must be my setup (other factors causing the issue), which it is not (thus the DI problem cannot be replicated with any of my other bass heads using the exact same external variables: same bass(es), instrument cable, xlr cable, power cable, etc).

Since my wife and I went out of town Friday night, I haven't had an opportunity to push this further along (I really do like the amp, and the lower power really fits the bill for the small gigs we play, BUT the DI issue is still something that has me a little concerned - even though I don't see me using it with this amp, though I could be wrong, as that has happened to me before, at least the first time when I said 'I do' lol)

GR Bass did get back to me (responding to my email), but they couldn't say what the culprit was without diagnosing the amp, which is 100% understandable and expected. They also informed me that, as I purchased it used, it was not under warranty; again I totally get that (my expectations were not unrealistic).

Sorry for the long response, but I felt it was only fair for me to post a followup in this situation.

Once again, I'm very grateful for any of the help I get from the members on this forum.

 

[agedhorse]

I just thought of something… what are you running the DI into? There could be an interaction between the two devices. This can occur with some laptops and desktop (due to the reasons I mentioned earlier).

Can you try into a regular mixer if you first tested it out with an interface and laptop?

 

[Envincibal]

@agedhorse - I don't have any other interface at my home (DI -> Scarlett, powered by my laptop).
I could take it to my singer's place aga run right into his PA and see if there's any issue, that wouldn't happen until later this week.
Thanks

 

[agedhorse]

@agedhorse - I don't have any other interface at my home (DI -> Scarlett, powered by my laptop).
I could take it to my singer's place aga run right into his PA and see if there's any issue, that wouldn't happen until later this week.
Thanks

That’s exactly what I’d recommend.

Are you running the laptop plugged in or on batteries? Try both.

Can you usb power (not with laptop) your Scarlett model and use headphones?

 

[S-Bigbottom]

Yes, I'm guessing. Jeesh.

Is there something irresponsible that I said to the OP?

I get and agree with your general POV and encouragement to not poke into things we don't understand and that can cost us a lot of money. I am grateful for the knowledge that I've acquired at little cost to me, too. There have been at least several times over the decades where your posts have taught me something new.

But come on man, I said it seems like, and is it not a reasonable statement to say that is seems like what I think it seems like?

Does every sentence that lives on FB have to be 100% defensible in a court of semantics and seven independently audited test benches?

"It sounds like" = "maybe, maybe not" to most people.

You can stand down, soldier, I'm not invading your homeland.

In the amp section guessing and throwing out ideas beyond basic trouble shooting do not help or solve a problem. A few trouble shooting procedures are all that can really be offered to diagnose online. This is also very limited, especially when it comes to the inner workings of an amp. They need to be hooked up to test equipment.

Repair advice of an amp is quite different then advice on gear to buy, hooking up or techniques for playing where opinions are helpful.
The results of guessing a possible cause in an amp can lead to someone taking said suggestion and with their false sense of confidence they "give it a shot" which can lead to more damage than they had before.

"Someone online said it could be this, lets do/try it."

Especially now in the days of the AI programs taking and condensing what is said in threads like this to create an answer, bad or guessing suggestions can be and often are presented as facts.
We all need to be careful with our responses.

 

[agedhorse]

Agreed, just want to actually help the OP with his problem. One way to avoid this is by providing inaccurate or misleading information and guessing.

 

[Ben Clarke]

I do apologize for taking anything personally and certainly know better than to speak my mind in these situations here.

I think I have a tendency to be pedantic and condescending so when I think I see that coming my way, I get a bit bent.

I still think you guys are a bit fussy to have such a big problem with "I think it could be X, you should send it back because it's not right".

There's no question that the value provided to the community by Andy far outweighs mine, but I think this is a bit much to lecture me over.

What reasonably foreseeable tragedy would fall upon the OP based on my comment?

 

[agedhorse]

I do apologize for taking anything personally and certainly know better than to speak my mind in these situations here.

I think I have a tendency to be pedantic and condescending so when I think I see that coming my way, I get a bit bent.

I still think you guys are a bit fussy to have such a big problem with "I think it could be X, you should send it back because it's not right".

There's no question that the value provided to the community by Andy far outweighs mine, but I think this is a bit much to lecture me over.

What reasonably foreseeable tragedy would fall upon the OP based on my comment?

Wouldn't you like to see the OP get his DI issue resolved without a bunch of likely wrong guesses? That's the whole point of troubleshooting, to avoid guessing.

It's ok not to agree with me, or others here, but we are all trying to help the OP, and I have a LOT of experience troubleshooting this sort of thing.

 

[DJ Bebop]

Sometimes reading words off a page can leave a lot to interpretation. It is not like reading music where there might be fingering or bow indications. Doted notes or ties that lead to a better understanding of how a piece is to be played or is to sound to all reading the music.