Need Help Using Pedals with VH4(fixed with iso power)

[steve_k]

Did you try cable with ground cut from pedal to amp yet?

No unfortunately I wont be able to give that a try until tomorrow. At work now and got band practice tonight. Ill post my results.

Will the delay pedal you are trying to use, take a 9V battery? If so, try using a battery for the testing the pedal.

Are you using some pedal power (Voodoo or other) on your pedal board? This will usually fix these sorts of issues, unless the pedal is defective.

A buffer will make no difference in the presence or absence of the ground loop, just make it sound different.

And, as Peter asked, you should change the topic title. The problem is in your pedal, not the amp.


Steve

 

[eonblue]

Did you try cable with ground cut from pedal to amp yet?

No unfortunately I wont be able to give that a try until tomorrow. At work now and got band practice tonight. Ill post my results.

Will the delay pedal you are trying to use, take a 9V battery? If so, try using a battery for the testing the pedal.

Are you using some pedal power (Voodoo or other) on your pedal board? This will usually fix these sorts of issues, unless the pedal is defective.

A buffer will make no difference in the presence or absence of the ground loop, just make it sound different.


Steve

No, the delay will not take a 9V battery. As for the power source, in both cases I am using the manufacturer supplied power source directly into the wall.

And, as Peter asked, you should change the topic title. The problem is in your pedal, not the amp.

This has not at all been established and when Peter made that request he was under the false assumption that I was using the FX loop, which I am not. Im sure Musicomlabs or Empress wouldn't appreciate such a hasty judgement to point the finger at their product any more than Peter would. And pointing my finger at the VH4 was not my intention.

The fact is that the sound is reproduceable now with two separate high quality units. The likelihood of them both being defective is pretty low since they are both brand new and work in every other application. I'm thinking its not a "problem" with either the VH4 or either of the pedals, but simply a common issue with effects chains. How about this, I'll change the title to more aptly describe the current situation as I see it stands now. If it isn't adequate, you guys can change it to meet your own requirements.

I just want to resolve the issue.

 

[eonblue]

By the way, Chris Campbell from Rockbox tested the unit with a Two Rock and his own custom amps and was unable to reproduce the noise using the chain I've described herein, but his power situation might be different, Im sure there are a number of variables one has to account for in these matters. He did not have a VH4 on hand to test with.

 

[slyvren]

Two rocks are low gain. His power could be different. You might also want to check your cables again. I'm telling you I doubt its the amp. Ive had several issues with noisy pedal chains in the past. 99% o the time it's ground loop. Factory transformers aren't ground loop isolated thus it wouldn't mean a thing. You need to get an isolated transformer and again I'm suggesting try different cables and guitars. By the way.

 

[stefvorcide]

I really don't get it. Why do you plug you unit in front of the VH4 when the Loop is great?? especialy a delay in front...

come on, it's not serious

 

[eonblue]

I really don't get it. Why do you plug you unit in front of the VH4 when the Loop is great?? especialy a delay in front...

come on, it's not serious

I specifically said in this thread that the delay in front of the amp is purely for test purposes and that my normal chain includes the delay in the parallel loop.

 

[eonblue]

I just want to make it clear that I love my amp and have for 4 years. Im asked about it constantly after gigs and always speak highly of it. That being said, this forum has always served as a place I can come and ask questions about various aspects of my rig which is why Im here. Im not here to bash anyones product or tarnish anyones image be it Diezel, Empress, or Musicomlabs. I consider being able to ask those questions in this forum above and beyond normal support for a piece of equipment, but then again you pay for it. But the fact is, this is where people go to ask questions about how to solve problems when a Diezel product is included in the chain and thats what Im doing

Two rocks are low gain. His power could be different. You might also want to check your cables again. I'm telling you I doubt its the amp. Ive had several issues with noisy pedal chains in the past. 99% o the time it's ground loop. Factory transformers aren't ground loop isolated thus it wouldn't mean a thing. You need to get an isolated transformer and again I'm suggesting try different cables and guitars. By the way.

As for the ground loop thing, I totally believe you and you've been extremely helpful with this issue and I thank you for that, seriously. This is why I come here and its most appreciated. As for your suggestions, Ive tried multiple cables and multiple guitars. The bit about the manufacturers power supplies not being isolated is interesting, unfortunately I dont have access to an isolated power supply at this time. That being said, I am going to unground a cable as you suggested in the morning and Ill post the results. The way I look at it, if its a ground loop thats awesome because thats easily addressable. But before I do that, you mention basically that you can get hurt doing that, could you explain how I can avoid killing myself?

 

[slyvren]

If improperly grounded you might serve as ground. It's very highly unlikely especially for short test. Just make sure you don't touch something metal and should be fine. The bigger risk is if you have a ground lift on the mains power connection (no 3rd prong) but we all do it any way. Please just be mindful when using equipment. It's more of something mentioned here for lack of liability.

In other words don't worry so much especially for testing briefly. Would be best to make connections and then turn amp on and listen for buzzing.

 

[slyvren]

Oh I forgot to say. Thank you for your kind words. You are welcome I try really hard to help around the diezel forums and its nice to hear thanks now and then. Sometimes I do more harm than good though. I understand what you meant. People here are mainly for troubleshooting problems with the amp. You have to understand where Peter is coming from too. If someone wants to buy his amp and comes on forums and sees a bunch of postings saying problems when the problems really aren't his amps then it hurts his amps reputation. It's gotta be frustrating for him because he cuts no corners and engineers his amps better than 99.99% of other builders. That's why people were asking to change topic. Not because they think you are a bad person or they think the question is stupid or whatever.

Anyways I hope that clears some things up. Good luck!! Let us know how it goes.

-John

 

[eonblue]

Oh I forgot to say. Thank you for your kind words. You are welcome I try really hard to help around the diezel forums and its nice to hear thanks now and then. Sometimes I do more harm than good though. I understand what you meant. People here are mainly for troubleshooting problems with the amp. You have to understand where Peter is coming from too. If someone wants to buy his amp and comes on forums and sees a bunch of postings saying problems when the problems really aren't his amps then it hurts his amps reputation. It's gotta be frustrating for him because he cuts no corners and engineers his amps better than 99.99% of other builders. That's why people were asking to change topic. Not because they think you are a bad person or they think the question is stupid or whatever.

Anyways I hope that clears some things up. Good luck!! Let us know how it goes.

-John

I completely understand. I always thought it was a shame that Peter had to field so many questions about problems where the source was simply bad tubes. At the same time, the issue that you bring up I think is just something inherent in a technical troubleshooting forum also serving as a form of advertisement. Kind of a double edged sword. But in the end, I think(hope) everyone realizes that you get to ask the maker of the f'ing amp questions and that this in itself is above and beyond.

 

[eonblue]

Alright, so I straight up snipped the copper sleeve solder point on both sides of an audio cable and the sound went from a buzzing to a much louder, outright hum. Does that tell us anything? Also, I found this description of a ground loop in a document by Ebtech.

"Going up the AC power cord ground from the electrical system wiring to a keyboard, going across a signal line ground
from the keyboard to a mixer across the signal ground, down the mixer's power cord ground reconnecting to the electrical
system wiring."

In the above chain if you replaced "keyboard" with "pedal" and "mixer" with "VH4" that pretty much describes my chain. (no instruments plugged into anything btw). Except, I just cut the ground in the signal line between the pedal and the VH4 right?

 

[eonblue]

Might have a breakthrough. For some reason I thought about comparing an extremely short cable to about a 15 footer and the difference in the noise level is staggering. Much much louder with the long cable. Surely thats got to point to something.

 

[slyvren]

I told you try different cables!! I'd try all new cables and also take your amp to a buddy's house next and repeat all experiments.

 

[eonblue]

I told you try different cables!! I'd try all new cables and also take your amp to a buddy's house next and repeat all experiments.

Heres the deal, I still get noise with the highest quality cable I own, an Evidence Audio Lyric 10 footer. The short cable I experimented with is a 4 inch Canare patch cable vs. the 10 foot Evidence Audio. Both extremely high quality cables. The noise between the two is exactly the same except with the 4 inch cable, the buzz is almost non existent and well within exceptable bounds whereas the buzz through the 10 ft cable is that same noise, only much louder and not exceptable. Doesn't this point to an impedance issue?

 

[slyvren]

... maybe.. Have you tried using pedal in one of the channel's inserts? Im still thinking ground loop or something. Isolated power. Worth every penny. Get one and end your problems.

 

[eonblue]

... maybe.. Have you tried using pedal in one of the channel's inserts? Im still thinking ground loop or something. Isolated power. Worth every penny. Get one and end your problems.

The pedal is dead quiet in serial and parallel effects loop, are the channel inserts different, Ill try it and see what happens.

 

[eonblue]

The pedal is dead quiet in the channel insert running long cables.

 

[slyvren]

Why not just run the pedal in an insert or the FX loop and call it a day?

 

[eonblue]

Why not just run the pedal in an insert or the FX loop and call it a day?

Can't do that because I sing when I play and to reduce tapdancing I need to run a pedal switching unit(the Musicomlab). That unit needs to include a fuzz which needs to run before the preamp from what I understand.

 

[eonblue]

Hey Peter, Slyvren needs a raise around this joint. I found a wall wart class 2 transformer supply laying around the house which matches the polarity of the pedal. When using this supply the signal is back to its pristine Diezel quietness! Awesome job and thanks everyone for helping, this forum is such an asset.

I also updated the title again to reflect the diagnosis