How much noise (hum) is normal/acceptable?

[Jeremiah]

Long post alert... please read fully before commenting.

I just got a new amp (Traynor Darkhorse head) and while I'm loving the actual sounds, I'm not so impressed with the level of background noise.

There is a definite buzz coming from the speaker whenever the amp is switched on and not in standby mode. It's noticeably louder than the noise produced by my other tube amp, a VHT Special 6 Ultra, at similar overall volume levels, and appears to be a definite "buzz" whereas the background noise from the VHT is more of a "hiss."

As you might expect, the noise level increases when the master volume is turned up - it also increases as gain is turned up, but less than with master volume, so that the best signal-to-noise is achieved with fairly high gain and low master.

What's puzzling me slightly is that the level of noise is sensitive to the guitar's volume and tone controls, with the buzz reaching a maximum when the guitar's volume is on 7-8, fading slightly at max volume and reducing more when the volume is turned down. There is still some buzz even with nothing plugged into the input.

This by itself would suggest that the noise was being generated in the guitar somewhere rather than the amp. EXCEPT that it is the same with all my guitars and does NOT occur with my other amp (the VHT.) Could this indicate a grounding problem?

I have also noticed that there is an audible hum emanating from the head itself (not the speaker) when it is in standby mode. I don't know if this could be down to the exposed transformers, or if it could mean the amp is faulty.

The buzz is not that noticeable if I am playing standing up, only if I put my head near to the speaker. Unfortunately, if I want to use the amp for recording that is where the microphone would go, so it would possibly be a problem. It's also not too audible during rhythm type power chords and other continuous loud playing - it's just in slow parts with sustained notes, when the guitar signal fades away the buzz becomes audible.

I have tried using different power sockets in different rooms, this doesn't make a difference. I have also tried some alternate preamp tubes. This might have reduced the problem a bit, it's kind of hard to tell.

I remember reading that the early production Darkhorses had a problem with noise due to wires being left excessively long inside the head but this was meant to have been fixed in later production. I'm pretty sure mine would have been one of the recent models as that was back in 2010 or something.

I could send it back, but before I do so I'd like to know if it is likely to be a fault with my amp or an actual problem with the whole design. Or whether it could be caused by something that is easily fixed like dodgy output tubes.

Thanks for reading...

 

[hermetico]

Re: How much noise (hum) is normal/acceptable?

Noise is always an uggly monster to chase.
Did you tried a good Noise Gate, as the ISP Decimator G-String between your guitar and amp?.

Some things to try:

1) Isolate your gear from your mains.
Use some kind of current adaptor or conditioner, with filters and isolated outputs (via a transformer) to feed your rest of gear. This should de-couple your gear's ground from your main's ground (that's usually a good source of noise).
If your home's ground is bad, will be bad in most of wall outlets.
Check Furman stuff, to have an idea but, there are cheaper solutions around.

2) Use quality cables and jack plugs.
I don't mean the expensivest cables but, good enough. With 100% shield and good RF or EMI rejection. Use metallic encased jack plugs of quality. Mogami cable and Neutrik jack often work as good as an LP and a Marshall.

3) Use quality patch cables and jack plugs on your pedal board.

4) Use a power adapter with isolated outputs again, specially, if you are mixing positive and negative ground pedals (i.e., if you are using some kind of germainum fuzz in your chain together with rest of pedals). Otherwise, run a separated one spot adapter for your germanium fuzz (when possible, otherwise, use batteries). The goal is to isolate every pedal ground from the rest of grounds...

5) Use HIGHGRADE LOW MICROPHONICS quality tubes for your tube V1. This is were you have to put your main money. This is the most critical on your chain. Any bad thing there will be highly amplified by the rest of the gain chain. If V2 is also part of the tone shapping stage, use good quality tubes also there.

6) Avoid to play under fluorescent lights and some other kind of electromagnetic sources.

7) if all these reduces the noise but doesn't removes it. Say welcome to a quality Noise Gate, as the ISP Decimator G-String (don't waste money on cheaper but not so efficient units, including the cheaper ISP Decimator!).

For sure, they are still more thing that could introduce noise but, I think those are the main things to get rid off first.

Just my 2 cts.

What are the tubes currently loaded on your VHT and in your Traynor?.

 

[ericmeyer4]

Re: How much noise (hum) is normal/acceptable?

Great advice from Hermetico.

Additionally...

1) Check the physical placement of your gear. If my wah is too close to my pedal power supply I get noise.

2) Shield your guitar

3) If you are running a lot of pedals or long lengths of cable try using a pedal buffer. This will convert your signal to low impedance (z). Low Z signals are less prone to excess noise.

4) Don't be near computers, tvs, etc.

 

[Jeremiah]

Re: How much noise (hum) is normal/acceptable?

Ok, thanks for the suggestions so far.

Just to clarify:

1. I am not using any pedals at the moment, just the guitar direct into the amp.

2. The cable I am using is made by Klotz - I guess it's not the best, but it's always been good enough so far, including with the VHT amp.

3. I have not tried using a noise gate as I don't have one available, however I have used a power conditioner and it did not make a noticeable difference.

About the tubes used: According to the Traynor manual, V1 & V2 are the power tubes (JJ 6v6.) V4 is the preamp and V3 is the phase splitter. The stock tubes are basic Sovtek 12AX7WA.

The preamp tubes in the VHT are a Sovtek 12AX7 LPS and a reissue Tung Sol - these are the tubes I swapped into the Traynor just to see if it made a difference, and maybe it did a bit, it's kind of hard to be sure after you've switched the amp off, waited for it to cool, then swapped the tubes and powered on again.

I'm actually wondering if the Traynor is an innately noisier design, possibly because it is MUCH more compact and having all those components and cables so close to each other on a small PCB might inevitably allow greater interference, while the VHT is much larger for a pretty simple amp. Is a push/pull amp also possibly noisier than single ended?

I know most tube dealers sell preamp tubes that are specially measured/balanced for use in V1/phase splitter positions - I wonder if it would be worth trying one of these to see if it made a difference. I could also maybe order a matched set of 6v6s in case that could be partly to blame. (The amp is cathode biased, so it should be possible to replace the power tubes without worrying about rebiasing.)

Also - I'm sure that SOME of the noise is coming from the guitar, as I notice more noise with just the bridge pickup selected than with both pickups on (even when they are both humbuckers.) However this cannot be the only thing, as with everything else being identical, the Traynor has more noise than the VHT.)