Randall RG100ES Guru's take a look!

[g1]

  There are no level controls for the loop on that amp.
But most FX units will have input and output level controls.  Try adjusting them, turn up the input and reduce the output level and see if it helps.  Or the opposite, turn down the input and turn up the output.
  Also it there are any -10/+4db level switches, they should be at -10 setting.

[Kizzlecake]

this is the noise with both gains and masters at zero.  its a little quiter with everything atzro but not much

[phatt]

this is the noise with both gains and masters at zero.  its a little quiter with everything atzro but not much

OK I'll try to explain a very simple reality that a lot of guitar players struggle with.

Fire up that super quite power amp you mentioned.
Now go and find every bit of fancy pants rack preamp gear as well as every super dooper TS999999 and plug them all together in series. One after the other.

Now turn all the dials up past half way and engage every one. :duh

I'd lay money on the fact that the hum, buzz, hiss, fizz feedback would be louder than any guitar chord played.

Hi gain + no brains = S**T sound.

Now if you hang around sites like this for long enough you will eventually realize that most modern amps are just old style amps with more gain stages.
Old amps had no Extra channels of added gain,, you did that with pedals. :tu:

Modern Amps are just old amps with pedal circuits inbuilt.

Frankly Few modern (all in one box) designs actually work that well and I've meet many players who end up not using the Hot channels on there rigs
(Insert bootweaked brandname of choise)
and end up resorting back to basic pedal circuits. 8|

Much like building a sky scraper you can't just keep going higher.
The Laws of fizzy things limits how far you can go no matter how much more you throw at it.

In your case all you are doing is amplifying transistor noise, any mains hum would be drowned out by electrons smashing into each other. (Google boltzmans noise)

Most players would think that if you want more distortion you turn up the Gain.
If I told you you can actually get better distortion by turning the gain DOWN You would likely think I don't have a clue about amplifiers. :loco

Well that is exactly how circuits in Trainwreck and Soldano and likely many other makes now do it with triode circuits.  You can do similar things with FETs.

Distortion is the easy part,, the TONE SHAPING is the real tricky part to overcome. :grr

Meantime,, As I own a Qverb,, try adjusting the *MIX* section.
Depending what config you are in the mix controls sends level (gain) to different parts of the efx.
Keeping a close eye on levels there can help the dreaded hiss issues you have.
I don't use my Qverb much these days as they are just way to fiddly to work with.
when I do use it, it's in a para efx loop just to add some subtle modulations.

If you own the GT Qverb then even harder to to keep the noise under control.
It bent my brain trying to come to grips with my unit and only made sense when I used software interface to control parameters.
Phil.

[Kizzlecake]

alot of good info thanks.  I forgot to mentio  the sound clip was just the amp at no volumes and nothing in the loop.  If you are telling me that is normal than I'll roll with it.

[phatt]

Oh I've heard a lot worse than that. :lmao:

Yes you may have to live with it.
The other option is bypass the whole front end with a better designed preamp and just plug into the return socket.
I gave up on guitar amps and now use my home grown preamp floor pedal which plugs into a power amp.
Phil.

[Kizzlecake]

Update....  Figured out the base noise hum is coming from the power transformers,  not sure if its cause they are old or junk or what.  Bigger question is where to get a replacement.  Anyone got any ideas?

[Roly]

Figured out the base noise hum is coming from the power transformers

What draws you to that conclusion?

Pardon me while I seriously doubt that.  Transformers simply don't have any mechanism for generating electrical noise such as in the sound sample.  Acoustic noise due to loose laminations, sure, but electrical noise?  Not unless it's arcing inside and just about to catch fire (which it should have done by the time your read this).

My first impression from the sound sample is that you are hearing mains-borne hash from something like a light dimmer or nearby switch-mode power supply, that it's mains-borne coming through the power transformer maybe, but not generated by it.

See if you can find a mains line filter and try the amp powered via that.

[Kizzlecake]

Even with the speaker unplugged you can still hear noise from the transformer. Perhaps it is the house,  there are a couple dimmer switches in the kitchen.  I have tried being plugged on the top floor,  bottom floor and the basement and all have the same result.  Niw as far as a main line filter I'm not sure what you are talking about but I have tried one of those Ebtech Hum x wall plug deals and it didnt help.

[Roly]

Even with the speaker unplugged you can still hear noise from the transformer.

This is physical noise I mentioned.  There is a loose lamination or winding turn in the transformer that is reproducing what is coming down the mains, not creating it.

The light dimmers would be prime suspects, but it could also be from the many modern appliances (even next door) that have switch mode power supplies these days.  Light dimmers are prime suspects because they generally have very poor internal noise filtering and are connected to long runs of cable between the dimmer and the light that can act as transmitting antennas, however in your case whatever the source it is almost certainly switching crud coming down the mains and into your amp that way.

Proper line filters (not "surge suppressors") aren't common in shops any more, but many computer and terminal power supplies contain real line filters which can be scrounged from old ones, e.g...



See also;
http://www.ozvalveamps.org/mainsfilter.htm

I don't know exactly what the Ebtech Hum x wall plug contains, but it's for a different  problem, a ground loop which isn't what you have got here, and isn't a line filter  (which wouldn't cure ground loop problems anyway).  In fact it seems to be the opposite of a line filter in that it treats the ground but directly connects the active and neutral, where a line filter treats the active and neutral and passes the ground directly through.


{I must remark that while the Ebtech Hum x may be effective in what it is intended for it is rather dubious from an electrical safety PoV.  I very much doubt that it would get type approval in LEN countries such as Australia or the UK, and in fact doesn't even seem to have UL approval in the US.  As a soundie and tech I would consider it a band-aid for a basic earth loop problem that should be fixed, not just hidden, particularly at the expense of human safety.}

[Kizzlecake]

Makes sense, I also hear the same thing from other lights and things like my surround sound subwoofer I'll try and locate a line filter. Thanks a ton.

[Kizzlecake]

http://tesco-online.com/15nw20nw.html

like this guy?

[Kizzlecake]

http://www.smarthome.com/4845ACF/Advanced-Control-Technology-AF120-15-Amp-Plug-In-Noise-Filter/p.aspx

or this guy

[Roly]

Ideally the problem should be fixed at source, the thing(s) radiating the crud should be filtered themselves to stop it getting out, but with so many light dimmers &c around it becomes impractical, so the only real option is to pull up the drawbridge and just filter the power to the amp.

Both of the devices you link to might work but they are to address a different problem again, line noise getting into X10 home automation networks.  These filter the specific band of frequencies that these systems work on but don't appear to filter down into the audio range which seems to be the cause of your problems.  The first one with four outlets and provision for Ethernet filtering seems to be way overkill, and being an X10-specific filter might not help.

This fella appears to be a straight line filter but has much more capacity than you need;

http://www.onfilter.com/products.html?s=20ASF


The filter I showed above is a combined power inlet and filter, but these are also available in various filter-only forms intended for internal installation.

Wire ends;


Spade ends;


These are generally pretty cheap but do require fitting, either by yourself or by a tech.

[Kizzlecake]

that one in the link looks good.  i'm looking for a plug in deal if possible. you think this one will suit my needs http://www.smarthome.com/4845ACF/Advanced-Control-Technology-AF120-15-Amp-Plug-In-Noise-Filter/p.aspx

[Roly]

No.  You can try it by all means, but don't be too surprised if it doesn't help.  It specifically gives "30:1 attenuator ratio on frequencies between 30kHz and 200kHz" and you really want a wide band one that actually covers the audio spectrum.

Frequencies less than 80kHz and greater than 200kHz are allowed to pass through the circuit relatively unaffected.

So it's simple to install all right, I just don't think this one (or any X10-specific filter) will do the job for you because it specifically doesn't filter the audio band, which is what you want.

"To every complex problem there is a neat and simple answer - neat, simple, and wrong."


Personally I'd get one of these (buy or ex-equipment) and fit it in a die-cast box with a suitable mains outlet (remembering to ground the box itself).  It shouldn't be any more complicated than fitting a mains plug, and the extra effort should result in a cheaper unit that will do a better job.