Volume drop w/ effects in FX loop and Transformer Hum

[dmt]

I have a Simul-Satellite amp, 85watts, w/ Graphic EQ, and I am having some issues with the FX loop.

If I run the amp guitar > amp (w/ hotplate) with the settings Master: 5.5 Volume: 3.5 I get this nice dirty clean or slight crunch sound.

When I have anything in the FX loop plugged in the crunch goes away. If I attempt to compensate by upping the volume of the effects in the FX loop I get either a squealing sound or blips. Odly enough they sound like a fuzz factory oscillating. I assume this is bad.

I am running an Ibanez AD202 Analog Delay, a DOD 866 Series II Compressor, and a DOD 830 Series II Graphic Equalizer. I have been experimenting with the order of those effects in the FX loop with mixed results. There is a gate in the compressor so I want that before the day, so that the delay doesnt get chopped short, but if I boost the output signal on the compressor for a little added gain it squeels, and alos pushes the delay harder, which I asume is not good for the circuitry.

What can I do to acheice the same sound I get from the amp with a straight guitar > amp setup while keeping my effects in place in the FX loop? The delay sounds better in the loop, and the compressor and eq arguably give me more control over the preamp sound and should allow me to get more drive from the preamp? Is there sometihng wrong with the amp? The FX loop? Or are all Boogie FX loops prone to this phenomenom?

Tubes in the amp are Sovtek KT66's and a pair of old RCA/Hytron tubes (12AX7A/12AT7).

 

[eltrain858]

i would think to put the compressor in front of the amp

 

[Dutchman]

Sounds like it could be an impedance mismatch between the output of your processing gear and the input of the boogie.
Another thing to check is if you amps FX loop is parallel or series, that creates some problems too.

 

[MrMarkIII]

I have a Simul-Satellite amp, 85watts, w/ Graphic EQ, and I am having some issues with the FX loop.

If I run the amp guitar > amp (w/ hotplate) with the settings Master: 5.5 Volume: 3.5 I get this nice dirty clean or slight crunch sound.

When I have anything in the FX loop plugged in the crunch goes away. If I attempt to compensate by upping the volume of the effects in the FX loop I get either a squealing sound or blips. Odly enough they sound like a fuzz factory oscillating. I assume this is bad.

I am running an Ibanez AD202 Analog Delay, a DOD 866 Series II Compressor, and a DOD 830 Series II Graphic Equalizer. I have been experimenting with the order of those effects in the FX loop with mixed results. There is a gate in the compressor so I want that before the day, so that the delay doesnt get chopped short, but if I boost the output signal on the compressor for a little added gain it squeels, and alos pushes the delay harder, which I asume is not good for the circuitry.

What can I do to acheice the same sound I get from the amp with a straight guitar > amp setup while keeping my effects in place in the FX loop? The delay sounds better in the loop, and the compressor and eq arguably give me more control over the preamp sound and should allow me to get more drive from the preamp? Is there sometihng wrong with the amp? The FX loop? Or are all Boogie FX loops prone to this phenomenom?

Tubes in the amp are Sovtek KT66's and a pair of old RCA/Hytron tubes (12AX7A/12AT7).

Yeah, compressors generally go in front of an amp, otherwise any pre-amp hiss/noise gets amplified again. Squealing is often caused by turning too many knobs all the way to the right. 5.5 on the Master is just about ALL-THE-EFFING-WAY-UP. Or, maybe too long a release on the comp? Or maybe your pre-amp tubes are microphonic. Are they long plates (17 mm)? I'm pretty sure the Satellite's Graphic EQ is post-loop, so why use two? On the third hand, try the same settings but with/without the Hot Plate. Maybe that's doing some thing weird.

 

[eltrain858]

try taking your effects out of the chain one by one and see if you can identify whether one of them is the main culprit.

 

[dmt]

Ok, so i have tried just about every combination for the last three hours. Heres my theories.

• A) The compressor was setup all wrong. I played with just that for a while to get it to sound a bit better. It no longer squeels. Turning it way the **** down genreally helped. Also, lowering the level on the delay helped as well.
  
  B) I did the same thing with the Ampeg (this is the right channel of the rig) I set it up how I had marked it years ago with some slight adjustments.
  Sometines what you have figured out in the past works better.
  
  C) In connecting and disconnecting the DOD EQ/DOD Compressor and Delay in various combinations this is what I found:
  
  • 1. The amp sounds fucking awesome on its own(dirty clean), crunchy with the preamp volume boosted, and crunchy as hell with just a boost pedal
    
    2. It still sounds bad *** with just the delay, but I need to boost the volume on the Delay to get the same level of crunch with nothing in the FX loop connected.
    
    3. Adding the compressor needs more compensation, and activating it doesn't do all that much, cranking it will not get more crunch. It stays becasue it has a gate on it.
    
    4. The EQ in the loop tightens up the distortion sound quite a bit, probably because I am scooping the low mids quite a bit. I originally put it there because the Simul-Satellite has only ONE knob for preamp EQ, so i thought this would help shape the sound quite a bit since it has 15 bands. Not sure if it further sucks more sound.
  
  D. I am begining to wonder if most of the tone sucking is simply due to alot of cable being added to the FX loop. Approximatley 19ft of cable connects the various rack compnents together. No cable is longer than 5 ft. These are 'regular' cables from guitarcenter, you know the shitty black ones with the blue trim by the plug.

I also listend for various hums/hisses and found that the fan is quite noisy. In unpluging it I also confirmed that there is still a humming noise and vibration present even if the fan is unplugged. Not good. It sounds loudest behind the graphic EQ of the amp; if it put some upward pressure on the chassis it stop humming, but the vibration is still present. Feels like it could be the output transformer. The sound it makes is identical to the large transformers in the building. I live in an old old building with very large, ineffeciant transformers from at least 40 years ago. This play used to be a Raytheon Missile Factory. I discovered the noise at my freinds place, cause the practice space at his house has really shitty wiring.

I have run the amp with a THD Hotplate attenuator for the 4 years that I have owned the amp. I remember reading someplace that having a resistance load (as opposed to a reactive load) on the amp can be damaging to the output transformer. What are the signs of transformer failure and is there some way I can check if my transformer is dying? Whats the cost of a new one. granted I know it will change the sound of the amp if I do have to get a new one installed.

I do run the amps on as clean of a line as I can get it. I have a APC battery backup unit that I use for a line regulator. It should in theory give the amps a nice clean signal. I need osme help with this one.

 

[dmt]

As for the poreamp tubes: Here are some pics. These are the tubes in the amp:

RCA? 12AX7A:

Hytron 12AT7WA

The Lowery is really an RCA or maybe Raytheon. The HYTRON i think is a Military Spec tube as far as I can figure. The RCA is in the V1 position i think (its farther forward toward the front of the amp)

 

[dmt]

I took out the compressor and the eq out of the FX loop of the boogie and it sounds more 'natural'. It seemed like the way I had it setup was probably harmful to the amp. And also a waste of good tubes. I lowered the volumes quite a bit and can actually get a nice overdrive out of the tubes with just a boost pedal and my Fuzz Factory sounds good through the amp agian. I don't need the compressor to further puch the preamp, nor the eq really. The eq was the main culprite for sucking the tone out and lowering the volume. I don't know how to check the impedance of either the DOD compressor or EQ. I won't have extra control over the eq, but i was maintly using it to scoop the mids a bit and push the lows/highs in the preamp and add some mids back later in the Amps Graphic eq.

 

[eltrain858]

did you ever try throwing the compressor out front?

 

[dmt]

Yeah. I didn't like it. And it made hooking everything up weird. The DOD compressor is very sterile. I prefered the amp wdie open. The Delay in the preamp (FX) sounds fine, minimal tone sucking. The amp sounds much warmer now, probably due to the fact that I am not scooping the mids in the preamp. Whats the point of having warm old Preamp tubes if you just crank the **** out of them and eq them out? Nothing. It's not as metal sounding (high gain) but I got my Fuzz FActory to sound awesome agian and thats plenty good.

 

[eltrain858]

yeah, i've never really been a fan of DOD/digitech effects (a select few excepted).. they can sound decent, but when you compare them to a more pure tone it's night and day..