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Troubleshooting 101


thebes

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Stuff happens. One day you turn on the system that has been running right forever, and, uh oh, somethin ain’t right.


 

This has been going on since they invented stereo systems. Sooner or later it will happen to you.

So what do you do?  Call Stereo Geeks? Shrug a lot? Cogitate in a meandering fashion while contemplating arcane stereo gizmo terms of which you know not what they mean? Pray intensely? Throw everything away and start all over? Employ logic, voodoo or hoodoo?


 

Or do you ask yourself, “what would a Thebes do?”.


 

Well now you’re getting somewhere. After all, if a Thebes can figure it out, can it truly be beyond the skills of a mentally handicapped Orangutan?


 

So the Thebes in question approaches his secondary system, which he hasn’t used in months and months.  Casting caution to the wind, he throws all the switches, jiggles all the dials, does a little dancing   jig cause he’s about to hear some righteous music, pops on a truly awesome piece of musical nirvana, and is stunned, yes stunned (I told ya he was stoopid) when he belatedly realizes something is amiss.

Yup it’s the dreaded one channel is way louder than the other, a trickier version of the classic “no sound coming from one channel” conundrum which has haunted audiophiles throughout the ages.

Believe it or not there is a logic tree that will, if followed haphazardly, will eliminate the most obvious causes of SSP’s (Simple Stereo Problems).


 

So lets look at what I’m trying to diagnose.


 

Two Channel system consisting of:

 

1 tube preamp

2 tubes monoblocks

A pair of Heresy 1’s

1 cd player

1 turntable

2 speaker wires

1 turntable rca cable

1 cd player rca cable

1 rca output cable from the preamp to the monoblocs

5 wall plugs but since everything powers up we can ignore them


 

Testing is done with the Right Channel Sounding Louder Than the Left Channel


 

Step 1 (well actually Step 2 cause this is America and you always have to watch anywhere you step, even in your home, because of random droppings by various pet,s animals and geriatric individuals):


 

Look and tug on all the various wires and rca cables, twist the cables to make sure they are not loose or not making proper contact.


 

Turn on the stereo (what do you mean you didn’t turn the system off before yanking on that stuff you dunderhead!).


 

No change. Turn everything off, and swap the output rca cables between the preamp and monoblocks (same holds true if you have a 2 channel amp).  If that’s the problem the loudness will switch from right to left. This simple test rules out any problems with the amplifiers.


 

No joy?


 

Step 2


 

Swap the rca cables between the right and left channel on the cd player, and or record player. No change means that the cd player, the turntable and their respective rca’s are just fine.


 

Step 3


 

Swap the speakers wires or swap out the actual speakers from right to left. No change. It’s not the speakers.


 

Step 4.  Kinda don’t need step four cause it’s obviously the preamp, and if it’s not the preamp cables (which you’ve already ruled out, then you obviously have a mechanical or electro problem with the preamp. Which means you are starting to swear. A lot, cause while you’ve passed Troubleshooting 101, you’ve still got along ways to go before your stereo is going to sound right.

 

Brought to you by Thebes-O-Rama University, Copyright 2018

 

 

 

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Iv'e got a tube Pre and a tube 2 channel power, all Kit stuff I built that if this happens to I can fix provided parts are still available...

My question... in the class D area, does one just replace the board/s???

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Does either the loud channel or the soft channel sound distorted?

 

Does the preamp have a balance control?  Does it, or any other pot, make noise when you rotate it?

 

Since it hasn't been used for quite a while, watch the preamp carefully while you heat run it.  Have a fire-extinguisher handy.

 

From here on out, do what a mentally handicapped Orangutan would do.

  1. Call Best Buy and see if they have a repair department.
  2. Look at the internal wiring of the preamp.  Purse and pucker your lips a lot.
  3. Like the astronauts, "When in doubt, rap on the panel."
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12 hours ago, jimjimbo said:

Is there a question there, since you stated it's obviously the preamp?

Nope.  Just a few simple steps to eliminate common problems that occur from time-to-time in many stereo systems.

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Now having identified the problem with the preamp, I've taken a few more steps. This is an Anthem Pre1 with six tubes in three pairs. I swapped all the tubes left to right and no change, so it's not a tube. From here it gets far more challenging. I'm going to have to take measurements either from the outputs and work my way back or start with the outboard power supply and work my way forward.  If I can't locate a simple problem, then its most likely beyond my skill set and will have to be sent off to Craig for repairs. No schematic has ever been released for this preamp, which also has a bunch of solid state stuff inside it, so troubleshooting is going to be a challenge.

 

Please understand that your typical Thebes has a very checkered history when sticking probes into live circuits, having on occasion rendered partially working gear into totally not-working gear.

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