Tube amp bias adjustment advice

you should set the bias per the amp specs....period.  This is not something you do by ear, only by measurement.

So I have no balance adjustment, why am I hearing more from the left speaker than the right when I am seated in the middle?  They are both exactly the same distance from the back wall and at the same angle, within a 1/8 of an inch.

mmporsche OP

Don’t touch the bias yet, before answering some questions.

1: Was it in balanced before?

2: If you swap the amps "only", does then the right speaker sound louder or is the left still louder?

Cheers George

Have you try swap the tube from left to right?

Have you try swap the tube from left to right?

Don’t do this as then you will have to re-bias both of the the amps.
Just swap the amp whole from left to right first, and say which side is louder.
(it could be the source or the speakers) that has to be ascertained first before doing any re-biasing, and a 211 biasing is not a very safe area to be fiddling with if your not confident, with the HT around that area.)
  
Cheers George

Swapping tubes,then cables is a start.Oftentimes it's sound waves building up on one side/ corner of the room. My room for instance has bass build up in two corners diagonal to each other. Behind the right speaker and behind me to my left. I solved my problem with room treatment and a *swarm* of subs.Not saying that's the case, but just something to check out.

@mmporsche 

you are biasing 'the first' set of tubes?

so new amp, or just new tubes in amp you have used for some time?  no channel imbalance before as you have been using this amp?

you need to clarify these critical contextual parameters to get any useful advice

You do not measure from the back of the speaker to the wall behind it. You measure from the front of the speaker to your nose at the sitting position. 

@needfreestuff I am following the instruction from the manufacturer.  I have single point source drivers, Voxativ 9.87.  I am centering myself between the speakers so the distance is the same so I am confused by your statement.  I find myself needing to sit about 2 feet to the right for it to sound balanced.  Both speakers have about 7' to the outside side walls.  

This is a second set of tubes, had the same issue previously so I am thinking it may be room acoustics. 

I will try swapping the speaker cables L to R and see if I notice any change.  

@mmporsche The first step is to swap the interconnect cables left for right at the inputs to the amplifiers so that you can determine if the amps are at fault. It could be something upstream.

If the problem stays put => amplifier problem
If the problem moves => problem upstream
If the problem stays put, swap the input tubes, not the power tubes. In this way no bias readjustment is needed. Most of the gain in the amp occurs in the input tubes so this is the most likely area to have a gain issue!

The bias will not affect the gain unless its a mile off! It affects *distortion* and usually at higher power levels.


Keep us informed of your progress.

"This is a second set of tubes, had the same issue previously so I am thinking it may be room acoustics. "
Had the same problem with center image staying in the center until I did room treatment. Problem solved.

You should also move the speakers left to right to see if the issue moves with the speakers. That'll eliminate the speakers as culprits. Simple enough.

1. at least it is a constant rather than a damnable intermittent problem.

2. when did this start? was it balanced before with a prior amp? With this amp before you changed the bias? this amp before you changed the tubes? did you move your speakers in/out of position? speaker wire connections checked?

3. anything else changed prior to the amp/tube/bias change? IOW, if nothing else was changed, then no need to suspect other equipment in the chain prior to amp and speakers.

4. but, even if not changed, a cable could have been inadvertently disrupted. my most recent imbalance turned out to be a cable, a very good cable, but became slightly loose on the rca input. Squeezed tight with pliers, problem gone, then replaced that pair with tight ones.

5. did you change which inputs you used on a preamp or integrated amp? gotta think that thru.

........................................

a. swap all left tubes with right tubes: problem still on left? not the tubes.
b. change speaker wires on amp, problem moves to the right, or still on the left? 
c. without changing anything else, move the speakers themselves. problem still on the left? good, speakers are fine!
d. put the speaker wires back correctly l/r on the amp.
e. narrowed down to ___ possibilities?
 

Room acoustics can be a bear to deal with, especially so when the room has to serve other family uses, or, for example, meet the decorating needs of a spouse. That said, small changes in speaker position and adjusting things like toe-in can often have a dramatic effect even if you can't add much in the way of wall treatments or the like. 

How about using your cell phone, buy a SPL plug in mic. Calibrate the mic and do a test or two. Quit guessing and see if one is actually louder than the other.

https://www.amazon.com/Dayton-Audio-iMM-6-Calibrated-Measurement/dp/B00ADR2B84/ref=sr_1_2?crid=3KHWP

ES posted this little mic and it works quite well. 19-20.00 usd

Order now and Prime usually gets it there in a day.
How are those ears? Make sure.

Most important, make sure you don’t have a speaker wired out of phase or something simple like that. A wire that is mismarked, or hooked up wrong.. Being that far off center is more than a balance issue.
Balance is time arrival, somehow that’s being messed with, right?
Phase shift, will cause a lower spl and late arrival..

Check for proper connection on the monitor section to the bass section.
Make sure they are in phase.
Check the SPL, make sure.. 20.00 one day...

Regards

My speakers are 20 inches and 23 inches from the back of the speaker to the back wall but if you measure from the front of the speakers to the sitting position they are both exactly 84 inches. Measuring from the back of the speaker to the back wall is a good starting point but if you want to be exact you must measure from the front of the speaker to the sitting position I’ve been doing this for over 50 years and I have yet to have the same measurements from the back of the wall to the back of the speaker there’s always some adjustments needed I hope this clarifies my position. Warmest regards

I had a chance to try a few things including different sources and swapping the speaker cables. I must have hearing loss out of my right ear because I noticed no difference. I will buy an SPL and verify but I asked my GF and she said it sounds balanced when seated in the middle.

One more thought, it could still be my room so I will explore that after I do the SPL.

@needfreestuff i hear what you are saying but my room is a large rectangle 25x20 feet. That being said, the spacing from the back wall is more important in my situation. There is 10 feet between the speakers and only 10 inches between my ears. BTW the speakers are 30” from the back wall on the inside and 32” on the outside.
Bigger issue I believe is a large skylight above the left and not one above the right speaker. If I could post a picture it would be much easier but I don’t see an option in Audiogon

@mmporsche 

you can get your hearing tested too... if you really are wondering

good luck

but I asked my GF and she said it sounds balanced when seated in the middle.

Yikes! Do you notice any hearing loss in other situations?

If I could post a picture it would be much easier but I don’t see an option in Audiogon

You can post picture via Systems page

https://systems.audiogon.com/

I must have hearing loss out of my right ear because I noticed no difference. I will buy an SPL and verify but I asked my GF and she said it sounds balanced when seated in the middle.

An Online hearing test may help.

https://systems.audiogon.com/systems/6261 @imhififan thanks for the advice. The first 3 pictures show my room. Please notice the large opening above the left speaker. Anyone know if the room could be causing my problem?

You got the answer.. Don't ride home with the window down, there is all kinds of stuff, to help.. That use to really mess with my listening sessions.

Take care of your ears... Make a big ear for one ear.. really. Take your hat off, NO HATS... The chair back.., needs to be BELOW your neck.. 

NO Smoking, cheap tobacco, or weed. Gargle with warm salt water...

YUP, you know what makes a good mechanic?   One that takes care of their ears... and hands, ALWAYS....

Regards

Not sure why my link to pictures disappeared. Here it is again:

https://systems.audiogon.com/systems/6261

mmporsche OP
Not sure why my link to pictures disappeared. Here it is again:

I assumed you had 211 monoblocks in my first post, now I see it’s a stereo, but same deal.
Don’t play with the bias yet, just swap left for right speaker leads and interconnects on the amp (this way the recording is still the same orientation) and see if the balance still favors the left.

Cheers George

OK, have your girlfriend sit dead center, and you sit to her right!

The balance control of many otherwise fine preamps and integrated amps have disappeared over the years. It is simply a cost cutting move as there is no reason that a balance control has to compromise SQ. I would not have a preamp without one.

There are many reasons a balance control may be useful as were detailed here.  An additional factor is that some recordings need a balance control to place the soundstage correctly.