Soundstage

As some of you may know I recently replaced my MF amps (X/A2 Int for treble and X-A200 for bass) with a Rogue Stereo 90 valve power amp (for volume control I use a passive attenuator at the moment).

Now, I'm happy with some of the improvements that the Rogue has brought but the soundstage has shifted to the left. I played a test disc where a drum note moves from left to right in 7 steps and this confirmed my suspicions. With the MF amps the notes moved from left to right in regular steps. With the Rogue the first 3 notes seem to come from the left speaker then they seem to move to the right but never quite seem to reach the right speaker (if you see what I mean).

I have toed out the right speaker and toed in the left for some improvement and also changed the input tubes around (in case the left was providing greater gain) but it's still nowhere as good as it was with the MFs. One other thing that has changed is that my TV packed up, so it's now in the skip, instead of being in the middle of the speakers, which may have an affect.

So, any suggestions? it's certainly room related but why should it affect the Rogue more than the MFs? what can I do about it?

 

Perhaps the valves are struggling Dev, might be interesting to switch them and see if you get stronger performance on the other channel.

 

Or even easier, swap you speaker cables round and see if the effect swaps sides. If it does then its up the chain from the speakers ... if it doesn't then its either room related or there is an issue with the speakers themselves.

 

Right, had a little play and I think it's room related. I've tried swapping channels and even swapping the speakers but it's made no difference. The stage seems to start from the left of the left speaker and ends to the left of the right speaker. Also with the test disc, the notes don't seem to be moving in regular steps. In other words, it inches across from left to right and as it proceeds to the right it takes bigger steps.

I can only assume that the large TV in the middle of the speakers brought it into focus. Ah well, I'll just have to play with speaker positioning and get the best I can. And finally, when I get a replacement TV, start again.

 

dev,
try draping a blanket over the tv (just to test - i know the boss wouldn;t permit it to be permanent) see if that improves things. if it does a plasma or lcd might be in order. hey a silver lining.....
have you tried toeing one speaker in more than the other and are you still using that odd mix of biwire cable you used to use - could try some other cable - might work???
cheers


julian

 

The TV is no longer there and I think that's what has changed things. I looked at plasma's but HD versions are too expensive at the moment and I feel if I'm going to buy a new TV, it might as well be an HD flavour.

Toeing the left speaker in and the right one out has improved things (i.e. moved the soundstage to the right) but it's not as good as before, there still seems to a be void between centre and the left/right extremes. I am using the Goertz cable we discussed a while ago.

Edit: I see what you mean about the blanket.

 

I also use Goertz. Are yours the same length as one another? I considered having different lengths (I need 5m on one but could get away with 2m on the other) but have stuck with equal lengths.

 

They are of equal lengths. In any case, I swapped them around along with the interconnects such that the left output of the amp fed the right channel and the right fed the left, the I/C swap undid the effect of the speaker cable swap. However, the soundstage still appeared to be shifted to te left.

Single cable swap (both I/C and speaker, but only one at a time) also highlighted the emphasis to the left, but obviously in this case the right channel appeared on the left and left on the right. So, now I'm going to give up .

 

move your armchair!

 

Dev,

FWIW I'm using different lengths of Goertz and it doesn't seem to have any effect. Apart from toe-in ,you might also try varying the distance of the speakers from the back wall. IME that can certainly shift the l-r balance of the image

Jeff

 

You could adjust the balance control to centre central images and see what that does to your skew on the test track. It seems most unlikely that removing a TV would make this kind of thing worse, in any normal sort of room at least.

(Or dump your retro stuff and get a nice modern solid state amp. Hi Mr L...)

Paul

 

I don't have tone controls and have just replaced a "nice modern solid state amp" with a more modern and even nicer valve amp.

To be honest, I'm not bothered about the test track, that was just to prove what I heard. So far the only thing to make any difference was the re-positioning of the speakers and I'd say badchamp has hit it on the head. It now just looks odd with both speakers pointing to the right I haven't yet finished playing, just tired, these beasts are heavy!