Can anyone help with Consonance M100 valve amp problem?


Hi all,

I have a valve amplifier that I really like the sound of, the Consonance M100. I have owned it for around 10 years and in that time it has been used on and off, in no way heavily at all.

Recently the problem I have noticed is that the sound coming through now seems to sound like I have an EQ on it, like having boosted the mids and high-mids. First thing I thought was maybe it's time for a tube change, but before that I wanted to confirm it wasn't just me so I took the amp to a friends place who previously owned the same model amp and he also confirmed the same issue on his set of speakers.
Now the amp takes 4x EL34 2x 6SN7 and 2x 12AT7 tubes, so I started by purchasing a new quad matched set of EL34's, popped them in and... no change. So I purchased a matched pair of 12AT7's and... no change. Having come that far I then purchased a matched pair of 6SN7's and as expected... no change.
The sound issue is on both channels left and right equally which is why I was originally skeptical of a valve problem. So after a full new set of tubes there is no change, so my question to any savvy tube amp owners is what could be causing this problem and have you ever had a similar issue?
Any help or suggestions would be greatly appreciated!
thetubester
Hi bryhifi, I'm outside the US, but I have done what tuberist suggested and contacted the distributor here where I purchased it from and they put me on to a technician I can drop it off to.The M100 is such a warm velvety sounding amp that I miss it a lot. Am currently using a pair of Focal Alpha 65 active monitors, they are nice and all but IMO solid state just can't compete with tubes.
+1 for tuberist recommendation.
Stephen Monte owns Quest for Sound and is a tube amp aficionado, especially when it comes to Consonance gear.  I’ve purchased several Consonance pieces from him over the years.  Have an M100plus here in one system and a pair of M400S mono blocks in main system.  The M100 integrated is a wonderful sounding unit and well worth the fix.

Thetubester,, where are you located ? 
Hey guys, thanks so much for your replies. My assumption was that it might be a cap also and a simple fix, really hope its not a power supply problem. Thanks for the suggestion tuberist, I will look into that also.
I would call the owner of quest for sound in Bensalem Pennsylvania since he represents that line and Surely can help you out
If new tubes didn't do the job IMO your looking at a component failure,maybe a cap going bad but that's just a guess.