Rumbling bass

[jj2005]

I bought an EAR/Yoshino912 pre due to the phono stage which is excellent on most records, however newer releases seem to give me a really bad rumbling bass which completely prevents listening at normal volume.
I know that some of these records are mastered like a CD to sound better in a small stereo but it is really bad with this pre-amp and even using only the line input from my streamer the bass is a problem!
does anyone have a idea if my unit is bad, or this is a known problem?, perhaps different tubes or replacing the coupling caps could help?

my speakers are Focal Sopra!

 

[Solypsa]

I bought an EAR/Yoshino912 pre due to the phono stage which is excellent on most records, however newer releases seem to give me a really bad rumbling bass which completely prevents listening at normal volume.
I know that some of these records are mastered like a CD to sound better in a small stereo but it is really bad with this pre-amp and even using only the line input from my streamer the bass is a problem!
does anyone have a idea if my unit is bad, or this is a known problem?, perhaps different tubes or replacing the coupling caps could help?

my speakers are Focal Sopra!

Can you clarify the part I bolded?

What cartridge are you using?

Does this 'rumbling bass' happen at low volume as well as high volume?

 

[jj2005]

The bold text is my line input such as Cd, AUX etc. coming from a NAIM NDX2 streamer.

I use several low output MC’s ZYX Airy, ZYX Dynamic, Hana ML, please note the rumbling or boomy bass does not come when I connect to a different RIAA amplifier.

The rumbling boomy bass comes at all volume levels but if I crank up the volume even the slightest it becomes unbearable.

I have read elsewhere on this forum regarding EAR834P which could have some issues with boomy bass due to the Buffer tube, but then again the 834P is a completely different design than 912.

Again this is only with some albums which seem to have been mastered for bass, like Lana Del Rey(Did you know that there’s a tunnel under Ocean Boulevard), George Michael(Older) where as others such as Pink Floyd(The Wall), And all my older albums are perfect.
what bothers me is that it also is present with my streamer, which lead me to think the output voltage is a mismatch or something.
Or maybe my unit is defective.

any suggestions to what I could try is greatly appreciated!

 

[Solypsa]

So if I understand correctly it happens with digital and vinyl? That should narrow it down a lot.

Do you have a schematic for the 912? It uses ( according to the internet ) two 7DJ8 tubes in the line stage ( and three more for the phono ). Since your problem is in the line stage ( see my opening statement ) an easy first step would be to swap out those two tubes. Nothing expensive needed.

If its not the line stage tubes its gonna take a little more digging

 

[Folsom]

I use a modified 834 and haven't noticed problems with bass.

 

[Republicoftexas69]

What is the output volume on your dac/streamer?

 

[jj2005]

Ordered some new tubes, will keep you updated

 

[jj2005]

Update:changed all five To BEL, Gold-Kontakte / NOS, no more issues with bass, my only concern is that the amp is new, and other NOS tubes have that same issue.