Frustrated with new pre-amp and need advice

Were I in your shoes, I would return the item for either a replacement unit or a full refund with preference toward the refund. Unless the unit is faulty, your use of an alternate pre proves there is something about the unit in question that makes it incompatible with your existing equipment. Good luck.

If the co. has a very consumer friendly stance, asking and getting a replacement unit this early on ought not to be an issue. Even if it’s mentioned some more run in time is required first.

A second same unit will do one of 3 things… alieviate the issue entirely, or determine it is a mismatch for your current setup or lastly, some revision is necessary to the current production models.

Each of those items ultimately formulates into a win win situation.

I don’t use all the inputs on my tube preamp. It has 4 pairs/sets. It is SE only. Normally I’ll use two. A while back after reconfiguring sources on the preamps inputs I mis-selected one of them. I forget exactly which one the selector knob was set to, and while in the other room used the remote to raise the vol. Both sources were on at the time too.

I kept raising the volume and could only faintly hear any source material. Turned out the knob was on a blank spot and the source I heard was on the adjacent or next position over.

So indeed there was some bleed through that could barely be heard yet the volume level to encounter this anomoly had to be at near the max setting.

Once previously on a 100% balanced preamp this exact same thing occurred. In both cases I feel I was very lucky.

During normal operating levels, all other sources were/are inaudible. Again, only when at the near full on vol level or at full on was anything at all audible from an adjacent source selected position… so we’re talking extremes here.

Not just run of the mill routine operating procedures.

I’ve had several preamps and amp combos in here… with some being quite inexpensive and some being very expensive. In none of those mixings have I ever had any bleed thru from one source to another aside from my above accounts.

Lastly… a brand new preamp… SS or tube… should not induce any thunks or plunks audibly to the speakers when sources are changed, especially if prudence with the volume is in force during the source changes… or at least I’ve never experienced such things with any pre or even proc I’ve yet owned..

Hopefully your brand will see to it you are treated fairly and satisfied very soon.

Proper cable dressing can go a long way in detering alternate signal pick up. Though actually being able to do it can sometimes be an excercise in futility. :-)

I am the OP in the thread that Aggielaw references above. Note that the issues this poster is experiencing are different. The POP I have with the Nagra unit is only when it is first powered on, NOT when I switch sources subsequently. There is also no bleeding from one channel to the next. I have also subsequently learned through correspondance with several real experts around the country)that many tube preamps ( will exhibit this characteristic (a pop) when first powered on, and it is not necessarily something wrong with the pre. But it does require you to always power on your amps AFTER the pre has been powered on. Which, as an aside, is a royal pain for me. Anyway, my point here is that I think that Slanski is experiencing different, and potentially more problemmatic issues with his pre.

somehow your preamp seems to me mis-manufactured in the sense of correct values of bias supply. if the tubes are over- or under- driven that would seem to show your case. Audio Research had done some mis-manufactured units and fixed them at no even shipping cost with no questions asked from anybody. The fix was to change input(grid) resistor values from 1K to 10k. or vise versa(don't remember precisely).