Audio Horizons TP 2.0 Preamplifier

Never had any problems in the two-plus years I've had my TP 2.0n preamp. Just as musical as the first day I received it. I'm still using the same tubes as well and I have put many hours on my preamp. I'm wondering if Joseph designed the circuit to put minimal stress on the tubes. I've thought of getting a good tube tester to check from time to time how much life is left on the tubes, but I'd imagine that I'll know when they start making noise and/or start losing their wonderful sound. Maybe Joseph or Victor can tell us what signs to listen for to let us know when the tubes need to be replaced.

Hi everyone,I'm looking for some insight into a technical glitch.I acquired an AH TP 2.0,upgraded to 2.1 status,for a friend.It apparently has a 60 cycle hum which is only noticeable when you stand by the unit and not in the listening position.Well you know how that goes it's driving him nuts.Any insight would be helpful and a pm would be fine.

Markwatkiss is it humming with no inputs connected.

I also have been enjoying my AH without any problems just great musical enjoyment. Though i am using Siemans cca i am looking into trying different tubes to hear what Telefunken and others would bring.

Its been a while since the announcement of upgrade to 2.1 by Joseph is any word known on this upgrade.

I had this same transformer hum - mechanical - coming from the unit itself and not through the speakers. Some transformer/power supplies do and some don't. May want to check to make sure it is tight as a loose bolt or two will cause a mechanical hum. Other then that, replace with a quiet transformer/power supply.

Bill

Sometimes adhesives that bind the stacked plates which are part of the power transformer will weaken and allow vibration. We hear it as a hum. I suspect that is what your friend is hearing. It is a common occasional problem with transformers of any manufacturer.

Knowing that it exists, even if you can't hear it while listening, is annoying. However, as long as the hum is inaudible, it does not degrade the quality of the music you receive from the system. It is not an electrical problem; it is a mechanical one - the unadhered sections of the transformer plates are vibrating.

If adhesive failure is the problem, then when you press down on the top of the power transformer to dampen the vibration,the sound probably will go away. I think the solution is replacement of the power transformer rather than repair of it. The adhesive failure is between the plates and cannot be repaired.

If that is the problem, it requires skill to remove the transformer withour damaging the pads of the printed circuit board (pcb). Don't attempt it unless you are good with a soldering iron.