Bad weekend for audio equipment

Yesterday while on a phone call, I was playing some jazz as is typical during the day for me. I detected a bit of low-level noise coming from my left speaker - like you hear from a tube going bad. I figured it was one of the tubes in my Quicksilver preamp. No big deal, I would change out tubes on Saturday.

So this morning I swapped in two new tubes. Powered on the preamp and waited for the green light. Once that happened, flipped on my McCormack DNA-0.5 amp and waited for it to stabilize. All good...I started some music. However, I soon noticed the same sound I heard yesterday...but this time from the right speaker. As I sat there thinking about what to do next, the noise from the right speaker got louder and louder and louder...and before I could get to the amp to power it down, the protection kicked in and down she went.

Since I changed out both tubes in the preamp, I thought the amp was the culprit. So I replaced my downed McCormack with a spare Rotel RB-980BX that was in storage and went thru the same process. Soon after everything was was powered up and the music was playing, the right channel noise started up again. This time I RAN to the Rotel amp and killed the power - saving it from potentially the same fate suffered by my beloved McCormack.

I set the Quicksilver preamp aside and replaced it with a spare preamp - a McCormack TLC-1 passive unit. Everything has been fine since.

After examining the fuse on the back of the unit at the power cable connection, I opened up the DNA-0.5 and replaced the four rail fuses (one on the right had blown) and powered it up. No dice...it is still in protection mode. So it looks like I have a preamp AND an amp in need of service. At least my speakers were not damaged.

I've heard bad news comes in "threes" - still waiting for the final blow.

 

Ouch!!!

 

Right, I am not amused by it all...

 

I feel your pain. I had an amp blow and in the process blowing a tweeter. Two repairs and double the money.

 

Aaaaggghh...
Bad juju....

You just cursed us all!

No seriously. Best of luck. Hope it turns out well.

 

UPDATE!

I decided to pull the replacement fuses I inserted on the right channel power supply rail just to make sure they were all indeed good and the right values - they were.

I go to put the two replacement fuses back in, and I can't get the lower one to stay in its holder - I tried several times. Apparently the metal pins which hold the damn fuses became loose between all the removal and insertion of fuses. So, I pinched the fuse holders down tightly and reinserted both fuses with a nice "snap" sound to them.

Reconnected the power cord and hit the power button and…no protection mode and POWER!
Preamp is still not in use, but my regular amp is back baby!

 

Not a terrible thing to have your McCormack combo back together again! Does the TLC-1 also have an active stage or is it passive only?(I have the Micro Line Drive which has both).

 

The TLC-1 has two sets of outputs - one passive and one buffered.

 

I have found that the better the rig, the higher the likelihood that something will happen that is usually small but makes you crazy until you sort it. It's partly expectations-- not that fancy equipment is more prone to failure. And that it is often something that is simple or easily fixable.

 

Not bad-mouthing Quicksilver at all...but this is the second different preamp from them I have had that has caused an issue with my amplifier. I thought it was perhaps just the combo. But hearing the noises as I did with two different amps is not right. Some part(s) must be going bad in their units and/or leaking DC to the amp.