Figures, the tube I do not have a spare dies

thsmith

I noticed my sound stage sounded different while playing an album. Check the bias on the AMP and it was 40 vs 60 for each of the KT88s where this morning it was 60.

Looked at the Mullard CV387s and noitice one was dark.

Switched the L&R and the dead tube remained lifeless. These are the only originals that came with the amp when new so the mullards are about 9 years old.

This is the only tube I do not have a spare for and I keep meaning to order one. I just ordered a pair and will now have a spare.

Now, to pull the rack out and put the SDAs on the Denon 2808 AVR :frown:. Luckly all the 2 channel stuff is on the preamp and can not be heard through the AVR just video.

Anyway, MAN 2 channel DOWN !

Jetmaker737

Sucks dude. Good reminder to get some extras. I always think about it but can't seem to pull the trigger on shelling out the coin for something that could sit on the shelf for years.

george daniel

you can bet that he's not gonna' buy just one

treitz3

I'm just taking a wild guess here, but was it tube 3 or 4? More specifically 4, by chance?

leroyjr1

HT rules, get your movie on!!!!!!

Didn't think that wright pre had HT bypass or were you just using one of the inputs?

thsmith

treitz3 wrote: »

I'm just taking a wild guess here, but was it tube 3 or 4? More specifically 4, by chance?

There are 2 GZ37s in my amp.

One per channel. I was surprised even with 1 tube working I had even voltage for all 4 KT88s, lower but even.

I know the one that is dead and not something else because I flipped them and it was still dead.


You are right George, I ordered a NOS pair.

The one that is still working will become my spare.

In the first picture the 2 in the center second role are the GZ37s/CV387

http://www.polkaudio.com/forums/showpost.php?p=1554790&postcount=6

thsmith

leroyjr1 wrote: »

HT rules, get your movie on!!!!!!

Didn't think that wright pre had HT bypass or were you just using one of the inputs?

One of the inputs no HT bypass

thsmith

In the middle of the night I woke up thinking what changed in your amp that may have caused the L channel 9 year old rectifier tube to go dark.

5 days earlier I put Treasure CV-181s in the input side.

Broke out the MIghty Might and the Treasures pass all test.

OK, just need to wait for NOS pair to arrive.

lesson to self, do not put off having a spare.

leroyjr1

thsmith wrote: »

In the middle of the night I woke up thinking what changed in your amp that may have caused the L channel 9 year old rectifier tube to go dark.

5 days earlier I put Treasure CV-181s in the input side.

Broke out the MIghty Might and the Treasures pass all test.

OK, just need to wait for NOS pair to arrive.

lesson to self, do not put off having a spare.

I take it you're not enjoying the 2 channel sound coming from the denon?

thsmith

Nope, CDP and TT are connected to Wright PREAMP which is out with AMP being down.

I just swung speaker cables off amp to AVR.

Normally the AVR main L&R outputs go to PREAMP then AMP.