Fender Hot Rod Deluxe general tube question

[CraigW]

I have some general questions concerning output tubes in a Fender Hot Rod Deluxe. (not mine, belongs to a friend)

He plays most every weekend ,2 nights/4 hours per night.

He currently has a set of matched “ruby tubes” in the amp they have been in for 2-3 years now. These tubes have been in place longer than any set before, I think he said these were his 3rd set in like 5 years.


My questions are:

How often should the output set need replaced ??

Replace them as a preventative measure ?? or run to failure??

Is it true if you buy a “matched pair” you don’t need to bias the amp when replacing them ??

Are ruby tubes a good brand or should he stay away from this brand ?? What would be good brand of tubes for him to purchase ??


Thanks for a great board btw, a lot of wonderful talented folks here.

[nickb]

This life of a power tube is depedant on it's construction, use and bias current. Usually they last thousands of hours. If we guess at 3,000 hours then replaceing once very five years would seem to be satisfactory for this level of use. It'll be interesting hear what others have to say.

Running to failure is not a good idea as you can damage other (expensive) components for certain failure modes.

You should always use a mtached pair - checking the bias is a really good idea if you want to optimise the life.

[Enzo]

How often should you replace strings? Once a day/session/week/month/year or only when they break? Your strings lose their tone slowly over time as they are used. If you play a lot they wear out faster, and if you bend your strings a lot they go dead faster. If you just finger-pick Greensleeves once a week at church, they should last a long time.

Power tubes slowly lose their quality over time. Kinda up to you when they have diminished enough.

But as a rule, I'd like to see new power tubes in it befoer they burn out on their own.

[Amp Kat]

Treble and volume loss along with red plating are all signs of tubes going bad and when they go is sometimes to late as they can take stuff out like screen resistors and hopefully only fuses. Rubys' are distributed tubes and sell many types. The cheaper ones are usually exactly that. A cheap pair of Chinese tubes which are what you pay for. Tubes or generally like cars in you get what you pay for and ocassionally you get a high dollar lemon. The Ruby STR is a pretty decent tube and so are the Svetlana Winged C. Some of the JJ's that are Dual Mica from Euro are good in combo's like yours. Of course NOS are in a league by themselves and you pay for them.

[txstrat]

Tubes can last up to 10000 hrs depending on sort of abuse.
I built a two 6L6 amp in 1992 which I biased quite cold (I believe it was around 35ma). I used it for over 12 years with the same tubes (Tubes Direct - The Tube Superstore - PM Guitar Tubes - Golden Dragon - Ei Elites). Rehearsals were once a week for about 3-4 hrs. Gigs 5-6 a year (4-5 hrs each). If you count that up you get around 2500 hrs.
A couple of years ago I thought it was time to spend some money on a new set of power tubes and bought a quality pair of 6L6 GC STR at our local music store. To cut a long story short, one of the new tubes had a short within the first week and took down a screen resistor. I saw the smoke come out of the chassis and switched it off immediately. Replaced the resistor and put in the "old" tubes. They're still playing fine although I don't use that amp anymore, just occasionally.
This ain't no ad for PM tubes but I'm quite impressed by the time they last in my amp. And their tone's been IT for me ever since. Back then I bought them in a music store and found them on the net a while ago. I might give em another try when I need a new set.

[ziggy007]

The HRD has been my weapon of choice for years now and my power tubes seem to 'last' for about a year. Obviously highly dependent on yr bias settings. Have tried them all and like the Winged C Svetlanas the best. Again obviously its purely personal.
Cheers

[CraigW]

Thanks for all the replies, I'm going to print everything. I have some biasing and HRD info for him as well.

Should be great help.

It does make sense to change them out as a preventive measure since this is his only amp. (he changes his strings regularly after a certain # of gigs)

Thanks again.