It is currently Mon Mar 16, 2020 10:33 pm

All times are UTC - 7 hours



Post new topic Reply to topic  [ 10 posts ] 
Author Message
Post subject: When to replace Valves?
Posted: Wed Feb 04, 2015 4:01 pm
Offline
Hobbyist
Hobbyist

Joined: Wed Feb 04, 2015 3:58 pm
Posts: 3
I own a new Eric Clapton Twinolux. I have had it for about 12 months and used it about 500 hours. When should I replace the Valves? If I replace them with exactly the same valves then apparently I need not get the amp rebiased. Is this correct?


Top
Profile
Fender Play Winter Sale 2020
Post subject: Re: When to replace Valves?
Posted: Wed Feb 04, 2015 5:03 pm
Offline
Rock Icon
Rock Icon
User avatar

Joined: Fri Feb 05, 2010 4:31 am
Posts: 14049
Location: Province de Québec, Canada
12xx7 are usualy good for many years .

6L6 ; if they sound good , keep them If they are biased cold like many Fender amps . But you don't know .
What's the name on 6L6 's tube ? Sovtek , J J or Groove tubes ?

IMO , 50% you need to adjust bias if you keep same brand .


Top
Profile
Post subject: Re: When to replace Valves?
Posted: Wed Feb 04, 2015 5:07 pm
Offline
Rock Star
Rock Star
User avatar

Joined: Tue Mar 01, 2011 3:10 pm
Posts: 5646
Location: Gateway to the West
Replacing is subjective, does it still sound good? Any loss of volume? Power tubes will need to be replaced long before the Pre-amp tubes.

As for replacing them with the exact same type from the same company you will still need to re-bias the amp. No two sets of tubes are exactly the same.

T2

_________________
-----------------------------------------------------------
What time is it? It's Fender Time.


Top
Profile
Post subject: Re: When to replace Valves?
Posted: Wed Feb 04, 2015 5:15 pm
Offline
Rock Icon
Rock Icon
User avatar

Joined: Fri Feb 05, 2010 4:31 am
Posts: 14049
Location: Province de Québec, Canada
T2Stratman wrote:
Replacing is subjective, does it still sound good? Any loss of volume? Power tubes will need to be replaced long before the Pre-amp tubes.

As for replacing them with the exact same type from the same company you will still need to re-bias the amp. No two sets of tubes are exactly the same.

T2




+1 Check Bias always . Adjust if needed


Top
Profile
Post subject: Re: When to replace Valves?
Posted: Thu Feb 05, 2015 2:06 am
Offline
Hobbyist
Hobbyist

Joined: Wed Feb 04, 2015 3:58 pm
Posts: 3
Thanks for the feedback. They are 6L6GE Groove Tubes a matched set Red. So if you were Eric Clapton's amp tech, would you wait till there is a tone or volume loss or simply replace every x hours? Or x gigs? If yes, then how many gigs and how many hours?


Top
Profile
Post subject: Re: When to replace Valves?
Posted: Thu Feb 05, 2015 2:19 am
Offline
Rock Icon
Rock Icon
User avatar

Joined: Fri Feb 05, 2010 4:31 am
Posts: 14049
Location: Province de Québec, Canada
Groove tube are not a tube manufacturer , GT buy tubes from many tubes manufacturers.

On your GT tube it could be write Sovtek or .... If you bought GT / Sovtek you may ( we can't be sure ) keep same bias .

How many hours / gigs before replace tubes ?
We can't tell ; how loud you play ? Is the bias is hot or cold ? Did you move amp when tubes are hot after the gigs ? Did you move roughly or carefully ?

I'll keep tube until I hear bad sound .

Until you need new tubes , keep you hears open to know a good tech in your area


Top
Profile
Post subject: Re: When to replace Valves?
Posted: Thu Feb 05, 2015 3:02 am
Offline
Professional Musician
Professional Musician

Joined: Tue Sep 11, 2012 2:14 pm
Posts: 2561
As mentioned, GT is not a manufacturer, they're a Private Label distributor. And they're owned by Fender, so most, if not all, current Fender Amps are equipped with them

Buying another set of GTs doesn't mean they're the same tube as you're replacing, as they source their tubes from several manufacturers. So a bias check is recommended (also as mentioned above).

There are 2 reasons to bias the tubes:

1.) Tone

2.) To be sure you're not pushing the Tubes too hard which will shorten their lifespan, but can also damage/prematurely wear other components.

There are affordable Bias tools out there, and learning to do it yourself is convenient, frugal and to some, satisfying.

All that said, I doubt you need a Tube swap given the use the amp's had. Especially if there's no noticeable loss of Tone or Volume.

There are those who actually like 'mature' tubes for the sound they produce, and keep them until they quit altogether.

cheers!

_________________
Image

'11 FSR Am. Vtg. Ltd. Ed. CAR '57 Stratocaster (SN# LE02639)
'14 American Deluxe Ash Stratocaster
'12 Telebration Empress Telecaster
'99 Deluxe Nashville Telecaster
'12 FSR Telecaster HH
'10 Heritage H-535
'99 Martin DC-1E
'13 Lanikai Tenor Ukulele


Top
Profile
Post subject: Re: When to replace Valves?
Posted: Thu Feb 05, 2015 3:07 am
Offline
Rock Icon
Rock Icon
User avatar

Joined: Fri Feb 05, 2010 4:31 am
Posts: 14049
Location: Province de Québec, Canada
A correctly biased amp will run efficiently and maximizes the life of your tubes.

Under - biased amps will lack of punch and tubes will run hotter , shorter tube's life .
Overbiased amps will sound thin and brittle. with tubes running too cool for proper performance .
A correctly biased amps will sound clean and tight a moderate volumes, than at higher volumes breakup and distort musically .


Top
Profile
Post subject: Re: When to replace Valves?
Posted: Thu Feb 05, 2015 5:17 am
Offline
Hobbyist
Hobbyist

Joined: Wed Feb 04, 2015 3:58 pm
Posts: 3
Thanks again for all the feedback, much appreciated. I presume that an Eric Clapton Twinolux must have gone through a fairly strenuous quality check before it got to me. So I think the bias must be OK. I will play them for another two years and see what happens. Thanks again, interesting feedback indeed.


Top
Profile
Post subject: Re: When to replace Valves?
Posted: Sun Feb 08, 2015 12:56 am
Offline
Rock Icon
Rock Icon
User avatar

Joined: Tue Jun 29, 2010 1:20 pm
Posts: 9640
Location: Indiana
If properly biased, and with proper use (ie, standby switch, care in handling amp, etc), 5000 hours is not unusual for a set of output tubes. At your rate of use, you could get 10 years or more use. Preamp/PI tubes can last even longer than that.

_________________
---> "The amp should be SWITCHED OFF AND UNPLUGGED before you do this!" <---

Por favor, disculpe mi español, no se llega a la práctica con mucha frecuencia.


Top
Profile
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 10 posts ] 

All times are UTC - 7 hours

Fender Play Winter Sale 2020

Who is online

Users browsing this forum: Google [Bot] and 2 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum

Search for:
Jump to: