How often do you guys change...

gitarjoe · August 17th, 2005, 04:54 PM

tubes in your amp. I have a 65 fender reissue reverb. It has a total of 9 tubes. Do I need to change all of them? Will I hear a big difference? If nothing is wrong with them, do they still need periodic changing? thanks.

Wally · August 17th, 2005, 05:13 PM

The power tubes work at higher plate voltages, so in normal situations, power tubes have shorter lifespan than do preamp tubes. Different tubes create different tonalities. As tube age, they lose some of their power,definition and musicality. Your amp should have the bias checked when replacing power tubes. The preamp tubes are self-biasing. When replacing power tubes, some people feel that you should also replace the driver/phase inverter...the 12AT7,,,or do the RI's use a 12AX7?.... closest to the power tubes. Some say differently.
How often? Factors....how much you play, how hard you push the amp, how picky you are about your tone. Working pro with a well-maintained amp....6 months to a year on power tubes....or whenever they feel the need based upon their ear.

11 Gauge · August 17th, 2005, 05:18 PM

preamp tube life is debatable. i generally change mine only if they are microphonic or need to step up or down (i.e. from a 12AX7 to a 12AT7).

one preamp tube that should always be changed with the power tubes is the phase inverter - it is usually located closest to the power tubes.

power tube life depends on how hot the tubes are biased, how hard the amp circuitry is on them, and how much the amp is used.

your '65 DRRI is most likely biased 'cold', and the power tubes hence will last a long time. i personally like 6V6's in Deluxes biased somewhere in the ballpark of 27 millivolts, the RI's have a bias adjustment access area on the underside of the chassis.

biasing your amp warmer may call for some better tubes that can handle the increased idle bias.

tjalla · August 17th, 2005, 05:34 PM

:D

When I did 2-3 regular gigs a week, I changed the Svetlana EL34s in my Riveras about once a year.

Now my Tone King Comet gets cranked to ten about once every two weeks at a gig, and is awaiting a fresh set of JJ 6V6s, but not because it needs it - I just wanted a different tone. The amp is about 2 years old, and this is the first tube change (stocks are Electro Harmonix). Apparently DRRIs benefit well from the JJ 6V6 upgrades too.

Use your ears... if the tone starts becoming muddy, harsh or low-powered, time for a swap.

Cheers,
Trevor

GuitarJonz · August 17th, 2005, 06:32 PM

Oh, I thought the question was gonna be "How often do you guys change...pickups", and was going to answer once a week :D

Never mind... :P

maestrovert · August 17th, 2005, 06:33 PM

my 3 fave amps ('63 Princeton, '73 Champ and '62 Silvertone) all have original tubes...the Princeton and Champ get used daily.....they're bone stock as a matter of fact.....every 2 or 3 years, i take them in for a checkup/tuneup....
so far, so good !

Ben Harmless · August 17th, 2005, 07:21 PM

I change tubes like I change my underwear: When they start to sound like poop.

Oh, man was that over the line...

gitarjoe · August 17th, 2005, 08:19 PM

that was a wealth of information. I have one more question. What are these.
1-6v6 groove tubes.
2-5ar4 rectifier tube.
Wally explained the 12at7, and I know the 12ax7 are the preamps. Be gentle with me, I am new to amps. thanks.
ps wally, what is the bias, and how do i check it.

Wally · August 18th, 2005, 12:33 PM

Quote:

Originally Posted by gitarjoe

that was a wealth of information. I have one more question. What are these.
1-6v6 groove tubes.
2-5ar4 rectifier tube.
Wally explained the 12at7, and I know the 12ax7 are the preamps. Be gentle with me, I am new to amps. thanks.
ps wally, what is the bias, and how do i check it.

1) 6V6 ---power tubes. Groove Tubes...Buys, manufactures, and markets tubes. What your Groove Tube tubes are regarding country of manufacture cannot be know form the info you posed.
2) As you state, this is the rectifier tube.
3) Bias....voltage that is negative in relation the the cathode voltage and which controls the flow of electrons from the cathode to the plate. Control of this flow(current draw) allows the power tubes to operate within their given performance parameters....not too hot and not too cold....70% dissipation as the norm.

One book that I found very helpful in a basic understanding, which is all I have by the way, of tube amp is Tom Mitchell's 'How to Service Your own Tube Amp'. Gerald Weber's book/books? are of use. Dave Funk has a great book for Fender amps...The "Tube Amp Workbook...First Edition". Libraries have basic tube electronics books, we hope. It would be a good thing to find a good tech near you and utilize their services to maintain and/or upgrade your amp until such time as you learn about these things.
Good luck with your tube amp life...I am adamant in my opinion about tube amps. There is no option for me for guitar amplification.

August 17th, 2005, 04:54 PM	#1 (permalink)
gitarjoe Tele-Afflicted Join Date: Sep 2003 Location: Long Island, NY Posts: 1,130 15 Photos	How often do you guys change... tubes in your amp. I have a 65 fender reissue reverb. It has a total of 9 tubes. Do I need to change all of them? Will I hear a big difference? If nothing is wrong with them, do they still need periodic changing? thanks. __________________ Just my two cents.

August 17th, 2005, 05:18 PM	#3 (permalink)
11 Gauge Friend of Leo's Join Date: Mar 2003 Location: The East Coast Posts: 3,083 10 Photos	preamp tube life is debatable. i generally change mine only if they are microphonic or need to step up or down (i.e. from a 12AX7 to a 12AT7). one preamp tube that should always be changed with the power tubes is the phase inverter - it is usually located closest to the power tubes. power tube life depends on how hot the tubes are biased, how hard the amp circuitry is on them, and how much the amp is used. your '65 DRRI is most likely biased 'cold', and the power tubes hence will last a long time. i personally like 6V6's in Deluxes biased somewhere in the ballpark of 27 millivolts, the RI's have a bias adjustment access area on the underside of the chassis. biasing your amp warmer may call for some better tubes that can handle the increased idle bias. __________________

August 17th, 2005, 05:34 PM	#4 (permalink)
tjalla Tele-Afflicted Join Date: Mar 2003 Location: Perth, Western Australia Posts: 1,947 7 Photos	Every time I get GAS to do so... :D When I did 2-3 regular gigs a week, I changed the Svetlana EL34s in my Riveras about once a year. Now my Tone King Comet gets cranked to ten about once every two weeks at a gig, and is awaiting a fresh set of JJ 6V6s, but not because it needs it - I just wanted a different tone. The amp is about 2 years old, and this is the first tube change (stocks are Electro Harmonix). Apparently DRRIs benefit well from the JJ 6V6 upgrades too. Use your ears... if the tone starts becoming muddy, harsh or low-powered, time for a swap. Cheers, Trevor

August 17th, 2005, 06:32 PM	#5 (permalink)
GuitarJonz Friend of Leo's Join Date: Mar 2003 Location: Central Mass. Posts: 2,863 7 Photos	Re: How often do you guys change... Oh, I thought the question was gonna be "How often do you guys change...pickups", and was going to answer once a week :D Never mind... :P

August 17th, 2005, 06:33 PM	#6 (permalink)
maestrovert Poster Extraordinaire Join Date: Mar 2005 Location: West Branch Mi. Posts: 6,732	my 3 fave amps ('63 Princeton, '73 Champ and '62 Silvertone) all have original tubes...the Princeton and Champ get used daily.....they're bone stock as a matter of fact.....every 2 or 3 years, i take them in for a checkup/tuneup.... so far, so good ! __________________ Sing the Song Bro' Play on Drummer www.godonthe.net

August 17th, 2005, 05:13 PM	#2 (permalink)
Wally Friend of Leo's Join Date: Mar 2003 Location: Lubbock, TX Posts: 4,212	The power tubes work at higher plate voltages, so in normal situations, power tubes have shorter lifespan than do preamp tubes. Different tubes create different tonalities. As tube age, they lose some of their power,definition and musicality. Your amp should have the bias checked when replacing power tubes. The preamp tubes are self-biasing. When replacing power tubes, some people feel that you should also replace the driver/phase inverter...the 12AT7,,,or do the RI's use a 12AX7?.... closest to the power tubes. Some say differently. How often? Factors....how much you play, how hard you push the amp, how picky you are about your tone. Working pro with a well-maintained amp....6 months to a year on power tubes....or whenever they feel the need based upon their ear.

August 17th, 2005, 07:21 PM	#7 (permalink)
Ben Harmless Friend of Leo's Join Date: Mar 2003 Location: Albany, NY US of A Posts: 3,374 12 Photos	I change tubes like I change my underwear: When they start to sound like poop. Oh, man was that over the line... __________________ "I think I'll go for the life of sin, followed by the last-minute, presto-change-o, deathbed repentance." - B. Simpson

August 17th, 2005, 08:19 PM	#8 (permalink)
gitarjoe Tele-Afflicted Join Date: Sep 2003 Location: Long Island, NY Posts: 1,130 15 Photos	Thanks guys... that was a wealth of information. I have one more question. What are these. 1-6v6 groove tubes. 2-5ar4 rectifier tube. Wally explained the 12at7, and I know the 12ax7 are the preamps. Be gentle with me, I am new to amps. thanks. ps wally, what is the bias, and how do i check it. __________________ Just my two cents.