When it's time to change tubes? - And what tubes to buy?

armindo__dias · #1 04-27-2001, 10:09 AM

I bought an used Marshall JCM900 2X12" combo a couple of months ago. It has 3 12AX7 and 2 5881 tubes. The guy that sold it to me bought it new in 1994 and never changed the tubes in it. He played it regularly but not everyday and not many hours.

My question is if it's time to change tubes in it or not. How do you guys discover that it is time to change the tubes in your amp? Does it loose volume, gain, high-end, bottom-end? I can't compare the sound that i now have with the sound when it was new, so i don't know if sounds very different or just the same. I just want to make shure that if i buy a new set of tubes i will actually hear some diferences in sound.

Also, i just asked a store about the models/prices of tubes and the store near me only has Sovtek and Groove Tubes. The GT's are WAY pricier than the Sovtek's. The guy in the store told me that the GT ones are made by Sovtek (they even have the Sovtek name on them!) but are choosen by GT (the best ones). The guy also told me that the differenece shouldn't be that much, so it would be better to buy the Sovteks.

What do you guys think? Are the GT's better than the Sovtek's? Will it be better to buy the GT's just because they are picked by GT? Are they worth the extra money?

Thanks,
Armindo Dias

pri0531 · #2 04-27-2001, 10:22 AM

Armindo:
I use Eurotubes in my rig and they sound INCREDIBLE!!!! *They are worth the extra cash.
Out,
Gregory

armindo__dias · #3 04-27-2001, 10:33 AM

I don't want to order tubes. They are a very fragile component and i'm afraid of the condition of how they would come (btw, i live in Portugal).

So my choices would be between the GT's or the Sovtek's...

Just one more question, how is the big diference between tubes? They have more gain, volume, low-end, etc.? How do you say one tube is better than another?

I've never dealt with tubes before, so sorry if this is a stupid question...

Armindo Dias

pri0531 · #4 04-27-2001, 10:44 AM

The sound is much warmer and the amp does not hiss as much. *The sine line is not spikey. *It is rounded off a great deal. *This has an effect on the distortion. *I am going after a more sustained sound than the gravelly distortion.
Out,
Gregory
PS. *I ordered mine and they we packed very well. *I would not worry about them breaking. *Just insure them. *It is about 4-5 USD.

**cerealk** · #5 04-27-2001, 10:44 AM

bom dia armindo

como esta?

I know a place near London that would be able to give you top advice on some valves.

I phoned them back in January, told them what I wanted in terms of bass, distortion etc. and what gear I was using and they recommended me some great valves.
That was in the afternoon, I paid over the phone with a credit card and I had the valves the following morning less than 24 hrs later!

I am sure they would happy to ship them to Portugal and they would get there safely.

Alternatively there is a website (I dont have the url right now but will find it later) that reviews all the available valves. and tells you everything about valves.

ate logo

Simon

armindo__dias · #6 04-27-2001, 12:06 PM

Simon,

that would be great. Please let me know when you get that URL.

But how do you guys know that it's time to change tubes? What are the characteristics of a tube in need to be replaced?

Thanks,
Armindo

**cerealk** · #7 04-27-2001, 12:23 PM

I would change tubes when there was an increase in noise (background hum etc.) or when there was a drop in output.

ripl3y · #8 04-27-2001, 12:55 PM

armindo,
i think Simon may be talking about www.watfordvalves.com

they test all their valves and pick out the top quality ones.
very experienced company
they've been raving about the Harma valves recently and the reviews in the guitar mags have been very good about them.
The best ones they stock appear to be the GE's (again, according to reviews, have been winning top marks), I even think that GE make the Harma's (but I may be mistaken)

Cheers
Steve

(Edited by ripl3y at 12:12 pm on April 27, 2001)

**cerealk** · #9 04-27-2001, 01:13 PM

that's it!

thanks Steve
I will double check where I got my valves from though but I am pretty sure it was there.

cheers

Simon

ripl3y · #10 04-27-2001, 01:15 PM

:biggrin:

ryan · #11 05-01-2001, 03:55 PM

I dunno what yer talkin' with extra cost...

I just retubed my 5150 with a whole set of Eurotubes ( http://www.eurotubes.com ) for $95.

That's 4 6L6GC tubes and five 12AX7 (ECC83) tubes.

It sounds so good now I can barely stand it. *The clean channel (which previously sucked a sheep's nasty booty hole) is gorgeously smooth and the lead channel is unbelievable. *The graininess is smoothed out and the EQ controls are much more sensitive and USABLE with the new tubes.

pri0531 · #12 05-01-2001, 06:48 PM

I will second that Ryan.
Gregory

armindo__dias · #13 05-02-2001, 01:29 PM

Thanks guys for all the replys.

Those Eurotubes seems to be great. But what about the Sovteks? Are they worth the money?

Also, i've never tried to change tubes. One friend of mine said to me that to change the tubes, i need to wear some gloves because of the static electricity between the glass and your skin (it could damage the tubes)... (???)

Well, i never thought it would be too hard to change tubes... Is this true? My whole idea of a procedure to change tubes is:
- Turn off the amp.
- Be shure that the tubes are cold...
- Remove the old tubes with you hands (no gloves!!!)

.
- Insert the new tubes (with your hands too!)
- Turn the amp on again...
- And play!

Is any special procedure that i have to follow to change them? Or can i do it "my own away" and touch them in the glass with my hands?

Sorry if this is a stupid question...

Armindo Dias

armindo__dias · #14 05-02-2001, 01:32 PM

Thanks guys for all the replys.

Those Eurotubes seems to be great. But what about the Sovteks? Are they worth the money?

Also, i've never tried to change tubes. One friend of mine said to me that to change the tubes, i need to wear some gloves because of the static electricity between the glass and your skin (it could damage the tubes)... (???)

Well, i never thought it would be too hard to change tubes... Is this true? My whole idea of a procedure to change tubes is:
- Turn off the amp.
- Be shure that the tubes are cold...
- Remove the old tubes with my hands (no gloves!!!)

.
- Insert the new tubes (with my hands too!)
- Turn the amp on again...
- And play!

Is any special procedure that i have to follow to change them? Or can i do it "my own away" and touch them in the glass with my hands?

Sorry if this is a stupid question...

Armindo Dias

rgr · #15 05-02-2001, 01:46 PM

Svetlana makes the best tubes I have found recently. *I would recommend taking the JCM900 to a good tech and have him convert it from 5881s to EL34s. *Those are the "Marshall sound" in my book. *I've had good luck with Svet EL34s, they are all I have used for the last 5 - 6 years. *

Good Luck,
Roger