Doug's Tubes

Different tubes in different amps...

2008-02-29T11:01:00.000-08:00

A customer had recently sent us this email -

"Just an update on the "bad tube". I put another GT12AX7C that I purchased from you a while back into the amp and it jingles also but not a bad as the new one. This older tube has operated quietly in my THD Univalve . So I put the new "bad tube" into the Univalve and it sounds fine. The amp that causes the tubes to jingle is a Fender Pro Junior. I think that the GT12AX7C is not a good tube for the Pro Junior. The tubes sit less than an inch from the speaker. I tried JJs and Soveteks in the Pro Junior and they are quiet . So I guess I'll keep the GT12AX7C and use it in my other amps that are heads and not combos."

Before sending back a suspected "bad tube" , trying putting in other amps that you own. As he notes here, the GT12ax7-C works fine in his Univalve, but not in his Fender Pro Junior.

Matt

Roccaforte preamp tube tester is in!

2008-02-21T09:50:00.000-08:00

We have been burning in preamp tubes for the past week and will continue to do so daily. If you order most 12AX7's - Penta, Tung-Sol, Electro Harmonix, JJ, Mullard, Shuguang 9th gen, Sovtek LPS, LP, and WB, they will be burned in. It will take us a few weeks to cover everything, so bare with us. Preamp tubes that are burned in mean less failures in the field, and the extra gas is burned off. More work for us, but less problems for you!

Thanks,
Matt

Learn how to play your favorite songs!

2008-02-15T10:41:00.000-08:00

A very cool idea.

New arrivals / back in stock.....

2008-02-11T09:53:00.000-08:00

We have some new arrivals.....

Ruby Winged 'C' EL34's - These are the same tube as the SED EL34's we've always had, just a different box. These test and match very close, and we have a bunch of tubes that match Bogner specs. We expect these to go fast.

Ruby Winged 'C' 6L6GC's - Again, same tube as the SED 6L6GC's, just a different box. Perfect for Bogner's or those who want early breakup.

Ruby Winged 'C' 6550's - Built very similar to the Valve Art 6550's, this tube is great for both high end audio and guitar amps. Expect a smooth and detailed listen in hifi apps.

Preamp vs. Power Amp - What do they do and which influences sound greater?

2008-02-07T09:13:00.000-08:00

An interesting topic came up in the forum over at Harmony Central:

Which has more influence on sound, the power amp or the preamp?.

Some good questions and we found some good answers. Doug Roccaforte, an amp builder and frequent HC poster, said that the preamp takes the tiny guitar signal, and drives it to the power amp. The power section then takes the the signal, makes it large enough to drive to the speakers. We agree.

Generally, our basic take is this (which is debatable):
The power section can help how early your sound brakes up in the volume controls.
The preamp section helps you dial in the EQ's of an amp.

Everything makes a difference from the speakers you use to the pick you are playing with.

What do you think?

Matt

New Preamp Burn In Rack

2008-01-28T15:27:00.000-08:00

Check out our new preamp burn in rack!
It will be coming in the next week.

This will do two things:
1. Insures you don't get any
premature failures. This means less hassles, less returns for the customer and us!

2. It also burns off
some of the nastyness/treble associated
with brand new preamp tubes. More clarity.

Thanks for Doug over at Roccaforte Amps for making it.

Lesson Learned: Retubing my Orange Rockerverb 50

2008-01-24T06:47:00.000-08:00

What a difference a few switches in the preamp can make (as if we didn't already know), especially when your tubes have crapped out.

I threw a Sovtek LPS in V1, V2, V3 and V6.

This amp rips!

It just goes to show you that you should be swapping preamp tubes one at a time. And you should also swap the power tubes separately from the preamps.

My amps levels were back to the way they were when I first bought the amp used. The amp is still a little bit on the mid-range heavy side. The cleans still breakup a little early, so I will have to make some tweaks in the power tube department. I still have the JJ 6V6's in there by the way, and they are sounding a lot better now that I put in some LPS's.

It takes a little time and energy, but tube tweaking it is well worth it.

Stay tuned for more.

For those interested, I attached the Orange Rockerverb 50 manual. It suggests all different types of EQ settings.

Matt

Tube Glow

2008-01-23T04:08:00.000-08:00

Tube Glow Thread

If your tube's grey plate is turning red, it's a bad sign, and you probably have a bad tube. This is often called "cherrying." Rotate spares to find the bad tube.

Don't worry, blue is a normal color.

Can a bad tube blow a fuse?

2008-01-21T14:34:00.000-08:00

We found this thread on harmony central...

Can a dying tube blow a fuse?

It sure can. I had this happen to our Fender 400 PA system (used 4 Svetlana 6L6GC's) and Vox AC30 (used Ei EL84's).

In both cases, there was a bad power tube. We've talked to our amp techs, and coupled with our own experiences, 80%-90% of the time a fuse is blown, its a tube.

Tube roll to find the bad seed. It's good to have extra tubes and fuses lying around.

-Matt

Tube Rattle?

2008-01-15T21:31:00.000-08:00

We wanted to elaborate on a forum topic found in the Boogie Forum:

Tube Rattle

Identifying tube rattle is relatively easy (especially with output or rectifier tubes).

Take each of the suspected tubes and shake them at ear level. See if you can hear anything. After that tap them lightly with a finger, and listen for a rattle.

This is pretty much foolproof method.

Other sources of rattle other than tubes can come from a loose speaker connection, loose sockets, intermittent grounding among other things.

-Matt

Testing out the JJ 6V6's

2008-01-15T14:25:00.000-08:00

This is the stock setup that came with the Rockerverb 50:

V1 - Sovtek 12AX7 LPS
V2 - Sovtek 12AX7 LPS
V3 - Sovtek 12AX7 LPS
V4 - Shuguang 12AT7
V5 - Shuguang 12AT7
V6 - Sovtek 12AX7 LPS

4 X 6V6 TAD 6V6's.

I was a huge fan of this set up. The clean channel was straight Vox AC30 with an added bonus of a little breakup at the end when pushed to levels 6-10. As for the dirty channel, I had a huge range of sounds - raunchy indie rock, blues leads, punchy rock, and nu-metal.

------------------------------------------------------------------
Swap in - JJ 6V6's

JJ 6V6's - (Note: I was able to get the same power tube rating as my old stock tubes)
So far I'm not liking what I hear. The mids are highlighted way too much on an already mid heavy amp. This amp really sounds through my bandmates SG. I can dial in some decent sounds on my notes in my clean channel, but when I play chords it is still way muddy.

More on preamp switches soon.

-Matt

Top 10 signs you may have a tube problem

2008-01-13T18:00:00.000-08:00

Well, my ears have certainly had enough. Aside from my less than mediocre playing, I have decided its time to change the tubes. How do I know? Here are some signs that your tubes have crapped out:

1. The amp is way too harsh on the ears
2. The bass is no where to be found
3. It's all mids, all the time
4. The clean sounds like the dirty channel, and the dirty sounds like rubbish
5. The reverb does not work
6. Your amps' levels are down significantly
7. Any EQ adjustment shows little improvement in the sound
8. You hear a hissing noise (usually a preamp tube)
9. You hear a rattling sound (could be a loose component in a power or rectifier tube)
10. Humming (unmatched power tubes).

When you start to notice a few things that go sour, keep playing around with your amp for another week or two. Switch preamp tubes around to see if you can find the bad tube. I noticed that my cleans became dirty about a month ago, however I played around with different guitars (Gibson SG, strat, tele), and played with different pedals. I was getting a better sound out of the SG, while the amp sounded way to bright and sharp for the strat and the tele. Finally, about a week ago, the amp just sounds like arse.

I beat the hell out of this thing.
I have easily put 10 hours a week on this baby for almost a year and a half straight.

Remember, the first step to the road of tube recovery is recognizing you have a problem :)

-Matt

This guy makes his own vacuum tubes

2008-01-11T07:50:00.001-08:00

Fabrication d'une lampe triode
Uploaded by F2FO

12AX7 'Gain' Controversy on Harmony Central

2008-01-09T07:37:00.000-08:00

Please read the thread before you continue to read,

You can check out the Harmony Central thread here.

As far as tube testing, all of our tubes are burned in, and tested for gain (in relation to proper specs) and microphonics.

Myles quotes - "What is generally true, and true at the moment, is the JJ ECC83S is the highest gain 12AX7 that is currently in production."

"One of the lowest gain tubes is the Sovtek 12AX7WA. The Sovtek 12AX7WC is not in the same class. It is average in specs with most of the other folks and is a good tube if you like the tone."

In short, with his findings, the JJ ECC83 is of highest gain, and the Sovtek 12AX7WA is the lowest of 12AX7's.

These test results are consistent with our findings as well (throughout 5 years), even though we use different equipment.

As always, we promise to deliver properly tested, quality tubes. To keep this promise we must accurately and successfully find tubes that won't fail, have proper gain, and low microphonics. Our business depends on this.

Thanks for reading,
Matt

Vinyl to replace the CD?

2008-01-08T09:52:00.000-08:00

We want to hear some reactions on the Wired Article we posted.

So...is the CD dead?

Where/how do you buy your music?

When was the last time you bought a CD?

What do you use most to listen to music?

-Matt

Vacuum tubes and Ipod's Sing a Warm Duet!!

2007-12-19T11:46:00.000-08:00

Check out this relatively new exciting article about Vacuum tubes and ipod docs posted in the New York Times.

Also, we linked the NBC Mike Matthew's/New Sensor article A battle for rock's soul

Nice article on Tubes Vs. Solid State

2007-12-19T08:14:00.001-08:00

A long article but interesting, especially for those just starting out with tubes.

From IEEE Spectrum Online Mag -

The Cool Sound of Tubes

Tone + Recommendations

2007-12-14T16:07:00.000-08:00

Many times, people will ask us to give them tube recommendations.
We usually ask the following series of questions:

1)What kind of guitar/amp set up do you have?
2)What kind of music do you play?
3)What do you like about your sound?
4)What would you like to change?
5)What tubes are in there now?

Once we cover this information, we usually give you the run down on the voicings of all the tubes you have questions about.

This is meant to be considered as a rough estimation. We do not consider our opinions or recommendations as final or absolute.

Our recommendations are meant to be a starting point of your quest for the right tone. However, you play the most important role in this journey! Our suggestions are a mere conglomerate of opinions and reactions from our own ears, and the thousands of customers we've had over the past five years.

We have added our 'Amp Kits' page so you can see what other people have bought, and see their reaction to what we sent them.

Having said that, have a happy holiday!

Doug + Matt

Biasing your amp - One thing you might need is a tech.

2007-11-19T07:31:00.001-08:00

After installing your power tubes, more often than not, your amp will need to be biased (unless it is a non adjustable, fixed bias amp). If you are not familiar with biasing, and don't have much of a technical background, it may be better to get the job done by an amp tech. Otherwise, I have provided some links to get started on biasing.

A good start

Biasing a Fender Hot Deville

How to bias a Carvin

Weber bias calculator

Thanks to Bryan K for the Carvin link!

Should I use an amp tech to change tubes? No!

2007-11-09T09:30:00.001-08:00

Common misconception when replacing tubes

Changing preamp tubes is easy and can be done by the newest of newbies.

Power Tubes

1) Grip the base of the power tube with your finger tips, and cup the glass top with the palm of your hand.
2) Gently start removing the tube in a circular (clockwise) motion.
3) Do it carefully as to not to damage or break the tube.

Preamp Tubes

1) Carefully twist off the preamp covers. (Its common to break a preamp by taking the cover off to harshly).
2) Gently start removing the tube in a circular (clockwise) motion.
3) Do it carefully as to not to damage or break the tube.

The only tech related tube issue one might have is re-biasing the amp.

Even this isn't TOO hard to learn, however it is recommended that one do HEAVY research and Q & A before attempting. You could damage the equipment, or more importantly, yourself.

Use our new rating system.

2007-11-09T09:24:00.000-08:00

You can now request a rating (hardness) for your power tubes through the shopping cart. For more, check out the power tube distortion rating in FAQ.

Domestic orders over $95.

2007-10-10T07:49:00.001-07:00

Those for what orders over $95 receive free shippingAll domestic orders over $95 receive free shipping. In order to distinguish you from an international customer, please type in the word 'usa' into the discount code area in the shopping cart. You will then receive free shipping.

Show us your music!

2007-10-09T13:35:00.000-07:00

Hey Everyone,

If you have ordered from Doug's Tubes before, and you have link(myspace, personal) or video you'd like to share with us, please post all the links here, and we will link it to our website/you tube page.

Cheers,
Matt

2007-10-09T13:32:00.000-07:00

I've compiled a list of forums where you can find useful information about tubes, and good reviews about our store :)
Harmony Central
Harmony Central(2)
Harmony Central(3)
Talk Bass
The Gear Page
Return To the Pit
Broad Run Studios
Carvin
Ernie Ball
Dr. Z Amps
The Boogie Forum
The Boogie Forum(2)

Thanks,
Matt

New Website

2007-10-05T14:34:00.000-07:00

We set up a new website, and launched it on Sept. 26th. We integrated a shopping cart that sits on our site. Also, the website should be easier to navigate.

Check it out and let us know what you think.

http://www.dougstubes.com

Best,
Matt