Which 6V6 tubes?

[Eddie]

I have a nice 1964 Blackface Deluxe Reverb and it is distorting quite early and I suspect the power tubes are getting tired. What would be great replacement tubes for this amp? Thanks.

[lenny]

jj's are really nice
i just loaded up my dr with a full set of jj's, for 89 bucks including shipping, picked specifically for my preferences from www.eurotubes.com
highly recomended

[hookstrapped]

I love my Brimars -- from KCA NOS

[BrianF]

I agree on the JJ's

You can also try Doug's Tubes www.dougstubes.com

Doug is a real nice guy and very knowldgeable. He will give you fast service and is available by phone for consultation etc

[eggman]

Hookstrapped,

I like my NOS Brimar 6V6's from KCA tubes. Contact Misha Kropotkin and ask for some.

Respectfully,
Eggman

[shakedancer]

I put them in my Super Champ. I love them.Every amp I have is getting JJ's from top to bottom. Call Bob at Euro tubes.

[mark norwine]

JJ's

[DADGAD]

Still the best: RCA 6V6GT.

[Tim Swartz]

If you've not had the filter caps changed that could also cause your amp to distort early. FWIW, I also like JJs, but feel Tungsols are the best 6V6.

[tweedtone]

Got a '67 BFDR with an EV EVM-12L in it and I was having a problem with Third Set Fade - as the third set of an all-nighter gig got rolling, the amp just seemed to lose a lot of its spank and dynamics. Tried various Sylvania and GE NOS tubes ... finally put in a pair of Electro-Harmonix' new 6V6 and it's sounding quite robust once again!

[MV80]

I completely retube my DRRI 5 months ago.
My amp never sound so good, what a big difference in tone, it's incredible.

Good luck to you

TUBES:
Electro-Harmonix EH 6V6GT
Tesla (JJ) GZ34/5AR4
Sovtek 12AX7LPS
JAN-Philips 12AT7WC

[Tremo]

For 6V6s, either the new JJ or anything NOS.

I've seen way too many EH6V6s short out from melted screen grids, which also frequently damages the amp. IMO they're junk. Pay your money and take your chances with those.

[Tim Swartz]

Ditto Tremo. When the EH 6V6 came out they were touted by some dealers as the new coming... They were only a slight improvement to the old black bottle Reflektor/Sovtec, but they were still unreliable and as Tremo said, have weak screens. I refused to put them in customers amps and ponied up a few more $$ for NOS. The JJs seem rock solid and sound very nice as well.

[Tremo]

You know, if you take a very close look at the "new" EH6V6, and compare it's innards to the old Sovtek black glass 6V6, and the new Sovtek/New Sensor "Tungsol" (lol) 6V6, you'll see a lot of similarities. They're basically the same damn thing. Same crapola, just new name and new hype. F- those things. They're junk.

Look at the screen grid support rods on the EH, and compare them to the rods in the new JJ, or in a good old NOS GE, Philips or RCA. The EH/Sovtek rods are tiny in diameter. Such a small cross sectional area will not conduct heat worth a CRAP. The JJ's rods are at *least* twice the diameter of the EH. Not only does that make them stronger and more rigid, it also enables them to conduct more heat away from the fine screen grid wires themselves.

New Sensor's misleading hype is that their tubes are designed for "high voltage". Well that's nice, but it's NOT the voltage that's killing them. It's the *power dissipation* in the screen grid.

The screen's ability to dissipate waste heat is a function of the materials it's made of, and the ability of it's components to conduct heat. A small cross sectional wire or rod will have a higher thermal resistance than a rod or wire with 3 times the cross sectional area. The EH just can't get rid of the heat, so it gets too hot, starts glowing, then melts and shorts to either the control grid or the beam former. When that happens, your amp goes down.

The amount of heat energy the screen dissipates is calculated the same way plate dissipation is. You take the product of screen to cathode voltage and screen current. Since in most amps, the screen voltage is fixed and is about the same as the plagte voltage, the variable becomes screen current. Ideally, the screen would just be there to set up an electrostatic field between the control grid and the plate, and conduct no current. But since we live in a non-ideal world, the screen since it is physically located between cathode and plate, will intercept some of the electrons flowing. The less the interception, the better. Screen interception in these aligned-grid tubes is a function of tube geometry and manufacturing precision. If the tube is put together well and the screen wires are properly aligned and are in the electron shadow of the control grid wires, there will be low screen interception. If it's thrown together sloppy and the alignment sucks, it will have high interception. Sad to say, I've seen a number of the EH tubes with high interception.

So, with the EH, you have the possibility of getting a tube with high screen interception, PLUS a weak screen design. With the JJ or nearly anything NOS, you're getting a beefier screen that can safely dissipate more heat, plus they seem to be well aligned. The screen current on the JJ 6V6s in my BFDR is very low, about 1 mA. I have yet to hear of a single instance of a JJ going bad from a melted screen. I have personally seen several EH die from melted screens, as have a number of my fellow amp hounds.

I can't believe it when I read posts from guys telling other people to use that EH POS. Clearly, they are speaking from a standpoint of less experience than the rest of us.

And as Tim correctly pointed out, the JJ sounds pretty damn good! Add to that that the JJ's plate structure is also **way** more beefy than the EH or even NOS. Lard Valve ran one and it didn't even red stripe until the dissipation was well over 20 Watts. I've seen Philips 6V6s start to stripe at 12 Watts. When LV was running the JJ 6V6 at 30 Watts dissipation (over twice it's rated max), the screen still survived, and the tube was not damaged.

Some people seem lucky and get hold of a good pair of the EH, with good alignment, and they hang in there and don't melt. That's great, good for them. However, with all the failures some of us have seen, it's clear that with the EH, it's a real roll of the dice. You're taking a chance.

Those of you looking for tubes for your Deluxe Reverbs really need to pay attention to those of us who work in this field as our professions. EH, no. JJ, yes. It's your money, and your amp repair bill.

[MV80]

Tremo, you begin to scare me a lot.

I don't no nothing about tubes and try to do my best when selected them 5 months ago.

The internet site I was look at said, at this time, that EH6v6GT was the best for DRRI. Now, it seems to have great talk for the JJ. I kept another pair of EH in case of trouble. Should I order new tubes from JJ and scrap the EH ? Money is hard to earn so it's a delicate decision for me and don't need superficial recommendations. I email Eurotubes and they told me to keep my tubes and order new JJ tubes in 6 months.

So, what’s your sincere recommendations?

[Tremo]

Well, a new set of the JJs is, what? $22 bux? That's not that much. If one of your EH takes a dump on you, how much will it cost you to fix your amp if it blows up a screen resistor? Plus you'd have to buy replacement tubes on top of the amp repair. Hey, it's your amp, your money.

Do the following simple experiment to get a feel for the relative safety of your set of EH crapolas:

1. - Remove the upper back panel of your DR so you can easily see the tubes in operation.

2. - Take the amp, a cord and your axe into a room that can be darkened.

3. - Plug in your axe to the amp, turn the amp on to standby and let it warm up for about a minute.

4. - Turn off the room lights and get the room dark inside.

5. - Looking at the back of the amp, you will see the heaters and cathodes of the 6V6s glowing orange. Notice how bright the orange glow is with the amp in standby. Now switch the amp to operate, and see if the brightness of that orange glow increases. (Ignore any blue glow.) If there is an increase in the orange glow brightness when you switch the amp from standby to operate, that increase is coming from the screen grid wires glowing. BAD NEWS.

6. - Now with the amp running, turn it up and blast some overdriven power chords. Watch the 6V6s as you hit the chords. (Again, ignore any blue glow.) If there is an increase in the brightness of the orange glow when you hit the chords, again, that's the screens glowing. Glowing screens is a meltdown waiting to happen. BAD NEWS. Also bad news if you see any red stripe on the plates.

Now if you don't see any increase in the light coming from within the tube when doing the above test, then your EH 6V6s appear to be good ones, and you're probably OK to continue to use them. OTOH, if you see them lighting up from glowing screens, you are on very thin ice. Get them the hell outta there ASAP. Throw them in the dumpster where they belong.

Seriously, with the beefy JJ 6V6 at only $22 a pair, there is no sane reason to take a gamble on the EH, when it comes to buying new or replacement 6V6s. Ignore New Sensor's advertising hype and BS, they're nearly as bad as Groove Tubes when it comes to marketing hype and BS.

[Tim Swartz]

And the only time you want to see Red Stripe is when you're on the islands mon!

[Mik]

Originally Posted by Tim Swartz

And the only time you want to see Red Stripe is when you're on the islands mon!

Now is another time mon: Red Stripe at Albertson's for $5.99 a sixer (then, in my fridge).

Mik

[MV80]

That's it...

I have just ordering JJ tubes from Eurotubes.

6V6 matched pair
ECC83S STANDARD(4)
ECC81 STANDARD (1)
ECC81 BALANCED (1)

I already got a JJ GZ34 rectifier.

I will give you feedback.

[Tim Bowen]

I certainly respect the opinion of the amp techs here. I use JJ's in most of my amps. Old blackface Deluxes saturate more quickly and have less headroom than do the current reissues. Among current garden variety offerings - I would choose JJ's for the "real deal" and EH for the reissues, based on "pure tone". JJ's have more headroom than do the EH's, and to my ear sound a bit stiff and unforgiving in a DRRI, especially as pushed hard. All of the rich harmonic overtones that semi-cranked Deluxes are known for, are better brought forward in the DRRI by the EH 6V6, in my opinion. I've had EH 6V6's in my DRRI for the better part of a year now, with no problems whatsoever, but as soon as they cause my amp to catch fire and self-destruct, all are welcome to say "I told you so." Until then...

[Tremo]

Tim, I have a real deal 1964 BFDR. I'll put it up against any DRRI for a headroom test anytime. I believe the reissue runs at slightly lower voltages than the originals, in order to better handle the crappy EH6V6 tubes.

The originals, for the most part, came with crappy speakers stock. The Oxfart 12K5 isn't very good sounding, and neither is the original Jensen C12Q. The stock speaker in the DRRI is beefier than either. That may be why you think the reissues have more headroom. A lot of guys I know who have original DRs replace the stock speaker with something better, and it really wakes up the amp.

Based on that, IMO, an original, healthy DR, with a good replacement speaker, will have more headroom than a reissue.

Best luck with your selection of tubes.

[lenny]

Originally Posted by MV80

That's it...

I have just ordering JJ tubes from Eurotubes.

6V6 matched pair
ECC83S STANDARD(4)
ECC81 STANDARD (1)
ECC81 BALANCED (1)

I already got a JJ GZ34 rectifier.

I will give you feedback.

that's the set i used in my amp and i love it. i now call my amp THE BEAST :). it made a big difference in sound. i had to use different eq settings, specifically a lot less treble, so be prepared :)
make sure to follow the tube chart but it goes,
ecc83s, ecc83s, ecc81 (standard) ecc83s, ecc83s, balanced ecc81, power tubes then recifier
good luck :)

[Tim Bowen]

Tremo, are current DRRI's issued/biased with EH's? I was not aware.

Regardless of speaker choice, all of the vintage BF Deluxes that I've played have clipped and saturated earlier in their capacity than have my lowly DRRI. But that would be terms of endearment, with regard to the oldies. A Deluxe is the last amp I would choose for headroom (for which a Super might be a better choice). 6L6's and re-biasing will bring forth more headroom and tighten the bass from that amp as well, but to me, it no longer feels like a Deluxe.

As a matter of fact, I chose the crappy EH's over the JJ's, based exactly on early breakup and overtones. Actually, I thought about your informed opinions at the point of choice, no kidding! Ultimately, I followed my ears and not my head. Time will tell if I'm a moron. Thanks for your thoughts and expertise.

[Bluesbob]

an amp will sound best right before it blows up.

[Tim Bowen]

Yep, I guess that's why fuzzboxes sound best with carbon batteries that are just shy of buying the farm. Unfortunately, amps cost more than batteries.

I understand that Mike Zaite prefers, and issues as stock, the EH 6V6's in his Dr. Z Z28's, so at least I'm in good company.