yellow jackets vs substi-tubes

[Thogthecaveman]

Alright guys, which ones should I get? Who has used them? Any reason to choose one over the other? This is for a '57 twin reissue, thanks!

[Kap'n]

If I had to buy them, I'd get the Yellow Jackets, simply because they aren't sold by Groove Tubes.

[powergus6000]

What is wrong with Groove tubes? I am curious not being a smart ass I do not know much about new tubes and people ask me all the time what is a reliable new tube and I always replay as far as I know there is not any.


I stocked up in the 80s on the old stuff.

[Kap'n]

Aspen Pittman is a huckster and a mojo man, selling snake oil at 2-3x the price.

[wingnut1]

The Yellow Jackets will fit in the tube retainers easier than the Substi-Tubes.

[crazy fingers]

I have some yellow jackets that I use on my dr reissue. You can kiss cleangoodbye, but man oh man it crunches with the best of them.
Before I got them, I would always struggle with a useable crunch sound with my single coils. Not anymore.
It should make your 57 sound like godzilla rampaging through tokyo.

[Wilko]

I bought my Yellow Jackets just a fewmonths ago.

I'd buy them again because they were first in market, and should have/may have a patent or copyright.

[tugboat]

What would these do in a Tweed Champ circuit? It might be fun to try one of these things once I get everything up and running. One of these days. (sigh....)


I can't imagine them making the amp any crunchier.

[Kap'n]

What would these do in a Tweed Champ circuit? .

It'd probably sound like crap, to be honest. They're not designed to be used in cathode biased amps.

Essentially, what a Yellow Jacket does is:

• Connects the pins of an octal tube to the corresponding pins for an EL84
• Puts a capacitor on the grid, to strip away the bias voltage
• Adds a big resistor (and capacitor?) to the cathode, to bias the tube.
• Probably adds a screen resistor.

Using a Yellow Jacket on an amp that's already cathode biased will bias the tube very cold.

[wingnut1]

How will they sound on a 5F6A Bassman?

[JJ Gross]

I have Substi-tubes.
Personally I'm no fan of GT tubes, but the GT adapters include re-branded JJs with Groove Tube logos on them. Compared to the YJs, the STs are much heavier construction, almost mil-spec in design. They fit VERY tight in the socket and can stretch your sockets out to the point that when swapping back your original 6L6s, they'll just drop right out of the sockets.

Internally, they're about the same. I use my STs without the metal jackets on the bases for 2 reasons. 1. They fit easily in the tube retainers this way. 2. They stay very cool as opposed to holding heat in the socket like the YJs or the STs with the base sleeves on.

They sound awesome in my HRDx. The clean is nice & shimmery kind of like a Vox and none of the boxiness when cranked up. Extremely nice sound on clean. The drive channel sounds about half way between a Vox & a Marshall with no more flabbiness in the bass - tighter than a frog's ass. Lots of whollop & I'm really loving the HRDx now. You do lose a little clean headroom, but that's the EL84s doing that, not the converter base they're plugged into. You'll also notice the volumes on both channels no longer go straight from whisper to scream between 1 & 2. Going up to about 3 or 4 is normal now and a lot easier to control. All this without touching a soldering iron.

I don't like them in my 78 Twin. To extreme of a change for my tastes. My Twin is slightly modded so I already have a handle on it's volume and I love the tone of it as-is. The EL84s just go too far, too much distortion, zero clean and the volume is about 1/4 of what it was with even just a pair of 6L6s in it.

In the HRDx: Smashingly good. Love it to death with the EL84s in there.
In the Twin: Don't like it - nope - don't like it one bit.

Cheers,
- JJ

* Don't know about the YJs, but the STs drop the plate voltage down to 370v. Any El84 will cruise on that all day & the JJ EL84s don't even blink at that.

[Mark Doebrich]

I put substi-tubes into a Germino Rockgrinder, played for a while, then went back to KT-66's.

Different tones & different volumes. If you're looking for a drop in volume, both are designed to do that. I can't compare the YJ to the ST as you've asked. You may simply need to ask if you want to change your volume AND your tone.

Good luck with playing "the tube game". I still have the ST and will probably use them again...when I'm being yelled at for playing too loud with a non MV amp.

[superduper]

one character

[Wilko]

I
You can swap out a 6V6 for an EL84? yes?

Someone mentioned 'twin', swap out a 6L6 for EL34 or EL84?

I'd be interested in trying an EL84 in my SF champ.

Interesting...

- D

Yep. You can use them in almost any amp. I've got one pair and have used them in my Hiwatt Custom 50, Marshall JTM45 RI, Vibrolux Reverb so far.

For them to sound good in a twin you'd need to buy 4 (four) of them. That puts you in AC30 territory.

Champ? That would just be silly. (and maybe not supported by the YJ due to bias circuit)

[dave hiwatt]

Yep. You can use them in almost any amp. I've got one pair and have used them in my Hiwatt Custom 50, Marshall JTM45 RI, Vibrolux Reverb so far.

For them to sound good in a twin you'd need to buy 4 (four) of them. That puts you in AC30 territory.

Champ? That would just be silly. (and maybe not supported by the YJ due to bias circuit)

Wilko, did you notice any change in sound with the Hiwatt? I have been considering the yellow jackets for my Hiwatt 100 watt lead.

[Wilko]

four yellow jackets is going to be expensive...

The amp sounds very much the same, but with a lower volume at breakup. I was pleasantly suprised. Retained much more Hiwatt sound than I expected.

[tugboat]

I'm new to the whole YJ concept, my next step would be to check out the makers site, but since I've got actual users here...

You can swap out a 6V6 for an EL84? yes?

Someone mentioned 'twin', swap out a 6L6 for EL34 or EL84?

Would it be sacralige to even contemplate trying these in a vintage super, even just for giggles?

I'd be interested in trying an EL84 in my SF champ.

Interesting...

- D

They advertise them as being 100% safe for any amp (with a slight tweak needed for cathode biased amps- I just checked them out at THD's site). Just pop 'em in and play apparently. Plugging them in is the only "mod" required, and you'd do that with 6L6s anyways. Besides, if Fezz does it to his vintage amps, they're safe to use.

Nothing is being done to devalue the amp, after all you can pop the 6L6s back in any time you want, so its not sacrelige at all (unless you get an anal retentive vintage purist who insists that Super Reverbs are only supposed to be used with 6L6s). No harm to the amp, no modifications, no foul. Therefore, no sacrelidge.

There's no way society would advance if we didn't tinker with everything. Leo himself was an incessant tinkerer.



BTW, there is a small modification you need to do if you intend on using these things with a cathode biased amp like a champ (it involves moving a ground wire if I remember right). THD tells you what to do on their website. That's something I might try one day for the hell of it with my Tweed Champ clone actually. I can't imagine it dropping the headroom any (Champ? Headroom? ), but I do think it would be interesting to see how it changes the amp (one day when I'm bored and want to tinker).

[Thogthecaveman]

well I did end up getting the yellow jackets, just cause I was in a store that happened to sell them and they had them so I thought why not. They sound pretty good, I haven't really had a chance to use them a lot so I need to play with them some more.

[JJ Gross]

You can use a pair in a Twin - I have.
I just didn't really care for the sound of it. Virtually zero clean and if I want a dirty amp, I certainly don't need a 112# combo to get it.
I only run two tubes in the power section anyway. Just yank out either the inner or outer pair of power tubes and Viola` ... half power Twin.
It's a TWIN fer cryin' out loud! Do you really need 4 6L6 bottles in there? ;)

[Thogthecaveman]

You can use a pair in a Twin - I have.
I just didn't really care for the sound of it. Virtually zero clean and if I want a dirty amp, I certainly don't need a 112# combo to get it.
I only run two tubes in the power section anyway. Just yank out either the inner or outer pair of power tubes and Viola` ... half power Twin.
It's a TWIN fer cryin' out loud! Do you really need 4 6L6 bottles in there? ;)

This is a '57 reissue twin, so it's only 40 watts with only 2 6L6s

[holmis63]

I´ve got a pair of those yellow yackets in my super twin reverb, actually real nice! If i set the eq neutral i still got a bit of headroom but it´s the dirty tones that is useful! In this case it was really necesery, 3 pairs of 6L6:s was way too much

[5er Driver]

It's a TWIN fer cryin' out loud! Do you really need 4 6L6 bottles in there? ;)

Right......I use 2 TAD ToneBones in my UL Twin. The Bones are a clone of the YJs & STs. If and when I need more clean volume I pop back in 2 or 4 6L6s

[Thogthecaveman]

Wow, this is an old post!!! But now that I'm here...let me ask just to confirm, I can use my yellow-jackets in my '65 deluxe reverb reissue right? I sold my '57 twin but I still have the yellow-jackets so I figure I can still put them to good use...

[Wilko]

You can use them there and they will be just fine.

It won't sound too different. I'd guess you'll lose some headroom and punch.

I gotta try this...

[Thogthecaveman]

Ok, I just tried it and so far I can't tell much of a difference in my DRRI...but it's also kind of late so I didn't turn it up very loud either. One thing I did notice was that it is it makes a lot more noise now. I don't know if that's the nature of running class A or if my yellow-jackets are messed up, but it definitely is noisier now.

[Kap'n]

Yellow Jackets do NOT run "Class A."

They run cathode biased.

There is a difference.

A big difference.

[steve25]

Did you folks hear that Fender has purchased and now owns Groove tubes.

[Kap'n]

It happened some time ago. It's not surprising. FMIC was absolutely GT's largest customer, I'd guess responsible for 50% or more of their sales. That's a lot of leverage.

GT fits well into their portfolio. Big margins for average product.

[Wilko]

Yellow Jackets do NOT run "Class A."

They run cathode biased.

There is a difference.

A big difference.

TESTIFY!!!

[CJ Neel]

I run the YJ's in my BFVR. Fendery with a litte extra crunch when cranked. I find 'em real useful.

[Thogthecaveman]

Yellow Jackets do NOT run "Class A."

They run cathode biased.

There is a difference.

A big difference.

I'm not saying you are wrong, as I don't know too much on amplifiers, but why does the little instruction booklet that comes with them say it changes the amp from running class AB to class A?

[Kap'n]

I'm not saying you are wrong, as I don't know too much on amplifiers, but why does the little instruction booklet that comes with them say it changes the amp from running class AB to class A?

Marketing.

[Wilko]

for a very basic "rule of thumb" count the power tubes. Pairs are in most cases indicative of a swap in the cycle that is not "Class A"

[Kap'n]

for a very basic "rule of thumb" count the power tubes. Pairs are in most cases indicative of a swap in the cycle that is not "Class A"

Pretty much. The only push-pull guitar amp I can think of that is Class A is Allessandro....maybe.

[Wilko]

I didn't use the term push pull because I think that it's a misnomer.


In class A the tubes does push and pull without rest. In paired operation that we call "push pull" they actually push push with breaks in between pushes. One pushes "up" (180) then the other pushes "down" (-180).

right?

[Kap'n]

it's caled push pull because one side pushes while the other pulls & vice versa.

[Wilko]

ah, thanks.

[Thogthecaveman]

Marketing eh? I should have figured thanks for clearing it up for me!