THD Yellowjackets 6L6

Tube adaptors that allows you to swap out 6L6's for EL84's. No real "features" except for easy install.

I've read people saying they bought these to decrease volume. I don't think they're particularly useful for that, those people should buy a power attenuator first. These are mainly to get that EL84 distortion out of your amp...by putting EL84's in it. Makes sense!

I put these in a Fender Blues Deluxe as a last ditch effort to get some use out of the gain channel. For a long time I blamed how loud the amp was for not being able to get any good gain, but after I bought an attenuator, I was disappointed to find that even fully cranked the dirty channel was pretty useless.

So I was just committed to using a boost->distortion pedal solution on the clean channel, which I wasn't thrilled about. Then I read about these in an online forum and decided to give them a try.

They're pretty damn good! My main concerns were 1.) Will this screw up my clean tone (which I like) and 2.) Will it give me good drive.

1.)Clean tone is still there, completely unchanged, except that you do lose clean headroom. This was never really a concern for me, I don't mind the clean tone breaking up some when cranked, for me that's a bonus. It may not be for you.

2.) I like the drive. It's nice and organic sounding, and good for most any rock n roll. On its own: Derek & The Dominos, with an attenuator or a boost pedal kicked in: I can keep up with an AC/DC song's grit pretty easily without the police showing up.

So, problem solved as far as I'm concerned. Distortion pedals are out of my life, cause I've got nice natural-sounding power-tube distortion without clipping my input signal.

They seem reliable. They're really just adaptors, so I can't imagine what would go wrong. The only thing people should be aware of is that they're gonna make the tubes stick out much further, so you should take measurements before ordering.

Haven't had the pleasure.

I don't gig, I just jam with friends now and then. I've been chasing tone for awhile now though, and think I have decent taste IMHO. I've been playing for 8 years. I've been through a good amount of gear, and am learning that you really can't get too much done with pedals. You gotta have a guitar and amp that you can get something decent out of to begin with or you're just chasing your tail.

This review is based on:

Clean: Am Stand Strat w/ Lindy Fralin "Real 54's"-> BOSS CS-3 -> Blues Deluxe

Gain: Strat-> TS-9 Tubescreamer (just for boost)-> Blues Deluxe

The price is right, easy install, and while they're probably not right for everyone, they're worth a shot before chucking a whole amp that you're only partially dissatisfied with. Really: if you like your clean channel already, you're halfway there. All you gotta do is find a way to get those power tubes distorting before you blow your speaker out and you should be happy. This could be the answer for you.

I have one thing to say: FENDER HOTROD DELUXE + YJS YELLOWJACKETS/JJ tubes = ****HEAVEN**** Fukk robbing some bloke to buy a Vox. Pick up a used HRDx, replace preamp tubes with NOS 12ax/at/au7's, swap out the speaker for one of your liking, and have a glorious creamy 15 watt Fender Hotrod Vox AC30 and not a 40 watt block of ice!!! The HRDx stock sucks, but for $250 in mods it's the best amp I have ever heard.

converts 6L6s to EL-84s. Drops power 50 to 70%. Simple to switch out: unplug amp, remove 6L6s, put EL-84s into the YJs, pop 'em in. Did the conversion on a mid '80s "The Twin" (red knob, 100w, super clean channel, super crappy dirt channel, louder than anything else I've come across).

I already had 2 of the 4 6L6s out of the amp, so putting in the YJs and EL-84s in their place, I think (at low power) the amp gets all the way down to 15 watts. The clean channel has some nice warm distortion now (NEVER did at any volume prior to this) and you can actually turn it up to 4 or 5 in the garage. The dirt channel has potential for some serious distortion now, with nice feedback and a really warm breakup. The Fender reverb sounds different too- only a teeny bit sounds good; too much and it mushes out. Overall, the amp is finally capable of good distortion on it's own, and with volume levels that can be managed on the guitar itself. I love it! The amp almost got sold a hundred times, to cover the cost of another tube amp that had more versatile/useful sounds. Not getting rid of it now!

Can't speak about reliability without more time invested.

NA, see above

Been playing for 27 years; love my amp now. play mostly acoustic and some electric (more now that I've got an amp I like). Well worth the cost, hope they last a long time.

The yellow-jackets came with a pair of JJ Tesla EL84's. There was no drama or skill required to swap them over for the Groove Tubes 6L6's in my Roland Bolt 60 Amp. The supplied instructions are perfectly adequate. The only caveat is that you must not use them on an amp of too high a plate voltage. (Common examples are given.)

The difference was immediate and marked. It was not that I am unhappy with the sound of the amp in its original configuration but the best sound came at too high a volume for general use. The qualities are pretty much as described by others and with the virtues generally attributed to Class A Amps. I have tested the amp with a variety of guitars and the observations are common to all.
The tone controls appear to work better and more predictably. The overdrive channel is much more versatile and smoother in operation. There is still ample headroom for the type of music I play -Jazz/Blues and I have far less need to use an overdrive pedal.
You can happily control the volume from the guitar which was far less precise with the 6L6's. It is, as the ad says like having a new amp with the benefit of class A operation without paying todays prices for it.

I see no reason to suppose that they will not be reliable either in their own right or as a component of the amp. it is said that the valves wear faster in Class A and I intend to get a spare set of EL84's which are small enough to carry in my guitar case.
I am happy to gig with the amp without a backup.

I have not dealt with THD but anecdotally, the company seems to be well regarded

If I went back to playing straight ahead rock with the need for the full volume potential my amp has I would pop the 6L6's back in but for the refinement that the yellow jackets bring to the sound they are a winner as far as my needs are concerned.

I tried them in a traynor ycv 40 tube amp, and Allen Old Flame and a silverfaced super reverb. They did cut the power and allowed easier break up. i like the el 84 tube but guess I prefer the 6l6 stock. I like these amps at the edge of breakup , and with a clean tone. These do the break up but the lack of headroom on clean is a problem. Lose some bass too. Probably due to the tube characteristics of the el 84. Heck I'm not an electronics guy, i play guitar. They are a fascinating product though and I use them sometimes for a change. Now I keep them as backup tubes

How brutal is the distrotion? Brutal. How clean is the clean, not so clean.
They add an intersting variety to your tone, and easy to change in or out and can serve as decent backups if you don;t like them that much.

So far so good they sit in the back of the amp I'm using in a padded case.

Nice responsive folks

Well they do vut the power. They do sound like el84.s In short they do what they are advertised to do. I just didn't need them cause I don't need brutal overdrive..

A very easy plug in modification. Cut my power some, as advertised, that was what I was after. My 68 super was too loud when I got it breathing, according to the guys. I went from giging at volume 3-4 to about 6 now, perfect.

I play a LP Deluxe with a minibucker in the neck, full shred Dimarzio in the bridge, also a Ibenez w 2 stock singles and an X2N bridge. All styles, Beck is my hero. Clean sounds are still clean, an oddly enough, overdrive is still cleaner using my favorite setting but with smoking tone and all the sustain I need. In overdrive for example with "Cause we've ended as Lovers", I can have infinite sustain-harmonics ringing out standing ~ 3 feet away from my amp, then end the sustain by moving 1 more foot away. I could do this before the yellowjacket, but no one could hear the rest of the band!

I have had them 3 months, no problems yet.

I phoned the company once before I bought just for info, was impressed.

Started playing in 4th grade, Im 45 now (still in 4th grade). I have a sovtek 50w 1/2 stack that I like real well also, put the groove tube adapters in it, didnt quite have the headroom at a gig, may go back to the 6l6s with it. Ilove the tone the 68 super is giving me too much now to gig with sovtek currently. The super smokes now, the other guitar player is considering trying the yellow jackets in his reissue 410 bassman or his 112 musicman. I tryed lots of expensive amps ie Orange, Dr Z, Matchless, Bogner, etc. etc. I always liked my super but couldnt be happier with it now!

There really aren't any features....They are plug and play!

The sound: I am defnitely not an electronic genius, but after reading several reviews, I decided it was worth a shot to change the tonality of my Hot Rod Deluxe. I love the amp overall, but like someone else mentioned, that something special was lacking. Hard to describe, but I've put up with it because the clean channel was very good and I predominantly use pedals for drive, so it was working. After putting these in, I immediately heard the "chime" or grease that I was after...AMAZING....There was no noticeable drop in volume, however, which I wanted, but whatever was lacking before is now there. I gigged this weekend and just had this goofy smile on!

should be good..not much to go wrong...

Support was excellent. Ed helped me through the installation when Musician's Friend actually sent me the YJCD instead of YJSD...told me no worries with my amp, just don't hook up the ground. Very knowledgeable folks with a great product. By the way, the JJ's they ship with are good in their own right!

yellowjackets in mesa boogie rectoverb: good cleans, made gain channel harsh and un-usable, still very loud--don't expect low

volume breakup, just loss of headroom. would like to try these in a fender (or similar) combo. WILL NOT FIT IN MOST

HEADS...REQUIRES A HAIR OVER 5 INCHES OF CLEARANCE for the regular model (short model is only about half an inch shorter)

********** If you want some serious volume reduction and low volume power tube distortion, I highly suggest some TADs by

www.smicz-amplification.com ... these are 1-2 watt tube adapters (6AK6, sounds similar to a 6V6) and at only 4 inches tall,

will fit in heads too. ************

fine

I have a custom Fender '65 reissue deluxe reverb. It's in a custom cabinet by Marsh Amps that has a 12" Celestion G12 "Blue" alnico, AND a Fender blue alnico 10" speaker. 5751's in 2 and 4 slots to tame the extra highs in the main channel. .47 bright cap, and a .82 slope resistor. Added the Yellowjackets and two EL-84's to try the class A sound. Absolutely fantastic sound! Been at the Blues since 1959, and this rig is tone Viagra. Could not be better. I couldn't believe it...

I play a Heritage 555 with twin Schaller humbuckers. Great guitar, and the sounds I can get out of this amp with the Yellowjackets are perfect no matter where I set the pickup selector. What's amazing is the tone from the bridge pickup which I never liked. Now I play it alot for leads. B. B. King city. The sound is really wide ranging with the combination of the 12 inch and 10 inch speakers, but it's the slight breakup, tiny dirt, subtle overdrive nuances of the tone that just can't be described. Tremendous is all I can say.

Don't know yet as I just got them. I'm hoping for the best. I'll let them know if they die on me!!

I spoke with Steve Lam, and he could not have been more helpful. So far, all is good...haven't needed any customer service.

Like I said, been at the Blues since 1959. Not many amps or guitars I haven't owned or tried, especially Fender amps. You just can't get the old sound out of modern products, but the Yellowjackets can sure bring it on!! Try them!!!!

simple... i'm using these in a blues deville.

they sound great! very voxy.

i actually have had to send one of the yellowjackets back to the company after about 2 months- and it looks like just recently the other one is going bad... it gets very hot!. i know its not the EL84's cuz i swapped them out to check.

the company was very friendly and sent me a new one free... hope they will send another one.

i havent had these for more then a year, i was hoping they would hold up longer for $100. i love the sound. i would reccomend others to take backups just in case one go's bad... or 2.

I'm can't remember the Yellowjacket model I'm using but its for 6L6s. This model cuts to output power by about 60%. You can also get the same thing without the power cutting ability.
These are totally amazing! Just plug 'em in and fire up. They'll have your old, loud, clean tube amp screaming with class A EL84 grease! If big, clean headroom is your thing, then these are probably not for you. If you're looking for a little hair around the edges of your clean notes or very kick-ass greasy overdrive, then order some.

I purchased these to tame a Blues Deville, and they did the trick. I've since sold the Fender and now run these in a Pignose 60 watt tube head fed through a 4x10 cab. My Telecasters just sing with these. Turn your guitar volume down and they clean up perfectly, roll it back and grind to your heart's content!
These will not make your 6L6 sound like a Vox AC30, but class A even harmonics are definatly there. If your a stickler for classic 6L6 tone, you may not like these, but for about $100.00, you can have two very cool amp sounds.

THD is known for their American made, quality products so I'm not worried. And for what they cost, I wouldn't mind having to replace them in a few years. Note: I ordered my first set from thetubestore.com and one on the plastic center posts on the adapters was broken off. Everything worked fine, but I emailed thetubestore and told them about it. They sent me a new set, didn't charge me shipping on the replacements, and had my credit card refunded as soon as they recieved the damaged set. A great bunch up there in Canada!

Never delt with them directly, but they're small and I'm sure you could talk to the techs any time you had a question.

Played (bashed) for 21 years now and live for a dirty rock and roll guitar sound. These turn any decent sounding 6L6 amp into a class A monster! This is now a must have in my signal chain. They have a very unique tone quality all their own that I've come to rely upon. I would/will replace these if and when needed. If you have limited space in your amp, you can order a shory version. The adapters and the included Testla EL84s a quite long. This is an incredable upgrade for $100.00. You wont be sorry. Check out ebay and see how many people are trying to get rid of them...always a good indicator.

Just a quick update. I gigged with YJs in my Hot Rod Deluxe for the first time Saturday. In every respect, this amp is superior with EL84s. There was no lack of stage volume, and the tone sits in the mix better than before. The clean channel is bright and chimey, even on the edge of breakup. The drive sounds "full throttle" even at the same volume settings - and the way it mixes with bass and keys is sweet! The "more drive" boost yielded sustain and harmonics that transcend the Fender sound. I'm hooked. This is a great product!

Duet Tube Converters -- Converts 6L6 Class AB Power section to EL84 Class A power section.

One feature -- and it is mind bogglingly cool

I got these as a last resort for my Hot Rod Deluxe. The amp was never "it." It never had the high-quality chimy, clear, inspiring tone that I wanted from it. I first changed to a Celestion Vintage 30 speaker -- and it got louder and tighter -- but not more "inspiring." Then I put in NOS tubes. No meaningful improvement in the "magic."

Then I bought the Yellow Jackets. Simple swap job -- turned on -- clicked off standby -- holy crap. The chime was there. The magic. The inspiration. Still very loud. But useful loud, sweet loud. I never wanna stop playing loud.

Here's what was wrong before the speaker change and the Yellow Jackets: all the HRD had going for it was huge bass, and ear-splitting power. I've owned a dozen amps in my twenty years of playing, and this was the loudest of them all. Louder than the 100-watt Yamaha I had in High School, or the 135-watt Peavey I had in Junior High. But the Fender Hot Rod Deluxe had no inspiring sounds. Below "6" it sounded mediocre at any safe volume level. On the drive channels, the distortion sounded amateurish and flabby (like shit). And, worst of all for a Fender, the reverb is incredibly boingy and useless above "3". No lush, rich, reverb here.

But now -- the HRD with Celestion Vintage 30 and Yellow Jackets sounds near to perfect. With my Robert Cray Strat -- this thing has chime, mojo, vibe, clarity, richness and lots of harmonic content above the fundamental. It has what it never had before. I don't think I'll ever need a better amp.

?

Owner handles it personally.

One feature - changes your 6L6 amp to EL84 Class A operation. Mine is a Fender Hot Rod Deluxe w/clean and drive channels. With respect to the single purpose of the product, it gets a 10. I purchased the YJs and the EL84 tubes separately at a cost savings.

Sound. This is complex, I'll try to keep it brief. The HRDx (with stock speaker) has a lot of bass for a 1x12 combo. I play a EB Music Man Silhouette with a HSH pickup set. I play in a cover/party band with pop-rock songs spanning the 70's to today. I use a Tech 21 XXL distortion pedal in front of the clean channel for crunchy rock, or the HRDx's lightly overdriven sound (drive on 3 or 4). Problem: my single coil/coil tapped tone was wallowing in bass. I had to use amp's "bright" switch and crank the presence to get some sweetness and clarity - an inconvenient amount of tweaking for gigs.

The YJs completely change the personality of the amp - mostly for the better. Brighter tone on the clean channel. Tighter bass. The clean channel distorts at a lower volume, and the result is a very cool "vintage british" OD sound - rich and articulated even with full chords. The drive channel OD is hotter than before. Essentially, it's now an amp with two OD channels, which leads to a couple of shortcomings:

The YJs impair the ability of this amp to be used for clean sounds at gig volume by cutting the power output by half. The background noise level is increased - quite noticeable at higher drive levels. I was able to remedy the noise problem by substituting a lower gain 12AT7 in the preamp section (V2). Now I'm really happy with the sound, but I regret the loss of the clean channel at gig volume.

Seems to be a reliable product (no moving parts). The EL84 tubes extend further into the cabinet of the amp, and I worry that they'll melt the power cord if left in contact - other than that, no worries.

No experience - can't answer.

Been playing for 15 years as a hobby musician, part of that time as a bassist. I have an EB Music Man Silhouette, a Sterling bass, a Taylor acoustic-electric and a variety of pedals. I'm a huge U2 fan, and the YJs get me closer to the sound of the Edge (with help from a Deluxe Memory Man). I've added tilt back legs and a Jensen C12N to my HRDx, and I'm now very attached to it. Were it lost or stolen, I'd probably buy another - but not without looking at a RI Deluxe Reverb or a Mesa Boogie Nomad first :-) Sound is very subjective - the YJ tone may not be for everyone. But for me, it's a good thing - and if I want the original tone of my amp back, I just pop em out and put the 6L6's back in. Cool!

Tone update only

I previously submitted a review for the YellowJackets in my HRDx. I finally got around to trying them in my Sovtek Mig 60, and do not like the combination. Although, in the HRDx I had to crank the treble down and got sweet tones, I was unable to find any usable settings on my Mig 60 to make the YJ's sound good. I have more difficulty getting a sweet tube tone out of the Mig 60 than the HRDx regardless of the output tubes, but I am going to experiment some more, probably with different preamp tubes. I tested the YellowJackets in the Mig 60 using (v1-v3) Chinese 12ax7 + JJ ECC83 + Svetlana 12ax7.

They have only one feature which is to transform a 6L6 amp into Class A EL84 operation

When I first read about these things, I thought it was all hype to the highest degree. If Class A operation requires such sophisticated engineering and most Vox amps are reputed to be so unreliable(well...thats what I heard) then how could a Fender amp be so easily converted? Hell if I know... but these things do exactly as advertised and then some! I stuck the Yellow Jackets in a Blackface Bassman top and I could feel the difference under my fingers immediatly...instant squish and a very soft ,detailed high end..I AB this unit with my Top Hat Club Royale and while they do not sound exactly alike, they are very close! For $100 you get a whole new amp with no modification at all to your Fender or whatever you are using. If you like class A as I do but are not ready to put out big bucks to buy a Matchless, Top Hat, Dr. Z etc. Try these and you won't be disappointed. What a great product!!

too soon to tell.

I emailed THD several times prior to my purchase and they responded very quickly and were very helpfull.I suggest you do the same as they can tell you what model is right for your amp and some of the distributors are not always aware of new developments in the product lines.

I really can't rave enough about these. It would be one thing to achieve the conversion to Class A and have an OK sound, but these things really do sound great! And if you tire of that particular sound, simply pop the original power tubes back in. It's like magic. I will definely get these things for my EL34,6V6 amps and my Ampeg Reverberocket II.

Converts 6L6, 6V6, EL43 Class AB > EL84 Class A
Plug and Play!

See my reviews on Tubeworks Real Tube and Fender Hot Rod Deluxe for more info on my setup. I play a Strat w/ bucker in bridge into a Fender Hot Rod Deluxe or a Sovtek Mig 60. I have not had a chance to try them in the Sovtek yet, because that would require removing the chassis from the head. In the Fender HRD, these things are amazing. I already have lower gain preamp tubes installed, and adding this feature just makes the tone JUICY. I can achieve power tube distortion at a much lower volume, and the Class A sound is great. For $70 I got a whole new amp! Just wish they were a BIT louder.

Haven't had a problem yet. Construction looks solid.

Haven't needed it.

I highly recommend THD Yellowjackets to people who are trying to tame their tube amp and/or people seeking Class A tone. I think I will get most use out of these adapters while recording.

www.deharmonic.net

Well...it only really has one feature but it's a killer and, as far as I know, nothing else does what the Yellowjackets do. Thus, the "10".

I use them in a reissue Marshall Bluesbreaker combo. When I plug them in the output drops to about 15 watts and it sounds AMAZINGLY like a reissue Vox AC30 (with Greenback Celestions like the Marshall) that I once had. For a hundred bucks or so this can't be beat as both a way of getting more sounds out of an amp as well as cutting the volume at which all out power tube distortion is reached.

The Yellowjackets themselves have never caused any trouble and the EL-84's used with them seem to have about the same life as the KT-66's I use in the amp when the Yellowjackets aren't in there.

I own these and a Hotplate power atenuator. I've never had to find out what THD's customer support is like because neither has ever given me any trouble at all.

The only competition for this product is really a second amp like an AC15 or other small tube amp. The Yellowjackets are a lot cheaper and the only disadvantage is that you can't play the amp both ways at the same time or switch immediately from one to the other during a song as you could if you had two amps! The only inconvenient thing about them is a result of my amps layout which makes the tubes awkward to access when I wish to switch back and forth.

I'm using these in a Mesa Boogie Nomad 55 combo amp with one Weber Thames 12" speaker. No features other than changing your amp into a class A vox-like amp which is pretty damn cool in itself.

Ok, I was shocked at the sound. I love the Mesa Nomad but there was something that just wasnt' clicking with me when I compared it to my Mesa rack system with a Triaxxis preamp and Dyna watt power amp. The rack system is so smooth and bluesy with a nice upper end chime. The Nomad was thick and raunchy. Then it hit me, the Mesa Dynawatt amp uses el84's. I didn't think that running tubes under there threshold (i.e. clean) would color the sound. I was wrong. Whether or not a tube is pushed has no bearing on the tone. Tone is tone, clean or distorted - EL84's have a unique tone that I love. So I figured I'd buy the Yellow Jackets to drop down the power and see if that magic would come to the Nomad. Well, volume-wise, don't expect a volume drop. The output dropped to about 30watts but these are class A watts which are loud. What I have noticed is that beyond a certain point, the amp won't go any louder but just compresses and distorts the output stage, whereas with 6L6's or EL34's, I can push it farther and louder before output stage distortion hits. The tone is there my brothers!! That rich, harmonic, chimey, Brian May tone. Very tight and focused in the upper mids and treble. It may be a little too bright for some amps but I have a Weber speaker that is chimey but not icepick harsh. El84's just have the sweetest tone ever and running them in class A is even better. Its like getting a whole new amp.

I've owned other THD products and they are built to last.

#1 product support. Phone personel is great and Ed DeGenero always answers his emails.

This is a must for any serious musician. Considering this is a plug-n-play system with no re-biasing for under $100 bucks is a no brainer. It will transform your amp into a semi-Vox. Honestly, my Boogie sounds closer to a Vox than any modeling amp I've ever owned, and I've owned several. That upper end chime is just amazing. I wouldn't really say its good for heavy metal since the low end is just not that big. Its tighter and more focused. Its just a rich, chimey sound that can only be appreciated by fans of EL84's (Matchless, Vox, etc.)If I get tired of it - I just pull them out and put in my 6l6 or el34's without any tools!!

They haven't got any features. You pull the old tubes out and put these in. They are self-biasing, which is a plus. That deserves a few points. As does the simplicity, I suppose. And the nice colour.
Alright...I'll give it a 10 then. It is pretty well like having an extra amp after all.

I got these for my Fender Hot Rod Deluxe (by the recommendations on this review page) because the HRD is too loud for many of the venues I've been in recently. I've tried turning it down but tube amps don't sound their best when the volume is too low. I tried a Laney LC15 but it was too bright sounding for my taste with the 10" speaker and when I found that the Yellowjackets would give my HRD a similar output I sold the Laney and got a set.
When I first tried them I was disappointed because the sound was very bright and piercing...like the Laney (I play a Telecaster which has enough treble to begin with). I then thought that it was some aspect of Class A operation that was causing it but after putting a question on the HC amp forum and also finding an old article in a guitar mag I learned that it's the EL84 tubes (which the Laney also had). 6L6 tubes (and EL34s) tend to emphasise the bass frequencies and EL84s tend to emphasise the upper mids and highs. Any amp which has been designed to bring out usable highs with 6L6s (like the HRD) will cut glass if you just plop in EL84s UNLESS you do some major EQ adjustments. I therefore played around and found that rolling off ALL the treble (and having the bright switch off) and having the mids, bass and the presence at about 4 or 5 made a fantastic sound. I also tried it with the treble at 3 or 4 with a Boss EQ pedal in the effects loop trimming off the highs a little and it sounded good too.
I've not gigged with it yet but it seems to have a much tighter bottom (oo er!) and switching between pickups isn't as much of a shock as it was with the 6L6s. The clean channel is chiming and almost like it has a chorus and the overdrive on channel 2 seems much smoother too, and it was good to begin with (since I'd put Tesla preamp tubes and a Celestion Vintage 30 speaker in). The 'More Drive' button results in a creamy overdrive boost rather than the shriek it used to make. It seems to have much the same power as before since a 20w Class A will hold its own against a 40w Class A/B, but the tone at low volume seems more usable. I'll see how it is when I gig a few times but volume issues aside, I think I prefer the new tone and feel. AND I won't have to pay anyone to rebias the amp when I replace power tubes anymore since the yellowjackets are self-biasing.

Too soon to say. I don't expect any problems since the reviews don't seem to show any problems occurring.

?

I've played since 1969 and I'm fussy about my gear. I've explained most everything in the 'sounds' section so I'll just say that I think these are dead cool and I like the sound (it'll take several gigs to get the feel of them properly but I'm pretty confident they'll be OK).
I think I'd replace them if I lost or broke them.
It's important to realise that you need to alter your EQ settings when you put these in.
I'll give them a 10 since you're virtually getting a second good amp for #85.

No features...plug 'em in...turn it on.

I decided to give these a try just to see what I was missing. Put them in an old BF Vibrolux Reverb. The tone definitely changes...quite a bit brighter than the stock 6L6's. I guess the final test is whether or not you leave them in...I always wind up pulling them back out after a couple days and putting the 6L6's back.
The sounds, to me, were not any better or worse than the stock amp...just different

I could not crank these any farther than the stock tubes. For any given setting on the volume dial, I noticed no change in volume.

haven't had to deal with the company.

7-8 overall...They appear to be fine well made products. The overall tone just is not my personal favorite.

I gave these a ten just because installing them is so easy - you're mother could do it. But, it's kinda hard to talk about features with this type of product.....so read on.

OK, now let's talk. I gave these little gems a try in my 4x10 Fender Hot Rod Deville. My biggest complaint about this amp is that it's just too damn loud. And when you do turn it up with some gain on the front end, it gets pretty noisy. You gotta tweak it just right to get a nice gritty but quiet sound. Anyway, I'm not gigging so using this thing in the bedrooom isn't what it's designed for to begin with - but even when I jam with friends, I can't turn it up past 3. That being said, I installed the yellowjackets to improve overall tone, and decrease overall power so I could theoretically turn the master volume past 1.5 - 3. Now, the tone issue was definately improved. But that's because I love the AC30 sound, and these things definately make my deville sound more like an AC30. It now has that glassy, class A tone that I really like. It distorts more nicely now too. Less muddy, more gritty with good midrange and highs. BUT, I still can't turn the damn thing up past 2. But, it makes sense because what they'r really doing is turning my 60Watt deville into a 30 Watt Class A amp. And believe me, anyone who has played through a class A amp know's that 30 Watts in Class A power is about equal to 50-60 Watts of class AB in terms of volume. I'd like to see a tube converter be able to cut my power down to about 10Watts. That would be cool. I know what you're thinking....buy another amp.

So, just in the tone category, I give these things a 9. (Hey, there's no such thing as perfection)

Can't really say. Haven't had them long enough.

THD was great. I ordered them direct because I couldn't find them anywhere. I called THD, asked a couple of questions, and had them at my door step 48 hrs later. They are very responsive.

I wrote enough in the sound category. That's what counts anyway. Once again, I say a 9 because there is no such thing as perfection. This easy mod was definately an overall tone improvement for my guitar set-up. If you're not happy with the tone on your amp, and you like that classic Class A tone of a Vox or Hiwatt, than these things are exactly what you need to avoid buying a new amp. Then, when you've got $1500 to waste, go get an AC30.

I bought these babies for my 65 re-issue Fender Twin. The amp was way too loud and brittle. The yellowjackets plud right in and warm up the whole thing. I can only use the center two tubes and effectively lower the power to 20 watts, great for small clubs and recording. It changed a clunker amp to one where people comment on my great tone.

I play a b-bender tele. Mellow pop-rock with psychelic and country elements. Sort of byrds meets galaxy 500, clean to slightly-overdriven guitar sounds. I found that the yellowjackets give my twin a more vox-like sound. The high-end on the twin was brittle and harsh. These smooth out the top with a nice vox-like sparkle. The amp is now more dynamically responsive, I can get a bit more grit with my pick attack.

One-year going, so far so good. I club-gig in Seattle about 1-2 times a month.

Very Helpful. I live in the neighborhood. Solid Ballard Blokes! I am going to install a reactive rectifier, their solid state rectifier designed to mimic a tube rectifier, for a nice spongy tone.

As I said, this product changed an amp that had no tone to an excellent sounding and reacting amp! Very Cool!

Yellowjackets replace the stock power tubes (in the case of my Hot Rod Deluxe, 6L6's) with EL84's, which effectively cuts the amp's output in half, from 40 down to 20 watts. Installation takes all of one minute, and the tonal results are tremendous.

I was very displeased with the confused and muddy bottom end on the highgain channel, and the Yellowjackets have delivered me from this tonal hell. Now, the amp really cuts, and I also get more bottom end definition on the clean channel. I could not be happier with the results of this modification, and I recommend Yellowjackets to all Hot Rod Deluxe owners.

I picked up my Yellowjackets today, so I cannot give a rating.

Same as above.

Buy them !!!! An excellent product, you will not regret purchasing them.

This product works on a simple principle of converting the current stock power tubes 6L6 Class AB to a more user friendly Class A EL84. There is no surgery preformed on your amp to complete this modification. I purchased the product from Songbird Music in Toronto. The EL84 tubes come attached to the converter jackets. This product is very easy to understand and does exactly what describes. Try it!!

I'm currently running a 40 watt Fender Hot Rod Deluxe with a 1x12 Sunn extension cabinet. By the way, an extension cab works great with this amp. I wrote a review on my amp. The EL84's work by allowing less voltage to pass through them. Most amps in the 30 watt plus range will run 4 EL84's to allow greater voltage to pass through them. Here's where the magic of this product comes alive. Although the Fender amp only has 40 watts, their a extremely loud 40 watts. In many cases too loud. This is another one of those Fender amps that sound great when you blast it and kind of shitty at low volumes, especialy on the distortion channel. The Yellowjackets allow half the power to pass through them which changes the amp to Class A and only puts out 20 watts. Now the amp in still very loud but you can achieve the same distortion at a much lower volume. Also the clean channel will distort at 5 with a nice SRV clean sound. I can nail the early Zeppelin sound with ease. My drummer can't believe it. The Yellowjackets also allow more midrange compared to the 6L6's. When I need extreme volume, I use the 6L6's. If I could give this product a 11, I would!! Its like having a new amp.

Never a problem. No worries.

I called then once, the owner said he's had good results with the HRD.

If your Fender amp is too loud, try it!! I've been reading the reviews on my amp and everyone is saying how loud the amp is. If you bought this amp for your bedroom, you bought the WRONG amp. The distortion on this amp is very good, although it needs volume to come alive. I,ve had the Yellowjackets for about 4 monts and gave it quite a workout. No problems. I'm thinking of getting a Hot Rod Deville with 4x10's. This will work great. This is the best thing you could ever do to this amp without ripping it apart.