For these tests I was lucky enough to secure the loan of some classic amps and some modern gear as well. The test amps used in this round included:
1961 VOX AC30 – No top boost
Mid 60’s VOX AC10 – Twin
Fender Blues Junior
Fender Pro Junior
All of these amps are combos and put maximum stress on power tubes when it comes to physical vibration and heat build up. The VOX AC30 should have a health warning for tubes since I have yet to encounter a harsher environment to operate in. On with the show.
There has not been a lot of space devoted to this tube in the past. The main reason was that current production provided a limited selection. Let’s forget about New Old Stock for the time being. They’re out there, they are expensive and sometimes represent the dregs of production.
Preferred Series 7189 (premium EL84) – This is the tube you want in just about every amp that calls for a 7189 or EL84. These tubes are bold, producing solid fundamental notes and shimmering harmonics. Don’t confuse these with any other EL84 on the market. These are Russian tubes built for Russia. To get the 7189 designation you build a tube that will handle both higher plate voltages and increased current. To handle those issues the glass has to be just as heavy duty.
If you are running older cathode biased amplifiers these tubes are about as good a choice as you can make for this kind of money. Many hours of testing in class A single ended amps and demanding push – pull circuits; such as the AC30, show it to be the way to go if your amp likes to eat tubes.
This tube is not fancy. It’s great sounding and well constructed for “professional” use. To qualify as a Select Series tube, thetubestore.com performs a full battery of tests and extra inspection to make sure you never receive a dud. The $$/tone ratio is excellent with this tube.
Gold Lion EL84 – All tubes in the EL84 family are tested in a cathode biased amp where they are really pushed and their harmonic content blooms. The Gold Lion’s just sound great at any volume level. The plates look to have a different coating than anything else coming out of new sensor in EL84’s and this, combined with a heavy gage crimped plate seems to really keep the noise down.
Clean tones are chimey and sparkling with single coil pickups and a bit darker with humbuckers. The overdrive on these tubes is smoooth. No gritty, raspy tones, the tubes have just the right amount of compression to track with the overdrive and keep it beautifully controlled while blooming nicely as the note fades out. This produces a very nice organic sustain.
I would take these over MOST NOS tubes any day of the week. If you figure in the extra cost of NOS, these are actually a better value. IF you can get Philips, Telefunken, or British Mullard then go for it. If not, try a set of the Gold Lion EL84’s.
Mullard EL84 – Blues guys will go crazy for the reissue Mullard EL84 tube. It has the least clean headroom and can be pushed into distortion with aggressive playing. When pushed into distortion the Mullard EL84 tube has a softer, creamier overdrive that is more musical than other EL84 tubes and is the tube to pick if you want dirt.
Electro Harmonix EL84-EH – For most applications this is a good bet. The sound of these tubes is very smooth when biased correctly. Tonally, it’s hard to go wrong. They are pleasant to listen to and have the creamy overdrive most people look for in an EL84. They have a nice chime but it’s not overbearing. It looks a lot like the standard Sovtek but a closer inspection will reveal differences. The plate looks a bit more polished with a different coating and internally they feature precisely wrapped grid wires with a bright metal shine. The only problem with this tube is that like the Sovtek and TAD product, they are tubby. The fattest one I measured was .886 inches thick against the G.E. maximum width spec of .875 inches. For most purchasers this will not be an issue. If you have an amp that requires the tube to pass through a hole in the chassis before the pins seat in the socket you should measure the diameter of that hole. If you’re still unsure, the JJ EL84 is the closest in dimensional specs to NOS measurements and the G.E. standards for the 6BQ5.
Sovtek EL84 – The Sovtek EL84 has been a staple for Fender, Boogie, Crate, Peavey and other manufacturers of tube amps using the ’84. This tube really is a good value. It is predictable, reliable and affordable. You can get good EL84 tone at a reasonable price. The Sovtek EL84 has been around a long time, and it has shown continuous improvement over the years. Using a matched set of properly biased tubes will yield a clear smooth sound that is fairly warm and transitions into a smooth breakup with that singing tone that EL84’s are known for. In cathode biased amps like the VOX they get a premium workout and will suffer some effects from heating and cooling. Being prone to mechanical noise in a combo amp, the EL84 is not recommended for amps with poor air circulation. The heating/cooling cycle inside an AC30 easy-bake oven seems to loosen up the mechanical structures within the tube causing them to become very noisy (mechanically) with time. This is true of any amp that uses an EL84 in a poorly ventilated chassis/cabinet arrangement, so if this is your rig, go for the JJ or Russian EL84M.
In the Fender Blues Junior the tubes can really put out respectable volume and great tone for all types of music. The highs are not harsh, the mids are warm and the bottom end is not lacking. If you want to really scream try a Pro Junior with full volume. Very crunchy yet smooth with great singing sustain. I personally like my tubes biased at 60% or 70% of static dissipation and the Sovtek EL84 performed well in this range.
TAD EL84-STR – The STR designation tells us that this was a Special Tube Request by the Tube Amp Doctor. In all honesty it looks and sounds like a pretty radical take on the EL84. The dimensions of this tube deserve your attention. Most tubes made in the U.S., England and Germany were built to a standard size. I often compare the new breed of EL84’s to the 1964 G.E. Essential Tube Characteristics Handbook. The TAD EL84STR is about a quarter inch shorter than any EL84 on the market and falls below the minimum GE spec of 2.344 inches. You may have to modify or adjust spring and clip type retainers for the shorter bottle. These are beefy bottles as well, with a measured maximum width of .874 inches. The GE specification is a maximum value of.875 inches. The TAD EL84STR also has the largest plate structure of any EL84 you can buy. I won’t give any more specs. Just trust me on this one, it’s enormous! There is very little clearance between the plate and the bottle and they get hot! This tube has the deepest bass, the highest highs and solid mids. In short, they sound a lot like a premium 6V6. No smooth creamy distortion here but tons of rock and roll crunch. If your bored with your normal EL84 tone these are definitely tubes to consider. Not recommended for some VOX amps as well as some smaller Mesa Boogie amps due to size issues.
Telam and Polam EL84 – Two wild and crazy tubes! I think for single coil guitars they are the best sounding tubes available. Fender amps love them. Pro Junior, Blues Junior two thumbs up. Mesa Boogie, VOX, Dr Z another two thumbs up. The midrange is very rich in harmonic content. JJ’s sound flat and one dimensional by comparison. The great mids transition into a smooth clear treble and the bass frequencies are solid with no flabbiness. I had a couple of players testing them and they had no problem in picking these tubes as their favorites. Numerous tube swaps were done and the boys would always be able to tell if Polam or Telam were installed.
From a construction standpoint there is more good news. They seem to have stayed very close to the original bottle specification. A lesson that a lot of tube makers have not learned. I’m convinced that the Telam and Polam tubes are out of the same factory. The bottles are the same, the spacers, pins and internal connections all look the same. The only difference is in the stamping of the plate. Telam has a ribbed plate that is spot welded while Polam has a smooth plate that is crimped. The coating on both looks identical. Microphonics or mechanical noise doesn’t seem to care about the construction methods as both are excellent. Picking one over the other is difficult because they sound so much alike. Both tubes sound great clean and both have a beautiful natural overdrive sound with bite and a good aggressive sound.
Tungsol EL84 / 6BQ5 – Combine the rugged build quality you find in Sovtek and the sweet tone you get from JJ and you’ll get a good idea what these tubes are all about. Structurally, they have the same bottles used in Sovtek, EH, and Mullard EL84 tubes. Thick glass, a bit on the tubby side, with nicely finished pins and rugged spacers. The getter design is different from all the other New Sensor tubes. Instead of a small cup these tubes have a single halo type getter up top. The plate coating is also different, having a dark burnished charcoal look. The screening is clearly applied. Overall they look very nice. If your amp will use any of the New Sensor EL84’s the Tungsol EL84 tube will fit just fine. Sonically, I compared the Tung-Sol EL84 power tubes with current offerings from New Sensor and the Tube Store Preferred series 7189. They sound very punchy and have lots of gain. The sound was more articulate than anything from Sovtek, EH or Mullard and was very similar to the Preferred Series 7189. I haven’t tried them in hi-fi equipment but I’m very confident they will be a hit in the audio community based on my guitar amp testing. Very low noise floor and no mechanical noise. Great crunch is easily achieved with a humbucker equipped guitar, while the sparkle shines through with single coils. When pushed into clipping these tubes just give off amazing harmonics and allow you to access some great, controlled feedback. I’m sold! The manufacturer claims the Tung Sol tubes are the best thing for VOX AC30 amps and I have to agree. Testing in my own cathode biased amp confirmed their statements. My amp eats lesser tubes from Russia and many NOS offerings, but the Tungsol EL84 tubes hung in. Not a hint of hot spots or red plating and no trace of mechanical noise or microphonics.
JJ EL84 – This tube has been a personal favorite of mine so the review is not entirely unbiased. With the JJ you seem to get a compromise between tone and reliability. Nice mids, sparkling highs and solid bottom end characterize this tube. From a construction standpoint I think JJ has hit the mark. As with any EL84 they can be prone to mechanical noise in combo amps. However, they seem to take the heat and vibration in stride without any negative tonal effects. In the AC30 the JJ tubes really delivered the VOX chime with lots of swirl and shimmery harmonic content. In the little Pro Junior just crank it up and you get a great, nasty, overdriven sound. That’s not bad, it’s good. When pushed hard into the land of the square wave they remind me a lot of a good 6V6. If you have tried the OEM Sovtek’s that shipped in your amp it’s worth your time to try a set of JJ EL84’s. Many convert and never go back. In cathode biased amps you can generally plug and play for that hot creamy “woman tone” that so many desire.
JJ EL844 (low power EL84 version) – I used a stock Fender Pro Junior to test these tubes. When switching between tubes no bias adjustments were made. This was a plug and play test and done this way because I figured most people would likely drop them in and see what happens. The EL844 does exactly what the manufacturer claims. You get all the tone of an EL84 with less volume overall. The difference doesn’t end there. Because the tube has less power to give, you end up with very nice distortion at lower volumes. I ran the Pro Jr. up to a point just at the start of audible breakup. With EL84’s, the Fender Pro Jr. was loud and punchy. Switch to the EL844’s and cool stuff starts to happen. At the same settings the distortion was now very nice. The EL844 adds a bit of compression so the distortion was smoother and more focused. These tubes have excellent response to pick attack. With a lighter touch you can get sparkling shimmer, dig in with the pick and you can push the tubes into overdrive. This characteristic is one of the highlights of the tube. I’ve used many amps with a low power switch and even on my own designs I don’t find it really useful or toneful. The JJ EL844 accomplishes the task very nicely. You can now get your AC30 to deliver the tone you want at a volume you can live with. And don’t be mistaken. Any situation that your EL84 equipped amp could tackle should be no problem for the EL844 equipped amp. What you gain is a very sweet overdriven tone that you can control from your guitar and a natural compression that firms up the tone as you dig deeper into overdriven sounds.