Have you ever heard of this tube? Not many people have, and it’s time to give it a little attention since there are currently great new versions of the KT88 available. Consider this a heads up. The KT88, originating in the U.K., is interchangeable with EL34s and 6550s with only minor adjustments to the bias circuit. To my ears, the KT88 sits in between the smooth, compressed, glassy tone and soft lows of EL34s and the harder, edgier 6550s. Listeners generally equate classic rock with EL34s and 6550s with metal. KT88s fit nicely in the middle of this tonal spectrum, delivering the smoother tone of the EL34 but offering a much tighter low-end, similar to 6L6s – very rich harmonics and considerably more output and clean headroom.
Rumor has it that Jimmy Page had his 100-watt Marshall heads modified to run Genelec/GEC-branded KT88s back in the day; give a listen to Zep’s The Song Remains the Same: Soundtrack from the Led Zeppelin Film for some sonic samples. A recent check of vintage tube dealers reveals NOS GEC KT88s are currently fetching up to $800 for a matched pair.
My latest encounter with KT88s came via a vintage ‘72 Park 75 head I picked up a few months back. Originally offered in Lead, Bass and P.A. models, my recent acquisition is the latter. Circuit-wise, it’s pretty much an exact Plexi-era Marshall model 1986 Bass 50 circuit, but with KT88s in place of the EL34s, hence the 75 notation since the KT88s offer up more clean output, affording the higher wattage rating. This amp sounds so good it’s ridiculous – think Ziggy Stardust and the Spiders from Mars -era Mick Ronson. This is the coolest Marshall amp I’ve ever owned (Park was a Marshall brand and was made in the same factory).
My Park 75 came with its original GEC KT88s. While they still sounded really cool, there was no denying that they remained 35-year-old tubes and as such, were fairly well spent. For replacements I ordered a matched pair or New Sensor/Electro- Harmonix Gold Lion KT88 reissues. To my very pleasant surprise, I actually preferred the tone of these tubes over the original GECs. Granted they were 35 years old, but I was able to get the gist of their original tone despite their advanced age and condition. The new Gold Lions have a beautiful, smooth clarity and are able to produce raging distortion when cranked while retaining an extremely focused low-end. Plus, the tube breaks no sweat whatsoever when pushed hard, so they should last a good, long while – a nice thing as a matched pair of these tubes aren’t cheap to replace.
New Sensor also offers the KT88EH tube under the Electro-Harmonix brand, reported to sound excellent at almost half the price of the Gold Lion reissue. Additionally, Slovakian tube manufacturer JJ Electronic offers KT88s, which I’m sure are worth a listen. The earlier Chinese manufactured KT88s I’ve used in the past work, but pale sonically in comparison to the tubes I have previously mentioned. Groove Tubes offers matched pairs of KT88s on their rating system – it’s a more expensive option, but no brain power is required and they come with a great warranty.
One last word to the wise: if you’re swapping out EL34s or 6550s for KT88s, take your amp to a qualified tech to have it biased properly to make sure the transition is as seamless as possible. But with that in mind, make sure to check ‘em out!
Peter Stroud
is co-founder of 65amps
www.sherylcrow.com
65amps.com
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Peterson StroboStomp Mini Pedal Tuner
| The StroboStomp Mini delivers the unmatched 0.1 cent tuning accuracy of all authentic Peterson Strobe Tuners in a mini pedal tuner format. We designed StroboStomp Mini around the most requested features from our customers: a mini form factor, and top mounted jacks. |
But by gosh, if delay—and its sister effect, reverb—haven’t always been perfect for the music I like to write and play. Which brings us to the Fishman EchoBack Mini Delay. The EchoBack, along with the standard delay controls of level, time, and repeats—as well as a tap tempo—has a toggle to alternate between analog, tape, and digital-delay voices.
I hooked up my Washburn Bella Tono Elegante to my Blues Junior to give the EchoBack a test run. We love a medium delay—my usual preference for delay settings is to have both level and repeats at 1 o’clock, and time at 11 o’clock. With the analog voice switched on, I heard some pillowy warmth in the processed signal, as well as a familiar degradation with each repeat—until their wake gave way to a gentle, distant, crinkly ticking. Staying on analog and adjusting delay time down to 8 o’clock and repeats to about 11:30, some cozy slapback enveloped my rendition of Johnny Marr’s part to “Back to the Old House,” conjuring up thoughts of Elvis trapped in a small chamber, but in a good way. It sounded indubitably authentic. The one drawback of analog delay for me, generally, is that its roundness can feel a bit under water at times.
Switching over to tape, that pillowy warmth evaporated, and in its place came a very clear replication of my tone—but with just a bit of the highs shaved off the top. With the settings at the medium-length mode listed above, I could see the empty, glass hall the pedal sent my sound bouncing down. I heard several pronounced pings of repeats before the signal fully faded out. On slapback settings (time at 8 o’clock, repeats at 11:30), rather than Elvis, I heard something more along the lines of a honky-tonk mic in a glass bottle. Still relatively crystalline, which actually was not my favorite. I like a bit more crinkle—so maybe analog is my bag....“That pillowy warmth evaporated, and in its place came a very clear, pristine replication of my tone—but with just a bit of the highs shaved off the top.”
Next up, digital. Here we have the brightest voice, and as expected, the most faithful repeats. They ping just a few times before shifting to a smooth, single undulating wave. When putting its slapback hat on, I found that the effect was a bit less alluring than I’d observed for the analog and tape voices. This is where the digital delay felt a little too sterile, with the cleanly preserved signal feeling a bit unnatural.
All in all, I dig the EchoBack for its replications of analog and tape voices, and ultimately, lean towards tape. While it’s nice having the digital delay there as an option, it feels a bit too clean when meddling with time of any given length. Nonetheless, this is surely a handy stomp for any acoustic player looking to venture into the land of live effects, or for those who are already there.
