London Power Studio

Features: 10
A basic preamp section (2 12AX7s, drive/bass/mid/treble) feeds the most technologically advanced power section in the world. You can control everything that happens to the power tubes-individual bias (sure, set them differently or use two different power tubes and bias them both correctly-it's easy), triode/pentode, single ended vs push pull. Then when you have the sound you're looking for, turn down the power output of the power tubes (down to .1w if necessary). This allows you to get power tube screaming for mercy without deafening yourself. No channel switching, but it's a studio amp.

Sound Quality: 10
You can make this sound like anything! Right now, I have a couple of nice GE 6V6s in it biased hot, with the rest of the setup set for a Plexi kind of tone, I get a very creditable 60s Plexi 20W tone. When you turn down the volume on the outputs, the distortion can get rattly or raspy, you can turn down the drive at the same time to maintain a nice balance. Distortion can be helped by patching the effects loop and cranking that. It'll go from crystal clean to Cream to Van Halen with no problem. I'm not sure it'll do Dual Rectifier, I really haven't tried to get that sound out of it, but just about anything else is available.

Reliability: 8
I've only owned it a couple of months. All handwired, VERY high quality parts, comes in it's own fibreglas rack case, looks pretty darn strong to me...

Customer Support: 8
Wonderful! Always happy to talk or email and upgrades are available essentially at cost (eg if you go for todays amp, and tomorrows has an option that costs $50, he'll upgrade yours for $50). The only problems is that it takes time to ship to Canada for upgrades.

Overall Rating: 10
I love this little amp. I've owned or played all the low wattage ones out there-I'm keeping my Emery Super Baby because of the tube rectifier, but the London Sound killes the Univalve/Bivalve (more flexible and better sound than the power soak option for reduced volume), the Allen Class Act, The Dr. Z prescription, vintage single tube Fenders/Danelectros/Ampegs etc. If there's a better low wattage solution out there I'm not aware of it (although I haven't tried Maven Peals Zeetas-a similar concept in some ways). Highly recommended, and yes, I'd try and find another if it was stolen.

Submitted by Bob at 01/01/2003 09:19

Features: N/A
This is a revolutionary product! I believe it be the most original and innovative amp design currently on the market. The Canadian-made London Power "Studio" is a rack-mountable guitar amp with some very unique abilities available nowhere else. I have the 10 Watt version, optimized for studio use. There is also a 50 Watt version oriented for those with stage volume needs. The Studio's most unique feature is the "Power Scale" control. Sort of like having a Variac built in to your power section, it can reduce the amount of power the amp puts out down to near the hearing threshold. Unlike attenuators which reduce the output signal between the power and speakers (losing frequencies and tonal interity in the process), the Power Scale reduces the amount of power produced from the power section itself. This allows full power tube saturation at any volume with no lost signal, reduced frequency range of other tonal compromises.

Does this "Power Scale" work? I tell you this is the only amp I had heard in 30 years of playing and gear-mongering that lets me dial down the true dynamic, rich, punchy blast of a wide-open tube power section to literally a whisper with no audible sacrifice of tone or touch sensitivity! In this regard the Studio smokes every attenuator and master volume circuit I ever heard by a country mile. I've been waiting for someone to get this right for a long, long time.

The amp can also accept any type of octal-based power tube in its power tube sockets, and even allows dissimilar tube types to be used together (i.e. a 6V6 with an EL34, 6L6 with a 6550, etc.) thanks to having separate bias pots for each tube. The amp is easily user bias-able with only a $25 Radio Shack Digital Volt Meter. The amp can be used with any speaker cab 4-16 ohms. It also features a dramatically effective triode/pentode switch, cathode/fixed bias switch, and a rotary dial allowing any blend of push-pull to single-ended opertiaon between the two power tubes. It has a built-in 2 stage preamp block which can be patched into the signal path if desired (like a typical guitar amp). It also has a mono send/return FX loop, and an "Input" dial for adjusting the strength of the signal into the power section.

Its a bit spendy. $1280 base price. Plus you will be spending more to take advantage of all the options it allows. Power tubes, preamp tubes, speakers, and cabs. The fun is only limited by your wallet.
But every time you change components you get a new amp! The Studio has little sonic character of its own. You determine that by the tube, speaker, and cab choices.

Sound Quality: N/A
The Studio provides an amazing degree of control over power tube characteristics and saturation, preamp drive, and final output volume. This yields a rainbow of clean, semi-clean, semi-dirty, and full crunch tones, from any tubes of your choice, at any volume of your choice. I use it like this - dial in my fat power tube saturation with the "Limit" dial. My razory, trebley preamp grind with the "Pre" dial (or I may plug direct into the power amp if I'm using an OD pedal or booster). Set Push-Pull vs Single-Ended balance to taste (full Push-Pull gives a bold, punchy sound, full Single-Ended, meaning one tube operation, like a Champ, gives a thinner, gnarlier). Set cathode/fixed bias, and triode/pentode to taste. Set max volume with the Power Scale. From that point I use it like any single channel amp, dial down my guitar volume pot for cleaner tones.

This amp's features allow for a huge variety of tonal options while keeping the signal path as clean as possible. There are no EQ controls. None. Guitarists may frown at this, but it's a common practice in high-end audio designs. The builder, Kevin O'Connor,
engineered this to have the shortest signal path possible. Use an EQ pedal if you want. I don't miss it. Pure tone, baby! Want it brighter? Change strings, speakers, or tubes. Why clutter this pristine signal path?

The 10 Watt version I have gets plenty loud for my purposes (home/studio/jamming). Remember that 10 Watts is exactly half as loud as a 100 Watt amp. The 50 Watt version is specifically to allow for gig-oriented power levels (but is otherwise identical to the 10 Watt version). This amp's forte, however, is not volume but its ability to give you the total clean to full saturation range of any power tube at fractions of the volumes usually associated with tube amps. You can use any 6L6, 6V6, EL34, or 6550 tube type in the amp. The only tubes it cant fit are EL84's, KT66's (about 1/4" too tall), and I question if KT88's will fit (their bases are very wide).

Kevin told me he designed this to sound good with any components/gear. Well, it does, but.....I think he made it too good for its own good. This has such high quality parts and such a pure, short signal path that it is virtually "tonal micrscope". I find it to be ruthlessly revealing, especially using the power amp alone.
Any sonic tendancies of your gear, good or bad, will be shoved right in your face. I think that's a plus. The different characters of various tube types shine right thru. The Studio has a pronounced sensitity to changes in tubes, speakers, cabs, guitars, and pedals. Just changing something as simple as preamp tubes will yield
immediate and obvious tone/feel changes.

One of my favorite ways to use the Studio is to plug direct into the power with an OD pedal or booster. Drive pedals sound like they are part of the amp when you do this. You've never heard your grind pedal so dynamic and alive. My old grey DOD 250 sounds superb this way. Conversely, most distortions/fuzzes I tried sound flat and muddy thru the Studio. As I said, this amp tends to dramatically amplify the inheirant tendancies of your gear. It is important to note that the direct input ('return' jack) to the power amp is at line level. A straight guitar signal is instrument level. That will only get you about 1/4 Watt of power (actually effect for bedroom playing/quiet recording). To get the signal up to line level you must use a signal booster. Any OD or booster (i.e. ZVex SHO, Klon, etc.) will do the job.

Reliability: N/A
I have only used this for home, studio, and jamming duties so I
haven't put any major stress on it. I believe the current version of
the amp, which has a dramatically improved chassis design from older
versions of the Studio (I owned one Studio prior to this review unit),
is a tank. I dont forsee any reliability problems. It comes with a
form-fitted flight case (included in the price). I think it would
travel quite well. The internal parts are of the highest quality.
I believe the capacitors are a type that never needs replacing.

Customer Support: N/A
I ordered my first Studio in Jan 1999. It took 6 months to get.
When it did arrive it was badly damaged due to carrier abuse and
inadequate internal packing. After that incident, Kevin redesigned
the whole chassis. He also volunteered to make me one of his new,
improved Studio models for gratis. The wait on the new unit was
5 months. So it took 11 months to get my unit, but I got the new,
totally redesigned unit (which could take any power tube unlike the
old units which only took 6V6). Throughout this Kevin was decent,
and professional. Looking back, I would wait it out again if I had to
because the new unit is such an improvement over the older model.

Overall Rating: N/A
The 10 Watt version I have would hold little interest to pro guitarist
who live and die by their gig amps. It isn't designed to provide lots of "on the fly" options. But to home players, studio tweakers, jammers craving "dimed" amp blast at garage volume, and tone-hounds in volume restricted situations, its an answer to a prayer. In a live setting its no more flexible than a single channel amp, but with the advantage of being able to set the exact volume that max distortion will occur. However, in a home or studio setting it has unrivalled flexibility. The tone recipes are limitless. Try a set of Philips 6L6WGB "stubbies" on triode power/cathode bias setting thru some Weber P12R's for a "Tweed of the Gods" tone. Or a set of hot-biased Svetlana EL34's tru Celestion Greenbacks for that "Marshall
in my pants" crunch at living room volume. Maybe a set of cold-biased Sylvania 6L6GC-STR's thru a Weber "California", with some tube
reverb, for a clean ultra-linear Silveface Twin tone. Perhaps an RCA 6V6 in one socket, a Tung-Sol 5881 in the other, thru a reissue Jensen for the "vintage Fender that-never-was" tone. I could go on all day.

I hope these examples offer a glimpse of the utility and FUN that's available with the unique London Power 'Studio". This amp ends any discussion about how to get the best tone and tube saturation at low volumes. It brings no-compromise boutique amp tone into small studios, practice rooms, and jam sessions with an unparalleled flexibility. The 50 Watt version gives the additional ability to set the maximum power tube breakup at the exact stage volume you want (dont you wish Marshall's did this?). There is nothing on the market
to compare it to. This is the Holy Grail of "quiet crunch".

Go to "http://www.londonpower.com" for more detailed information on the 10 Watt 'Studio', the 50 Watt 'Studio', and other London Power products.

Submitted by Rich Hessian at 01/11/2000 22:57