I have been using OTL amplifiers with ESLs for 3 decades. But I am always looking to improve my OTLs and ESLs, so it is ever evolving. Just getting into vinyl in a bigger way than ever before. I never before had more than one tonearm/tt/cartridge combo.
Lenco L75 w/mods mounted in custom slate plinth using PTP3 top plate and Jeremy's Super Bearing (see Lenco Heaven). Tonearm Dynavector DV505. The Lenco is now featured in my basement system, based on Beveridge 2SW speakers. Performance upgraded by the Phoenix drive amplifier in conjunction with the Roadrunner tachometer, controlling platter speed very accurately.
Kenwood L07D
Direct-drive turntable with built-on tonearm, uses coreless, slotless motor, factory plinth brings total wt past 65 lbs. The quietest turntable I ever heard in my life. Seemingly antiquated tonearm sounds fab. I love this thing.
Technics SP-10 mkIII
I found this Mk3 NOS in Florida. I made a slate and wood plinth for it, and Bill Thalmann went through the electronics. Bill also performed the Richard Krebs mod, and JP Jones added his chip made of discrete parts, which is a replacement for the OEM chip, MN6042 (I think). The slate is 2.5-inches thick, and the base is made of solid cherry and baltic birch. Imbedded in the bottom of the wood base is a large threaded brass block. A threaded brass rod traverses the block and contacts the underside of the bearing housing, a la Albert Porter's idea, to drain energy. A 10.5-inch Reed tonearm is mounted on a slate armboard. I also have some aluminum armboards and other tonearms to try. Lately using the Boston Audio Mat2.
Atma-Sphere MP-1
highly tweaked by moi. A wonderful unit to begin with.
Silvaweld SWH550
All-tube phono stage, now discontinued. I use it for MM and MI cartridges and with the MC2000 via the outboard current-driven gain stage. Its output runs thru my 3160 phonolinepreamp linestage section.
Atma-Sphere MA240
Many, many power supply and circuit upgrades since original. Originally used six 6C33C output tubes in circlotron OTL. Now modified to use four type 7241 triodes in output stage. Output tubes are driven by four discrete Super Linear Cathode Followers, a la the late Allen Wright. This facilitates very accurate matching of output tubes for bias current, so no single tube is either hogging current nor not carrying its fair share. Uses solid state cascode constant current sources throughout. Now using type 7199 triodes as input dual differential cascode voltage gain section.
Sound Lab 845PX
modified audio step-up transformer and crossover, to present a high impedance for my OTLs. All resistors and capacitors were removed from the passive crossover in the backplate. The OEM Sound Lab treble toroidal transformer was replaced by a full range EI type transformer with a 1:90 step up ratio. This full range transformer is in parallel with the OEM Sound Lab bass step up transformer. Photo shows old M1s in my listening/living room. Picture the same black monoliths only taller and wider, if you want to envision the 845PX.
Ortofon MC-7500 and MC2000
The MC2000 is my current favorite LOMC cartridge. Neither of my two high gain phono stages (MP1 or 3160) by themselves have enough gain for the 0.05mV output of the MC2000. I run it either through an outboard current-driven phono booster (think head amp or pre-preamp) built for me by Dave Slagle, into the MM section of my Silvaweld phono stage OR into the BMC MCCI ULN Signature current-driven phono stage, and then in either case to the linestage section of the 3160.
I listen to a lot of different vintage phono cartridges. I have a small collection, many of which I have not yet heard. To date my favorites are the Stanton 980LZS, the Grace Ruby, the Acutex LPM320STRIII, and the B&O MMC1 and MC20CL . In many ways I prefer these cartridges to higher end LOMCs that I have heard, but the jury is out and probably always will be out. Best MC types I own are the Orto MC2000, Koetsu Urushi (now at home in the Fidelity Research FR64S on my Victor TT101, to be found in my basement system), and the Dynavector 17D3.
3160 Phonolinepreamplifier Full function preamplifier
Fully balanced, dual mono, solid state preamplifier with two completely discrete high gain phono stages plus linestage. I have been using this unit for a few years along with the MP1. It's by far the best solid state phono stage(s) I have heard in my system, and it rivals any tube unit as well. Built by R&J in Mexico.
Denon DP80 turntable
Found this 100V unit in California. Bill Thalmann replaced the single chip and upgraded all the discrete transistors and then calibrated it. I use an inexpensive 120V to 100V step down at the wall socket. I had a 60-lb slate plinth made and mounted my Triplanar on the slate surface. The Denon replaced the Lenco in my "upstairs" system, when I moved the Lenco to the basement Beveridge system. Using a Boston Audio Mat2 here.
Do you still have the Victor TT-101? Didn't see it in the photos. JP should be just about finished with mine. Plinth is ready with new teak veneer. Love your speakers!
That looks like an incredible sounding system. A friend of mine has Sound Labs with Red Rose 1 amps. I can only imagine how great they sound with the MA 240 amps.
Beautiful system and knowing the products I can't just imagine how it sounds. The Soundlab using autoformers with the MA240's must be amazing, Duke LeJeune who build my speakers used to be a Soundlabs dealer and he and Ralph mentioned how incredible the match of the Atmasphere's with the Soundlabs was. The Goertz are ribbons?
Would love if you could update your system listing to what you are currently running... been following you for years, and just now getting back in (with new gear!) after many years of absence.
Thekong, Sp38s on eBay makes a high-quality stainless steel platter for SP-10 MkII. Alternatively, I find that the 15 lb. 1.5" tall lead/delrin/cork platter from my early VPI TNT drops right inside the lip of the stock SP-10 platter. A layer of ERS cloth could be sandwiched between the two platters as a shield, with the possible added advantage of dampening at the interface. A spindle extension could be easily fabricated.
Jim Howard at Applied Fidelity does the sapphire bearing modification. This also entails enlarging the spindle diameter.
Have you opened up the motor housing as yet to inspect the thrust cap? Of the two MkII motors that I have, one thrust cap is worn through entirely. The other evidences minimal wear. My guess is that durability of the trust pad was a function of proper re-lubrication through decades of use. Does Richard Krebs provide a fresh thrust cap?
Lew, apologies for hijacking your virtual system page.
Dgarretson, 20 lb. stainless steel platter, ruby thrust bearing, wow these are serious modifications, which, unfortunately, are way beyond my DIY skills!
Instead, I am going for the Kerb mod on the motor, and in the process replacing the remaining electrolytic caps. I hope this can take the SP10MKII much closer to the Exclusive P3a!
Thekong, I'm in the process of refurbishing and modifying an SP-10 MKII. This will eventually include a 20 lb. stainless steel platter, ruby thrust bearing, and an Albert Porter-style bearing well. FWIW I started by replacing all 31 electrolytic caps in both PS and plinth circuit boards-- tedious but relatively simple work. The strobe is now rock-solid, though I have yet to hear the TT in action. I've spoken with an "insider" modifier who believes that a heavily modified MkII can surpass a MkIII. This was at least sufficient encouragement to attempt what can be done to evolve the MkII for comparison to my L-07D.
but that both the L07D and the Mk3 are "better" yet different from each other. L07D is closest to the Lenco in character. Mk3 is very "disciplined", like Sgt Joe Friday in Dragnet: Just the facts, ma'am.
Lewm, for my Technics SP10 MKII partially updated with new electrolytic caps, and in the stock plinth, I also found it to be neutral in general, but lack some of the tonal colors of my other TTs. The Exclusive P3a sounds much more organic in comparison.
I wonder whether this is due to the SP10 MKIIs aging caps in the controller under the motor (not the external power supply), or the stock plinth, or something else.
My next step is to get the Kerb mod, and a slate plinth, to see if that can be improved. The only problem is the difficulty in getting thick (2) slate in Hong Kong, let alone has it cut by water-jet.
Lewm, Great looking system. I share your love of the MKlll of course. In my experience nothing beats a direct mount plinth on that one. My Krebs modded table is currently being reconfigured into a direct mount plinth because I just like my direct mount better. I don't think a more quiet and speed accurate table has ever been devised even in the six figure range. That being said, someday I would love to get my hands on a minty L-07d. What an audio legend. Nicely done system!
Dear Peter, If I were to shell out the dough for a Vibraplane, I might first of all put one under one or another of my turntables. Maybe the preamp/phono stage would come next. THEN the two monoblocks. But I am sure all of the gear could benefit to one degree or another. I do know that the amps sound much better when they are up on their Walker Audio tiptoes than when not. They sit on Sound Anchor stands, which themselves are up on Audio Physics tiptoes. On top of that there are butcher board slabs. Then the amps sit on very large Walker Audio tiptoes, as mentioned. I originally thought that was a good idea mostly to allow air circulation around them. However, I have found that they do improve the sound. Much more musical "air" when the amps are up in the air.
Great looking system. Though I know next to nothing about OTL amps and ESL speakers, I bet it sounds pretty convincing. One question, have you considered putting those amps up on Vibraplane isolation platforms. I tried them under my massive SS Class A amps and was really surprised by the improvement in resolution and clarity and just how much more natural it sounds. Love the various turntables.
We now have a few things in common, that being a Dynavector tonearm (501), and Acutex cartridges. 415 III STR, and just purchased, and in transit, an M320 III STR.
The Dyna tonearm is on a DIY restored Garrard 401, the results have been very pleasing. The Actex carts have proven to be surprisingly good, considering how light they are.
Love the system, I can only imagine what a pleasure listening to it might be.
Dear Voaratc, Sorry for the long delay in resounding to your question. If I had to describe the difference I would say that the Mk3 has tremendous "drive" and is most lacking in any artifact attributable to the table itself, while the L07D (with TI Shield over the motor) might be said to have less drive but to be a shade more "musical", more relaxed sounding. I know these are typical audio cliché's. One must also keep in mind that my opinion of the L07D is based on its sound with the stock Kenwood tonearm, which uses 30-year-old Litz wire, a detachable headshell, and a massive physical connector in the signal path (a non-DIN type plug at the base of the tonearm). Whereas my opinion of the Mk3 is with the Reed tonearm, which uses cryo-treated silver wires and a straight uninterrupted path from the cartridge pins to the phono inputs.
Guys, I am having trouble editing my system page, which is to say I cannot get in to the page at all. Even though I am using the correct username and password, which work fine to allow me to post, etc, I am blocked from editing. I sent an inquiry to the Audiogon administration, got a new password, which once again works fine EXCEPT when I try to edit this page.
Suffice to say that the Sound Lab M1 speakers have been replaced with Sound Lab 845PX speakers. The input to the 845s was then highly modified in that a foreign treble transformer was substituted for the Sound Lab treble transformer. This permitted removal of all crossover components. All I can say is that this makes a huge difference in the right direction. Also, (1) Denon DP80 has a place of honor in storage but is not in use. Turntables in use include Kenwood L07D, Technics SP10 Mk3, Lenco. (2) Sold the Colibri cartridge long ago. (3) Main cartridges are now Grace Ruby and Stanton 980LZS, and I have several more MM or MI cartridges yet to audition. (4) In the latest modification to my MA240 amplifiers, 6C33C output tubes were replaced with 7241 output tubes, plus many other mods. (5) Using a Silvaweld SWH550 phono stage for MM cartridges; it feeds the line stage section of the MP1. All low output cartridges go thru the MP1 phono stage.
Hi Lew, away from the captains and colonels I thought i'd send you this link to a webpage which provides brief, cogent explanations of the differences between the TMD & FMD bearings including a history of Transrotor's achievements -http://highfidelity.pl/!ev/artykuly/13_06_2007/transrotor.html Regards, Mg
