ATMA-SPHERE M-60 OTL MONO BLOCKS (UPGRADED M-50s) – Interest Check for Trade (or Part Trade)
I never thought I would do this, but I have learned to "never say never". These are the best amps I have ever owned (and I have owned quite a few). I believe there is something to the OTL (output transformerless) magic when done right.
I have, however, come to the point where I don't feel I use these enough, there are some other things I want to try (see below), and I still have another smaller Atma-Sphere amp (S-30), so I am putting these up for possible trade or trade+cash. Unless the cash offer is outrageous, I really don’t want to sell these outright because, frankly, I think I can get better value with trade and the "boss" will likely not let me use any significant cash for something else.
PLEASE DO NOT ASK ME THE VALUE OF THESE AMPS OR HOW MUCH I AM LOOKING TO GET – I will NOT answer those questions. Just make an offer and see where it goes.
This pair is somewhat unique (as are many early Atma-Sphere amps). I do not have the whole history, but they started off as M-50s, and the internals were subsequently upgraded to M-60s (Mk 1 status). The original M-50s and M-60s had two 12AT7s as the input gain stage (top and bottom sections of a differential cascode amplifier), one 12AT7 as a constant current stage for the input stage, and one 12AU7 as the driver stage. In the ultimate conversion, the single 12AT7 and the 12AU7 were replaced with 6SN7s. I do not know all the specifics of why this was done, but the guys at Atma-Sphere have told me that, while the 6SN7 replacement was an upgrade for sound and performance, the retention of the two 12AT7s has some benefit as well (as opposed to being replaced by 6SN7s as in the current versions of the Atma-Sphere amps).
The original feet have been replaced with three cones per amp.
I believe I am the third owner.
This pair has been back to Atma-Sphere within the last 2 years for a checkup. Both meters and some caps were replaced, and they were given a clean bill of health. They have performed stably and beautifully since that time. I have always used these hooked up to an original Tice Powerblock (plus Titan) fed by a Monster AVS-2000 voltage regulator, and I try to use these at least once per month for several hours to keep them “fresh”.
The current tube lineup is identical in both amps – 2 1970s Mullard 12AT7s, one Sylvania JAN-CHS-6SN7WGTA (brown base), one Sylvania 6SN7GTA, and a mix of Russian and Chinese 6AS7Gs (6 Russian and 2 Chinese each side).
I will put together one basic full set of spare tubes, although it will not be identical to the current compliment. I will work out the specifics with the ultimate buyer (premium tubes can be provided for extra). It is, however, highly recommended to use Russian/Chinese 6AS7Gs (no 6080s or USA 6AS7Gs), and 6SN7 GTAs and GTBs (no GTs or 5692s), with these amps (just as recommended by Atma-Sphere).
The original M-60 manual is included, as are some basic power cords. The tube coolers on the 12AT7s are NOT included. There is some operational know-how to setup and use of these amps, such as using a DC ammeter for accurate DC Offset and Bias setting (only use the meters for a quick check), and only using speakers with an 8 ohm or higher impedence (unless you have something like a Speltz autoformer). I will pass this knowledge along to the ultimate buyer.
These are in good shape physically, particularly considering their age (+/- 20 years) and the fact they have been shipped a couple of times. The faceplates are solid but not perfect (for example, #2 has a slight nick on the bottom left of the faceplate), with only a few minor nicks elsewhere (for example, #1 has a nick in the middle back of the top cover). Easily a “6” on the Audiogon grading scale, and most would call it a “7”. The photo quality is unfortunately not great, and is not really a good representation of their nice appearance.
Just as a general note, the guys at Atma-Sphere are great (as are their products), and have always been available to answer any questions I have with these amps.
I can provide additional pictures or info on request.
GENERAL TERMS AND CONDITIONS
Please note that these units are being sold ‘AS IS’; however, I will guarantee against DOA. In such event, I will refund the purchase price (less shipping) upon return of the component to me (in the same condition as shipped).
As indicated, I am really looking for trade, but it will need to be good value from my perspective. One problem is that I really don’t know what I want, so try me to see if something catches my interest. A couple of things that come to mind include a single-ended KT88 amp, a Mesa Tigris, a Decware Zen Triode Integrated (EL34/KT88) and an Atma-Sphere preamp (I can dream). Other interesting tube and solid state equipment might be considered as well (McIntosh is always nice). Smaller things of interest include SACD/DVD-A discs, vacuum tubes and a little bit of shielded speaker cable.
Any cash payment can be via money order/cashier’s check/personal check preferred but, except for US Postal Money Orders, all must clear my bank first. I also accept Paypal for convenience (add 3% to for USA, and 4% for Canada).
My strong preference is to NOT ship, but I will consider shipping within the USA and Canada. In any case, the buyer is responsible for all shipping charges. Each unit will be packed individually and securely (two boxes), and the tubes will be sent in a third box. Shipping will not be cheap, and insurance will be required, which is why I would strongly prefer a local sale (I am in Chadds Ford (PA) and can demo as well). In the USA, I would prefer to ship via FedEx ground.
Please check my feedback on Audiogon, Videogon and Ebay (ID=baileyler) and buy with confidence.
