WallySkater and Reference.

Greetings,

Thanks for the nice write up.

 I have the Skater, Reference and Tractor in my audio tool box.

I also highly recommend the Skater. As stated highly repeatable outcome. I would recommend that it is the one tool you should purchase for you analog system. Yes I understand it might be pricey to some. Maybe purchase with other audio friends to split the cost.

‘The Reference is another great tool for getting your cartridge to a very level reference staring point. Those of us that have expensive cartridges (5k +). Will probably send off our cartridge to Wally for complete analysis to use the Reference to its fullest potential. I’m tempted by the Wally Scope but just haven’t pulled the trigger yet.

I would like to thank JR at Wally’s tools for all the fine instructional videos and information he has assembled. 
To those who can’t afford the Wally tools at this time, please take the time to look at the website and watch the videos. Great information.

Joe Nies

" Atma-Sphere MA-2's."

Congratulations! MA-2's and your speakers will be an event. They look like they can charge up a Tesla in a minute!

Anytime I see pics of them I think:

@tablejockey  , I've been pestering Ralph for over a year. By all accounts they are the perfect amp for my speakers and I pray they are as I will not get away with another pair for a long time. The JC 1s are getting shifted to subwoofer duty.

@joenies , Hang on for a little while on the WallyScope. It is a work in progress. The scope itself is excellent but the stage is going to get some improvements soon that will make the scope easier to use. Right now there are certain situations that make life difficult like low tables like the Technics and tables with thinner platters. Imaging the cartridge by itself is always easy. Imaging the stylus on a record on turntables with vastly different morphologies is ...not easy. As always there is a cost to benefit ratio and when dealing with high magnification stability is crucial and stability is expensive. I think Wally Tools is still looking for the ultimate compromise between cost and stability. In focus and stable the WallyScope gives an excellent picture and its program makes measuring angles a breeze but on some turntables it is not possible to line it up correctly for a number of reasons.

miljostyn - I hope you like the MA-2’s. I have MA-1s (3.2) that are a joy every day. I recently realized (once more) how much a good amp means for the sound, connecting some bookshelf and desktop speakers to the MA-1s. The speakers all rose to the next level, or more. Quite amazing! I love the OTL "sound" or lack of it, - nothing better, to my ears. My ordinary use of the MA-1s is with Audiokinesis Dream Maker speakers that were inspired by big Sound Labs - a great match with the amps.

@o_holter , Thanx! My understanding is that MA 1'a and MA 2's sound very much the same just more power in the MA 2's but in reality that only amounts to another 3 dB. This is a great example of matching the amp to the loudspeaker. With ESLs as the frequency drops the speaker's impedance rises and at 20 Hz can be as high as 30 ohms. Atma-Sphere amps do not lose power into high impedances like SS amps do. They maintain the same power regardless of load and are the only amps I know of that do this. This makes them ideal for driving ESLs. 

Enjoy following along. When I wake up early in the morning, I watch the Wally  videos.

Dear Mijostyn, while I am a 25-year devotee of Atma amplifiers and OTL amplifiers in general to drive ESLs, I am afraid I must differ; Atma amps, like any other amplifier especially tube types are definitely sensitive to the load impedance, since all the named amplifiers have an output impedance significantly greater than zero. The point is that at very high frequencies where ESL impedance goes very low, the energy demand also goes very low. So the loss of power is not very noticeable or important.

@lewm , now you have me very confused Lew. As the impedance of the load drops current demands increase and solid state amps will increase current to the point that their power supplies give up or something blows. Need I remind you of the high frequency balance control I burned out. 

I am no electronics engineer but I have heard Ralph say on several occasions that his amps maintain the same power output regardless of load. Perhaps I misunderstood him. 

More important to me is that the MA 2s do not loose power at the lower frequencies.

What all this does to the frequency response of the system is an unknown to me, but I will know for sure once I get the amps as I have frequency response curves of the system with the JC 1s and will compare them to curves generated with the MA 2s. 

All amplifiers driving all speakers have to obey the same physical laws. Yes, SS amplifiers tend to have a vanishingly low output impedance (<<1 ohm) and can therefore drive very low Z speakers with aplomb. For tube amps, output impedance is determined by the output transformer and the amount of NFB used at the output. (SS amps also often use NFB to reduce both distortion and Z.) For an OTL, output Z is determined by the parallel electrical sum of the plate resistances of the output tubes. Plus also the effect of NFB if the user adds NFB. Modern consensus is to avoid global NFB so in most cases that’s a nonfactor. So one major advantage of the MA2 vs the MA1 is lower output Z because more output tubes. For driving our SL speakers, that’s more important than the added power, in my opinion, because the stock crossover causes an impedance dip at mid frequencies where there IS some need for power delivery. As I told you, I’ve ameliorated that issue in my speakers by essentially ditching the crossover.

You gotta wonder what this guy's new obsession is to get rid of this setup.

@lewm , Are you driving the transformers in parallel ?

I replaced the treble transformer with a full range transformer and run it in parallel with the OEM bass transformer. There’s a bit more to it but not much.

I did a similar thing with my old Acoustats. Since I cross to subs at 100 Hz, getting one transformer to handle the entire range is something I am toying with, but Sowter stopped making ESL transformers and nobody I know of makes a suitable one. Things are sounding so good and I have weaknesses elsewhere I need to conquer. The MA 2s are a big (expensive) leap of faith. Hope I'm not making a misstep.

@lewm  See above 

One transformer won’t work for both great low bass and extended treble. Different turns ratios are optimal for each. But maybe you could get away with it since you’re removing frequencies below 100Hz. You’re on your own there.

@lewm , I did with the Acoustats but unless I have custom transformers wound I do not know of anyone making a step up transformer that big anymore.

Correct. The full range one I bought from Australia to replace the OEM treble toroid is huge and out of production, but it used alone was insufficient to get decent bass response from my 845PXs. The SL bass transformer is necessary. I use an inductor in front of it; it rolls off above 2KHz.