As this is my first Tube Amp and Preamp, I have no idea who sells these, nor who is a good source. So, where do you guys get these tubes?
Bob
Bob
Amps Atma-Sphere M-60 Mono blocks OTL design
I just purchased a used OTL Atma-Sphere M-60 mono blocks that I have sent to Atma-Sphere to be upgraded to the current model 3.3 and I also added the option of a higher quality power supply and V caps.
I have sold my old trusted Eggleston Andra 2’s speakers and have built some monitors using Aurum Cantus ribbons (102db) and Aurum Cantus midwoofers (90db) that are both rated as 8 ohm nominal. I have a DEQX Premate and will be crossing over to (2) JL Audio F-113 subs at 80hz.
Currently I am using a solid state high power stereo amp (Pass Labs) that I used with the Andra 2’s.
The Atma-Sphere M-60 is rated at 60 watts class A and is said to work better with higher impedance loads.
It will probably be a few weeks until I get the M-60 and was hoping someone could provide opinions of what to expect.
I listen to late 60 early 70’s classic rock music mostly. Sometimes loud.
ozzy
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Hi Bob, I’m not sure that even the ancient drugstore-type tube testers some of us remember from our childhoods measured heater-to-cathode leakage. Most of the better professionally oriented testers from those days did, however. (I have a vintage Hickok 800a). For most users I suppose the only practical alternative is to see how the tubes perform in the particular application, and hope for the best. And given the many positive experiences that have been reported with Sophia tubes, including the 6SN7, I suppose the odds of success are good. Although note that in some of the cases I referred to the hum problems didn’t arise until the tubes had been in use for some period of time. And of course I have no way of knowing if the problems that I and a couple of others reported represented atypical examples of the particular tube type, or were due to a combination of tube characteristics that are more typical combined with sensitivity of the particular component designs to those characteristics. Note also that as I said in the thread I linked to Ralph has indicated in the past that he rejects tubes having heater-to-cathode resistances of less than 10 megohms (i.e., 10 million ohms). And for the 8 Sophia 6SN7s that were in my possession (4 originally purchased; 4 replacements provided under the warranty) ... The heater-to-cathode leakage in my Sophia’s, as measured on my vintage Hickok tube tester, was as low as 3 or 4 megohms on some sections of some of the tubes, and was in the 5 to 10 megohm area on most of the others.FWIW, I personally don’t envision Sophia tubes as being in my future, despite all of the glowing praise they have received from others. Best regards, -- Al |
gdnrbob, Well since they are currently in production you can buy them new from the Vendors charles1dad mentioned. Buying through EBay is a little more risky but like on Audiogon you check the sellers reviews and take a chance. I have not had a single Sophia or Full Music tube fail thus far. But, I have had a NOS vintage RCA fail. almarg, You always post such great information and I thank you. Perhaps with other tube amps the Sophia/Full Music tubes would be a problem but with the M-60's they are good. ozzy |
So far we've yet to hear about any hum problems with the Sophia or TJ Music tube. Al's report is the first I've seen. We made a circuit change in our amps regarding how our filament circuit is handled about 12 years ago. That really reduced the hum issues caused by cathode/filament leakage; every now and then we run into a bad tube in the field causing a problem but its nothing like it was before we made that change. So I suspect much relies on the circuit design. FWIW in our preamps the leakage would be a non-issue. |
We've got a lot of positive comments from customers using audiophile fuses. The location on the amps that makes the most difference is the one by the power cord. That is also the one that is most likely to be blown, as a power tube failure can blow that fuse. The other fuses only blow if there is a serious service issue with the amp; over the last 30 years I can count those failures on one hand. Because there are three fuses rather than just one, the sonic effect of the fuse is reduced somewhat but you can still hear it. |
Early on I did have a couple of the power tubes blow that took out the fuses. So I’m reluctant to put a $100 fuse there. But, I have coated the fuses with graphene. Now that the tubes and other changes have settled down someday I will probably try the SR black fuse. Ralph, What value is that first fuse? I think it was a 3 amp slow blow, is that correct? ozzy |
I have Ordered the following: TJ Full Music 6SN7 Black Treasure 6SN7 Natural Sound Series 6SN7 These will be used for my MP-1 Pre-amp and Mp-3 I am still looking for tubes to replace the Atma-Sphere Nirvana Amplifier and the 6SN7 that go with the amp. I have ordered some NOS Sylvinia tubes too. The TJ Full Music is the same as Sophia. I was told both come of the same production line but are labled for 2 different markets. |
Im still looking for more 6SN7 Tubes, but wont buy any untill i have spent enough time with the above. Someone Asked About Atma-Sphere new Amplifier called the "Nirvana" Maybe Ralph can chime in and explain what so special about these amps and why do they sell for more than the MA2 but produce less power. |
The Nirvana is a project to see how far we could push the technology. Its power transformers are spec'd differently, it has regulated DC filaments for the driver section and regulated high voltage for the driver section. The amp section is mounted on a subchassis and overall the chassis work is pretty over the top. Because of all the polishing, its been really hard to shoot photos of it! |
As I noted in this thread I am using a pair of the Zero Autoformers with my M-60’s. The M-60’s were made with dual binding posts for bi-wiring. Since my DIY speakers and external crossovers were also built with bi-wiring in mind, I am going to try a second set of the Zero’s to complete the Biwire set up. Has anyone tried this? Will a pair of the Zero's on each speaker change the impedance? ozzy |
It shouldn't as long as both are properly crossed over. The portions of the transformer's operation that are out of band with the crossover will see a fairly high impedance which will be transformed to a high impedance to the amplifier. Worth a try- you can't hurt the amp with an adverse load BTW. But I really doubt that it will yield much in the way of an improvement. OTOH, I don't know of anyone whose tried this, so report back :) |
I've said it before, and I guess I'll say it again: For lovers of Magneplanar speakers, there is another magnetic-planar that is much better suited for use with tube amps---the Eminent Technology LFT-8b. It's nominal impedance is 8 ohms, but the m-p drivers themselves are a resistive 11-12 ohm load. Bi-amp (or even passively bi-wire) them with a tube amp on top and ss on bottom (for the 8" sealed box woofer, which operates via a 1st order-6dB/octave x/o from 180Hz down), and you won't miss your Maggies at all. Actually, many who have heard both prefer the ET's, even if they run them with a ss amp. |
If you want my opinion on someone who owns the M60, The New Nirvana OTL Amp from Atma-Sphere and the MP3 as well as the MP-1. Their is nothing that comes close to OTL Sound when paired with the right speaker your more or less at the end of your journey. These amps will give you transparency that only more expensive Solid state amps can achieve. A Sound which is neither Tobey or SS. Goose bumps during listening and a feeling of being their at a live event. Iv exchanged audio gear for the past 20 years and when I heard OTL nothing ever seems the same or sounds good enough. Speed, PRAT, Expansive Soundstage, Emotional Feelings, Live Sound, Transparency. The Amplifier just sounds like it does not exist. Their is hardly any colouration or distortion. Personally i think Ralph sells his gear too cheap, the only gripe with OTL is they need to be paired with a good Speaker but their are alot of options on the market and if you cant find one suitable then the Zero can help you out. |
realdeal, dragon_vibe, I still can’t believe how great the sound quality is with my updated M-60’s. I am using dual Zero’s with my DIY bi-wire speakers and will not turn back. With the Zero’s I noticed no degradation in sound quality but they sure did allow my DIY speakers to really open up. Especially in tone. Now, I have such a soothing sound but detailed and with a wide open soundstage. I never came close to achieving this sound with solid state amps. ozzy |
Yes, I have the Vandy 2w's, but just bought a pair of 2wq's. I probably didn't have to, but it was in the back of my mind, so heck, I did it. I was looking at a pair of Quatro's here on Agon, but decided to keep the Treo's as I: 1. Love the way they look and sound. 2. Can't get the energy to move another pair of speakers. B |
