sorry not familiar with the MP-3 do you have links i can look at? thanks...
Is that mean I can use Pin 2 for R input/output and Pin 3 for L input/output for one channel? I still have 2 PCB aikido and haven't made decision what to do yet. If it's correct, I will put them together.
The MP-3 is a preamp that we make. It uses a Circlotron output like the M-60 does. It also uses a servo to control DC offset at the output (something for which we obtained a patent). Its a wider bandwidth (both low and high) than the Aikido. It is also a simpler signal path.
Differential preamp based on the Atma-sphere MP-3
That's fair.
My concern is its less able to drive low impedances (mostly on account of the coupling capacitors) and does not support AES48. I'm not saying its a bad circuit; I'm sure its low distortion and wide bandwidth. On paper though it looks a bit more complex to me.
high gm and or high mu, in other words very low rp.....6528 comes to mind..
or a Pete Miette source followers using high voltage mosfets like the irfb820 and depletion mosfet, input stage can be a triode with mu of 20 or thereabouts...A2 Buffer
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Egellings, I've heard every amp made by Atma Sphere with the exception of the MA-3 and I can tell you that while they are power hungry amps, you'll be hard pressed to find something that sounds as good. I like tube amps and Ralph's are some of best regardless of price. They're not for everyone but what is?
Those are stunning. I love the fitting of the meter on the top and then the switch gear on the side out the way - only thing I would do is simply remove the LED lights from the front.
Yes. At first, the leds were not intended to be seen directy : they were supposed to light the panel to magnify the engraving in the dark. But this did not worked fine enough, so I went for that front led "eye-attracting" solution which stays discrete do to the compact size of the amps...
A+!
Hello
First i would like to wish everybody on this forum a great new year.
I begin the year to share my most recent DIY project. It is a pair of OTL mono amplifiers based on Atma sphere MA1 with some changes on input and power stage to get a higher power. I decided to build them without enclosures. I like them most as they are now.
These amps are absolutely stunning and capabable to drive demanding speakers. I have a pair of Amphion Kripton 2 that match really great with these amps. With a VT-25 preamplifier, i'm in heaven now. If i had the money i certainly will order one pair of MA-2 directly from Atma sphere.
Cheers
José
First i would like to wish everybody on this forum a great new year.
I begin the year to share my most recent DIY project. It is a pair of OTL mono amplifiers based on Atma sphere MA1 with some changes on input and power stage to get a higher power. I decided to build them without enclosures. I like them most as they are now.
These amps are absolutely stunning and capabable to drive demanding speakers. I have a pair of Amphion Kripton 2 that match really great with these amps. With a VT-25 preamplifier, i'm in heaven now. If i had the money i certainly will order one pair of MA-2 directly from Atma sphere.
Cheers
José
Attachments
Merlin Blencowe posted a link to a VERY interesting 1986 patent here: #US4614914
https://www.diyaudio.com/community/...ancellation-transformers.371254/#post-6627067
https://patents.google.com/patent/US4614914A/en?oq=us4614914
By eliminating (effectively, using positive current Fdbk) the primary resistance of an OT, the magnetizing current (and hysteresis component) are eliminated, as well as the primary resistance of the OT. So a conventional tube amplifier using an OT can perform identically to an OTL amplifier.
https://www.diyaudio.com/community/threads/suggestions-for-new-build.381592/#post-6905264OTL sound -without- the heat or expense.
https://www.diyaudio.com/community/...ancellation-transformers.371254/#post-6627067
https://patents.google.com/patent/US4614914A/en?oq=us4614914
By eliminating (effectively, using positive current Fdbk) the primary resistance of an OT, the magnetizing current (and hysteresis component) are eliminated, as well as the primary resistance of the OT. So a conventional tube amplifier using an OT can perform identically to an OTL amplifier.
https://www.diyaudio.com/community/threads/suggestions-for-new-build.381592/#post-6905264OTL sound -without- the heat or expense.
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