Atma-Sphere MP-1 in Rare Gold/Silver Chassis

[Phantom-Audio]

I thought id show the group here a Brand New MP-1 in Gold and Silver Chassis.

The Gold and Silver Finish is a special request and does cost a hefty amount, but overall i think this looks sweet.

This unit is brand new and posted in the classified section; the client has become ill and is letting go of his stuff.

Atma-Sphere MP-1 MK. 3.3 Tube Pre-Amplifier: Brand New open Box, Price Drop!

Atma-Sphere MP-1 A World-Class Pre-Amplifier In Custom Gold/Silver Casing! Over 45 years in the making this is the first true Balanced Pre-amp on the planet and has undergone 45 years of refinement and updates. A True Titan in the Audio world...

www.whatsbestforum.com

The MP-1 comes with all the upgrades Atma-Sphere offers, plus some more!

This particular unit has RCA outputs with a Switch to allow using the balanced pre-amp with Single-Ended Systems.

It also has been fitted with an RCA Phono Input (Ralph usually uses balanced Phono Inputs) again with a switch and grounding post.

All the upgrades, Such as the Caddock Resistors internally, Vcaps All the way, and Caddock Volume Control, which I feel have made some bigger improvements to the overall sound as compared to the many others MP-1 I have had come and gone,

All the previous MP-1s we have sold never commissioned the Caddock Volume control upgrade due to the price, but I feel now this is a necessary upgrade. by far, it's probably the most expensive upgrade Atma-Sphere offers but to my ears; it brings a certain quality to the sound. Once heard, it's hard to go back to a unit without.

Iv had a few MP-1 Units come and gone, usually, break-in time takes from about 30-60 hours.

This unit has done less than 10 hours its open box and tested with new LinLai Tubes, and i already could tell it has been the best sounding MP-1 to date. I assume this is because every other one which we have used or sold did not come with full Caddock Volume control.

I'm very impressed with the overall sound and build quality. Dynamics, tonality, bass, smoothness, transparency and soundstage all seem a few notches better than our previous units.

Iv did not have enough time to evaluate the unit further as it's for sale. We will have to get our demo unit upgraded in the new future with the new volume pot.

 

[Phantom-Audio]

Here are the internals of the latest MP-1 Pre-amp.

 

[bazelio]

I see V Caps, a lot of resistors and a belt driven attenuator! Pretty cool stuff.

 

[Phantom-Audio]

I see V Caps, a lot of resistors and a belt driven attenuator! Pretty cool stuff.

caddock resistors in the line stage and phono stage. Full Caddock resistors in the volume control as well. costly upgrades over the standard unit, but the performance is elevated.

 

[tima]

... a belt driven attenuator!

Remote control -- uncommon with A-S preamps, but Ralph speaks to his customer's requests. Construction of that attenuator is a work of art.

 

[tima]

From the past, here's mine without a motor :

 

[Young Skywalker]

From the past, here's mine without a motor :

View attachment 93570

View attachment 93572

View attachment 93571

These preamps are works of engineering art. How quiet are they, on typical sensitivity loudspeakers, compared with some of the better transistor products? For example, can one hear the tube noisefloor (from around 2 metres) when no music is playing? How reliable and easy to source are the vacuum tubes in the line and phono sections? Does tube rolling improve the overall performance?

 

[tima]

These preamps are works of engineering art. How quiet are they, on typical sensitivity loudspeakers, compared with some of the better transistor products? For example, can one hear the tube noisefloor (from around 2 metres) when no music is playing? How reliable and easy to source are the vacuum tubes in the line and phono sections? Does tube rolling improve the overall performance?

Hi - Noise from the Atma-Sphere MP-1 partly comes from which tubes one uses. It is an all tube unit having a total of 18 tubes: 10 6SN7s in the line stage and 8 12AT7s for the phonostage. I owned one for several years and really enjoyed it.

Here is a quote from my review of the model in my above pictures.

"Without the buffering effect of output coupling caps or transformers, this preamp quickly makes you quite aware of any tube's microphony or noise issues. This is especially true of the 12AT7s in the phono section. When the phono stage is engaged and no music is playing, turning up the volume control can increase the amount of audible tube rush. This becomes more relevant the lower the output of your phono cartridge and the more gain you apply to it. The manual proclaims there are no quiet NOS 12AT7s still available and only modern tubes should be used here."

I found the 6SN7s and 12AT7s quite reliable and modern tubes are available. Tube rolling can, imo, make a genuine difference to overall performance, depending on how fanatical you are about wringing maximum top performance by rolling tubes. The MP-1 is fine with stock tubes. NOS versions of certain models are increasingly more difficult to locate. Although the manual says 'no more NOS 12AT7s' I tried several varieties and for my taste I really like the Sylvania 12AT7. There are several 6SN7s that I like, including the Sylvania VT-231/6SN7GT, Ken Rad VT-231 (black or clear glass), RCA 6SN7GT/VT-231 gray glass. Take a look at this WBF thread on the 6SN7. The trick is to find quiet NOS tubes. With new modern tubes of both types, the MP-1 can be very quiet.

I cannot speak to a noise comparison with transistor preamps -- I've owned only one years back, a Pass Labs XONO. Compared to the Audio Research Reference 10 + Ref 10 Phono or the Lamm LL1.1 linestage + the Lamm LP1 phonostage, and working from memory, I think there is a greater noise potential from the MP-1, again depending on which tubes are used.

Of course all of this is relative to the amp paired with the preamp. I used an Atma-Sphere MA-1 paired the MP-1.