The UV-1 (UltraViolet) preamplifier is based on a circuit that we have used for many years, but not marketed before. About 40 years ago,
Ralph Karsten began developing his own circuit for use for friends on a budget but with high end audio aspirations. It was originally used as
a modification to the venerable Dynaco PAS-3.
Over a period of decades, the circuit has seen a lot of refinement. It is a simple circuit (and obviously a complete departure from our
other products), based on a very capable and refined 6SN7-based line section with a simple phono section based on 12AT7s. We have seen this
preamp best preamps costing up to five times more; when we say 'refined', we mean it!
We never really considered marketing the preamp as it is so different from the rest of our product line. But friends and associates
convinced us that we had something special, especially for its price so here it is.
The preamp is available in four forms: a basic line stage, a headphone power amp that also works as a line stage, a full function preamp with
high output MM capability, or with the addition of a set of Jensen stepup transformers works with any low output moving coil cartridge as well.
The headphone version of the UV-1 uses the full tube complement of the UV-1. It has four inputs and can be used as a line
stage as well. This version does not have a phono section.
- Simple zero feedback line section
- Cardas RCA connectors used thoughout
- standard dual output connections, optionally reconfigurable
- Shunt-style balance control
- heavy-duty seamless aluminum chassis
- Precision components used throughout
- Low-noise "star" grounding topology
- Three-year general coverage warranty with one year warranty on tubes
Line stage frequency response
2 Hz-200 KHz, +0 dB, -2dB
Line stage gain
Line stage input impedance
100 Kohm Ω single-ended
Line stage output
12V; 17VRMS at clipping
400 Ohms from 2Hz to 100KHz
Phono stage input impedance
47 K Ω,
Phono stage input overload
Phono stage gain
70 dB (Low Output Moving Coil version)
5 Hz-90 KHz within ½ dB
Within .1 dB
RIAA Phono sensitivity( for 0.5 V @ 1 KHz )
2 x 12AT7 phono
2 x 6SN7GT line section
15 3/8" wide x 7.5" deep x 5." high
Three years, transferable
One year for tubes
For support requests or any questions about your Atma-Sphere product, contact us directly at (651) 690-2246 or send us an email
Available as full function with phono or line stage only.
Contact your local dealer
for pricing information.
Contact Atma-Sphere tel.: (651) 690-2246 or email