Spatial Coherence Preamplifier TVA-1 / Knapp T-Fet Valve / McCormick
Außergewöhnliche und seltene Vorstufe aus Kalifornien. Eine Entwicklung von Richard Knapp und Steve McCormick (ModSquad). Rare Europa/230V Version. Die von R. Knapp entwickelte T-Fet Valve Schaltung verbindet die Tugenden der besten Transistor- & Röhren- Preamps seiner Zeit von z.Bsp. Mark Levinson, Spectral, Audio Research, Conrad Johnson etc. Preislich bekam man damals schon fast einen VW Käfer/Beetle für den geforderten Einstandspreis, zumindest einen sehr guten Gebrauchten ;-) Schweres und vibrationsarmes Gehäuse mit eloxierter Alufront. Netzteil in separater Kammer. 2x Phono MM, 3x Aux, 2x Tape (Monitor mit Überspielmöglichkeiten), 2x PreOut. Neben feinfühligen Balance- und Klangreglern bietet die Vorstufe auch noch den früher beliebten Mono/Stereo/Reverse Modus, auch heute gut brauchbar. Guter Zustand. 6 Monate Garantie.
Spatial Coherence was a high-end boutique audio company with a relatively small number of hand-built pre-amps made every year that were considered “state of the art”.
It is still a much better pre-amp than 99% of all modern pre-amps being made today especially if you are into turntables and vinyl records.
The legendary TVA-1 pre-amp was made by Spatial Coherence around 1979. Spatial Coherence only made the state of the art hand-built pre-amp the model TVA-1, an audiophile grade pre-amp.
The TVA-1 uses T-FET valves designed to emulate the warm rich sound of vacuum tubes but are more reliable than tubes. The pre-amps were built to last a minimum of 50 years of continuous use so there is no on/off switch on the pre-amp since it’s designed to never be turned off once it’s plugged in.
It sounds very good after it’s first warmed-up (about 20 minutes) but when it finally stabilizes completely the sound gets even better with greater separation of the instruments, a holographic 3-D sound-stage, and it makes vinyl records sound more like live-music than any other form of audio reproduction.
The TVA-1 has the sound of the very best tube pre-amp available, but with much more reliability since its built like a tank. Richard Knapp and Steve McCormick had the idea of building the very best pre-amp they could if money was no object, according to Steve McCormick.
The basic TVA-1 pre-amp sold for 1200 dollars in 1979, later goes up to 1.600 US$
In 1979 (just like today) the very best audio is achieved with vinyl records and the TVA-1 was made specifically for use with vinyl with two phono inputs for this purpose.
Other features are a separate out-board power supply that is connected to the main chassis with a five foot 3-prong shielded cable to make the unit as quiet as possible, two separate pre-gain controls to balance the sound to a room’s acoustics, and a master post-gain volume control. All the other components in the unit were also up-graded to the best ones available.
Full-function solid-state preamplifier with two phono inputs, three line-level inputs, two tape loops with selectable two-way dubbing. Original published specifications: Frequency response: 10Hz–40kHz +0, –0.5dB. Max output: 10V. THD: 0.05%. IMD: 0.05%. Phono S/N ratio: 80dB. Measured performance (footnote 1): RIAA accuracy: R channel, –0.25dB at 20Hz, –0.75dB at 20kHz (net: ±1dB); L channel, –0.25dB at 20Hz, –0.25dB at 20kHz (net: ±0.5dB). Line level frequency response: R channel, 20Hz–30kHz, +0dB, –0.1dB; L channel, 20Hz–30kHz, +0.5dB, –0.1dB. Phono S/N ratio, ref. to 2.5V output: R channel, 92dB (input shorted), 89dB (input open); L channel, 94dB (input shorted), 90dB (input open). Phono crosstalk: R channel, –64dB, L channel, –67dB. S/N ratio, line level, ref. to 2.5V output: R: 90dB (input shorted), 89dB (input open); L: 90dB (input shorted), 89dB (input open). S/N ratio, line level, ref. to 10V output: R: greater than 102dB; L: greater than 102dB. Crosstalk, line level: R: –57.5dB; L: –55dB. THD: L channel, 0.01% at 20Hz, 100Hz, 1kHz, 0.017% at 10kHz, 0.045% at 20kHz, 0.12% at 30kHz; R channel, 0.005% at 20Hz, 100Hz, 1kHz, 0.001% at 10kHz, 0.03% at 20kHz, 0.07% at 30kHz. IMD: R channel, 0.07%; L channel, 0.0035%.
Dimensions: 3.5" H by 19" W by 14" D. Weight: 22lb.
Be aware of the two major concerns when using the TVA-1:
1. the number of weeks it takes for the pre-amp to sound its absolute best
2. the large transient spike that is sent though the line when its first plugged in.
The spike is guaranteed to take out any tweeters in its path regardless if the volume control on the TVA-1 is completely turned down or not.
You definitely do NOT want the amplifier turned on when the unit is first energized.