Amazing effect lofi and very characterful, It imparts a very peculiar colouring to the sound.

This unit fully working and is in very good condition 220v EU plug

Specification
16-bit linear, 128X oversampling ADC
16-bit linear, 8X oversampling DAC
44.1kHz sampling frequency
199 program memories
11 algorithms
+4/-10dB input level
Dynamic range: >90dB effect (120dB direct)
RV70 ALGORITHMS:

REVERB: Room 1-3, Hall 1 & 2, Garage
NON-LINEAR
REVERB + DELAY: Hall-parallel, Room-parallel, Room-series, Hall-series
MIDI EDITABLE:
Algorithm selection (1-11).
3-band EQ, with peaking or shelving low and high bands, and peak mid.
Parameters relating to the Reverb and Reverb+Delay-based algorithms, as follows: room size, reverb time, density, pre-delay, HF damp frequency and gain, LF damp frequency and gain, release density, early reflection level, reverb level, delay time and level (left, right and centre), delay feedback level, delay time scale.
Additional parameters for the Reverb+Delay algorithms: reverb level, delay time and level (left, right and centre), delay feedback level, and delay time scale.
High-cut filter frequency.
Output level
Parameters for the Non-linear algorithm: Density, pre-delay, four-way envelope with time and level for each point, non-linear filter, non-linear filter type, delay feedback level, non-linear time, high-cut filter frequency, output level, non-linear filter type and resonance.

Boss RV-70 - programmable Midi Reverb/Delay Stereo Made in Japan 19" Rack mount

The RV70 Digital Stereo Reverb from Boss is cool. It is simply a great reverb/delay, and yes, editing is undertaken by just four knobs. If you can tweak the knobs and press the 'Write' button, you can work the RV70, and this is as far as you ever need to go if you're a hands-on, plug-in-and-play type of person. This wouldn't be a Roland/Boss product if you couldn't go deeper, however, and it comes as no surprise that there are indeed hidden -- MIDI -- depths to the RV70. To be more specific, there are certain features of the RV70 that can only be accessed over MIDI and which make the RV70 a more sophisticated beast than it might at first appear to be
PHYSICAL WORLD

As you can no doubt see from the accompanying photo, the RV70 comes housed in a 1U rack and features a slightly jazzier colour scheme than the usual black. Apart from the four editing knobs, there are the expected input and output level controls, a Direct button (which selects either the effects-only output or a mix of effects and input signal) and a central display which features a three-character, seven-segment LED display, peak LED and a trio of indicator LEDs which show you what effect type is currently selected. A pair of up/down buttons to the right of the display select Programs and parameters, and the MIDI and Write buttons are self-explanatory. At the rear, there are stereo input and output jacks, +4/-10dB level switch, MIDI sockets, a remote socket for remotely turning effects on or off, and the captive mains lead -- no external power supply!
PROCESSING

Inside this deceptively simple package is a 16-bit DSP (44.1kHz sampling frequency) that utilises what Boss call AF -- Adaptive Focus -- to "significantly reduce quantisation noise by combining multiple samples to optimumly match signal levels through analog to digital conversion." That's a quote from the manual, but it does mean in practice that the RV70 is one of Boss' quietest units.

My mention of the three 'effect type' LEDs above might indicate a fairly simple machine internally; in fact, while there are three types of effect possible from the RV70, these broad definitions hide a total of 11 different algorithms. The three groups of effect types are:

• Reverb, a sophisticated, dedicated effect.

• Non-linear, a filtered, delay-based digital algorithm that can produce wicked, metallic sounds.

• Reverb + Delay, which offers a choice of two parallel and serial reverb/delay combinations.

Without any recourse to MIDI, editing is simply a matter of selecting a program that features an algorithm you want to use or has a sound close to what you want, then twiddling the four knobs and, by pressing the Write button, saving the result when you're happy. The four knobs have different functions, depending upon which Preset and which algorithm you're editing. The parameters they control for each group of effect types are as follows:

• Reverb: reverb time, pre-delay, HF damping and density.

• Non-linear: non-linear time, pre-delay, filter and density.

• Reverb + Delay: reverb time, pre-delay, delay time and feedback.