Tag: Barry Rudolph

Posted on

NEW TOYS by Barry Rudolph

Retro instruments Sta-Level Gold Edition

Retro’s Sta-Level is an updated version of the venerable Gates Sta-Level tube radio broadcast compression amplifier. Still based on the original 1950’s all-tube design, Retro adds modern features and new adjustability for more recording studio applications possible than the original units.

The Retro Sta-Level is capable of 40 dB of gain reduction with a signal-to-noise ratio of greater than 70dB and a THD (total harmonic distortion) of less than 1% at 30dB of GR. It has a near ‘ruler-flat’ frequency response within 0.5dB from 20-20,000Hz.

Read more of the complete review @ https://www.barryrudolph.com/newtoys/toys4/retrostalevel.html

Posted on

Barry Rudolph Review: Retro Instruments Revolver

Dual-Channel Tube Compressor Recalls the Vintage Audio Gear of Yesteryear

Retro Instruments’ Revolver is the company’s latest all-tube processor, having started out as an experiment back in 2011. It seems that Retro’s Phil Moore was not satisfied with it as a viable product until the 2018 Winter NAMM Show, when he showed the first units. Revolver fits perfectly into the Retro Instruments product line and upholds the company’s unwritten mission of building—to the highest-quality standards—the “new classics” that recall the most coveted and vintage audio gear of yesteryear.

Revolver’s ratios range from a 1.5:1 (full CCW) to 5:1 (full CW). A good starting point is to set the Dual Threshold knob fully CCW so that the compressor’s threshold is least-sensitive. By using the input level control and driving more level into the detector, not only will you control the saturation of the fully differential tube path, but be able to compress to any amount using a low 1.5:1 ratio. As you turn the Dual Threshold clockwise, you get more compression at higher and higher ratios, although it may require readjusting the input gain control and the unit’s output level.

The entire detailed review you can find here.
https://www.mixonline.com/technology/review-retro-instruments-revolver-dual-channel-tube-compressor

Posted on

MIX Online: Barry Rudolph’s Review Retro 500PRE

 


The 500PRE is Retro’s third 500 Series module, joining the original DoubleWide I and the updated DoubleWide II–both dual-slot, single-channel tube compressors. The 500PRE incorporates the same basic double-balanced Class-A circuit topology as in the company’s Sta-Level limiter.

WHAT DO WE HAVE HERE?

The 500PRE works both as microphone preamp and line-level amplifier; it has an input operating range of -72 dB to +12 dBu. The output clips at +18 dBu, with maximum output at +24 dBu. The 500PRE has two switchable gain ranges: high gain at 75 dB using all three of its TAD 12AT7 tubes, or low gain at 48 dB using just two of the tube stages.

SOME TECHNICAL DETAILS

The total slot current drain for the 500PRE is 160 mA. This exceeds the allowable current drain in the API Audio VPR Alliance specification of 130 mA for a single-slot module. A check in a tube manual shows that the 12AT7 requires 150 mA filament current each, and there are three.

Taking an idea from old ’50s tube television sets, the three tube filaments are wired in series and powered directly from the 500 rack’s +/-16-volt rails, or 32 volts total–that’s nearly 11 volts DC for each tube. The tubes’ plate voltage is supplied by the 48-volt phantom power supply, and the current drain is just 3 mA.

If your Lunchbox or rack does not have phantom power, the 500PRE will still work, albeit with reduced headroom as the plate voltage will automatically switch over to the +/-16-volt rails.

I ran the 500PRE in an API 8P High Current 500 rack (250mA per slot) and..

Finish reading this detailed review @ Barry Rudolph’s website: https://www.barryrudolph.com/mix/retro_500pre.html