Another post, another Rega RP6 modification. In a previous post we took an in-depth look at the anti-vibration circuit of the 24V motor responsible for spinning the platter of our RP6; and, by adjusting the motor phase, we were able to reduce motor vibration, thereby reducing the amount of audible hum the motor inevitably causes.
However, even with the motor’s anti-vibration circuit tweaked to perfection, due to the motor being physically bonded to the underside of the plinth it is inevitable that an amount of noise, however small, will make its way through the plinth and be picked up by the cartridge/stylus; at which point it will become audible.
Furthermore, the RP6 as with any Rega turntable is of a non suspended design, and is therefore susceptible to external influences such as footfall, vibrations caused by other hi-fi components, and the natural resonance of the furniture on which it rests. I decided to tackle both problems at once with the aid of a product from SRM/Tech; a company whose products we’ve previously explored in this series.
The product in question is the SRM/Tech Rega silent base. Effectively an isolation platform, the silent base has the added advantage of allowing the Rega motor to be “dropped” from the plinth, and supported by a ring of material dubbed the motor vibration absorber (MVA) which decouples the motor from the main turntable plinth (and to an extend the silent base), filtering out unwanted motor vibration. The silent base is fashioned from 10MM extruded acrylic, and comes in jet black and crystal clear finishes with black chrome or gold plated spikes and furniture protection cups.
Straight out of the box, it’s clear that this is a well made product. It’s well packaged, too – resting in foam packing peanuts and neatly wrapped in multiple layers of bubble wrap. A small box contains the sorbothane suspension domes, spikes, spike cups and some step-by-step instructions. The silent base is well presented; everything from the way the base itself is wrapped, to the presentation of the parts inside the accessories box (including the way the instructions are neatly folded to perfectly fit the box) shows that SRM are, quite rightly, proud of their product. It’s great to see SRM offering great first impression; something that is often overlooked.
The bass itself is fashioned from a rigid acrylic sheet, with polished edges and the 3 spike bases recessed into the underside. It features a large tonearm cutout to support the use of VTA adjusters with arms that utilise the older-style single-point mounting system, a hole directly under the motor to support the use of a motor thrust bearing, and a hole for the Rega bearing housing. There’s also rear cutout to clear the Rega motor PCB, and 2 pre-drilled holes to allow you to screw the tonearm cable retainer to the silent base itself.
Fitting the silent base is a simple task. I began by preparing the base by screwing the spikes to the underside, before turning to the RP6 and removing the feet, motor cover, and tonearm retainer. Of course, before flipping your turntable up-side-down it’s important to remove the main platter and secure the subplatter with a strip of tape to prevent any oil leakage. I’d also recommend fitting your stylus guard, removing the counterweight and securing the tonearm with a piece of tape to prevent damage to it or your cartridge.
The next step is to place the sorbothane domes atop the silent base. These are responsible for providing the deck’s sprung suspension, and also filtering out any extraneous noise that makes its way through the MVA and into the base. I placed mine over the locations of the spikes, though providing they’re evenly spread their location isn’t of vital importance. THey’re slightly sticky in nature, and do a great job of gripping both the silent base and the plinth itself. It is worth noting that if you use a dust cover with your turntable, the weight of the dust cover pressing down on the rear of the plinth may cause the platter to become slightly tilted from front to back.
Next, the motor must be removed from the turntable plinth. On newer Regas, and those touting the 24V motor upgrade, the motor is secured in place by a strong double-sided adhesive pad. removing the motor from my RP6 proved to be quite a challenge, as the usual method of a firm sideways twist yielded no result. My solution was to gently prise the motor from the plinth with the aid of a small flat-bladed screwdriver, using the triangular brackets of the top plate for leverage. The tape is strong, and did take a very thing layer of the unpainted wood with it (though so thin as to be of no concern should the motor ever need to be reattached). It also proved difficult to remove the sticky pad from the top of the motor as it was well adhered and came off in small chunks, it and the glue making quite the mess in the process.
Once removed, the motor must be placed into the MVA. This is by far the most difficult part of the installation, as theM VA offers a degree of adjustment for both height and angle and the motor cables are a little on the short side. It’s important that the motor doesn’t come into contact with the acrylic bass itself, and it’s of equal importance the the motor sits low enough so as not to contact the underside of the plinth. My installation was further complicated by the use of a triple belt pulley, so alignment was critical to achieve even belt tension.
The motor itself simply presses down into the MVA. it’s a tight fit, so don’t be afraid to apply some pressure. There’s a small triangular cutout in the MVA to facilitate locating the wiring leading too the motor which can be enlarged if necessary, but with a bit of careful positioning i found it to be more than adequate for my needs.
with the motor installed, the plinth can then be placed over the base, allowing the motor pulley to protrude through the pulley hole, and the bearing housing to sit in its respective cutout. Once situated, the belt (or belts) can be installed, and the position of the plinth altered to adjust the belt tension. This simply requires a bit of trial and error, and was by far the most frustrating part of the entire process especially with a multi-belt setup. You may find it necessary to remove the plinth to adjust the height of the motor; similarly, if you need to adjust your pulley height, you’ll want to support the motor from beneath to prevent it slipping within the MVA.
The cable retainer can now be mounted to the underside of the silent base using the original screws provided by Rega. Installing the retainer isn’t easy as the turntable cannot easily be flipped up-side-down with the silent base in place, but it’s do-able and helps to protect both the cables and their soldered connections from accidental or gradual weight damage.
Finally, it’s time to locate, and level, the silent base. The base adds approximately 21MM to the height of the turntable; rising to 27MM if using the spike cups. The spikes offer an adjustment of approx 15MM to enable you to level the deck. The larger diameter portion of the spike itself is ridged for extra grip, allowing them to be rotated with the deck in place; the spike cups are also ridged to match aesthetically.
Installation of the silent base should take no more than half an hour. Once complete, you’re ready to play; though I’d always advise resetting (or at least checking) your tonearm’s tracking force and anti-skate settings before playing your first record.
I had no idea what to expect as I lowered the stylus for the first time. Of course, I’ve used isolation platforms before with varying results; I’ve also owned many turntables, some of them suspended and de-coupled designs. . What I wasn’t expecting, however, was the difference the silent base has made to the turntable.
The difference is certainly far from subtle. Immediately noticeable is a dramatic drop in the noise floor, and a complete absence of any hum. With the silent base in place, spinning the newly released pressings from Queen’s Studio Collection box set resulted in a background consisting of only a faint, tape-like hiss; an artefact that I’m sure is present on the record itself and not one caused by the turntable.
While the silent base changes the sound of the turntable for the better, it does not alter its character. The RP6 retained the musicality that makes a Rega a Rega, yet there’s more of it; there’s more punch, more rhythmic drive and better timing; but it’s now complimented by a sense of openness which makes the stock table sound valid and muddled in comparison. The difference is breathtaking.
In summary; this is an upgrade that should be on everybody’s list. The silent base is affordable, simple to install, looks great and takes the sound of your turntable to a new level. I kept mine; and that’s the highest praise a reviewer can give. Highly recommended.