Audio Proz Service and Sales

Electrix Repeater

(Modification)

Jan 19th, 2015

Although the Electrix Repeater is a great tool/instrument, there are several things that can be done to make it even better. Vince's modification takes care of many clicking noises made by the clocking circuit. As well as greatly reducing these noises, the modification also reduces the hum floor. The overall improvement is about a 10-20 dB drop in the overall noise. More importantly, this modification gives the Repeater increased clarity and more dynamic range. These changes greatly improve the sound when overdubbing. These changes partially effect the quality of prerecorded CFC's, but it is suggested that you re-record the CFC's after the modification for maximum quality. We will also provide you with information on using the correct CFC's.

For the last few years, I have been explaining the modification to reduce the noise and improve the fidelity and I will be making a more complete description in the near future because this has become a very popular request. But the quick explanation is that I alter the power supply, grounding circuits between the audio and digital, and some careful ground wire updates.

As a specific example, I fine tune the noise out of the power supply systems with capacitors and ground wires. It’s taken me quite a bit of experimentation to resolve the issue and indeed recently, I’ve come to one of the best modification levels I have done which reduces the computer noise ingress, ground loops, etc. The improvement of fidelity is phenomenal. I’ve owned 3 of these and sometimes more and have done full complete recordings on them with great results in fidelity.

Most people don’t recognize the noise inherent in these machines because they don’t own good audio monitors or simply haven’t been paying attention-but once you point out the noise problems (which is the clock ticking away and the growling of the power supply and other stuff) it becomes obvious the modifications I do improve the signaled noise by almost 12DB as well by reducing the computer noise ingress the fidelity of the audio becomes far superior and clearer especially for complex program material. (The unit apparently has some special type of digital compressor circuit which can make certain audio frequencies and transient responses sound smeared or grainy.

My modifications vastly improve the fidelity. Unfortunately, the unit will never make a 96DB noise floor according to published specifications (yet they have often referred people to me for this problem.) The unit will still exhibit some background noise but it’s down to 80DB noise floor typically. The unit also requires some other proper installation requirements to reduce the noise. One is to ground the chassis of the machine to the rack really well and then to make sure your rack is grounded to your mixer well to prevent ground loops. The new level of internal modifications to the Repeater costs about $160.00 which typically includes shipping back (see shipping inquiry on bottom).

The only reservation is that the front panel guitar input jack will now be converted to a basic line level input, which many people have preferred anyhow (this is the only way to modify it to improve the noise floor effectively). Previously recorded CFC cards (which have to be a special card to operate all functions effectively and fast i.e.: reverse and overdubbing) will probably have to be completely erased and rerecorded again to get the BEST benefits to my modification. Ultimately, even the overdubbing capability is vastly improved for fidelity, and to my opinion, the digital outs and the CFC cards seem to run cleaner! As an overview, these machines are incredibly rugged and I’ve never seen any major failures in them. My modification is mostly topical (added on parts) with no cutting up of the units circuit foils. It’s a very clean modification.

To date, I have succeeded with over 40 machines, unfortunately the exact details of modification I keep private because it took me a long time to develop the strategies. The digital noise problems are so common from everything to computer audio recorders as well as so many units which have some type of digital converter inside of them. We've also come to realize, that if hooking a repeater up using its analogue and digital outputs into a computer, it can sometimes defeat or reduce the effectiveness of the modification. And if a repeater has not been modified and is used with other repeaters which are modified going into a mixing system, this also can reduce the effectiveness of my modification. Therefore, its almost imperative that all repeaters are modified similarly.

Most people are not aware that in any computer digital audio recording device (and even in mic preamps, reverbs, and processing devices which use digital converters) the clocking noise ingress can get into the audio circuits creating an unusual heterodyning of supersonic frequencies and audio domain frequencies, therefore, blurring the true quality of audio i.e.: its timbre and harmonics can become skewed. Although Repeaters are a great functional unit and I love mine to death, they suffer from this effect unless modified. I hope to help the best that I can. Please call before sending in a unit for modification.

The cost of this mod is $160.

This includes all modifications and shipping within the continental US.

PLEASE-YOU MUST DOUBLE PACK OR OVER PACK THE UNIT SO THAT WE MAY REUSE THE PACKING TO RESHIP IT TO YOU EFFICIENTLY. MOST REPEATERS ARE MODIFIED AND RETURN SHIPPED WITHIN 3-7 DAYS. THANKS AGAIN.

ADDENDUM - 1/19/06.

I have tried out another (the other most important) modification to the Electrix Repeater. Indeed this technician has recognized the problem of interfering digital and analog grounds too. He does some similar modifications as I do, and I certainly recognize his excellent efforts to improve upon the repeater. However his modification is very involved and requires a major dismantling of the unit, cutting of numerous board connectors and lifting of IC pins to create a result similar to my modification. My modification is a clever way to improve the data grounding and improve power supply with a more simple and much less surgically involved procedure. Virtually all of my modifications are add-on, and only a few foil cuts. My alteration appears to work better once the unit is in the audio rack as it is crucial that the rack chassis will "see" similar "earth ground" (at the wall socket) as any other devices racked up and hooked into it will not create chassis, ground loops. I also recommend now to install phono shorting plugs into the phono input as this circuit is also responsible for some noise contribution. I repeat again: Install RCA shorting plug to the RCA phono ins. As a general rule (to be competitive) I will be lowering my modification cost from $175 to $160 which will include return shipping costs. If you don’t need the phono preamp circuit I advise removal of the IC to reduce noise further. Almost all Repeater updates are done and return shipped within 7 days.

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