Taperssection members are no stranger to modified gear offerings. While many well known businesses and individuals are involved in modification services, here at Sonic Studios I tend to do things a bit differently than most in this business.
Sonic Studios may well be the very first to offer deck modification with the arrival of Sony's TCD-D7 DAT deck in 91-92' where the stock deck's mic powering feature was workable, but somewhat marginal for my DSM mic power requirements. Later TCD-D100/PCM-M1 Sony models plainly would not power DSM mics without very audible poor performance, and occasional gross clipping type distortion from having way-too-low available mic powering current, and therefore, these particular Sony DAT models absolutely required MOD-3 internal deck modification, or any number of external mic power solutions.
Started mod services with a simple (MOD-1) D7 internal deck in-house modification, but potential
warranty issues prompted me to contact the then HiFi Sales/Service (the Oade Brothers) to sell my customer new & MOD-1 service on their owned decks. HiFi SALES was a certified Sony sales/service outfit, so I was hoping to avoid potential
warranty issues by offloading mod service to them, and did in fact instruct them schematic/PCB and clear suggestions on soldering technique/equipment on how to initially do the MOD-1 upgrade (the very first deck mod for them)
on up to a hundred 7/D8 model decks.
However, with more experience, a more involved
MOD-2 version upgrade seemed necessary, and Oade Brothers (now known as Oade) declined dong more technically complex board work, and also were finding their own resources taxed to provide the simple MOD-1 modification customers timely services as was too often requested. Sony warranty issues were then resolved to everyone's satisfaction and I took on all deck modification service for my customers, and also did a few MOD-2's for OADE.
So from about 93-94' onward, Sonic Studios did all MOD-2/3 mic powering Sony deck upgrades on D7/8/100 and M1 DAT models so that DSM mics could be directly deck mic-input powered with no mic performance issues. MOD-2/3 upgrades did have a secondary effect of reducing input noise by 1-2 dB, but this improvement was mostly not audible or advertised.COMMON MODIFICATION
The usual tact for those doing modified gear service, is to claim
custom work done makes for a better performing deck. Therefore, customers must take the moder's word solely on faith
, and subsequent good word referrals of satisfied customers.
The most common modification is to reduce an external preamp or deck's first stage microphone preamp gain by 12-to-20dB so high output mics recording loud POP/ROCK venues do not clip distort the gear's mic preamplifier. Alternate workaround to deck mod is to apply attenuation to the output of the microphone itself, feeding the mic pre with a lower signal.
However, some preamplifiers/deck's have a rather noisy mic input and so this tack does not reduce noise, and will often make preamp noise more noticeable with having the pre's gain turned up to compensate for the mic attenuation.
ALSO, if the pre or deck is also powering the mic, this precludes using an external in-series attenuation network that disconnects the mics from the powering pre or deck input.
So in this case, a modification lowering the mic pre 1st stage gain is preferable. And this modification involves changing the value of just two resistors
, lowering the pre's gain by 12-to-20 dB, AND this action automatically lowers noise by 12-20 dB; exactly the same amount of the pre's gain reduction!
While those doing such a modification rarely if ever state before/after specifications or test data (the moder's snake oil factor), customer's faith is most always vindicated by an after-modification experience of no more preamp clipping, and very audible lower preamp noise.
So the input clipping/noise reduction modification, often done solely based on customer's faith accepting the moder's word, and previous customer referrals, is most often successful in performing real technical magic on the gear, and in this case, involves the changing two internal resistor values with another!
Yes, it's still considered by me 'snake oil' due to the non-disclosure environment of the moder. However, it does work to both generate customer appreciation, and an income source for the moder who's providing an on-demand technical service with clear results-proven
customer value. MORE SNAKE OIL MODS
Besides the anti-input-clipping mod that simply decreases an input stage's gain/noise with 2 resistor swaps, there's a second type of mod with maximum snake oil content
This is where the modification claims lower distortion/noise improving performance exclusively separate from gain reduction by replacing preamplifier IC s and other components refining the audio quality of the modified gear
. The problem with these type mods is without before/after specifications/graphs commonly derived from simple bench testing, this type of modification is the most suspect to have 'high snake oil'
Being an experienced systems engineer/PCB board designer with over 40 years working discreet and IC components on very low level analog signal circuits, I know that simply changing an IC and/or a few components may or may not improve performance, and may even hurt performance
due to the many variables that determine analog output qualities.In summary
, and in other words, modifications beyond gain reduction change not documenting before/after performance
in clear specifications/measurement graphs are all suspect
even if customers rave about experiencing improved gear quality. We all know how subjective personal audition based reports of quality can be, and I personally feel this is no way to verify the truth
high content snake oil type gear mods. EDIROL R-09HR MOD-4
Fast forward to the present state of the art compact flash deck, specifically the Edirol/Roland R-09HR model I technically reviewed a few months ago. See review at: www.sonicstudios.com/r09hrrev.htm
The R-09 and newest R-09HR is NOT a candidate for needing gain reduction modifications as it's mic input is quite good at handling very high level mic inputs. However, the R-09 does have mic (power on or off) input noise issues, and though much improved, the R-09HR has very audible noise with mic power on
to make this mode almost unusable for anything but louder POP/ROCK venue recording when powering higher output mics.
As discussed in several threads, and my site's mic powering page, DSM mic powering MODs are available for current flash deck models Marantz PMD-620, Edirol's R-09, and now announcing MOD-4 for R-09HR that differs from all previous MODs in advertising both DSM mic powering AND NOISE REDUCTION at least when mic power is turned on, and chance of MOD-4 version 2 reducing non-audible, but quality affecting high frequency noise.
While mic powering upgrade usually does not include preamplifier noise reduction features, I personally like the R-09HR a bit more that previous compact flash models, and especially motivated to improve the noise/quality performance because of its excellent build quality, discrete very low noise dual mic preamp IC, easy 2 AA cell powering, and uncommon 24bit/88.2K .wav recording feature.
Also different from snake oil type mods, MOD-4 IS FULLY DOCUMENTED not depending on 'faith' or highly subjective customer's audition based proclamations of worth.
While the DSM mic powering part of MOD-4 is self evident by first trying a stock deck mic power on feature finding the DSM does not work in the least, to having MOD-4 modified R-09HR fully operating any DSM mic without any performance issues. Furthermore, the very audible excessive noise heard with mic power turned on is NOW GONE!
To document MOD-4 (v1) noise reduction performance see the below before/after graphs.
Since MOD-4 does NOT change noise performance over stock deck w/mic power off, MOD-4 power off plot is removed for simpler viewing of the below graph.
The graph above shows that MOD-4 accomplishes reducing the mic power on input noise to be NOW VIRTUALLY IDENTICAL TO THE STOCK DECK WITH MIC POWER OFF. MOD-4 version 2 may reduce or even eliminate the higher frequency noise, and may also further lower the low bandwidth noise (that's still 3-4dB higher below 20 cycles than mic power off mode)
regardless of mic power mode as there's a few areas in the circuitry I'm waiting for ordered parts that may make further noise reduction improvements, so stay tuned for version 2 documented results.
The R-09HR review posted on my site has a 15 second .wav file comparing previous R-09 mic input noise followed with 5 seconds of newer STOCK R-09HR MIC PIP=OFF, then 5 seconds of R-09HR PIP=ON as depicted in the noise graph above, but amplified by 35 dB so very audible.
If interested, anyone can download this file using it to audibly hear MOD-4 results as it will sound EXACTLY the same as the MIDDLE 15 second portion of the STOCK R-09HR recorded with mic power off. This comparison file is at: www.sonicstudios.com/-35dB_R-09vsHR.wavTHE REALITY OF DOING MODIFICATION SERVICE
The physical aspects of PCB surface mount circuit modification is physically and technically challenging. While many of us find viewing deck circuit diagrams and enlarged images of PCB component placement challenging to our experience, and made more practical/possible with the availability of very detailed service manuals, the fact remains that removing/replacing the every shrinking size of currently used components is quite challenging. Not only is skill most needed, special soldering/optical tools are most required to do this type of work successfully.
While many doing gear modifications perform this as an in-house service same as I've done since the early 90's, businesses like Oade now outsource this work to a specialized 'deck repair' company that handles the actual design/physical realities of modification work. The physical challenges and difficulty in working with current surface mounted component size may be better appreciated with viewing the component size comparison image below.
As shown above, chip resistors, and (not shown) same sized but slightly thicker chip type capacitors, are shrinking to be the size of a pencil dot! In the 90's, most of the Sony DAT decks used the 805 sized chip components, and in later years also included a mix to 603 size on 5-6 layer PCB boards.
While there are many 603 sized resistor/capacitor chips inside the R-09HR, MOD-4 mostly deals with the smallest 402 size (actually EIA 0402) resistors/chip capacitors on the analog (center) board inside this model. So for doing effective modification work, not only is uncommon understanding of component/circuit/PCB physics needed, but also a significant investment in specialized solder, soldering tools, and optical gear essential for proven quality results. In summary
, this is not the kind of work well suited for the inexperienced and poorly equipped, unless those claiming to do this kind of service have solely 'faith' customers requiring no documented reality to moder's claims of mod-service value, and who then spread the good news of their subjective satisfaction with having paid the price of admission for (maybe having) a 'high content snake oil' mod label on their gear. Please make no mistake
, I have no argument with those doing/accepting 'high snake oil content' modification sold at face value, just suggest this should not be confused with really knowing the truth
about untested/undocumented gear's actual
value in terms of audio quality/performance.