A few points on the subject of the Krebs mod -
The krebs website has a legal exclusion for any damage incurred in doing the mod. ( see my post above )
The mod is not reversible.
Richardkrebs has acknowledged in his post above that some SP10mk2's have had a breakdown in the motor glue
05-03-14: Richardkrebs
Ironically there is a type of glue used in the MK2 motor which on random units has broken down. If required this is repaired when the motor is disassembled.
This would suggest that there is a risk of the motor glue breaking down over time after the owner has taken delivery.
There are a few other concerns :
05-03-14: Richardkrebs
one part of my upgrade is the targeted application of an organic oil. I can assure you, this oil does not harden, but does stop being sticky, after around 4 months. It then becomes stable and enjoys considerable longevity, it also stops smelling. I first used this material in my electrostatic EHT power supplies back in 1993. A recent check has confirmed that it has retained its elasticity and shows absolutely zero sign of any breakdown or tracking. It is being used as a dielectric in this supply, exposed to 5000 volts.
Ironically there is a type of glue used in the MK2 motor which on random units has broken down. If required this is repaired when the motor is disassembled.
I have studied Physics, Chemistry, & Engineering at university and find it curious that one could conclude that if an oil remains stable in an EHT power supply then it would remain stable in a turntable DD motor. These are entirely different applications and have no correlation whatsoever in terms of how the oil performs.
05-11-14: Richardkrebs
in my view, Technics did not pay particular attention to the loop between platter and arm. This in the form of rigidity and resonance control....
My upgrade improves this situation by helping to control resonances in the motor chassis. In standard form it is quite resonant and flexible.
This change produces an immediate and unambiguous improvement.
This claim could be easily measured with simple test equipment such as an accelerometer and by putting a frequency sweep resonance through the TT with before and after the mod test results. I note there are no test results provided on the krebs site that support his claims.
05-11-14: Richardkrebs
There are a number of materials used in my upgrade, most of them man made. The organic material used is the same as that employed by Duelund in some of their products. Once dry it is stable and enduring.
Again, I find it curious that one would argue that if an organic oil is used in a capacitor, then it would be stable in an electric motor. These are entirely different applications and environments. It is unproven as to how long the product will remain stable in the field.
05-11-14: Richardkrebs
Firstly I will leave it to the growing number of industry leaders who are using my upgrade in their MK2 and Mk3 motors, to attest to the efficacy of my work.
Growing number of industry leaders. Richardkrebs, could you advise how many & who are they ?
05-11-14: Richardkrebs
Further while measurements are of great importance, we cannot listen to them. See my web site for unedited customer reviews.
Customers cannot post onto the krebs website. Selected customer comments have been posted by the website host, therefore the claim of "unedited" is erroneous.
I have heard SP10mk2 before and after the krebs mod and cannot hear any improvement. The sound is different, smoother and gluggy. To my ears it sounds worse. In the ET2 thread krebs agreed with this but claims that over time it will get better.
Richardkrebs, perhaps you could advise if the SP10mk2 I heard had the glue breakdown ?
As Audiofun points out, customers should be fully informed of any modifications and potential risks so that they can make an informed decision.
This information has not been provided thus far on the krebs website. In reading krebs description of the mods above, he still does not articulate precisely what has been done. It is not possible to assess the risks based on the paucity of information provided and therefore Audiofuns sage advice of CAVEAT EMPTOR should be taken on board.
