Arkless Electronics
Trade: Amp design and repairs.
As I keep getting asked the same questions I thought I'd answer them here and can then link to this as necessary.
There are two basic versions, the Arkless 640P and the Arkless GTI:
Arkless 640P: £225. MM and MC, switchable on back panel. Loading for either type of cart can be set by loading plugs which go into the redundant "MM" sockets on the unit (both types of cart use the sockets marked "MC" after the conversion). One set of loading plugs is provided and can be anything the customer requests for either type of cart, ie capacitors or resistors or a combination of both, but my default is 100R resistive plugs for MC carts if no preference is expressed. Further loading plugs can be supplied to spec for those who do not wish to solder up their own and are £15 for one set including postage and £10 for further sets if ordered at the same time.
Arkless GTI: £285. MC only. This is a transimpedance type MC stage in which the cart drives a "virtual short circuit". The Dynavector P75 calls this "phono enhancer mode" or "Dr T mode" but it is an old idea.
Gain is set by the internal resistance of the cart itself, the lower the resistance, the higher the gain, hence for a given vol control setting loudness will vary considerably for different cart models. This is intrinsic to the operation of such a phono stage.
It requires no loading, again this is intrinsic to this type of phono stage.
A donor unit is required and this must be a Cambridge Audio 640P or 651P. Either is equally suitable and no other Cambridge Audio models can be substituted. They do not need to be working units.
A Turbo version can be ordered or these extra mods retrofitted to either version. £360 for Arkless 640P and £380 for Arkless GTI. This includes a multitude of further upgrades and results in a small improvement in performance.
A further variant of the GTI Turbo with passive HF EQ is also now available for £420.
A volume control can be fitted to any version for an extra £50. Note that the aesthetics of this will leave something to be desired as the front panel was not styled around the fitting of a vol control and that it will look much better on a black unit than a silver one.
Any unit can be re-capped for an extra £35 (£25 for Turbo units as some caps are replaced with much bigger and better ones as part of Turbo mods and so there are less remaining to change out). This is a new service and replaces all electrolytic caps which are still in use after the conversion with much better long life, low ESR non Chinese brand electrolytics.
It is not intended that this has any effect on sound quality and these units have proven reliable even with the standard capacitors fitted. It is intended more as a "peace of mind" thing in that one will usually not know how much use a secondhand unit bought in as a donor has had. FWIW I've had one unit that arrived for conversion with a duff cap in the PSU section and this one cap was replaced as part of the work and one unit out of all the ones I've now done that has come back with a duff electrolytic (in the PSU again).
The wall wart that powers these is AC and literally nothing but a transformer. The PSU proper is inside the phono stage and no "improved" wall wart's etc should be used and in fact attempts at using higher rated units etc can cause faulty operation.
I use Royal Mail Special Delivery insured, tracked and signed for next day courier service to return completed units and this is £11.
There are two basic versions, the Arkless 640P and the Arkless GTI:
Arkless 640P: £225. MM and MC, switchable on back panel. Loading for either type of cart can be set by loading plugs which go into the redundant "MM" sockets on the unit (both types of cart use the sockets marked "MC" after the conversion). One set of loading plugs is provided and can be anything the customer requests for either type of cart, ie capacitors or resistors or a combination of both, but my default is 100R resistive plugs for MC carts if no preference is expressed. Further loading plugs can be supplied to spec for those who do not wish to solder up their own and are £15 for one set including postage and £10 for further sets if ordered at the same time.
Arkless GTI: £285. MC only. This is a transimpedance type MC stage in which the cart drives a "virtual short circuit". The Dynavector P75 calls this "phono enhancer mode" or "Dr T mode" but it is an old idea.
Gain is set by the internal resistance of the cart itself, the lower the resistance, the higher the gain, hence for a given vol control setting loudness will vary considerably for different cart models. This is intrinsic to the operation of such a phono stage.
It requires no loading, again this is intrinsic to this type of phono stage.
A donor unit is required and this must be a Cambridge Audio 640P or 651P. Either is equally suitable and no other Cambridge Audio models can be substituted. They do not need to be working units.
A Turbo version can be ordered or these extra mods retrofitted to either version. £360 for Arkless 640P and £380 for Arkless GTI. This includes a multitude of further upgrades and results in a small improvement in performance.
A further variant of the GTI Turbo with passive HF EQ is also now available for £420.
A volume control can be fitted to any version for an extra £50. Note that the aesthetics of this will leave something to be desired as the front panel was not styled around the fitting of a vol control and that it will look much better on a black unit than a silver one.
Any unit can be re-capped for an extra £35 (£25 for Turbo units as some caps are replaced with much bigger and better ones as part of Turbo mods and so there are less remaining to change out). This is a new service and replaces all electrolytic caps which are still in use after the conversion with much better long life, low ESR non Chinese brand electrolytics.
It is not intended that this has any effect on sound quality and these units have proven reliable even with the standard capacitors fitted. It is intended more as a "peace of mind" thing in that one will usually not know how much use a secondhand unit bought in as a donor has had. FWIW I've had one unit that arrived for conversion with a duff cap in the PSU section and this one cap was replaced as part of the work and one unit out of all the ones I've now done that has come back with a duff electrolytic (in the PSU again).
The wall wart that powers these is AC and literally nothing but a transformer. The PSU proper is inside the phono stage and no "improved" wall wart's etc should be used and in fact attempts at using higher rated units etc can cause faulty operation.
I use Royal Mail Special Delivery insured, tracked and signed for next day courier service to return completed units and this is £11.
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