Naim NAC 62 pre-amp...
Posted: Sun Mar 11, 2012 7:47 pm
Naim NAC 62, serial number 55218 - great condition, comes with box and packaging (from a SNAPS originally). The sleeve could do with a wash with a toothbrush in warm soapy water - Naim finish attracts dust! One small scratch on left hand side (see if you can spot it!) for super critical.
Can be supplied with Naim MM or MC cards for an extra €40. I can also wire link the phono card inputs (RCA, but RCA-phono adaptors will come with it) to give an extra line input if needed.
I extensively modified this over a 2 year period with the following changes;
- Removed balance pot (replaced with 2k6 rc55y's) - I still have the original balance control, which can be blu-tacked in place for appearances sake
- Removed input cap to gain stage, replaced resistor with wire link (this is used to filter noise - necessary when using a HiCap, but not with a better PSU)
- Changed gain cct to NAC 82 spec; R10 & C3 to 10K and 100pF
- Replaced 10uF tantalums with Wima polyesters
- Changed feedback cct to lower gain, using 2k RC55Y's and Evox MMK 22uF's
- Removed all non signal related ccts from power rails (Naim lamp on front panel, and muting relay cct). Note: this means the muting relay is bypassed, so pre should be switched on before power amp!
- Snipped single power feed from 4 pin output socket (intended for use if using a NAP power amp to provide power, done to allow this socket to be used for signal only)
This is best used with dedicated dual rail power supply, and if so can be used as-is with 4 pin output for signal, and 5 pin for power. I just happen to have a suitably over-engineered one that I will list separately - ALW Super regulators set for 25.5v, fronted by a VBE cct, separate centre-tapped transformers per power rail, running full wave rectification through 2 Schottky diodes. Basically about as far as you can take a Naim PSU and keep it external. However, mine is built on a piece of chipboard...I never got around to boxing it up in a case.
It sounds great, but definitely one to be auditioned (and best in your own system) - for me it is about the best I have heard a transistor pre-amp sound. However, I made the mistake of trying a valve pre, and the trade off of lower dynamics but for a more organic sound with better imaging was enough to steer me that way (I now run an early Croft Micro II with increased PSU capacitance and better output caps as the only mods).
I can also revert it back to standard if so desired (though I would at least replace the original tants with some BC128s), or any stage in between. For instance, the tants are what make a big part of the Naim sound, and swapping the Wima's back for tants would make it sound better perhaps if you like the Naim sound :-)
€280.
Thanks, Richard
Can be supplied with Naim MM or MC cards for an extra €40. I can also wire link the phono card inputs (RCA, but RCA-phono adaptors will come with it) to give an extra line input if needed.
I extensively modified this over a 2 year period with the following changes;
- Removed balance pot (replaced with 2k6 rc55y's) - I still have the original balance control, which can be blu-tacked in place for appearances sake
- Removed input cap to gain stage, replaced resistor with wire link (this is used to filter noise - necessary when using a HiCap, but not with a better PSU)
- Changed gain cct to NAC 82 spec; R10 & C3 to 10K and 100pF
- Replaced 10uF tantalums with Wima polyesters
- Changed feedback cct to lower gain, using 2k RC55Y's and Evox MMK 22uF's
- Removed all non signal related ccts from power rails (Naim lamp on front panel, and muting relay cct). Note: this means the muting relay is bypassed, so pre should be switched on before power amp!
- Snipped single power feed from 4 pin output socket (intended for use if using a NAP power amp to provide power, done to allow this socket to be used for signal only)
This is best used with dedicated dual rail power supply, and if so can be used as-is with 4 pin output for signal, and 5 pin for power. I just happen to have a suitably over-engineered one that I will list separately - ALW Super regulators set for 25.5v, fronted by a VBE cct, separate centre-tapped transformers per power rail, running full wave rectification through 2 Schottky diodes. Basically about as far as you can take a Naim PSU and keep it external. However, mine is built on a piece of chipboard...I never got around to boxing it up in a case.
It sounds great, but definitely one to be auditioned (and best in your own system) - for me it is about the best I have heard a transistor pre-amp sound. However, I made the mistake of trying a valve pre, and the trade off of lower dynamics but for a more organic sound with better imaging was enough to steer me that way (I now run an early Croft Micro II with increased PSU capacitance and better output caps as the only mods).
I can also revert it back to standard if so desired (though I would at least replace the original tants with some BC128s), or any stage in between. For instance, the tants are what make a big part of the Naim sound, and swapping the Wima's back for tants would make it sound better perhaps if you like the Naim sound :-)
€280.
Thanks, Richard