Interesting. The SP-3A1 had a tone defeat switch for the tone controls. It does not however have a tube rectifier in it. I have an SP-3C preamp. The preamp uses a newly designed ARC FET regulated power supply which IMO is vastly superior to the old power supply with it's lousy twist lock lytic filter caps and it's string of zener diode regulators. They can easily go out of voltage tolerance and the FET supply is eminently quieter. I recommend the upgrade without reservation.
Robin or Rodin Mod of an ARC SP3-A1???
Topic: Robin or Rodin Mod of an ARC SP3-A1???
I just purchased a modded SP3A-1 on ebay, item number 310503686812. On the transformer are the words "Robin or Rodin Full Mod". It has a completely different tube power supply with a tube rectifier 6BE3. Also, the number 1 main out does not have contour or bass/treble connected, only balance. This line output sounds like a SP8?? clean, open, transparent...especially on the phono stage where it appears the circuit has been updated. The number 2 main/line out has all the tone controls connected and sounds like a vintage SP3! deeper soundstage and rich/warm. How did this guy do this? It's like having two different sounding preamps in one. Has anyone ever heard of doing this to a SP3? Also, the problem in one channel appears to have been from a Beldon wire touching a resistor on the phono board...can been seen in one of the pics. I may have lucked out on this one..after getting the wires not to touch it has played perfectly for several hours.... Any comments would be welcome. Thank You.
I just purchased a modded SP3A-1 on ebay, item number 310503686812. On the transformer are the words "Robin or Rodin Full Mod". It has a completely different tube power supply with a tube rectifier 6BE3. Also, the number 1 main out does not have contour or bass/treble connected, only balance. This line output sounds like a SP8?? clean, open, transparent...especially on the phono stage where it appears the circuit has been updated. The number 2 main/line out has all the tone controls connected and sounds like a vintage SP3! deeper soundstage and rich/warm. How did this guy do this? It's like having two different sounding preamps in one. Has anyone ever heard of doing this to a SP3? Also, the problem in one channel appears to have been from a Beldon wire touching a resistor on the phono board...can been seen in one of the pics. I may have lucked out on this one..after getting the wires not to touch it has played perfectly for several hours.... Any comments would be welcome. Thank You.
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- 5 posts total
- 5 posts total