Aikido Phono Pre.....any good???

[Freecrowder]

Was just wondering if anyone has built the JB phono pre kit that he sells??? How does it sound? Good SNR??

RG

[MarkER]

I have built the Aikido phono stage kit along with the preamp kit and use a common power supply for B+ and a separate DC heater supply for the phono stage. The phono stage is hard wired to the prepamp stage. I really like it. Signal to noise is good and the sound is neutral, extended and detailed. Signal to noise will depend on the power supply which is not part of the kit. I am using a tube rectifier into a CLCRC filter with no exotic parts and Sprague and FT electrolytic capacitors. It has replaced a Bottlehead Seduction phono stage in my primary system and that is a very good phono stage as well. Highly recommended.

[Freecrowder]

Thanks for the response. I've just finished up an Aikido pre using 6sn7's. Didn't know if the JB phono would possibly be too much "Aikido". Very interesting though I was going back and forth between the Seduction and the Aikido phono. Do you prefer one over the other? Does the seduction have enough gain for high output MC. I'm currently using a BPS 2 about 2.5 mv output.
RG

[MarkER]

The Seduction with the C4S gives about 40dB output. The Aikido with 12AX7/12AT7 about 46dB. Then you have to look at your pre which is about 8dB if you are using the 6SN7 Aikido, the watts on your amp and the sensitivity of your speakers.
All those caveats aside, I am using Lundahl step up transformers with a low output moving coil to add gain; the rest of the system are 8 watt Bottlehead Paramount 300B amps running 96dB efficient speakers. I have used high output moving magnets without the step-ups and you can get away with it if there is enough front end power. If I was using a cartridge with 2 mV output, I would probably still use the step ups. This helps with your first question which is don't force the phono/pre to run high gain, this will accentuate any noise.
You can see pictures of my system over at Audio Asylum under inmate MarkER, including the Aikido. I am using the 6CG7 version, essentially the 9 pin version of the one you have.