Phono Stage Help

[nayr]

I just bought a Project Phono Box II SE.

The impedience settings on the back do not match the manual. The settings on the back have jumpers for: 220pf 150pf 100pf 220ohms 100ohms. The manual lists: 220pf 120pf 220ohms 100ohms 22ohms.

I'm at a loss for what to set it to. My cartridge is a Audio Technica OC9 that recommends 20ohms. The manual says put jumpers on 22ohms and 220ohms and 120pf....

[wkhanna]

is this your manual?

manual

[nayr]

Yes it is - but the values on the phono stage do not match with the manual.

[wkhanna]

I do not know enough about cartridges to know if setting your phono-pre incorrectly may damage it. I would recommend you contact the manufacturer if you bought it on-line, or the shop you purchased it from.

Maybe try the guys over at the AudioAsylum forum, they are a V good group of enthusiasts who are knowledgeable and more than willing to help with such issues.

[Glen B]

I just bought a Project Phono Box II SE.

The impedience settings on the back do not match the manual. The settings on the back have jumpers for: 220pf 150pf 100pf 220ohms 100ohms. The manual lists: 220pf 120pf 220ohms 100ohms 22ohms.

I'm at a loss for what to set it to. My cartridge is a Audio Technica OC9 that recommends 20ohms. The manual says put jumpers on 22ohms and 220ohms and 120pf....

I have owned an OC9 for a number of years. Read your instructions again. The ideal recommended loading is 100 ohms not 20. The 20 ohm figure is the minimum recommended. I have found the OC9 tolerant of various loads so it is not necessary to get it exact -- the recommended loading is only a guide. Load capacitance is of little significance to an MC cartridge. You will not damage the cartridge with different loads; only frequency response is affected. Let your ears ultimately determine what settings sound best to you. Experiment.

[nayr]

I really appreciate the advice! For the 20ohm figure, I was going by a online table I found not the original instructions.

I've just tried playing around with it. Adjusting the capacitance does nothing to my ears. 68ohms and 100ohms sound similar, with 68 ohms having slightly emphisized bass. I haven't decided which I like best.

Either way, the awful hiss of my pre-amp's phono stage is gone! it sounds miles better

[Glen B]

I really appreciate the advice! For the 20ohm figure, I was going by a online table I found not the original instructions.

I've just tried playing around with it. Adjusting the capacitance does nothing to my ears. 68ohms and 100ohms sound similar, with 68 ohms having slightly emphisized bass. I haven't decided which I like best.

Either way, the awful hiss of my pre-amp's phono stage is gone! it sounds miles better

PM me and I will send you a PDF of the setup instuctions.