Bias for Ipod Input

[Glowin Plates]

Hi Everyone

I am working on a old stereo amp that I pulled from a phono console.
It has 6AU6 pre amp tubes that feed 6AQ5A for each channel.
I would like to play my ipod through this amp but I feel it is biased incorrectly.
(For a ceramic cartridge input).
Right now it has about 1KΩ resistors on the cathodes and 270KΩ on the plates
at about 100V.
With the Ipod full, I get negligible volume until the amp is about 3/4 of the way up.
Sorry I don't have the tools to include a schematic.
I'm a newbie trying to puzzle though this any help would be appreciated.

Thanks
Rich

 

[mastodon]

If you hook the amp up to a regular line level device (i.e. the line output of a cd player), do you get the volume you want?

Right now it has about 1KΩ resistors on the cathodes and 270KΩ on the plates
at about 100V.

Is that 100V at the plates of the AU, or at the top of the 270k resistor? And is the tube used in pentode or triode mode (i.e. where is g2/pin 6 tied to)?

What sort of testing equipment do you have? Sine wave generator, oscilloscope? Those things tend to make life a lot easier in this line of work.

Also, a schematic will probably still be needed; is there no way for you to trace it and post it here? If you don't have a scanner or camera, use one of the many freeware schematic capturing tools that you can download (e.g. LTSpice if you run Windows, or Oregano if you're a tuxman; both can be used for spice modelling as well!)

 

[andrew_k]

From your reference to turning the iPod up it sounds like you're using the headphone output rather than the line out.

You need something like this to get line out IPOD IPAD IPHONE Audio Line Out & USB Dock Cable EA215 (eBay item 200535944402 end time 23-Feb-11 14:10:19 AEDST) : Phones

 

[Glowin Plates]

Thanks for the responses.
I didn't realize you could get a line level out of the Ipod.
The 100V was at the top of the resistor.
Pin 6 has a 470KΩ resistor to ground and a 680KΩ that goes to same B+point as plate resistor.