Soundcraftsmen PM840 input inpedance?

Options
00p225
00p225 Posts: 100
edited August 2004 in 2 Channel Audio
Does anyone have an owners manual or specs on the PM840? I need to lower the output level on my Foreplay preamp to get rid the hair trigger volume control and knowing the input impedance of the PM840 would help in matching the two. Thanks.

Zane
Main System
Pre - Homebrew 12au7 tube preamp
Amp - Eico HF-87 with EHEL34's
Source - Modded Toshiba 3950
Interconnects - DIY Belden
Speakers - Polk SDA-1C

Basement System
Pre - McIntosh C-28
Amp - McIntosh MC2100
Source - Modded Toshiba 3960
Tape - Pioneer RT-707
Turntable - Thorens TD150MKII with Denon DL-160
Speakers - Pioneer HPM-100
Post edited by 00p225 on
· Share on FacebookShare on Twitter

Comments

  • madmax
    madmax Posts: 12,434
    edited August 2004
    Options
    I don't know what the advertised input impedance is but on the schematic they show a 47K resistor going from + input to ground. I would say this determines a 47K input impedance.
    madmax
    Vinyl, the final frontier...

    Avantgarde horns, 300b tubes, thats the kinda crap I want... :D
    · Share on FacebookShare on Twitter
  • 00p225
    00p225 Posts: 100
    edited August 2004
    Options
    Ok, rather than lowering the output of the Foreplay which may cause probs running long interconnects in the future, I just went to radioshack and bought a pair of male and female shielded rca jacks and soldered a 22K resistor in a series on the + side. They are only an inch long. Just plugged them into the inputs of the amp, then plug the interconnects in. Not as handy as variable gain on the amp, but 10 seconds to remove if running a different pre. The Foreplay's volume is now between 8 and 9 o'clock for normal listening. Good deal.
    Main System
    Pre - Homebrew 12au7 tube preamp
    Amp - Eico HF-87 with EHEL34's
    Source - Modded Toshiba 3950
    Interconnects - DIY Belden
    Speakers - Polk SDA-1C

    Basement System
    Pre - McIntosh C-28
    Amp - McIntosh MC2100
    Source - Modded Toshiba 3960
    Tape - Pioneer RT-707
    Turntable - Thorens TD150MKII with Denon DL-160
    Speakers - Pioneer HPM-100
    · Share on FacebookShare on Twitter
  • madmax
    madmax Posts: 12,434
    edited August 2004
    Options
    I need to do that or maybe a step down transformer to cut the output of my CD player to my preamp. It is way too loud and my TT is too low. Just makes for too much confusion while listening.
    madmax
    Vinyl, the final frontier...

    Avantgarde horns, 300b tubes, thats the kinda crap I want... :D
    · Share on FacebookShare on Twitter