Sharing phono between two amps?

Discussion in 'General Audio Discussion' started by filmis, Sep 12, 2017.

  1. filmis

    filmis Active Member

    What's the best way to share one phono as an input to two amps?

    1) I could connect one amp to the tape monitor output of the amp to which the phono is connected. But does the signal get RIAA equalized before it gets to the second amp, or do I then have to connect the tape monitor to the phono input of the second amp?

    2) Another option I have it to use an RCA splitter to connect the phono directly to the phono inputs of both amps. Just worried whether this might be "bad" for the signal or either amp.

    Thanks for any input.
  2. mhardy6647

    mhardy6647 AK Subscriber Subscriber

    Assuming there's no on-board preamp/EQ on your record player, I think the tape output option is better, because you'll be dealing with a much more robust line-level signal to "share". And, yes, if you use the phono input of one component and then send the signal "out" of its tape monitor, you'll have a preamplified, equalized signal -- suitable for any AUX, TUNER, TAPE (deck) PLAYBACK or other line level input.

    The signal from a typical moving magnet cartridge, as such, is low level (millivolts) and rather fragile. Adding a switch between the "native" output of a record player and a receiver (or preamp or integrated amplifier) will most likely adversely impact treble response, increase noise/hum and maybe even reduce overall signal level.
  3. filmis

    filmis Active Member

    Thanks! It makes sense that a switch could adversely impact the signal - but what I have is not a switch, it's just a connector that splits one RCA input into two outputs.
  4. mhardy6647

    mhardy6647 AK Subscriber Subscriber

    That (using a pair of Y-connectors) would, I suspect, likely be even worse than a switch in terms of signal degradation.
    This isn't exactly analogous to your situation, but a pro audio company of good repute, called Rane, invested a fair amount of effort into explaining "why not Y?" in the case of line-level signals.
  5. lini

    lini just me...

    Munich, Bavaria
    filmis: ad 2.) A decent signal switch wouldn't be much of a problem. Whereas simple splitting would make the cartridge see half the usual input impedance plus some additional load capacity - this might even work with the one or other high output MC, but in combination with regular MM and MI carts one could expect pretty significantly altered frequency rensponses due to that.

    ad 1.) Think about it: If the phono stages wouldn't come before the tape-outs, connected recorders would need extra switchable phono sections of their own to record both line-level and phono-level signals.

    Greetings from Munich!

    Manfred / lini
  6. mkane

    mkane AK Subscriber Subscriber

    103 miles N. of S.F.
  7. pdm4606

    pdm4606 Super Member

    Las Cruces, NM
    You're going to have to isolate the preamp circuits from each amp to the other amp. That would require you to use a simple selector switch in reverse. The main out of the selector would be the phono in. Then each selector in would be connected as an out to each pre.
  8. Chrisxo55441

    Chrisxo55441 AK Subscriber Subscriber

    Twin Cities Minnesota
  9. jetstream

    jetstream Active Member

    Turntable to phono in on amp1
    From amp 1 rec out to any aux of amp2
    That's it.
    Outta Ammo likes this.
  10. mjw21a

    mjw21a Super Member

    Brisbane, Australia
    I've found the usual Y splitters introduce distortion into the chain though I have had some success with monster branded splitters, and the Beresford TC-7240 line selector is fantastic. Sounds like it's not in the chain which is the highest praise you can give it really. These I placed between the phono stage and amp.

    If it's multiple tables or tonearms I suppose this could work too though I simply run modified SUT's with an inbuilt 3 way input selector, a bypass for MM's and 3x gain levels (10x, 20x and 40x) for MC's which allows me to utilise the one Phono stage with multiple arms.

    Last edited: Sep 13, 2017
  11. twiiii

    twiiii Super Member

    west Texas
    The best way is to use a separate phono pre-amp that brings the signal to line level and then connect to the line inputs on each zone control pre-amp section. Mine has multiple digital and analog out puts. So Just hook it up and go. In my case one digital output for the HT processor, one line out put for the Stereo Pre-amp. I could use the balanced output for the HT processor if I wanted to stay pure analog.

    Using your tape out is a pretty good idea. But the success going to depend on the output design of the phono section of the first unit being able to drive the second unit. Normally the tape loop signal level is below line level of the auxiliary input level. Possibly increasing random noise level on the second unit.
  12. rwartner

    rwartner Super Member

    Scottsdale, AZ
    I connect TapeRec (output) to Aux (input). But my source is DAC from laptop. The source passes directly through first amp to second.
    The volume/tune controls of first amp have no affect on second. I would think your second amp would get phono straight through. It shouldn't hurt anything to try. Turn down all volume controls first. Second amp will get volume level from source - in my case the volume level of DAC.
  13. cademan

    cademan Addicted Member

    YUP! Basic connection. All the other options are available if you want to experiment later on down the line.

    And yes, when in phono mode, it does do the RIAA on the tape outs.

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