stax amp as a preamp

Discussion in 'DIY (Do-It-Yourself) Discussions' started by mllm1, Apr 28, 2008.
  1. mllm1
    Hello, Is it possible to use an Stax amp like the SRM-007t (tubes) or SRM-717 (solid-state) as a preamp? (line-level I guess, not as a phono preamp, unless that is possible too). Would it be a good preamp? How could it be done, and would it be easy to do? I guess at least a special cable to conect to the headphone connector would have to be made. Any help in that area would be greatly appreciated, since I have no preamp and maybe I would like to experiment with a tubed preamp.
    Thank you very much,
  2. d-cee
    they don't have pre-amp outputs

    they have multiple inputs but the only outputs they have are for electrostatic phones

    don't know if it could be modded to do so but i don't think electrostatic circuitry would pre-amp into balanced/unbalanced line levels
  3. ericj
    No, not in the slightest.

    Though Stax did make a preamp with a normal-bias earspeaker socket on it once.
  4. spritzer
    You do realize that there are about 400v RMS at the Stax socket when a power amp is overloaded by 10v? Electrostatics need a lot of voltage and it will burn up any poweramp. That being said it's possible to use transformers to step down the voltage at the output but that will cost about 200$ and probably sounds like crap. Another way would be to install a switch after the signal wire leaves the pot inside the amp so you can switch between the amp and an external set of RCA's. A much better way is a 100$ passive attenuator or finding a Stax SRM-T1W which has a passive preamp built in.

    Phone preamps are very different beasts yet there were some old Stax amps with them built in though they are all from the 60's and 70's. I have the SRA-3S and it's a nice little amp but no preout though that can be installed like I said earlier. It has tubes but only for the earspeaker output so the RIAA stage is all solid state.
  5. mllm1
    Thank you for all your help. So it seems it can't be done easily, since a high voltage is used for the signal (somehow I thought the signal was kept at usual preamp levels). Well, a pity, since I wanted to re-use a Stax headphone amp I have as a general preamp without spending more in a preamp.
    Regards, mllm1
  6. zzhetanay
    Hello Stax sr-7s is a preamplifier?

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