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Thread: Leslie 925 speaker imedance

  1. #1


    Leslie 925 speaker imedance

    The Leslie 925 i just got came with an EV SRO 15 speaker which is 8ohm. Yet when i look at the service manual it specifies that this should have had a 4ohm speaker in it for the bass and a 16ohm for the horn. Seems odd someone would have put an 8ohm in there...
    Being a solid state amp, is it critical? I know most stereo amps can handle various load speakers... I imagine it wouldnt be as loud at 8ohm as 4ohm.

  2. #2


    Spoke to a EE friend tonight who said it wont harm the amp but wont be as loud.

  3. #3
    Senior Member jimmywilliams's Avatar
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    Quote Originally Posted by jeffshammond View Post
    Spoke to a EE friend tonight who said it wont harm the amp but wont be as loud.
    True ... an 8-ohm load attached to a SS amp designed for a 4-ohm load will not damage the output transistors but will cut the volume. With SS amps you have to be careful about dropping the load too low however. Doing so can short out the output transistors.
    Where the speaker impedance difference you mention will matter is if there is a passive crossover on that channel - because the values of the inductors/capacitors are designed to work with a certain load. If the load is changed then the cutoff frequency will change.
    Jimmy Williams
    Hobbyist (organist/technician)
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  4. #4


    hmmm so what's interesting is that this setup with a woofer only wont be much louder than my 125 then.. The 125 is a tube amp rated at 20w into 8ohm... This 925 is rated at 50w woofer amp, 50w tweeter amp, 40watt reverb amp.. The woofer amp is 50w into 4 ohms which is 25w into 8ohms... My past experience with amps tells me that a 20w tube amp sounds much louder/better than a 25w solid state amp would.. Think i will start looking for a 4 ohm speaker for it.. Of course if you hooked up a horn too, the ss one would be much louder since it has its own amp for the horn, where the 125 would be using some of its 20w to power the horn....

  5. #5
    Senior Member jdoc's Avatar
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    50w Leslie ss amp can make your ears bleed, I am temporarily using a 130 Leslie 30w amp in my 860 at 1/4 the Leslie's designed rated power and with the preamp it is awesome, maybe it is the strength of the signal in , try the treble amp, sure you are not on the reverb amp?
    Last edited by jdoc; 08-26-2012 at 11:26 PM.
    1956 M3, (2)51 Leslie under upgrade, 860 (130 powered)Leslie with Preamp, S08 Yamaha and two K2000S, Young Chang spinet, Roland VR700 clone and Korg SV-1 73
    Looking for that mythical cheap or free A, BV, CV, C2, C3 or A100 but wouldn't say no to a free B3

  6. #6


    hmmm maybe this isnt working to its full potential or maybe its cause it has the 8ohm speaker which makes it only 25w

  7. #7
    Senior Member jdoc's Avatar
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    have you adjusted the trim/gain pot?, and how hot a signal are you putting in, I am using a combo preamp to drive mine from an M3 with line out
    Quote Originally Posted by jeffshammond View Post
    hmmm maybe this isnt working to its full potential or maybe its cause it has the 8ohm speaker which makes it only 25w
    I have never noticed a significant volume drop by a minor change in ohms, especially solid state amps.............and boy have Itinkered over the years.....sometimes successfully

    - - - Updated - - -

    updated for type O's and additional comments

    - - - Updated - - -

    updated for type O's and additional comments
    1956 M3, (2)51 Leslie under upgrade, 860 (130 powered)Leslie with Preamp, S08 Yamaha and two K2000S, Young Chang spinet, Roland VR700 clone and Korg SV-1 73
    Looking for that mythical cheap or free A, BV, CV, C2, C3 or A100 but wouldn't say no to a free B3

  8. #8


    I have the trim pots on the 925 all the way up.. I had the pedal on the m3 floored. It's loud, just not really any louder than my 125 which makes sense to me.. an 8ohm speaker on that 50w amp should cut it to 25w.. 20w tube amp will typically sound louder i think than a 25w solid state. It is possible this thing isnt working right too. You have to remember i bought the entire top/bottom for less than $100!

  9. #9
    Senior Member jdoc's Avatar
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    Quote Originally Posted by jeffshammond View Post
    I have the trim pots on the 925 all the way up.. I had the pedal on the m3 floored. It's loud, just not really any louder than my 125 which makes sense to me.. an 8ohm speaker on that 50w amp should cut it to 25w.. 20w tube amp will typically sound louder i think than a 25w solid state. It is possible this thing isnt working right too. You have to remember i bought the entire top/bottom for less than $100!
    yes, too many variables IN THE SIGNAL DEPARTMENT, JUST REPORTING ON MY SETUP TO COMPARE, maybe the 130 amp has been swapped for a 50? but yes, a great deal, I turned down a L100 Porta B with a 915 and preamp a while back for 500..........DOOh
    stupid caps lock, stupid arthritis.......not yelling
    1956 M3, (2)51 Leslie under upgrade, 860 (130 powered)Leslie with Preamp, S08 Yamaha and two K2000S, Young Chang spinet, Roland VR700 clone and Korg SV-1 73
    Looking for that mythical cheap or free A, BV, CV, C2, C3 or A100 but wouldn't say no to a free B3

  10. #10


    The 925 is rated at 140w.. But it is split in 3.. 50w bass, 50w horn, 40w aux.
    Have not tried the other amps, just the bass. Plus i have not bypassed the cross over so that could be part of the difference too. My 125 is getting all the signal and my 925 is just getting bass signal...

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