1. Win a Broadcaster or one of 3 Teles! The annual Supporting Member Giveaway is on. To enter Click Here. To see all the prizes and full details Click Here. To view the thread about the giveaway Click Here.

swapping preamp tubes

Discussion in 'Glowing Bottle Tube Amp Forum' started by popthree, Jan 25, 2021.

  1. popthree

    popthree Poster Extraordinaire

    Posts:
    6,941
    Joined:
    Jan 25, 2005
    Location:
    a hawk makin lazy circles
    by way of an estate sale i came into a box of old tubes. among the collection i have a handful of varied 12ax7a preamp tubes. 2 of note, an old western germany telefunkin & a holland made amparex.

    my amp is a kalamazoo reverb 12. it uses a pair of el84 power tubes and also has 3 12ax7 preamp tubes. if i were going to swap out one of the preamp tubes, am i correct in thinking i want to swap V1 ?

    should i expect to hear a discernable change in tone by doing this?

    thanks
     
    Geo likes this.
  2. corliss1

    corliss1 Friend of Leo's Platinum Supporter

    Posts:
    4,628
    Joined:
    Sep 13, 2008
    Location:
    Lansing, MI
    Yes, v1, but you could try them all.

    Maybe? Tone is subjective. You may or may not hear something due to the quality of the tube that's in there vs the quality of what you're replacing it with. The thing you hear, may or may not be good.
     
    muscmp, Jakedog and popthree like this.
  3. Oldsmobum

    Oldsmobum Tele-Meister

    Age:
    34
    Posts:
    408
    Joined:
    Aug 15, 2020
    Location:
    SoCal
    I spent over an hour swapping tubes (a mix of old and new) in an amp, and it did make a difference. Definitely more than you would think. I found out that I was not big on JJ 12ax7’s, they made it sound too dark and loose. there was a position (I think it was the phase inverter?) where it worked really well. I did 0 internet research before doing so, I’m pretty sure I was checking for microphonic tubes and I just noticed and took off from there.

    Tubes are one area that I am less skeptical of the cork sniffers.
     
    Jakedog, popthree and Cali Dude like this.
  4. Collin D Plonker

    Collin D Plonker Tele-Afflicted

    Posts:
    1,541
    Joined:
    Jun 2, 2020
    Location:
    Delaware
    I'm not familiar with that amp, but lots of amps have V1 and v2 as gain stages.
     
  5. Cali Dude

    Cali Dude Tele-Afflicted

    Age:
    58
    Posts:
    1,060
    Joined:
    May 20, 2020
    Location:
    California
    What a cool find. Congrats! I think there are significant differences to be heard when swapping preamp tubes. Enjoy the experiment.
     
    popthree likes this.
  6. popthree

    popthree Poster Extraordinaire

    Posts:
    6,941
    Joined:
    Jan 25, 2005
    Location:
    a hawk makin lazy circles
    Cali Dude likes this.
  7. corliss1

    corliss1 Friend of Leo's Platinum Supporter

    Posts:
    4,628
    Joined:
    Sep 13, 2008
    Location:
    Lansing, MI
    Yup - that's the real prices. It's worth noting that these are completely in NOS condition, and have been tested by a very well-respected tube dealer, so that helps with the numbers a bit.
     
    popthree and Cali Dude like this.
  8. strat a various

    strat a various Friend of Leo's

    Posts:
    4,116
    Joined:
    May 9, 2008
    Location:
    Texas
    No kidding, that's how I like my JJ tubes and my women.
     
  9. popthree

    popthree Poster Extraordinaire

    Posts:
    6,941
    Joined:
    Jan 25, 2005
    Location:
    a hawk makin lazy circles
    that's wild. so far every one of these tubes i have put in my amp, works fine. there is an old RCA 7025 that i really like a lot. thanks
     
  10. archetype

    archetype Fiend of Leo's

    Posts:
    5,471
    Joined:
    Jun 4, 2005
    Location:
    Williamsville NY
    I wouldn't go by Tube Depot for normal selling prices. Those guys have their customers who buy at those prices, but TD has the highest prices I've seen amoung the good tube vendors. Look at audiotubes.com and kcanostubes.com for mainstream NOS pricing.
     
    popthree likes this.
  11. Wally

    Wally Telefied Ad Free Member

    Posts:
    38,245
    Joined:
    Mar 17, 2003
    Location:
    Lubbock, TX
    that $350 sounds expensive until you get into some serious audiophile stuff.....like a pair of Telefunken 12AX7s with four matching triodes for....$1695! Yes, if you search you will find such prices. But then, if you need 4 matching triodes for a stereo amp you gotta have matching triodes. And how many NOS Telefunken tubes are available for analysis to find four matching triodes????
     
    popthree and muscmp like this.
IMPORTANT: Treat everyone here with respect, no matter how difficult!
No sex, drug, political, religion or hate discussion permitted here.