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New tube for the Super Redhead

Discussion in 'Amps and Cabs [BG]' started by DougP, Jul 18, 2004.


  1. DougP

    DougP

    Sep 4, 2001
    I am looking to put a new tube into the Redhead (ha! that sounds so wrong). after doing a search and reading for about 2 hours, i see that some users have changed their tubes, but nothing about the sound was included in the threads.

    i like the hi-fi sound that i get from the Redhead, but when i run my SansAmp DI with about 50% blend into it i get my perfect sound. Before i go talking to tube dealers, i would like to get some info. What kinds of tubes would get me a sound like the SansAmp sound? Also, any brands or models that i should stay away from?

    Thanks all
     
  2. nonsqtr

    nonsqtr The emperor has no clothes!

    Aug 29, 2003
    Burbank CA USA
    Stay away from anything Chinese. The new Groove Tubes 12ax7M is a pretty good tube (expensive though, mine cost about 25 bucks). JJ's are "not bad". If you're willing to shell out a little extra bread for NOS, you can't go wrong with an RCA. It's hard to say, preamp tubes can be pretty subjective. I had to experiment for a while before I found tubes that were pleasing to my ear. eBay is good, you can experiment with used ones for relatively cheap, until you find the sound you want, then go out and buy a new one of the selected specimen.
     
  3. Its funny that you say to stay away from Chinese tubes but in the same breath praise the new Groove Tube 12AX7M which is a Chinese tube. Some Chinese tubes actually don't sound bad but I will not buy them because they were probably made with slave labour. Any way I would probably go with USA NOS because of a smoother sound and longer life than current tubes being made. But that change in tone is going to be pretty subtle especially in single pre tube solid state amps. Also for $25 you can usually find used Mullards that test as new on Ebay all the time if you are patient.
     
  4. nonsqtr

    nonsqtr The emperor has no clothes!

    Aug 29, 2003
    Burbank CA USA
    Yeah, point well taken. The difference is, that GT actually has quality assurance, which most Chinese "manufacturers" do not. Also the GT tube is made with vintage American and British tooling, which is a whole lot better than any tooling made in China. Granted the Chinese have gotten "a little" better in terms of the tube quality, but really it's only a late and inadequate response to market conditions. The new "9th generation" tubes are supposed to be reasonably good. The thing is, based on my experience so far, I'm in a "prove it" frame of mind, and I'm not willing to be on the bleeding edge of that particular equation. I've had Chinese tubes actually blow up in my amps. One of them even took a power transformer with it. No thanks. I'll err on the side of safety. :)
     
  5. DougP

    DougP

    Sep 4, 2001
    anyone know what comes standard in the Super Redheads? i havent cracked it open yet. Also, where is a good place that i can get these from? i found the tubedepot.com site.

    thanks
     
  6. IvanMike

    IvanMike Player Characters fear me... Staff Member Supporting Member

    Nov 10, 2002
    Middletown CT, USA
    i belive that the redhead comes with a 12ax7 from groove tubes and that it is in fact a chinese tube. i've swaped them out for sovteks which are a little darker sounding
    personally, i like the combination of an swr amp with a sans amp pedal in front of it as the sans amp adds a little heft to the sterile swr sound
    that said, there's nothing better than trying a bunch of different tubes in rapid succession (with another musician for a 2nd opinion)
     
  7. tornadobass

    tornadobass Supporting Member

    Nov 20, 2000
    Iowa City, Iowa
    Endorsing Artist: Black Diamond & SuperSensitive strings
    I have both an SWR SM-400 and and SM-400S. With each amp, I've listened to a variety of tubes and with each, I've settled on a JJ/Tesla ECC83. Full, round sound, yet clear.

    The SM-400 came with a GT 12AX7, SWR's stock tube, I believe. I thought it was good until I tried the JJ, which had increased clarity. I think the DI sounded better with that tube, too, since that's the main thing that shapes the direct sound from an SWR amp.

    Dan
     
  8. DougP

    DougP

    Sep 4, 2001
    I have never changed a preamp tube myself. is it pretty much plug and play? i remember reading that there is no biasing involved with preamp tubes.

    sounds like ECC83 might be what i am looking for. is this a direct replacement? not converter/adapters or anything?

    i will get a few tubes and check them all out.

    any words of wisdom on where to get some of these?
     
  9. tornadobass

    tornadobass Supporting Member

    Nov 20, 2000
    Iowa City, Iowa
    Endorsing Artist: Black Diamond & SuperSensitive strings
    It's an easy job...just pull out the old tube, carefully push in the new one. Check first that all the pins on the tube are straight and that you've aligned the pins with their holes correctly...the tube can only go in one way...look for the gap between pins and match to the socket. No biasing for preamp tubes...correct.

    The ECC83 is a direct replacement, one of many 12AX7 variations.

    The biggest challenge on changing a preamp tube, at least on the SM-400, is all the screws you have to remove. There are about a dozen on the top, plus 4 more on the face. Because the chassis is aluminum, be careful not to tighten the screws too much or they'll strip out the holes.
     
  10. DougP

    DougP

    Sep 4, 2001
    very cool, thanks for all the help.

    perhaps after i go through a few, i'll post up some opinions and reviews.
     
  11. Bongolation

    Bongolation

    Nov 9, 2001
    California
    No Bogus Endorsements
    So is the unmarked stock tube that comes in the amp.
     
  12. Bongolation

    Bongolation

    Nov 9, 2001
    California
    No Bogus Endorsements
    Here's the skinny:

    Yes, any 12AX7* or ECC83 variant will work, more or less.

    Just remove the old one and put the new one in. SWRs seem to be a bear to disassemble for this sort of thing, though, so be careful and steer clear of those big electrolytic capacitors.

    If you get a JJ, be sure to get the ECC83S, not the ECC83, which is an older, inferior tube. JJs seem to be losing a lot of their reputation lately for some reason.

    What you want to avoid is long-plate tubes as they don't handle vibration well over the long haul. Many go bad and/or microphonic in a very short time.

    The stock tube is a very short-plate design, as it should be in this amp.

    A Mullard may also suffer from microphonics in this application, as I have heard numerous complaints to that effect. I use vintage Mullard and Dutch Amperexes (which are essentially the same tube) in most of my gear, but not in my Black Beauty, which still has the stock tube.

    The best bass preamp tube in terms of sound is almost certainly the Sovtek 12AX7LPS, but it is extremely vibration sensitive, as it is a longplate. I use it in heads, but not in combos.

    Honestly, I don't think you are going to see a huge difference in sound with a different tube in this amp due to the way the tube is used in the circuit.
     
  13. DougP

    DougP

    Sep 4, 2001
    So many choices...

    Thanks for the info Bongolation. Pardon my ignorance on the matter, but how is the tube wired in?

    i am not looking a huge tone change, i just want something a little bit softer with less of the hi-fi sound.

    and...i figure for about $30 i can get three different tubes just for experimenting. seems like one of the cheaper experiments that can occur in the bass world.
     
  14. Bongolation

    Bongolation

    Nov 9, 2001
    California
    No Bogus Endorsements
    The tube is merely plugged into a socket. Mine was very tight, so if yours is as well be careful and work it out gradually while supporting the circuit board. You don't want to break anything.
     
  15. DougP

    DougP

    Sep 4, 2001
    sorry, what i meant to ask was: how is the tube used in the circuit that it wouldnt make much of a difference by changing the tubes?

    thanks for checkin up on me though
     
  16. Dr. PhunkyPants

    Dr. PhunkyPants Guest

    Aug 11, 2002
    USA
    The "ECC83" is the European descriptor applied to the US "12Ax7". You'll see the two used interchangeably.