Does reverb on restored 1972 Twin Reverb sound correct?

Discussion in 'Shock Brother's DIY Amps' started by itsGiusto, May 7, 2021.

  1. itsGiusto

    itsGiusto Tele-Holic

    Posts:
    763
    Joined:
    Dec 31, 2017
    Location:
    Massachusetts
    Hey, I've recently completed restoring, modding, and blackfacing my 1972 Twin Reverb that I bought recently. It mostly went well.

    However, in listening to the reverb sound, I'm not sure if it sounds correct. This is complicated by the fact that I'm not 100% sure how it's supposed to sound. So I'd like feedback from some people who are more familiar with what a vintage TR is supposed to sound like.

    To me, I think maybe it could be correct, but the reverb sounds a little fluttery, and maybe less smooth than I thought it would. Maybe this is what is meant by a "drippy" reverb, not sure. Or maybe there's some problem with the amp that I need to fix.

    In the clips, I'm playing on the vibrato channel. The tremolo is turned off, and the reverb is turned on. I'm playing on the neck pickup of a strat, with the tone full up and the volume on 7. Amp dials are set to:

    Volume: 3
    Treble: 5
    Middle: 8
    Bass: 2.5
    Reverb: 6

    I turned up the reverb really high and am trying to play some things with short bursts, so you can hear the reverb trail and how it sounds. Sorry for the poor-quality recording, it's just a phone camera mic!


     
    Last edited: May 7, 2021
  2. corliss1

    corliss1 Friend of Leo's Platinum Supporter

    Posts:
    4,865
    Joined:
    Sep 13, 2008
    Location:
    Lansing, MI
    I always struggle without being in the room and hearing it for real, but that sounds like amp to me :D
     
    itsGiusto likes this.
  3. itsGiusto

    itsGiusto Tele-Holic

    Posts:
    763
    Joined:
    Dec 31, 2017
    Location:
    Massachusetts
    IDK, I'm really unsure. Like, for example, compare it to this guy's amp sound:


    The reverb in that video sounds a lot smoother to me. Whereas mine sounds kinda spanky, clangy, drippy, maybe, which can be nice, but can be a bit much, since it sounds a little bit like banging trashcans. I think mine sounds a lot more like the standalone reverb unit featured in this video:


    Maybe I need to change up my amp a little bit. Maybe I could install a dwell knob by changing the 1M grid leak resistor from the reverb-driver tube into a pot, like Robrob says here. Maybe that'd allow more flexibility in this regard?
     
    VonBonfire likes this.
  4. Wally

    Wally Telefied Ad Free Member

    Posts:
    39,359
    Joined:
    Mar 17, 2003
    Location:
    Lubbock, TX
    It sounds odd to my ear, but I cannot say whether the problem is in the amp or in the room/recording situation. I would suggest closer ‘micing’ and getting that amp head out of the way.
     
    itsGiusto likes this.
  5. Boreas

    Boreas Friend of Leo's Silver Supporter

    Age:
    66
    Posts:
    4,021
    Joined:
    Nov 3, 2019
    Location:
    Adirondack Coast, NY
    Was the tank ever replaced? If so, with what? Tanks are a living, breathing organism. Much difference between manufacturers and models. And a tank can grow old - and not always in a good way.
     
  6. VonBonfire

    VonBonfire Tele-Meister

    Age:
    100
    Posts:
    275
    Joined:
    Apr 21, 2021
    Location:
    Texas
    I would try a couple different preamp tubes for your reverb driver position first. Also, if yours sounds like a standalone unit I'm not sure what's to complain about. It's a great sounding unit. Very similar to but more tweakable than the built in unit is. Best on your search for the tone you seek.
     
  7. JohnFender

    JohnFender TDPRI Member

    Age:
    35
    Posts:
    17
    Joined:
    Dec 6, 2019
    Location:
    Canada
    I have 3 twin reverbs and its hard to tell for sure but i think it sounds right , you can swap the ax7 for an at7 tube for less harshness in the reverb but me i always have my reverb set at 3 , and if i want alot of reverb i put it at 4, anything over that is too much
     
  8. itsGiusto

    itsGiusto Tele-Holic

    Posts:
    763
    Joined:
    Dec 31, 2017
    Location:
    Massachusetts
    Hah, yeah, I don't know actually. I bought this amp in December, and the cab got damaged in shipping, so I used the insurance money to buy a new cab and transplant everything, including the old tank. There was no indication either way when I bought it that the tank was the original or replaced.

    Haha, yeah, I know those standalone units are highly sought-after! But mine does lack the extra dwell and tone controls. Maybe I'll add a dwell control, dunno. Like I said, mine sounds interesting, and maybe even good, just not what I expected, which was something smoother and less clangy.

    Cool, thanks. I am currently running an 12at7. I could try some different tubes in there, though.
     
    Boreas and VonBonfire like this.
  9. Wally

    Wally Telefied Ad Free Member

    Posts:
    39,359
    Joined:
    Mar 17, 2003
    Location:
    Lubbock, TX
    What are the numbers on the tank? From here, the reverb echoes are very quick and shallow...but that is here.
     
    TwoBear and Boreas like this.
  10. Boreas

    Boreas Friend of Leo's Silver Supporter

    Age:
    66
    Posts:
    4,021
    Joined:
    Nov 3, 2019
    Location:
    Adirondack Coast, NY
    Yes - when investigating a reverb tone, start from the source of the tone. Determine if it is an original tank or a replacement. Tanks are pretty cheap and easy to swap compared to digging into the guts of the amp. Most people seem to think the new MOD tanks are closer to the vintage sound of the original Accutronics. But your ears may say otherwise.

    Also, does it still have a bag/cover on it? Even this and the way it is mounted can subtly effect tone.
     
  11. Wally

    Wally Telefied Ad Free Member

    Posts:
    39,359
    Joined:
    Mar 17, 2003
    Location:
    Lubbock, TX
    The reverb driver tube, V3 in that TR, should be a 12AT7. If the reverb is stronger than one would like, a 12AU7 will decrease that drive signal. V4 has one triode that is the reverb return and one triode that is a gain stage. I don’t go away from a 12AX7 there because the AX is need to make up for the gain loss that occurs 8n that channel due to the two effect circuits.
     
  12. Telenator

    Telenator Doctor of Teleocity Vendor Member

    Posts:
    14,109
    Joined:
    Sep 19, 2005
    Location:
    Vermont
    It sounds to me like the 12ax7 reverb tube is a bit microphonic. Otherwise, it sounds great.
     
  13. itsGiusto

    itsGiusto Tele-Holic

    Posts:
    763
    Joined:
    Dec 31, 2017
    Location:
    Massachusetts
    Cool, yeah, I'll definitely look into this, but I can't right now. The amp is serving its secondary purpose, which is a very comfy bed for my cat. And then, in about 15 minutes I'm going out of the house for a few hours. So I'll post tonight what my findings are.

    Yep, it's got the bag, and the cardboard insert as well.

    Yeah, I could try that. But I also love modding my amps, so maybe a dwell control would be really useful, and then I could vary the signal strength sent to the tank however I want, without having to change the tube. I just don't know where I'd mount the dwell knob. Drill a hole on the back panel?

    The drive tube or the recovery tube? For the drive tube I'm running a 12AT7, and could definitely be microphonic, it looks really old!
     
  14. Boreas

    Boreas Friend of Leo's Silver Supporter

    Age:
    66
    Posts:
    4,021
    Joined:
    Nov 3, 2019
    Location:
    Adirondack Coast, NY
    itsGiusto likes this.
  15. kafka

    kafka Tele-Afflicted

    Posts:
    1,838
    Joined:
    Oct 18, 2013
    Location:
    Potomac, MD
    That sounds totally wrong, like it's the wrong tank. Sometimes they get replaced with the wrong model. IIRC I changed one on one of my amps once, because I didn't like the factory tank. StewMac says 4AB3C1B is the standard Twin Reverb tank.

    https://www.stewmac.com/electronics...-tanks-and-parts/accutronics-reverb-tank.html
     
  16. Matt Sarad

    Matt Sarad Tele-Afflicted

    Posts:
    1,192
    Joined:
    Apr 29, 2003
    Location:
    Buckers Field!
    My Deluxe Reverb has a Mojotone tank. Sounds awful. I get better luck with a Boss'63 Fender pedal.
     
  17. Telenator

    Telenator Doctor of Teleocity Vendor Member

    Posts:
    14,109
    Joined:
    Sep 19, 2005
    Location:
    Vermont
    Just turn the amp on, give it a little volume, and tap the tubes with a pencil. The microphonic tube will make itself known quite readily.
     
    TwoBear likes this.
  18. Wally

    Wally Telefied Ad Free Member

    Posts:
    39,359
    Joined:
    Mar 17, 2003
    Location:
    Lubbock, TX
    Mojotone does not build tanks. If one likes or doesn’t like a reverb tank, a speaker, or tubes that are rebranded; one would do well to know tube, speaker, or tank has been rebranded so as to be able to either replicate or avoid a situation.
     
    SnidelyWhiplash, corliss1 and Boreas like this.
  19. schmee

    schmee Doctor of Teleocity Ad Free Member

    Posts:
    15,352
    Joined:
    Jun 2, 2003
    Location:
    northwest
    Sounds like most Fender tube amp reverb to me. I thought I heard a microphonic tube in there once or twice.
    At 7 it ought to be pretty big reverb going on.
     
  20. Matt Sarad

    Matt Sarad Tele-Afflicted

    Posts:
    1,192
    Joined:
    Apr 29, 2003
    Location:
    Buckers Field!
    https://www.mojotone.com/amp-parts/Mojotone-Reverb-Tanks

    When I bought the amp I was told it was a Mojotone tank.
     
    Wally likes this.
IMPORTANT: Treat everyone here with respect, no matter how difficult!
No sex, drug, political, religion or hate discussion permitted here.