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Anyone here ever mod their Twin Reverb?

Discussion in 'Glowing Bottle Tube Amp Forum' started by funkyguitarman, Apr 20, 2021.

  1. funkyguitarman

    funkyguitarman TDPRI Member

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    Background: I've been playing Twin Reverbs consistently now for the better part of 10 years. While I was a musician in the Army, I had access to a number of Reissues that served me well for a variety of uses. I loved the ones at work so much that I ended up buying my first TRRI back in 2012 and have never been without one since. Over the years, I dabbled in other amps at work and in my civilian playing, but always came back to the twin for it's tone and volume. Not surprisingly, the Twin Reverb became "my" sound over the years. One of the TRRI we had at Ft Bliss had a speaker swap done before I arrived, it had Eminence Legends in there. That amp in particular was fantastic. I remember it being more balanced and perhaps more musical as a result of just the speaker swap. The other TRRI during that time included a then new 68 custom which was a fine amp and my own, a Guitar Center special edition TRRI in white tolex with a oxblood grille. My white TRRI was the exact same amp as the standard 65 TRRI, just with different cosmetics. However, I eventually retubed mine and had the shop bias it hotter per my request. I knew even less back then about amps and it seemed like a cool and easy way to lower the headroom so that I could push the amp harder. That white TRRI sounded incredible and it definitely is the one that got away ampwise.

    Currently, I have a TRRI from the early 2000s that I bought off the original owner here in Boston for a good price and excellent condition. I did the typical thing and had it looked at and serviced by an expert tech. After playing TRRI's so much over the years, I have begun to wonder if there is something else out there that I can do to mine. I'm not unsatisfied with my amp and it certainly does what I require out of it. Alternatively, my Marshall stack being a completely different approach just begs to be played and I always feel inspired when I fire it up. At this point, I think swapping speakers would be the easiest and most effective method for accomplishing what I want out of the amp. The idea being that different speakers would liven up the sound some.

    What mods have people done to their TRRI's besides speaker swaps?

    What amps exist in the same territory as the TRRI?

    What types of speakers should I consider for a possible swap?

    Am I just being an insufferable moron who is being incredibly trivial and non productive?









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  2. Lowerleftcoast

    Lowerleftcoast Friend of Leo's

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    Before going down the speaker or amp modding rabbit hole, try different bias settings and different tubes. V1 for the normal channel or V2 for the vibrato channel will be a place to try different tubes. Many of us can hear the difference in 12AX7 tubes. A JJ 12AX7 does not sound the same as a EH 12AX7 for an example. There are many 12AX7 to choose from. Since you have another amp try some of the 12A_7 from the other amp in the twin.
    Try different type tubes like a 12AY7 or 5751 in V1 & V2.

    Sometimes power tubes make a difference, even when they are biased the same. For instance there was a huge difference between the tall bottle Ruby 6L6GCBSTR and the short bottle TAD 6L6WGC in an amp I serviced. It happened the bias measured the same for both sets of tubes. I did not have to reset the bias when swapping between the two brands. The TAD couldn't compare. It was not a small difference. It sounded like two completely different amps.
     
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  3. Wally

    Wally Telefied Ad Free Member

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    Funky guitarman, there are ways to give two different channels there.I leave the Vib channel as is and mod the Normal to have more gains and less midscoop. I rebuild the tone stack. One can do as far as one would like in boosting the mids there. One can also apply the effects to that channel if wanted.
     
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  4. corliss1

    corliss1 Friend of Leo's Platinum Supporter

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    The answer to every "has anyone ever" question is always "yes"
     
  5. Blue Bill

    Blue Bill Poster Extraordinaire Ad Free Member

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    Silly question. People here will mod anything, myself included. The only reason not to try some mods is the thought that an un-molested TR has a much higher re-sale value than one with a non-factory element. If you are not worried about future market value, go for it. Take a look at Rob Robinette's website, it's packed with ideas:

    https://robrobinette.com/

    My 2 cents, FWIW: Over the years, I've tried many and various mods to TRs ad DRs, some mild, some wild. Every time, I eventually return them to stock. I've never found one that was much of an improvement. Even things like adjustable negative feedback, that sounds like a good idea, for me, I just find the setting I like and never think about it again. Have fun!
     
    Last edited: Apr 21, 2021
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  6. VonBonfire

    VonBonfire Tele-Meister

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    Modify one of the most legendary musical instrument amps of all time? You could buy a dumble style amp, basically a modded Twin circuit to a greater or lesser degree depending on the maker. I don't consider it an improvement, at least for the stuff I play. Other guys love them but I like cleans and edge of breakup and so am satisfied with factory Twin blackface tone straight in with the guitar, no pedals.

    I have two twins, '69 I traded a reissue Plexi for and a '72 I got for cheap. Had both gone through and blackfaced and they have proven very reliable over hundreds of shows now.

    I've tried a couple preamp tube substitutions including the V1 tube removal trick. None of that was an improvement. I do highly recommend using a JJ ECC803S in the V2 position if you plug into the vibrato channel or V1 position if you plug into normal channel. A very sensitive, clean, hi-fi sounding tube. About 25 bucks a pop but a cut above a standard JJ ecc83

    As for speakers, JBL D120/K120 all the way. I have some english celestions in one of mine that previous owner had put in there and they have been very tough and serviceable as well as decent sounding but nothing touches those JBL's. I like loud and clean and they deliver that big time. Very efficient speaker if you can get away with that sound level. However they will blow if driven real hard over the course of four to six months of regular gigging, depending on the quality of the recone work that was done, as all JBL D/K are basically using a JBL E series recone kit as D and K kits are long gone.

    VonBonfire
     
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  7. BobbyZ

    BobbyZ Doctor of Teleocity

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    Tried all the common mods on a SF TR years ago. Mostly the same common stuff a lot of "gurus" repeat online now, I was likely pulling it out of a Gerald Weber book then.
    In the end is was pretty much back to stock with some BF mods and a PT out of a BF Showman. I did not revoice the normal channel, probably should try that sometime.
    Just like what they do and still have a BF and SFTR.
    Less loud speakers I like.

    Don't know if you do pedals? I haven't in years but I'm watching a video the other day and a guys got Fuzz Face. He's going from really nice clean to dirty with the volume knob at like low volume.
    Never cared about the Fuzz Face cause Hendricks used one. I ain't into that distortion like he did but like his cleans. Guess he used a FF on cleans? Not a pedal gut so I missed that.
    I ordered one. We'll see.
    Reminds me I need to call my buddy at the Music store and see if he remembered to order it.
     
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  8. Ringo

    Ringo Poster Extraordinaire

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    I am not familiar with the Twin RI (or other Fender RI) amps as far as construction, I do beleive they are all PCB not tagboard like the originals, so they would be more difficult to mod IMO. I'd say if you aren't happy sell or trade it for something that you do like. Don't waste a lot of time and money and then still maybe not be happy with it. Way way back I had Dan Torres do a lot of mods on a Super Six chassis (same as a Twin) but I was never really happy with it, I was able to sell it and recoup what I had in it fortunately.
    If you can't get a good sound out of a Twin with some pedals, then it's not the amp for you.
     
  9. Wally

    Wally Telefied Ad Free Member

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    I have successfully modded the Fender BF/SF RI amps, which are PCB as Ringo notes. Their tube sockets are still chassis mounted, and the PCBs are of good quality, imho.....they are far superior to the Blues/Hot Rod amps for build quality. The Super .soni amps are built in the same manner as the RI BF/SF amps. Yes, it is more trouble to do it, but some simple mods can give a person a much more versatile amp, ime. People’s eyes go wide at the difference. And no, the ‘mods’ Fended did to the Sr Custom RI amps do not go very far in giving a user some dramatic versatility. The hype there is better than the results.
     
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  10. LeDocteur

    LeDocteur Tele-Meister

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    I'd like to have a pre-out, power-in arrangement that I could break into. This would allow an effects loop, or possible to use the power amp and speakers as a slave to another amp.
     
  11. Wally

    Wally Telefied Ad Free Member

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  12. nedorama

    nedorama Tele-Meister

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    Mod away if you want, but important to understand what about the TR is key to your sound.

    Tubes can make a difference, and in Fenders a Mullard CV4024 for the Phase inverter is $30 well spent.
    Speakers - while the JBL D120 is a classic speaker for the Twin Reverb or Showman, they're also really bright. I had Weber California's with the metal dust cap and way too much high end - brittle. I'd look at different speakers - Warehouse G12C/S sound great in Fender combos and have a little give vs. just the G12C's.

    Modding on a PC board is a lot different than discrete hand-wired components. Approach with caution, and find a competent amp tech who's worked on them and knows what he/she is doing. For every good amp tech, there's 10 crappy ones who promise to turn your Twin into a Dumble, or a HiWatt, or a Marshall...

    If it were me beyond speakers and tubes I'd use a pedal to get wherever else I needed to get to.

    Curious - where do you live that you can use the volume of a Twin Reverb? I think that's why there are so many of them for sale - way too loud for most people.
     
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  13. Cosmic Cowboy

    Cosmic Cowboy Tele-Meister

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    This is where I went from the Twin. Wish I still had it. Soon as I get the scratch together, Ill have another one.


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  14. funkyguitarman

    funkyguitarman TDPRI Member

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    I appreciate all the awesome responses, as usual I learned something here because of folks like you, thank you. A while back my amp tech did do some power scaling/tube removal nonsense that resulted in a severe volume drop and made the reverb basically unusable. I was not a fan and had the amp restored back to stock. I don't want to give the impression that I'm unhappy with a stock Twin Reverb. I have used and continue to use one because it continues to serve a purpose and elicit smiles from me. I generally run the amp on three at home in my apartment, living on a noisy street near Boston has its perks sometimes. I actually considered a Lone Star Mesa for some time, having one amp that could cover a whole gig was an attractive notion to me. Besides a Twin Reverb, I use to play a Mesa 5:50 express + combo for a lot of gigs during my Army career, great little amp. Ultimately though, I think I just really desire that massive 2X12 open back sound that the Twin. Seems like I could stand to perhaps experiment a little with different tubes.
     
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  15. Wally

    Wally Telefied Ad Free Member

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    Funky guitar an, there are reversible, non-invasive mods that can give you a much more exciting and versatile amp and that will still allow you to have that stock BFTR sound.
     
  16. Lowerleftcoast

    Lowerleftcoast Friend of Leo's

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    Sorry for being off topic.

    I have found getting the transistors in a fuzz dialed in right is like getting an amp right. Not only does the bias have to be in a zone, the voltage has to be in a zone. Otherwise, it will work but, it won't behave/sound the way we like. The two transistors need to complement each other as well. Fuzz pedals are very temperamental in that regard imo.

    I hope you enjoy your fuzz purchase. If you are disappointed don't judge all fuzz pedals by one experience. Hendrix would try all the fuzz pedals he could get his hands on. Only a few were chosen.
     
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  17. Les H

    Les H Tele-Holic

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    I've swapped speakers, pulled the V1 preamp tube, tried different tubes, ran only a pair of power tubes for half power, used a 12ax7 preamp tube in place of the 12at7 in the phase inverter slot etc and only the speaker swap was the only noticeable difference in my opinion.

    If you're happy with the amp "as is" I'd leave it "as is", or explore speaker options at most. (as I never cared for the stock Jensens that came in those amps)

    I would explore other amps before throwing a lot of money at a TRRI trying to make it sound like something else.
     
  18. Wally

    Wally Telefied Ad Free Member

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    Some simple but meaningful changes to that TRRI will result in Sonic differences....no doubt about it. These changes should not cost a great deal, either. A handwired Fender is easier to work on therefore working on that PCB takes more time=more money. But...not an arm and a leg. The front panel PCB has to be pulled in order to access the tone stack. The RI are much better amps on which to work compared to the Blues/Hot Rod amps...better build quality. The changes that can be had will be exhibited through whatever speakers one uses. These changes are far more influential than what Fender did in the ‘68 SF Custom amps, which are more hype than actual change, ime. I have never found a person who did not hear the very noticeable changes.
    I agree that a speaker can be a great change in sound. I also agree that I don’t care much for modern Jensen’s. However, I have to accept that speakers are not the only defining piece of the puzzle. If changes to circuits did not change sonics, there would only be one circuit for all amps. That is not the case because people search for differences and personal preferences.
     
  19. BobbyZ

    BobbyZ Doctor of Teleocity

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    Picked up the new Joe B fuzz the other day, still in the box. Guitar playing has unfortunately been bumped to the bottom of my priorities list lately.
     
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