That's great! Glad it worked out, for sure. Take a look at this page to see if there's anything of interest. Non-intrusive mods to control volume, though from what I've read, mixed results. My error on the tube swap for volume control. It is more specifically seen as a "gain" treatment; you'll get gain at lower volumes, if I have it correct. Anyhow, glad to hear the results, and take a look at this link, if you're interested!Did the grunt work of moving my equipment…to get to & open the cabinet. Drove a long screw into the rear panel to keep it open about 2”, cuz it goes right smack against a wall. Good thing my neighbor right next door is 1/2 deaf…
Worth the effort as it did what I hoped it would do. Took away the boominess of the bass response.
Was doing the same thing when I use a ‘65 BFPR (also hooked-up to cabinet). Cured that as well. All is good & it really kicks A$$ in conjunction with a Klon Horsey pedal.
also trber: A Tungsol 12ax7 was in the V2 vibrato channel socket that I swiped from the Princeton Rvb, but have put it back & put a Sovtek back in its place.
Thx all
View attachment 1052491
What Gives a Twin Reverb Its Sound?
- Thread starter trber
- Start date
colchar
Friend of Leo's
Agreed, on both.
I am thinking it's the sum...but I am not much of an expert so defer to experts.
I love my champs, but the smaller speakers seem to set off the hearing problems. Something about the frequency and concentration of the sound that doesn't work for me. Much prefer larger speaker formats.
My current amps are a Marshall SV20 (the baby Plexi), an Orange AD30 (insanely loud for 30 watts), and a vintage Traynor YGM3 (their version of the Twin and beyond insanely loud). I wouldn't trade the fullness of their sound for any smaller amp.
ETMusic777
Tele-Meister
This is amazing. What a jam and the percussion is off the charts. It does not seem like bands take that approach these days and they should.
Back at it
Tele-Meister
Damn those are right at ear level…. Nirvana until you can’t hear anymore
enorbet2
Tele-Meister
Hello. I really don't want to toot my own horn but it is probably somewhat relevant to note that I dabbled in electronics since I was around 8 years old, took Electronics Shop in High School, where I repaired TVs and the school's tube PA system, and worked much of my 76 years repairing, modding, designing and building amps (mostly tube amps) some for a few global stars. What's far more important in my view is I see guitar amps as NOT being mere reproduction devices (like a PA or HiFi) but as musical instruments in their own right.
Comparing a Twin to your Champ, obviously the major differences are power and speaker complement, but what matters most is comparing a Twin to other high powered gear. There, the output transformer is very important to tone and other potent factors are in the Power Supply (especially filter caps and decoupling) and also the level of both Bias and Negative Feedback.
The preamp design is less important to tone than it is to feel. For example Tweeds and their clones like Marshall, Vox, some HiWatts, Sound City, etc., have the Volume control preceding the Tone Stack while post Tweed Fenders (especially Black and Silverface) have the Tone Stack preceding Volume. This means the Q of the tone stack changes a LOT with Volume settings, creating a tonal touch sensitivity in Tweed and clones at the cost of sounding more similar (but less "vocal") at a wider range of signal levels, including guitar volume setting, pedals, and how hard you hit which is what Tweeds, Vox-es and Marshalls etc respond much more dynamically to, either to your ecstacy or chagrin depending on your style.
You can drastically change the respionse of the Twin (or really, any amp) by changing the value of the filter caps, the Bias and/or the Negative feedback. Both the Bias in most amps and certainly the Twin, and with a minor, easy to return to stock, mod (adding a temporary potentiomerter) alter Negative Feedback for more or less headroom and change the position of Edge-of-Breakup. Obviously trying different filter caps to affect headroom and "stiffness" is a bigger job and can't easily be done on-the-fly but all 3 are very instructive if not revelatory.
For a bit of reference regarding headroom and "feel" consider EVH tone achieved by starving mainly the outputs but also all tubes by using a Variac, It should be obvious what comes out, in tone and feel, is most controlled by what goes in as power supply capability and how much the amp is "reined in" by negative feedback..
Comparing a Twin to your Champ, obviously the major differences are power and speaker complement, but what matters most is comparing a Twin to other high powered gear. There, the output transformer is very important to tone and other potent factors are in the Power Supply (especially filter caps and decoupling) and also the level of both Bias and Negative Feedback.
The preamp design is less important to tone than it is to feel. For example Tweeds and their clones like Marshall, Vox, some HiWatts, Sound City, etc., have the Volume control preceding the Tone Stack while post Tweed Fenders (especially Black and Silverface) have the Tone Stack preceding Volume. This means the Q of the tone stack changes a LOT with Volume settings, creating a tonal touch sensitivity in Tweed and clones at the cost of sounding more similar (but less "vocal") at a wider range of signal levels, including guitar volume setting, pedals, and how hard you hit which is what Tweeds, Vox-es and Marshalls etc respond much more dynamically to, either to your ecstacy or chagrin depending on your style.
You can drastically change the respionse of the Twin (or really, any amp) by changing the value of the filter caps, the Bias and/or the Negative feedback. Both the Bias in most amps and certainly the Twin, and with a minor, easy to return to stock, mod (adding a temporary potentiomerter) alter Negative Feedback for more or less headroom and change the position of Edge-of-Breakup. Obviously trying different filter caps to affect headroom and "stiffness" is a bigger job and can't easily be done on-the-fly but all 3 are very instructive if not revelatory.
For a bit of reference regarding headroom and "feel" consider EVH tone achieved by starving mainly the outputs but also all tubes by using a Variac, It should be obvious what comes out, in tone and feel, is most controlled by what goes in as power supply capability and how much the amp is "reined in" by negative feedback..
otto jackson
TDPRI Member
I got a '74 TR sliverface for $200 in 1989 and the only reason I have another amp is to have something easier to carry. Part of the amazing sound (even at lower volumes) is tubes, and when you replace them you might need to bend the pin contacts in the sockets back into place for full contact. Another reason is the massive transformer which allows for nearly unlimited headroom. An additional thing I have wondered about is the odd placement of the speakers on the back of the baffle board. I think this is a likely source of the intensity inside the notoriously narrow cone of sound in front of the amp (I have seen old school blues guys like James Cotton run a pair of twins on either side of the stage and not even mic them up for the mains). To experiment with this effect, I built a new cab and put the original speakers (re-coned, probably Jensens) into it outset on the new baffle board. I stacked the amp (with new Ted Weber Chicagos) on this and ran ("speaker out" jack) out to the cabinet (the massive transformer absorbs the impedance without need for a matcher). The resulting stack produces the legendary, intense narrow cone and the extra cab spreads it out. I've had the whole rig running for more than two hours with no sign of overheating. I would rather have this than any re-issue or hipster amp from Orange any seven days of any week. To TR doubters, I say sometimes more is, well, more.
Attachments
Brown sound!
I'm working on my technical understanding of amps, and your response is helpful and appreciated. I have the basics and am entering into a more detailed understanding of the nuance involved. Right now, as I play the twin, I have the chassis on top of the cab and am reminded of the behemoth transformers every time I look at it, so that part is sinking in from the visuals. Lol
I'm also going to install a Bias pot so I can adjust it so the huge 6l6s are at their best. I'll be interested to hear how it affects the tone, and I know from adjusting my Princeton kit amp it is quite audible. I'm curious if the tech who worked on it last got it mostly right.
I've also been considering adding a variable Negative bias to the ground switch. If I do, I'll be able to explore a most/all of the variables you mentioned. I did just pick up an inexpensive variac but don't really know if it's sufficient to explore varied input voltage, but I could try it to see.
Many thanks. I appreciate that you shared your expertise.
That's awesome! What a great find and story. I'd never have thought about speaker mounting location, although the celestions in my 2x12 for the Champ are externally mounted. I just figured each maker had a reason for how they're mounted and never questioned it beyond that. Good info!
Regarding the tube pins, is that just to ensure good contact, rather than there being something about new tubes and how their pins align? I did retention the sockets... would that do the trick?
Thanks for the response!
Still GASing all these years later for a rosewood Tele. I'm thinking about going wenge though, wenge top on swamp ash and a wenge neck. Otherwise, just like that rosewood Tele.
TromNek
TDPRI Member
I've got my '74 TRSF for sale. But after reading all these posts, I think I might keep it !
I bought it back in '74 (when I was 14) for $200. It was a floor model at a music store.
It was my first 'real' amp and it's one of my best friends.
I keep it up at my mom's house in Upstate NY and rock out on it when I go up there to visit.
My Mom must be getting hard of hearing. She said;
"Turn it up !"
Really thinking now that I should keep it.
But it's probably better to sell it to someone who will actually play it more.
I bought it back in '74 (when I was 14) for $200. It was a floor model at a music store.
It was my first 'real' amp and it's one of my best friends.
I keep it up at my mom's house in Upstate NY and rock out on it when I go up there to visit.
My Mom must be getting hard of hearing. She said;
"Turn it up !"
Really thinking now that I should keep it.
But it's probably better to sell it to someone who will actually play it more.
stratisfied
Tele-Afflicted
They look and sound like Super Reverbs to me.
misterdontmove
Tele-Meister
Except when your outdoors. I tilt my Super Reverb for the very reason you stated, but on an outdoor gig, with no ceiling, or mic on the amp, you're the only one who can hear you. I was ATOMIC BOMB loud, but people kept asking me to turn up. Just an FYI.
Bob M
Friend of Leo's
I once had a Dual Showman Reverb in the seventies. 2 15” JBLS. Big ass cabinet. At any volume it was incredible sounding. These days if I had one I would have to hire a cartage company to move it for me. There is something about 4 6l6s moving air that is exhilarating.
studio
Poster Extraordinaire
Yes, especially a Tele into a Twin = Instant Badass!
studio
Poster Extraordinaire
Excuse me while I kiss the sky!
studio
Poster Extraordinaire
Steve Howe was famous for using Dual Showmans back in the day, with a Gibson ES175! Craaaazy!
Now I think he uses all Line6 stuff.
Cosmic Cowboy
Tele-Afflicted
Coming at the question as a player, and not being an amp tech in even the slightest, its a combination of big, powerful amplification...the negative feedback circuitry and the bassy response of the OT and speakers.
The sound you are describing is why the Jazz cats love those things (twin reverbs). When I was studying in school, every guest guitarist either opted to play through the school's twin reverb, or brought their own.
They are warm, big and organic-sounding amps.
Yeah you dont have to crank em to hard rock stage volume to get a steller sound.
Guess I am saying I dont know, but I agree.
The EQ of the circuit is a big part of how an amp sounds, it's essentially how an 'amp in a box' pedal can make something sound 'vox-y' or 'marshall-y' .. it's probably at least 80% EQ.
Cosmic Cowboy
Tele-Afflicted
I really dont think that many guys understand just what kind of big sounds these stage setups are.
We get told to turn down our Deluxes to the point of not being able to hear it without monitoring. Correct me if Im wrong but I didnt see Carlos leaning into a wedge to hear his guitar.
In order to get a big sound, you need to have big poweful sound pressure.
Live music should hit you in the gut, and if you have powerful amps and good music...mixed right, its not really that 'loud'. Just clear and powerful...puches you in the heart and lungs and guts with pressure.
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misterdontmove
Tele-Meister
Check out Clapton on an ES335 plugged directly into a Blackface Showman (I think it's a "Dual" you can see it in one of the shots) in this clip from The Rolling Stones Rock and Roll Circus. Listen through to the solo at 2:48. He looks like he's all geeked out on blow, but WHAT GREAT TONE!!!!!!!
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