| Author |
Topic: Taming treble on a twin.. |
Dave Meis
From:
Olympic Peninsula, Washington, USA
|
Posted 22 Aug 2017 11:38 am |
|
| I can barely crack the treble control before it's too much.. is there a resistor change or something I can modify to allow me to have a 'softer' control of it? |
|
|
 |
Ken Metcalf
From:
San Antonio Texas USA
|
Posted 22 Aug 2017 1:28 pm
|
|
| Turn up the bass and turn up the volume, cut mids |
|
|
|
Lane Gray
From:
Topeka, KS
|
Posted 22 Aug 2017 2:15 pm
|
|
Yup. Turn things up a bit, like volume around 5 (throttle it back with the volume pedal, but it changes the internal behavior of the amp not to have it throttled internally).
Run the bass higher than the mids, and the mids higher than the treble.
I never could get a Twin turned to 2 or 3 to sound good, but they behave much different when opened up.
_________________
2 pedal steels, a lapStrat, and an 8-string Dobro (and 3 ukes)
More amps than guitars, and not many effects |
|
|
|
Bobby Nelson
From:
North Carolina, USA
|
Posted 22 Aug 2017 2:55 pm
|
|
| That seems to be the case w/most of that type Fender schematic. There are two type fender wiring systems (for lack of a better word): The first one is like the old Bassman, Deluxe, Concert maybe and others, which, for that creamy growly sound, the more you turn them up, the better they sound - like a Marshall (which was a sort of clone of a '59 Bassman with different tubes and transformers); Then, a little later, came the type which Supers, Pros, Twins, and Vibroluxs (among others) had, and they have a sweet spot, somewhere between 2.5 and 6 - you play above or below that sweet spot and they sound like Sh&t (sorry, but, that is what they sound like when played outside the sweet spot). The Vibrolux, and maybe the Deluxe Reverb (not sure about that one, but I do believe it is a different schematic than an old tweed Deluxe) is (maybe the Princeton, but I see that as a practice amp) is about the quietest of this type of schematic, while the Twin is among the loudest (along w/the Dual Showmans and what-not. These have just been my observations over the years and by no means do they qualify as the last word. |
|
|
|
Paul Sutherland
From:
Placerville, California
|
Posted 22 Aug 2017 3:33 pm
|
|
You do have the bright switch off I hope.
What do you mean when you say you can barely crack the treble control? How high can you set the treble before it becomes objectionable? Give us a number.
How old is this amp and have the capacitors been looked at by a tech anytime recently?
Has the bias been checked recently?
How old are the power tubes and preamp tubes?
What speakers are you using?
What kind of tone are you looking for?
_________________
It don't mean a thing if it ain't got that swing. |
|
|
|
Dave Meis
From:
Olympic Peninsula, Washington, USA
|
Posted 22 Aug 2017 4:42 pm
|
|
The amp is a '79, thoroughly serviced in the last couple of years. The tubes are a few months old, and I re-biased them recently (to allow for the burn in over time). I've had the amp for years, and over time I've rolled probably a dozen tubes through v1, and the darkest tube I ever had let me set the treble at 3 or so, and even less with reverb. If the mids are below 6.5, there is NO string separation.. with the mids around 8-9, the string separation is heavenly, but of course the sound is toward the bright side. I know I'm in the minority for running my mids high, but I know what I like, and I know my amp..maybe its component drift or whatever, but it sounds great with the mids UP on all 5 of my PSGs, most of which have new TT pups in 'em.  It's in a new Rick Johnson cab with a JBL K130, which I think is a 'bright' speaker. I've always had to run the treble 'barely open' (it's OFF at 1), and was looking for a way to use a little more of the pot. I don't have a problem dialing in the sound I want, I was asking if there was a way to 'soften' the pot since I've always wanted to have more control over it. Thanks again to all! |
|
|
|
Paul Sutherland
From:
Placerville, California
|
Posted 22 Aug 2017 4:59 pm
|
|
Dave: You are not in the minority running the mids high. Many others on the forum have recommended doing just that, including me. There really are at least two schools of thought on how to set a twin. I hate the sound of my twin running the bass as high as others have suggested above. But who is to say who is right and who is wrong? Do what sounds best to you.
Your twin is almost certainly an ultralinear twin. It probably says 135 watts at the speaker output. Am I correct? If it is an ultralinear twin then you may use somewhat different settings than would be appropriate for a non-ultralinear twin.
For what it's worth, my 1970 twin (non-ultralinear) sounds best with treble just a touch above 3, mids at 8 to 9, and bass at 3 to 4. Plus the volume needs to be at 3 or higher to sound decent. For gigs I've been running the volume at 5 to 6.
The treble knob on my twin is very sensitive. Just a small movement of the knob can make the amp sound really great, or the opposite. Having a less sensitive treble knob would be nice, but it would take someone more knowledgeable than me to suggest how to go about that.
You mentioned the reverb. On my twin 3 is plenty. 4 is a whole lot. 5 is Sleepwalk level. I never go beyond 5.
_________________
It don't mean a thing if it ain't got that swing. |
|
|
|
Lane Gray
From:
Topeka, KS
|
Posted 22 Aug 2017 10:23 pm
|
|
If you're running Windows, get the Duncan tone stack calculator: it'll let you play with the tone knobs virtually, and find something that works.
http://www.duncanamps.com/tsc/
_________________
2 pedal steels, a lapStrat, and an 8-string Dobro (and 3 ukes)
More amps than guitars, and not many effects |
|
|
|
Brad Sarno
From:
St. Louis, MO USA
|
Posted 22 Aug 2017 10:32 pm
|
|
Curious... are you pointing the JBL at your ears, or are you listening to it off axis?
On a Twin with pedal steel, I see treble in the 2.7 to 4 range mostly. If you're way down at 1, something's not right.
B |
|
|
|
Dave Meis
From:
Olympic Peninsula, Washington, USA
|
Posted 23 Aug 2017 1:05 am
|
|
Paul: it is a UL 135, and I love it! I've been able to run the treble at 3 or so (depending on V1). Your settings are what I run as well, but I'd like to have a little more control of the treble. Like you said, the Treble is sensitive (to say the least!), and the bass over 3.5 is mud. When I add reverb over 3 or so, it gets real 'Clangy' (is that a word?) with unpleasant overtones. When I have enough 'knob' to turn the treble down a number, I DO use the bright switch, and it gives a wonderful 'glass' on the top!
Lane: Thanks for that link! I'll be checking it out tomorrow! Just finished a practice, so, I won't be doing it tonight.. but looking forward to seeing it!
Brad: I listen to it off axis.. and 1 is 'off', the way my knobs work, so I'm running 2/2.5 on the Treble (so, 1.5 or 2 on the knob (if it 'zeroed.))
All: I can get the sound I want, but would like to use more of the treble pot for 'fine tuning'. So far, I've been able to find it, but, as Paul said, it's an infinitesimal adjustment, and I'd like that to be easier. Thank you ALL for taking the time! |
|
|
|
Bill Hatcher
From:
Atlanta Ga. USA
|
Posted 23 Aug 2017 6:49 am
|
|
easy. change the ceramic bleed cap to a silver mica cap ala the tweed amps. i dont have a schematic in front of me right now, but its a little cap on one of the pots on the front panel. there will be one for each channel.
also, you have a very bright sounding speaker if you are getting that much top end. if your speaker has an aluminum dome. change it to a paper one. if not, change to another speaker. |
|
|
|
Godfrey Arthur
From:
3rd Rock
|
Posted 23 Aug 2017 7:37 pm
|
|
| Brad Sarno wrote: |
Curious... are you pointing the JBL at your ears, or are you listening to it off axis?
B |
Was going to suggest using beam blockers on your speakers if your ears are getting clobbered by high freqs.
_________________
ShoBud The Pro 1
YES it's my REAL NAME!
Ezekiel 33:7 |
|
|
|
Dave Meis
From:
Olympic Peninsula, Washington, USA
|
Posted 23 Aug 2017 8:11 pm
|
|
| First off, a BIG thank you to all who have responded! I think I mis-stated my mission here, so I'll try to correct it. The title was misleading, and should have read: Can I make a mod to the treble pot to make it less 'sensitive' (ie: could I have at 4 what I now get at 2)? Components, values ect... Sorry for the confusion! |
|
|
|
Godfrey Arthur
From:
3rd Rock
|
Posted 23 Aug 2017 8:50 pm
|
|
| Dave Meis wrote: |
| First off, a BIG thank you to all who have responded! I think I mis-stated my mission here, so I'll try to correct it. The title was misleading, and should have read: Can I make a mod to the treble pot to make it less 'sensitive' (ie: could I have at 4 what I now get at 2)? Components, values ect... Sorry for the confusion! |
Yeah you can, (didn't know how much tech experience you were wanting to invest).
There are mods out there for the tone stack.
But unless you have the time and patience, wherewithal to keep opening your amp and redoing a solder job and ordering/swapping parts which is what it would take, sans taking it to an amp guru and have him dial it in for you custom, it would be exactly that you, as the end user be on hand with the amp guru to dial this in and all that that would entail
Here's an old post though that may add some insight.
https://steelguitarforum.com/Forum11/HTML/002315.html
Aside from the above, changing pre tubes like the 12at7 at the phase inverter slot to a 12au7 gets the amp to lower the response so you can turn up the amp further than normal.
But with all this, its the proverbial YMMV and some will say what Leo came up with should not be tampered with as one end of the equation goes into see-saw effect and you get diminishing returns and he made the amp to play as clean as possible.
My suggestion of a beam blocker would appear to be another way that didn't mess with the internals of the circuitry if your ears are hearing too much treble.
They use them in recording situations.
If you change the amp's circuitry and switch rooms/venues, will that amp function properly in any/all rooms?
You may find the amp mod lost the highs in a certain room, the room sucking up too much of those frequencies.
_________________
ShoBud The Pro 1
YES it's my REAL NAME!
Ezekiel 33:7 |
|
|
|
Stephen Cowell
From:
Round Rock, Texas, USA
|
Posted 23 Aug 2017 9:06 pm
|
|
Does the Normal channel have the same problem? In the Reverb channel there's a 3.3M/10pF network that is pretty touchy with respect to component values... this is not in the Normal channel.
http://schematicheaven.net/fenderamps/twin_reverb_sf_135_schem.pdf
_________________
Too much junk to list... always getting more. |
|
|
|
Dave Meis
From:
Olympic Peninsula, Washington, USA
|
Posted 23 Aug 2017 11:21 pm
|
|
Godfrey, I don't think that would be something I'd be capable of.. I was hoping for a simple resistor change! The 'beam blocker' is a good deal.. I fashioned one a while back that consists of a CD hanging on a string in front of the amp..not quite the parabolic model, but it did help when the stages are small and I'm in the line of fire! I should invest in a real one, and will soon! Edit to add: Thanks for the link! Looks like something *can* be done!
Stephen, I don't usually use the 'non reverb' channel, but I did plug into it yesterday, and it seemed less bright. I swapped the V1 tube to V2, went back into the Trem channel, and it *seemed* better (as in, I could turn the pot up to 2.5/3). As I said, I can always get the sound I want, but sometimes the value on the control is very minimal, and I was hoping for an easy mod...guess I don't get that this time!
I really appreciate you guys and your help! Thanks! |
|
|
|
Tony Prior
From:
Charlotte NC
|
Posted 24 Aug 2017 1:25 am
|
|
what speakers are in the TWIN, speakers matter . One may very bright, the next may be very middy and NOT very bright.
Speakers and EQ curves are not equal.
Whats in the Twin ?
Like many here, I have used TWINS for 30 or 40 years, never had this extreme TREBLE issue.
I would have it serviced again by a good Fender tech, saying it was serviced at some point years back may be irrelevant. It sounds like something is really wacky in the tone stack. It's even possible that E-Caps are having an issue.
_________________
Emmons L-II , Fender Telecasters, B-Benders , Eastman Mandolin ,
Pro Tools 12 on WIN 7 !
jobless- but not homeless- now retired 9 years
CURRENT MUSIC TRACKS AT > https://tprior2241.wixsite.com/website |
|
|
|
Dave Meis
From:
Olympic Peninsula, Washington, USA
|
Posted 24 Aug 2017 8:13 am
|
|
| I currently run a JBL K130 that I got from G.D. Walker. It seemed pretty bright when I put it in (compared to the SICA that I originally put in the new Rick Johnson combo cab I had built),and knew it would take some 'break-in'. I probably have 30-40 hours on it now, and figured it would break in by now. Probably time to switch it back and see how much difference that would make. Thanks! |
|
|
|
Brad Sarno
From:
St. Louis, MO USA
|
Posted 24 Aug 2017 10:07 am
|
|
| Dave Meis wrote: |
| ... I DO use the bright switch, and it gives a wonderful 'glass' on the top! |
My gut reaction to this is DON'T!!!
The thing about the bright circuit is that the amount of added brightness (very high frequencies) changes depending on the volume knob setting. The bright switch lets the super-highs thru 100% no matter the volume setting. So at low volume settings like 3 or 4, that's TONS of glassy highs. If you turn a Twin volume to 10, the bright switch does nothing. I've never been able to enjoy the bright switch ON using a Fender circuit with pedal steel. That seems to be the range we're all fighting to tame. I even offer a "dark" switch setting option on my preamps for steelers because the crispness up top is often too much. I'm not the least bit surprised that you're struggling with treble. The treble knob can't really help you when the bright switch is on. The available "glass" is abundant without the help of the bright switch unless some tone is getting lost somewhere in the cable capacitance or if the amp is a bit out of spec.
Brad |
|
|
|
Bill Terry
From:
Bastrop, TX
|
Posted 24 Aug 2017 10:41 am
|
|
| Quote: |
| My gut reaction to this is DON'T!!! |
Yeah, same here. I hate the bright switch on Fender amps, but I've heard some folks (Ricky Davis I think... ) that make it work somehow.
There was a link I found at one point that recommended a different value for that bleed cap to help with that but I can't seem to find it now. |
|
|
|
Godfrey Arthur
From:
3rd Rock
|
Posted 24 Aug 2017 12:11 pm
|
|
If you're itchin' to get hands on with the solder you can tweak the bright cap on the switch, change the pf values.
But it takes experimenting with a handful of different caps.
Here's a clip by James D. Whiteside who in the clip shows a software calculator for bright caps.
Info on what not to do:
https://www.youtube.com/watch?v=ZCrS5ehDnuc
Here's James' site:
http://www.deepblueharp.com/
I knew a tube amp designer who would always have a solder iron in his hand changing resistors on his amps and listening.
_________________
ShoBud The Pro 1
YES it's my REAL NAME!
Ezekiel 33:7 |
|
|
|
Dave Meis
From:
Olympic Peninsula, Washington, USA
|
Posted 24 Aug 2017 1:33 pm
|
|
Brad..thanks for the tip. I didn't know that about the bright switch circuit. I run my vol. between 5 and 6 for sustain purposes..maybe that's why it didn't seem so offensive when I had the stock 2-12;s in it! I certainly don't use it with this speaker/set up I have now!
Godfrey.. not really itchin' at this point, as I can still get what I want for now..maybe over the winter when the gigs slow down, but I'll definitely check out the vids! Thanks for the links!
As I stated, I use the bright switch when can turn the treble down a notch, otherwise, no.. I'll swap out that speaker tonight (gig tomorrow night) and try it out on stage! Thanks again to all! |
|
|
|
Brad Sarno
From:
St. Louis, MO USA
|
Posted 24 Aug 2017 2:20 pm
|
|
Keep us posted Dave.
B |
|
|
|
Godfrey Arthur
From:
3rd Rock
|
Posted 24 Aug 2017 2:41 pm
|
|
Easier to swap a speaker.
According to James in his video the bright switch is meant for low volume setting to add highs that get lost when turning down the volume.
He explains this and uses graphs that he's modeled within his software.
_________________
ShoBud The Pro 1
YES it's my REAL NAME!
Ezekiel 33:7 |
|
|
|
Dave Meis
From:
Olympic Peninsula, Washington, USA
|
Posted 24 Aug 2017 4:34 pm
|
|
| Dang! the internet is an amazing thing! I really appreciate the help, and I'll certainly post about the sound at the gig tomorrow night with a different speaker! |
|
|
|
