135 WATT TWIN into a STEEL AMP---HELP!!!!

James Morehead · From: Prague, Oklahoma, USA - R.I.P.

I have a Twin Reverb that I would like to make into my steel amp. I play an S-10 Marlen with a 705 pickup, and will soon have a D-10, so need to cover the C-6th "lows", too. My twin is 135 watts and has the master volume you can pull out for "boost". It already has a 15" baffle installed. I am ultimately interested in how to achieve optimum tone out of this particular amp. I am seeking ideas I can take to my local amp tech ( he deals mostly with guitar pickers, but very few steelers, and I am an "electronic illiterate!!

"). He can easily and competantly do the mods, if I can just communicate what I need for that great "steel sound" that hides within this twin's cabinet.

So, now I am asking for direction from those who have gone before me to "tone land" for some "Do's & Dont's concerning twins of this generation--------Thanx in advance!!!!

[This message was edited by James Morehead on 18 September 2003 at 12:18 AM.]

Ron Whitworth · From: Yuma,Ariz.USA Yeah they say it's a DRY heat !!

Hello James;
I would suggest you print this thread out the take it to your amp tech along with your amp..He may or may not be able to do all of these mods but he will have a very good idea about what you are after..Good Luck on your Twin..Ron http://steelguitarforum.com/Forum11/HTML/004096.html

jim milewski · From: stowe, vermont

I put a BW1501-4 shallow basket with the non-metal dust cover in mine and it sounds great

C Dixon · From: Duluth, GA USA

135 Watt Twin amp?

Are you sure about this? May I ask where you came up with this figure?

Thanks so much,

carl

James Morehead · From: Prague, Oklahoma, USA - R.I.P.

Hi Carl, Glad your in on this!!! I always enjoy your posts. I'm pure sure this is a 135 watt'r. It is stamped 135 watts right under the speaker jacks. Also, mastervolume that pulls out fits the late late 70's early '80's when the 135 watt'rs came out. This amp also has Jan Phillips 6L6 wgb's.

James Morehead · From: Prague, Oklahoma, USA - R.I.P.

Ron, That is what I will probably do. A picture is worth a thousand words(unless it's me doing the talking, then it's worth ten thousand, just to get to the point!!! HA

) The Forum here is so informative and helpful to everyone---especially newcomers like me--it's amazing. Thanx b0b, and everyone else!!! Jim: I think I might head that way for a speaker--the BW-1501-4sb. I feel, from what I've read, this twin will munch a JBL D-130, especially after mods. I haven't run across a 4 ohm JBL yet. I have found a couple reconed D-130-8's, though. I own an EV 15B I might try when this amp is out of surgery, and see what tone it will give me. It is, however, an 8 ohm speaker. The BW is really sounding like the best way to go, so far

C Dixon · From: Duluth, GA USA

Hi James,

I am not saying it is not 135 watts. But I will share this with you. First it has been many years since I was heavily involved with servicing Fender amps. Also, a lot of silver hairs have popped up on this over the hill person's head. As a matter of fact, they are 100% silver now

But to the best of my recollection I did not know it possible to achieve even 100 watts RMS out of 4 6L6's using Fender's standard power supply voltages. Not saying it isn't. I just never thought it possible.

I do know this. many amp manufacturer's put a wattage rating on the back of their amps. But this rating was how much the amp drew from the electical connector plugged into the wall. Not how much power it delivered to its speaker(s). In addition, very few amp manufacturers ever denoted the wattage it put out, because of the long debacle over fraud when rating various amp's power capability.

Is it possible (again I do not know) that what you are seeing is the wattage your twin consumes, rather than what it delivers? There is a world of difference in the two.

My very best regards to you friend,

carl

Grant Johnson · From: Nashville TN

In the late 70's Fender made a twin with an ultra linear output transformer. I think that the output was 135 watts. Very loud and clean, the heaviest combo that you could wish to lug around to a gig!

Ken Fox · From: Nashville GA USA

Most definitely rated at 135 watts on these amps. However, I have never been able to pull over 100 watts with a test signal, load resistor and a scope. I would bet they were rated at 10 percent distortion to get a figure of 135 watts. This is the ultimate clean machine of Fender Twins.
The plates on these amps run at 500VDC! Best to use a darn good tube that can handle the voltage, such as the JJ/Telsa 6L6GC.

Stephen Gambrell · From: Over there

I'm currently using a 135 watt Twin, that I bought from Ken Fox's brother. I put 12" EV's in it, and I don't think anything sounds any better! The low C-to-A on C6 is still clear as a bell.
I just need a LITTLE help lifting it

James Morehead · From: Prague, Oklahoma, USA - R.I.P.

Yes Carl, it is rated 135 watts rms

. Now, whether it actually "delivers" that or not would take some test equipment to tell. I am just going off what fender stamped on the back of the chassis directly under the speaker input jack. By the power cord is a rating sticker that says this amp draws 200 watts, 120 volts, and 60 hertz.(then again, I have a Super Twin that is rated 180watts rms. It draws 510 watts!!) Grant, you wouldn't want to lug my Super twin around for sure!!! 95lbs!!! Anyways, This is what I have and want to make a steel amp out of it. Stephen, your amp sounds like the direction I'd like to go with mine. Ken, did you do the mods on Stephens amp, or did your Brother??

[This message was edited by James Morehead on 18 September 2003 at 10:26 AM.]

C Dixon · From: Duluth, GA USA

Thanks,

I stand corrected then. Apparently, a lot of changes were made after I stopped servicing amps. It just proves what happens when a new kid comes on the block.

IE, in rolls the transistor and because of its inerrent "current" design it blows the tubies away when it comes to power output.

Little wonder Fender had to back up and punt with their basic tried and proven tube design.

I learned something here folks. Thanks a million and may Jesus bring you all joy always,

carl

John Bechtel · From: Nashville, Tennessee, R.I.P.

I bought a new 135-Watt Silver-Faced Fender Twin-Reverb in Honolulu, in 1980. Before I left the dealer, I had the original speakers replaced by JBL K–120's. Although it weighed near a ton, it was definately the best sounding amp that I've ever owned! If it were not for the weight, I would have gotten anouther to match when I started hooking up Stereo! But, I was and am far from Mr. America, although I did know him! I know nothing about Electronics, and I keep forgetting, but; I did replace the (4) big 6L6 GC's with either 5881's or was it 7027's? I can remember much about tube sizes. (Lg. or Sm.), But; it was either one or the other. (considered Industrial-Grade for 6L6 GC's)
When it's all said and done, I always thought a Fender Twin Reverb was a Steel Amp. and I don't understand why anyone would want to go into the chassis and begin re-working a good amp.! It seems like everyone is re-working every amp. as though there are not already good amps. available!
------------------
“Big John” {(<< Uh~
http://community.webtv.net/KeoniNui/BigJohnBechtels

[This message was edited by John Bechtel on 24 September 2003 at 11:08 PM.]

Bob Metzger · From: Waltham (Boston), MA, USA

The 135 watt chassis is the "name" of the amp given by Fender and everyone uses this designation to differentiate it from the 100 watt chassis. Now, if either of these really deliver that kind of power is another question. It is just a name given the amp chassis by Fender. I say amp chassis because this chassis supports a number of different speaker/transformer arrays and hence, different amp models but they all share the same chassis. The 135 watt chassis has the UL taps and is a different power amp/power supply circuit from the earlier 100 watt version. Is the 135 watt version really 25% more powerful? Who cares; it's about tone anyway.

Tell your tech: make sure the filter caps are new-ish. I'd put 2x 220ud@300VDC on the first filter position.
Pay attention to phase inverter (you might want to blackface the PI) for good values. Don't set the bias too high (like the rock/blues guys do). Pick a really clean 1st preamp tube, try several first.

Bob M.

Stephen Gambrell · From: Over there

John, I believe you're thinking 5881's. And James, my amp hasn't been modded, other that the speakers, which I bought from brother Jim Milewski.
And on a side note, Carl, the world would be a better place if everyone were as willing to learn something new, with such graqce, as yourself. May God CONTINUE to bless and enrich your life!

Bill Crook · From: Goodlettsville, TN , Spending my kid's inheritance

DO the math.....

Using a "RCA" tube manual,of that time frame, It wasen't possible to get that kind of output wattage from 4 "6L6"'s,no matter what voltage you ran it at. In order to atain 135 watt sound output,it would have demanded over 1,000 volts on the plate element. A value far exceding the tube manual max values for that tube.

So,I must say that the 135 watts is a subjective value for that amp, (if indeed,it was ment to convay that was the output value of power at that time-frame.

Bill

Ken Fox · From: Nashville GA USA

I agree, that is why I feel they rated the amp at about 10 percent distortion. Regardless,it has a bit more power than a 100 watt Twin, though barely noticeable to the ear. The real deal is the use of the hi-fi world inspired ultra-linear output transformer. That reslutled in the cleanest tube amp design Fender ever made. Guitar players hated this amp for the most part back then. Everbody else was building amps that would distort, Fender was going the wrong way for the market at the time. But they created a great steel guitar and clean guitar amp!
To answer the other guestion, my brother's amp was stock to the best of my knowledge. He lives in North Carolina and I saw the amp last year while there on vacation. It had been re-tubed and serviced by the previous owner.
It is kind of funny. I am a very active member of the Fender Forum. For several years players have scorned the 135 watt Twin and the other U.L. transformers amps as too clean and sterile. Lately a lot of guys over there are admitting now how they really like these amps! It is fun to see opinions change. Maybe some of these guys have discovered the beauty of a clean sounding guitar! It just requires a little better and talent to play clean, right?

James Morehead · From: Prague, Oklahoma, USA - R.I.P.

John B., I'm glad to hear how so many think this is a great sounding amp. I think I will be pleased when mine is saddled up and ready to go---. Seems most folks like JBL's, EV's or BW's in this style twin. Bob M.--well said. It is about tone. This model twin packs plenty of power, and I want to explore tonal possibilities. I will check into the mods you suggest. I want this twin to "drip honey out the grill" for tone!! Bill C., your right about how wattage is subjective. Lots of cool comments!! Keep em comin'!! So as to not drift too far toward what the actual wattage and power is, "What would you do to make this model twin into a very nice TONED steel amp?" I know there are quite a few mods for the blackface twin sound, ect. It seems that there should be newer ways for these newer twins. Any more mod ideas for this style twin?

Dennis Wood · From: Savannah, TN USA

I just installed and setup 5881's in my 135W Twin. I don't think i could ask for a better tone even with the low strings on my Sierra U-12. Plenty of lows and the highs sparkle. Its just soooo heavy.

------------------
Sierra U-12 Crown Gearless, Peavey Nashville 400,
1971 Fender Twin Reverb,
Peavey Tubefex,
Peavey Stereo 212,
Peavey TT Bandit w/ex speaker. Regal Reso, Tele, Strat, 1970 Les Paul Std.

Kevin Mincke · From: Farmington, MN (Twin Cities-South Metro) USA

"What would you do to make this model twin into a very nice TONED steel amp?"

Send it to Ken Fox would be my suggestion.
Always enjoy your vast knowledge & input on the tube stuff Ken!

Steve Schmidt · From: Ramsey, MN, USA

I am using a 68 twin that I had blackfaced. The only difference that I did was to take Brad Sarno's advice and change the midrange slope resistor from 100k to 56k. This amp is by far the best sounding amp I've ever had. Kevin, there is a place in Savage MN called Savage Audio that specialize in Fender work. They are doing another twin for me as we speak. These guys are good. I do recommend the slope resistor change though. It really gives you that sweet spot on the midrange.

Ken Fox · From: Nashville GA USA

Brad's slope resistor change sounds like a great mod. Some Blackface mods are OK. Changing the bias to an adjustable control is great. On 135 watt Twins, I keep the bias balance adjustment that is there and add a bias current adjustment. This way the tubes can be balanced and biased to the correct range. Blackfacing the inverter section would just increase distortion in the amp. The Silverface era amps had a different approach in the inverter section to obtain a cleaner sound. The Silverface era reverb section is ran hotter and is preferred by many over the Blackface reverb drive scheme.
Another nice mod is to add reverb to channel one! Just download the schematic from Fender on the Custom Vibrasonic and see how it is done. Now you have a usable channel for guitar or even running the left and right outputs out of say a Profex 2 into two channels. This does not work well on a non-modded channel one, as it is out of phase with channel two (two gain stages as oppposed to three in the reverb channel). Each gain stage is a 180 degree phase shift for signal. By adding reverb to channel one, it now has 3 gain stages and is in phase with channel 2.
I prefer Orange Drops caps and Silver mica caps in the tone sections, as many other do. It is a nice mod. Also a 2.5uf or smaller bypass cap (tantalum maybe) strapped around the cathode bypass caps (those are 25 uf/25 volts DC). Brad might offer some help here on the type of cap. This would allow the high end to be a bit cleaner.
The Custom Vibrasonic has a channel voiced for just for steel. The bypass cap on the first gain stage is removed to lower the gain. This is an attempt to compensate for the high output of a steel pickup.
The above are just some ideas, certainly not original thoughts from myself. It is a collection of many things I have read on other forums, found by studying schematics and things I have tried myself.
I think the most help to these amps for steel is a 15" speaker, period! Also good power tubes are a must in these amps, due to the high plate voltages they use.

[This message was edited by Ken Fox on 18 September 2003 at 08:42 PM.]

Kevin Mincke · From: Farmington, MN (Twin Cities-South Metro) USA

You're right Steve! GREAT guys!
Jeff & crew worked on my WEBB in the past. I have an early 70's w/master volume that I put a JBL D-130F in many years ago and was used as my main amp. Like a fool sold it but was able to buy it back years later no worse for wear other than a speaker recone. I like Ken's idea of having reverb added to channel 1 and voicing the steel channel like a vibrasonic. I may look into this

www.savageaudio.com

[This message was edited by Kevin Mincke on 18 September 2003 at 09:39 PM.]

James Morehead · From: Prague, Oklahoma, USA - R.I.P.

Thanx Ken, I will take these ideas to my tech. 99.9% of his biz are folks wanting the SRV sound out of their amps. And here I come wanting just the opposite!! This will make perfect sense to him of what a steeler needs out of his twin. Thanx much.

Donny Hinson · From: Glen Burnie, Md. U.S.A.

You might already have a good sounding amp! Try playing with the mid control set very low (at 1), the bass control high (7-10), and then "dialing in" your tone with the treble control (usually somewhere between 2 and 5).

Works for me!

Forum Index > Electronics	Goto page 1, 2 Next	Next oldest topic :: Next newest topic