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Topic: 76 Fender Vibrosonic |
Jerry Roller
From:
Van Buren, Arkansas USA
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Posted 27 Jun 2006 8:56 pm |
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I have this amp with the original D130F and tried it out Saturday night. It sounded OK but not great. I have not taken enough time to tweak it. Can someone give me a good starting point for settings and any other advise that might help?
Jerry |
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Lefty
From:
Grayson, Ga.
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Posted 28 Jun 2006 2:26 am
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Jerry,
I have one of these I bought recently. I had another about 20 years ago that I traded in for a Session 500. Later I regretted that. I believe my memory of that amp was better than reality.
I set mine at 4 1/2 max volume and set the Mid and Bass about 4. The treble I set pretty high (7 or  as this amp seems more bassey than the old one. I don't use the bright switch.
This is all subjective. My Mesa Boogie 1-15 blows my Fender away though. That and maybe I got use to the Session 500 super clean sound.
regards,
Lefty |
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Rick Johnson
From:
Wheelwright, Ky USA
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Posted 28 Jun 2006 3:33 am
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Jerry
Has the amp ever been serviced?
It may just need a cap job and
some fresh tubes.
Those are awesome amps.
Rick
www.rickjohnsoncabs.com |
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David Doggett
From:
Bawl'mer, MD (formerly of MS, Nawluns, Gnashville, Knocksville, Lost Angeles, Bahsten. and Philly)
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Posted 28 Jun 2006 6:05 am
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I'm not sure the tone stacks are exactly the same, but with my Dual Showman and a 15" speaker I use something like: bass 4, mid 8, treble 3. I turn the bright on or off depending on the room.
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Student of the Steel: Zum uni, Fender tube amps, squareneck and roundneck resos, tenor sax, keyboards
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Darrell Owens
From:
California, USA
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Posted 28 Jun 2006 7:11 am
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Jerry,
That amp is worth the time and expense of a good service tech. I had a twin reverb that I recently had serviced. They replaced the tubes and found a few other monor problems. Made it like new and it sounds great now. It's amazing what a tune up will do for one of these amps. |
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Steve Waltz
From:
USA
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Posted 28 Jun 2006 9:16 am
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I have two vibrosonics, each from 1972. I made some upgrades but prior to that I A/B-ed the two amps to see which one I wanted to upgrade. Everything was the same, same caps, same brand new JJ tubes and I used the same speaker. Each one got a new set of electrolytic caps. One amp just sounded much better than the other. There may have been a few differences in resistors near the phase inverter on the one I didn't like as much, those may have been closer to black face numbers. I took the good amp and put in a number of high end caps and changed some to silver mica and now that amp is even better.
One thing I did notice is that these amps seem to be very touchy on the tone controls. With to much treble and mid they sound very sterile. I set mine a t-4, m-2 and b-4, treble switch on. It seemed strange to do that at first but it does sound really nice.There seems to be large changes in tone even between 2 and three on mids, for example. You really have to play with it a lot to get where you like it. Each of mine already had the bias chaged to adjustable bias like a black face so you may want to check to see how yours is set up.
BTW I put the other amp into a repro showman head and use it with a single 15" altec 421 B speaker for bass and it is a really nice bass amp, warm and full. It works well since it's an 8 ohm speaker out.
Steve[This message was edited by Steve Walz on 28 June 2006 at 10:18 AM.] |
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Ricky Davis
From:
Bertram, Texas USA
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Posted 28 Jun 2006 10:57 am
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My settings for my Sho-bud are exactly like Steve just stated. Also; check and make sure the speaker is moving forward. These JBL's are wired backwards.....meaning the possitive prong is the negative and negative is possitive. To check and see which is the possitive prong....touch a 9volt battery to the prongs at the same time with both prongs of the 9v....and see which way the speaker throws...>and when it throws forward(that's what you want) with what ever the possitive of the 9v hits...than that's where you want the white wire coming from the speaker wires.
And run the master all the way open.
and yes caps and tubes do make a diff....but that should get you started.
Ricky |
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Ken Fox
From:
Nashville GA USA
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Posted 28 Jun 2006 11:48 am
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Is this the 135 watt model or the 100 watt model?
Bias is very importnadt but not adjustable on these amps! The bias is a balanace circuit. I just finished a Dual Showman Reverb that had all new JJ tuibes in it. Amp was very weak! The bias was around 10ma per tube and not adjustable! This is the nature of JJ tubes. I love them but they run cold. I changed the bias to adjustable, Blackfaced the inverter section and set the bias to 35 ma per tube. It came alive! Great sounding amp. I further modded the reverb back to early Silverface specs (I far prefer it over Blackface reverb circuits), another great improvement. |
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Ricky Davis
From:
Bertram, Texas USA
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Posted 29 Jun 2006 8:39 am
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here's a series of pictures of Pete Burak's Vibrosonic that Pete sent me to put up; showing details/mods/speaker...etc.
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Pete Burak
From:
Portland, OR USA
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Posted 29 Jun 2006 1:58 pm
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Thanks, Ricky.
Fender amps!
Fun Stuff! |
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John Bechtel
From:
Nashville, Tennessee, R.I.P.
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Posted 29 Jun 2006 8:56 pm
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How many servings of spaghetti would you say it takes to fill that chassis like that? Does my ’65 Re-Issue Twin~Reverb Custom™ l©©k anything like that inside? Gosh! I don't even know how to l©©k at it, let alone work on it! Nice looking meatballs though!  Just clowning! (Not my expertise either!)
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“Big John”
a.k.a. {Keoni Nui}
Current Equipment
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Jim Sliff
From:
Lawndale California, USA
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Posted 29 Jun 2006 10:01 pm
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" With to much treble and mid they sound very sterile. "
That's the nature of the D130F, not the amp. One reason I've never been a huge fan of JBL's. WeberVST's California series with the paper dust cap stays about as clean as a JBL, but is a much warmer sounding speaker.
With the JBL it's likely the 100 watt model. Basically a Twin Reverb with a 15" speaker. There are a ton of reversible mods that will warm that amp up. first, as mentioned, make sure all electrolytics, including the bias cap, are fresh. Put a set of JJ's or some NOS tubes init and bias it a little on the hot side - around 37-39ma, usually (you have to do the BF conversion on at least the bias and phase inverter to do this right - if you know how to solder and find a copy fo the layout on the 'net, it takes about 15 minutes, plus time to bias the amp). Then stick a 5751 in the V2 slot - the preamp tube for the reverb channel. It's a slightly lower gain 12AX7-type.
You'll have a clean, warm sounding amp that will blow you away compared to where you started from. And it will keep up with any of the 400-500 watt SS amps with no difficulty, with far superior tone IMO. Plus it's loud enough to crack concrete!
That being said - I prefer the 40-50 watt amps, like the '64 Vibroverb, the 50-watt Vibrasonic (note the "a") and the Pro Reverb. nearly as oud as a Twin/Showman/Vibrosonic, but much warmer and smoother sounding. If I need more volume I just run two in stereo.
But that Vibrosonic is a neat amp with a little tweaking. you may like the JBL after the tweaking, if you like crystal-clear clean tones...but they are way too sterile for me. |
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Jim Sliff
From:
Lawndale California, USA
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Posted 30 Jun 2006 4:11 am
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| FWIW - Pete's amp pics show an amp that's had a cap job and it looks like a BF conversion as well. |
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Jon Light (deceased)
From:
Saugerties, NY
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Posted 30 Jun 2006 4:15 am
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| Quote: |
| With the JBL it's likely the 100 watt model. |
I've got an Ultralinear 135W Vibrosonic Reverb w/ D130F. |
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Ken Fox
From:
Nashville GA USA
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Posted 30 Jun 2006 11:57 am
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| Jim, you echoed my exact sentiments on the JBL speakers! I also recommend the same mods. Good call on that one. I found the old Altec speakers a lot warmer than the JBL. Still, with the mods and a little tweeking it will be a super amp for Jerry. |
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Jim Sliff
From:
Lawndale California, USA
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Posted 30 Jun 2006 1:33 pm
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Ken - ditto on the Altecs - much warmer than the JBL's.
Eminence is also making some good 15's nowdays. I'd really use almost anything *except* a JBL in that amp! Far too much top end - the proverbial icepick-though-the-forehead in action. |
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Joe A. Camacho
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Posted 30 Jun 2006 3:39 pm
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| What would you recommend for preamp tubes. I pulled the covers off the other day and notice that my '67 still has the original preamp tubes, I'm currently running a set of Ruby 6L6's with a Weber 15" California with a paper dust cap. Thanks, Joe |
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Ken Fox
From:
Nashville GA USA
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Posted 1 Jul 2006 5:31 am
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I used NOS RCA and Sylvania for several years in my shop repairs. For over 4 years now I am using JJ/Telsa preamp tubes exclusively. Great warm tubes and far more dependable than NOS tubes, in my experience. I found a lot of NOS tubes were microphonic. A recent study had shown this can be a result of the tube pin aging process. They form a covering on the pins that is glass like in its makeup! I am not sure what can be done to clean the tube pins when this has occured. I have had no luck with denatured alcohol or electronic cleaners.
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Pete Burak
From:
Portland, OR USA
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Posted 1 Jul 2006 8:42 am
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That original JBL in the '76 I have sounds absolutely killer for Guitar!
Definitly not optimum for steel (too much high end, I agree).
I got it in a buy/sell/trade deal a few months ago. It had been AB763'd (no more master volume), and cap job'd.
I played it on a gig Thurs night with steel in one channel and guitar in the other.
Fun Stuff!
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Jim Sliff
From:
Lawndale California, USA
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Posted 1 Jul 2006 9:11 am
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Joe - I'm with Ken. I much prefer JJ's over any other new tubes. I still like a NOS 5751 in the V@ (second preamp tube) socket. Its lower gain really warms the amp's sound up.
BTW Ken - Have you tried the Caig stuff? Pro Gold is an amazing contact-enhancing product, as is their Deoxit for cleaning corroded pins/sockets. It's all I use now. I had the same opinion of most contact cleaners and lubricants, but switched about 3 years ago - the stuff literally ressurected a 1950 Gibson GA50T. |
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Pete Burak
From:
Portland, OR USA
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Posted 1 Jul 2006 9:16 am
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I just pulled a 5751 out of another amp. 'Didn't even realize I had one.
I will try it in the Vibrosonic.
Cool. |
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Marty Nemanick
From:
Madera, California, USA
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Posted 4 Jul 2006 9:19 am
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| I am using a 1979 Bassman 135 with a JBL K-130 15" 4 ohm speaker how does it differ from the Vibrosonic 135? Just curious. BTW, my settings are: T=5, M=10,B=2. Thanks...Marty |
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Pete Burak
From:
Portland, OR USA
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Posted 4 Jul 2006 9:24 am
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Would it hurt anything to try a 4ohm Black Widow (from my Session 400) in the 8ohm Vibrosonic?
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Jon Light (deceased)
From:
Saugerties, NY
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Posted 4 Jul 2006 10:00 am
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Marty--not too much different from the 135w Vibrosonic, minus the reverb. The reverb does add to the gain structure on CH 2 of the Vibro so that does have a tonal impact.
Pete--the general answer is that it's ok, but I know that back when my Vibrosonic was running (it needs a doctor with far more skills than I have) it ran VERY hot (fry an egg on the faceplate) and it would have worried me to further stress the transformer with an impedance mismatch so......[This message was edited by Jon Light on 04 July 2006 at 11:16 AM.] |
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Ken Fox
From:
Nashville GA USA
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Posted 4 Jul 2006 10:42 am
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The 135 watt Bassman's main speaker jack is set for a 4 ohm load. When adding another 4 ohm load to the external speaker jack the two loads are wired in series for 8 ohms. Insertion into the external jack switches to the output transformer's 8 ohm tap and away from the 4 ohm tap.
The 135 watt Vibrasonic uses the same output transformer but a different switching scheme. The main speaker jack is wired to the 8 ohm tap. When an external speaker is plugged in it is in parallel for 4 ohms and the external jack switches to the 4 ohm tap on the output transformer. To use just a 4 ohm speaker you need to "trick" system by putting a dumny jack (open jack, nothing wired to it) and then plug the 4 ohm load into the aux speaker jack. Caution!! Do not unplug the aux speaker and leave that dummy jack in!! An open load can burn out the output transformer. The main jacks on Fender amps have a shorting contact that goes to ground when the speaker is unplugged. That dead short to ground on the transformer's secondary will save the transformer from a sudden death.
Remember tube amps do not ever want to see a no-load on the output transformer!!!![This message was edited by Ken Fox on 04 July 2006 at 11:45 AM.] |
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