freestompboxes.org

Earlier this year I had the good fortune to buy a mid 70's (I'm guessing) Fender Super Twin amplifier chassis that was installed in a wooden cabinet for a Blackface Fender Bassman, I'm planning on doing some restoration work on it to firstly make it safe and also to get it working at it's best, although the guy I bought it from said that it does work, I'm also planning on building 4 X 10 or 4 X 12 speaker cab for it, here's a pic of the Fender Super Twin sitting on top of my Marshall amp:

Apparently these Fender Super Twin amps are capable of putting-out about 395 Watts Peak power, and 180 Watts RMS power, the one I've got is the non-reverb version, and it has six 6L6 power tubes....yikes!!!

Some more pics of the Fender Super Twin amplifier:


Apparently, these things make really good bass amps.

So, how much did it cost me to buy it?....only $300.00......


Here's what I think needs to be done before I even think of plugging it in and trying it out:

1, Give it a thorough electrical check-over to make sure it is electrically safe.

2, Replace all the original preamp valves with brand new ones, I tested the originals by plugging them into my Baja Real tube Overdrive pedal and some of them were a bit weak in gain.

3, Build a speaker cab for it that's capable of handling at least 400 watts of power and a minimum of 4 Ohms impedance.

4, Re-glue the four corners of the wooden cabinet because they are loose.

5, Make a new front panel for the wooden cabinet and cover it in Paisley Cloth.

6, Re-Tolex the cabinet and install new chrome corner protectors and handle, I'm thinking of going with Tweed Tolex just for something different.

7, Source a new chrome Fender logo and install it on the front panel of the cabinet.

Here's a pic showing all the circuitry inside the Fender Super Twin amp chassis, it's all built on eyelet boards:



Preamp valves are as follows as per the attached schematic pdf:

V1: 7025.

V2: 12AU7.

V3: 7025.

V4: 12AX7A.

V5: 12AT7.

Nice but of history there Simon, I bet it weighs a ton.

I stopped using a tube amps for bass in 1997 when I bought a Trace Elliot 15" combo, that weighed in at about 96lbs so I added wheels and a strap to pull it by. I now use a neo bass cab (about 40 lbs) and an 800W class D power amp (7lbs). There is no way my valve amps will ever get gigged again!

deltafred wrote:Nice but of history there Simon, I bet it weighs a ton.

I stopped using a tube amps for bass in 1997 when I bought a Trace Elliot 15" combo, that weighed in at about 96lbs so I added wheels and a strap to pull it by. I now use a neo bass cab (about 40 lbs) and an 800W class D power amp (7lbs). There is no way my valve amps will ever get gigged again!

Yeah it does, I only just managed to carry it up two flights of stairs before I had to stop for a rest, and then my left arm and shoulder started hurting me, I was carrying the amp with both my arms at the time so I think I most likely pulled a muscle, ever since then my left arm and shoulder have been a bit painful, serves myself right....lol.

The thing is, the amp is too good to get rid of so there's no chance of me selling it for the foreseeable future, I bet Bajaman would have a lot to say about it, I reckon he might follow this thread with a lot of interest since he services valve amps for a living.

Seems like a nice project , great buy

strato56 wrote:Seems like a nice project , great buy

Cheers, I'll see if I can document the progress on the restoration project for the Super Twin amp in this thread, there's a fair bit of work that needs to be done on it and I'm going to have to wait till next year to make a start on it, but should be interesting to see what the amp is like once the work on it is finished, should turn out to be a real beast of an amp for gigging with it's 395 Watts peak power output capability, apparently Ted Nugent used to use Fender Super Twins onstage at some point in his career.

Update:


Since it's been a while, I thought that it was about time I posted an update, so here we go.....


About a fortnight or so ago, I managed to buy a second hand Ashton GQ-100 8 Ohm 200W 4 X 12 quad box from my local Cash Converters shop, last week I did some work on the Fender Super Twin amp, which involved replacing the power and standby toggle-switches with new ones, and installing a new 240V AC mains cable, after checking that everything was all good, I put the Super Twin amp on top of the quad box, connected it all up, and plugged the amp into a power board, then I gingerly switched-on the power, no bangs, smoke, or any other weird behavior occurred, next I switched the amp off standby so it was fully powered up,, still no bangs, smoke, or weird, abnormal behavior, I turned up the volume controls of the amp while plucking a string on my guitar, I was greeted by a nice clear twanging sound....it's alive!....It's Alive!!....IT'S ALIVE!!!


The Super Twin amp seems to be working fine with the Ashton quad box, nice and clear sound, very clean and Fender-like, well of course, it's a Fender amp afterall, really happy with it, and it takes pedals really well.


Here's a pic of the Fender Super Twin amp on top of it's quad box, I fitted a new wooden front panel to the amp's wooden cabinet:

Here's a link to an audio demo recording of the Super Twin amp I just uploaded to my account at soundcloud, feel free to check it out whenever you like, and let me know what you think:

Yep big sound with a ton of clean headroom, You won't be able to turn that up in the house lol.
Would be great for pedal setups when you want lots of volume without the amp reaching it's SPL limit too early.
But yes way too heavy for us old blokes with bad backs.
Phil.

phatt wrote:Yep big sound with a ton of clean headroom, You won't be able to turn that up in the house lol.
Would be great for pedal setups when you want lots of volume without the amp reaching it's SPL limit too early.
But yes way too heavy for us old blokes with bad backs.
Phil.

Yep, the amp was designed to be clean and stay clean even at high volume levels, as evidenced by it's six 6L6 power tubes ( ) being connected up in what's called the "Ultra-Linear" configuration, it's a configuration that's normally used in high-end tube HiFi amplification equipment, since it produces very low harmonic distortion levels, even at full power.

Here's another demo I recorded of the Super Twin amp, this time I'm using my Ibanez TS-9 Tube Screamer to dirty-up the sound a bit:

Update:


My Fender Super Twin has two 6.5mm sockets on the back panel, one labeled Equalizer, and the other labeled Distortion and Volume Boost, since I don't have the original footswitch that would have came with the amp when it was bought brand new, I'm going to be making a new one this afternoon from some bits and pieces I bought from my local Jaycar electronics store, I'm also going to be sorting-out one issue with the cooling fans too, the cable that's supplying 240V AC to the cooling fans passes through a small hole drilled through the back panel of the amp, by rights, there really should be a rubber grommet to protect the cable from being chafed by the edge of the hole, if that happens then the wires carrying 240V AC to the cooling fans could come in contact with the chassis and make it live, fortunately the chassis is connected directly to mains earth, but, I'm going to fit a rubber grommet, just to be safe.

Update:

Okay so I've got the new footswitch pedal for my Fender Super Twin amp all built, and I just finished testing it out with the Super Twin amp to make sure it's working as it is supposed to, and yes it is working perfect, the built in 5-band EQ, Distortion, and Volume-boost are now all foot-switching as they are supposed to, as opposed to being always-on without the footswitch plugged into the two sockets on the back-panel of the amp chassis itself, now, I've read that the distortion effect in these Super Twin amps is considered to be not the greatest by some Super twin amp owners, and I can see why, to my ears it sounds fuzzy like a slightly mis-biased preamp tube rather than say the distortion you get from a Mesa/Boogie Mk I or a Marshall amp, it's nothing to write home about, you have to crank both the distortion control and the preamp volume, while keeping the master volume down, to get any distortion out of the amp, lower settings barely produce much distortion, this is a moot-point anyway cause you can easily get a better tone by turning off the distortion and volume-boost, and just use a distortion pedal, since the amp does take pedals well, assuming it is set to give a clean tone.

The front-panel bright switch is handy, you can use it to cut highs to reduce any tendency to ice-pickiness, and since the EQ is foot-switchable you can use it to further refine the resulting tone.


This whole project turned-out better than I had hoped it would, so I'm very happy, it was worth all the work I put into it.

I'm going to post a couple of pics of the footswitch I made for the amp....stay tuned.


Here we go:

Just curious : wich stompbox is that "real tube overdrive" at the bottom of the picture of the cab ?

strato56 wrote:Just curious : wich stompbox is that "real tube overdrive" at the bottom of the picture of the cab ?

Oh that's the one that Bajaman designed, you can order a set of professionally made PCBs from him if you want to build one for yourself, they sound pretty good.

Just pm him if you want to order a set of PCBs from him.

DrNomis wrote:Update:


Since it's been a while, I thought that it was about time I posted an update, so here we go.....


About a fortnight or so ago, I managed to buy a second hand Ashton GQ-100 8 Ohm 200W 4 X 12 quad box from my local Cash Converters shop, last week I did some work on the Fender Super Twin amp, which involved replacing the power and standby toggle-switches with new ones, and installing a new 240V AC mains cable, after checking that everything was all good, I put the Super Twin amp on top of the quad box, connected it all up, and plugged the amp into a power board, then I gingerly switched-on the power, no bangs, smoke, or any other weird behavior occurred, next I switched the amp off standby so it was fully powered up,, still no bangs, smoke, or weird, abnormal behavior, I turned up the volume controls of the amp while plucking a string on my guitar, I was greeted by a nice clear twanging sound....it's alive!....It's Alive!!....IT'S ALIVE!!!


The Super Twin amp seems to be working fine with the Ashton quad box, nice and clear sound, very clean and Fender-like, well of course, it's a Fender amp afterall, really happy with it, and it takes pedals really well.


Here's a pic of the Fender Super Twin amp on top of it's quad box, I fitted a new wooden front panel to the amp's wooden cabinet:

Nice!

That’s a cool amp you have here.

Good work of fixin’ it up

Very nice! Be sure to post if you ever turn it up past "2" (using a really long cable)!