Why not a UL Fender Super Reverb?

i don't know about the capricious pricing, but with twins and supers that have master volumes: to me they seem to behave like the non-master volume models when you open the master pot all the way wide open.

 

I'm curious about this too. What is it about the Master Volume Fenders that people don't like?

 

The UL amps have higher operating voltages, higher output wattage, more pristine, clinical, clean core tone. If you're looking for an "organic" sounding amp that breaks up (without a pedal) at reasonable volumes, look elsewhere.

 

Eric a UL super might be perfect for you.
As for the MVs myself I just like old stuff. My TR had the MV I just left it on ten.

Funny the two newest amps I have are a 73 SR and a 74 Marshall 50 watt. Thayed be the last amps I'd sell.
Ok so I never sell anything. (exwife sold the twin)

 

There's nothing wrong with the UL circuit by my estimation. I just picked up a 78 SF Pro Reverb and it sounds fantastic. True, it is nothing like a BF, but it was designed for very clean tone at higher volumes. It has a very glassy clean sound, which sounds great with any dirt pedal you feed it.
As for the Master Volume, I've found it sounds MUCH better if you leave it dimed and adjust the channel volume to taste. I've noticed that the lows are attenuated with the MV rolled down.
The Pull Boost is complete garbage, but doesn't affect the tone if left in.

If you want an amp that doesn't break up, the UL Fenders are superb. (This is all anecdotal, take it for what it's worth.)

 

MV on Super and Twin reverbs is kind of like the Pull boost on my 78 Silverface DR. I just don't pull it.
UL's are different beasts, but if you are only going for clean, they can't be beat.

Pretty sure Super Reverb UL started in 1978.

 

Aside from the increase in wattage, I do believe that Supers also went to solid state rectifiers when they went UL. That is going to change how the amps sound and feel.

I don't think it's so much that they're bad amps, it's just that they're yet another change from something that was already really awesome, and the changes were somewhat misguided. The master volume amps may operate fine when they're on 10, but many people think they sound bad otherwise, and the addition of that feature is just unnecessary crap cluttering up the amp.

That said, I don't really have anything against the MV or UL amps.

 

I have read of a number of people on the ax84 forum simply removing the NFB on UL amps to help them out and have had great results. From what I understand, UL is just another form of NFB. No reason to have two of them. And as mentioned, lowering the voltage a bit can help as well.

 

I play clean with occasional dirt pedals, and I'm a big fan of the U.L. Fenders.

 

re: Ultra-linear Super Reverb (or other Fender UL design) Myths

I've posted about this many times here on the forum. (Yes, I'm VERY familiar with the UL principle, with the history and circuit design of Fender's UL amps, and the origin and the physics behind the UL concept. Thank you David Hafler, et al).

#1 Myth - the "Ultra-Linear" design is "more powerful" than non-UL designs because they are Ultra-Linear. This is a myth. An ultra-linear design, by it's very nature ALWAYS puts out less power than a non-ultralinear design of the same components, all else being equal. Ultra-linear applications are inherently less efficient in terms of power, but also better performing in terms of higher order distortions, especially at lower levels...when they're acting like triode designs. That was why UL transformers were developed - in the late 1930's...and made popular in the early 1950's. Even then tube designers recognized that triodes sound better than pentodes...at the expense of power.

In Fenders, it is the the increase in plate voltages which makes those amps more powerful. They're driven harder - they make more power. Incidentally, Leo Fender would have been WELL aware of the UL concept...as it was the defining "new thing" for push pull AB1 designers of hi-fi equipment in the mid 50's. (It was also expensive and apparently unnecessary for a musical instrument amp, in Leo's estimation.)

#2 Myth - You're stuck if you have an Ultra-linear Fender. That's simply not true. It is simple and easy to remove the ultra-linear circuit feature without changing anything except a few wires and a couple of resistors. A UL transformer, when conventionally wired, performs exactly like a non UL transformer. (Now why you WOULD do this is a mystery to me...but you could. You would, of course, have to reduce the plate voltage to get equivalent power section results, as compared to a typical BF circuit. A London Power power scaling device http://www.londonpower.com/pscaling.htm is one simple way to accomplish this. There are others)

#3 Myth - the Fender master volume inherently changes the tone. No it doesn't. Turn it to 10, it's a straight wire. It is OTHER aspects of Fenders which happen to have the Master Volume which changes their tone...NOT the MV control.

Cheers,

CBG

 

You know when your from Kentucky when you look at this thread title and you think the OP is talking about a University of Louisville DR

 

Great info!
Now the big question, can you get earlier breakup with the MV Fenders? Do they give up the goods with the channel volume dimed and the MV set low as on a Marshall? I've never had the chance to play around with one, so I've always been curious.

 

the UL amps were the 70 Watters. Not as sweet sounding as the older 40 Watters.

 

"Earlier breakup" with MV Fenders. Can be done - takes some work. Probably better to get an amp purpose built for that.

"Do they give up the goods with the channel volume dimed and the MV set low as on a Marshall" Not really. The design is different. The results are different.

If someone wants to experiment, here are some simple ideas to try. These are not the most effective, but they are the simplest for the amateur to attempt. One gets slightly harder as you go down the list...but #4 is generally well within the skills of anyone who's ever held a soldering iron and opened a Fender amp up.



1. Try 12AV7 or a 12AU7 in place of the 12AT7 in the phase inverter (reduces gain, turn up front end to compensate, might get a little dirtier - 12AU7 has half the gain of a 12AV7, which has about half the gain of a 12AX7.)

2. Try a 12AU7 in place of the 12AT7 in V3 (reverb driver) and THEN try the pull boost (Your reverb will be, of course, wimpy - but the pull boost might work for you now...The pull boost uses the reverb driver as an additional gain stage, so reducing the gain there might make it useful without being ridiculously over-gained like it is now) not sure how important the reverb is to you...some guys don't use it, some can't live without it. Sounds like you're a pedal guy, so worth a try?)
3. While you're abandoning your reverb, try a 12AV7 in V4. If that's not enough, try a 12AU7 there. Those both reduce the V4 gain on the "extra" gain stage of the vibrato channel. Same game... reduce post tone stack gain, forces you to turn up front end more to compensate for lost gain, front end gets modestly dirtier.

For this one, all the usual cautions apply about death and disaster if you touch the wrong thing.

4. remove the 820 ohm negative feedback resistor and run the amp with no negative feedback


Just some thoughts to try. Nothing big or amazing here - but not too hard to try.


Cheers,

CBG

 

Agree with all of the above. I have a '79 in my arsenal (with 4 Jensen c10qs) and just about every player in town who has used the amp has loved it- big, bold and ballsy, and a great pedal platform. Definitely not a BF sound, but who wants every amp to sound the same?

 

Twangmaster,

I echo your sentiments...but for heaven's sake don't TELL everyone! Ooops...we just did.

Ah...we were just kidding. See, those UL Fenders are actually CRAP! They sound HORRIBLE! VERY unreliable too...Tube eaters, I've heard? and HEAVY? They are SUPER heavy, uncomfortable and blow speakers like a hop head blows coke. HORRIBLE ! stay away...ah, don't buy them. They are hard to work on... and they ah...have...ah termites and bedbugs too!

harhar

Cheers,

CBG