UA 8110 "Shape" switch

Hey there.

I have some questions about this feature.  Here is a video that about 2/3 the way through describes a bit about what this switch does. 

http://www.uaudio.com/products/discontinued/8110/index.html

From what the guy says, it is just changing some transformer loading of some sort.  Since I don't know much about transformers, how might this be implemented?  Could it be done easily? Or involve their "custom" input transformer. 

I just think that this could potentially be a useful switch on a preamp to make it that much more versatile.  Keep it clean, or color it up.  then it gives that preamp more jobs potentially.  more bang for the buck if you will.

with out watching the video. The shape switch would most likely select between 2 different windings.... but that's just a guess

If the level doesn't change substantially, it may just be different load resistors. The UA 8110 is a FET design. As with a tube input, this allows for quite some variation in the grid/gate resistor to ground. Normally you would choose a value that produces a flat response with the input transformer, but you could use a higher value to retain some transformer resonance in the upper octave or you could use a lower value and get a slight treble roll off. It's a cheap trick for some sound variation. But frankly, I'd rather have a preamp with just that one correct value. These days people like to fiddle around with switches, thinking they can get the sound of three preamps in one box. In fact you pay $$$ for a $ switch which only makes it harder for you to get optimal performance. You can't really blame the manufacturers. People want to be tricked, desperately. The less expensive UA Solo 110, which is based on the same design, was a great preamp. It didn't have that mysterious mojo switch, though, and maybe that was why it got discontinued. People, who never just listen, thought it was a lame box.

it seems more like Rossi's explanation.  He definitely states in the video something about transformer loading for harmonic enhancement at the vintage setting, and then saturating the transformer for soft clipping in the saturate mode, and no effect in the clean mode.

I could really care less about that specific preamp, I really just want to get a little more insight into how this is done.  How to "enhance harmonics" with transformer loading, and how to push it into saturation without ramming more signal into it.  I'm sure some of the preamps that we all know and love from years past didn't have the "correct" value for that optimal performance, but maybe thats part of what makes them known and loved.  I might be confused here, but isn't this mildly describing the older api preamps?  Some of the harmonic textures were actually derived from a method similar to this (i don't think intentional on this one though)?  I might just be crazy or confusing some of the millions of things i've read about this idea. 

Either way, I wouldn't mind having a really solid preamp as a foundation, and try something like this.  Instead of having to lug a rack of preamps around, I can lug a few space rack bag!  I do a lot of recording outside of conventional studios, so having to carry and hook up less shit is always a plus.  I know I know I should jump on the 51X train then! 

phishman13 said:

I'm sure some of the preamps that we all know and love from years past didn't have the "correct" value for that optimal performance, but maybe thats part of what makes them known and loved. 

Click to expand...

I think that's a common deception. In the past engineers always tried to achieve optimal performance. A V72 for instance was never meant to sound colored. It just happened to be built in the tube era, and a certain tube/transformer colorization was unavoidable. But it certainly performed optimal given the technology that was available.

It's only in modern times that manufacturers consciously try to make stuff that produces a variety of "colors" at the flick of a switch or supposedly(!) sounds better because it does stuff that traditionally would be considered wrong. Personally I couldn't care less about "character" switches. A preamp has one character, and anything else is affected. It's like a comedian impersonating the President. Kinda funny, but you wouldn't want him to rule the country.

yeah, like i said, couldn't be sure about that.  probably read it on gearslutz. 

but like i said before.  I really just want to learn more about this application.  I understand you don't like that type of thing, but its something I want to look into.  The more I know about it, the less I'm "fooled" when I buy commercial gear.  And I learn something useful.

Could it really be as simple as switching different value load resistors in the spot you mentioned? I guess by loading the transformer too much, it will go from working properly to some upper octave resonance and then to saturation and soft clipping?  Like I said I only know the basics when it comes to transformers, and I haven't found a concise easy to read intro that covers stuff like this.  If anyone knows of some info online like this, I'd love to see it!  I've checked the metas and am about halfway through deciphering those to see if anything there can help here.

we talked about putting a switch to control an unbalanced dc to purposely saturate the core, did somebody dive into the diy treasure trove of booty,

well, we reversed all their crap already so don't we owe them one?

throw the dog a bone once in a while, no big. hey, did you check Putmans yellow golf shirt?  big $$$$$

those sales guy, they can turn saturation into "smooth, creamy, buttery, slick snake oil sales geeks

make me wanna blow chunks! 

He says :

" Setting one gives a more vintage character - transformer loaded with harmonic enhancement"

From the RDH: p.519  Transformer Loading

" A resistor shunted across the secondary reduces the value of Q, thereby giving more uniform hi freq response, and also extends the low freq response.  A resistor shunted across the primary extends low frequency response. . . . .  Loading (primary) results in higher tube distortion  and secondary loading also results in higher transformer distortion.  Loading is generally undesirable . . . it reduces the max peak output voltage and the gain."

One would assume they spent some time finding a flattering and most importantly widely useful loading setup.  It's easily enough done with a bank of resistors on a switch.  Effects could be subtle to wild and wacky.

I agree with Rossi - people often want to be bowled over with options to the point where simple and sensible seem boring.

Yesterdays prudence is today's press copy. 

resistors will shape the sound a bit, but i think there is more than that going on, as the change you hear with a zobel is no way near the change you hear with a ni vs steel core, etc,

Alright, this is what I'm looking for!  Thanks guys!  Looks like I'm gonna have to (virtually) crack open the RDH!