Analogue Modelling?

singemonkey

Time to reveal just how clueless I am:

What's the deal with an "analogue" amp modeller? Surely an amp modeller is digital by nature if it applies mathematical algorithms to a signal to simulate the effect on that signal that a tube amp circuit has? Is it that the algorithms are hard-wired into the chips? I mean what's it all about?

I say this because I'm interested in the Sansamp blonde pedal for jamming away from home through a little transistor amp, and saving a lifetime's physiotherapy from hauling 20+ kilos of bassman around with me every time. The pedal sounds amazing in the demos I've seen. And it's contrasted against the boss '59 bassman pedal (which has got a lot of lukewarm reviews) as analogue vs. digital. I just don't understand what that means in an amp modeller.

Bob-Dubery

I think in this case they're talking about the interface rather than the innards. Looking at pictures it seems that you control this device by (gasp!) turning knobs attached to pots rather than using a menu display and push buttons.

Also it doesn't (assuming I'm looking at the right thing) allow you to set up patches and recall them at the push of a button.

singemonkey

But the Boss Fender Bassman pedal is the same - a stomp-box with knobs, a single LED. But as far as I can make out, the sansamp is claiming it's 100% analogue (which it claims is the reason for its warm, organic sound) and the boss bassman is pure digital, as I read all the copy.

Bob-Dubery

singemonkey wrote But the Boss Fender Bassman pedal is the same - a stomp-box with knobs, a single LED. But as far as I can make out, the sansamp is claiming it's 100% analogue (which it claims is the reason for its warm, organic sound) and the boss bassman is pure digital, as I read all the copy.

Well we're getting close to the limits of my technological skills here, but another possible explanation is that ANALOGUE devices offer a smooth, constant continuum for adjustments whereas digital devices do everything in small but discrete steps.

This may not be what you're looking for ?

Heath

the way i understand it is , that they are emulating the amp with componets rather then with a processor .

singemonkey

Tailon. wrote the way i understand it is , that they are emulating the amp with componets rather then with a processor .

That's what I was thinking. But I don't understand how it'd be possible to get the level of complexity you find in a tube amp and speaker. I mean, isn't that essentially just an overdrive pedal then? When it actually reacts differently at different volumes - even compressing at max gain, don't you need some maths to be running to make that happen? And those little sansamp boxes even emulate a range of unique amps in each unit. My electronically challenged mind can't figure it.

AlanRatcliffe

Tailon. wrote the way i understand it is , that they are emulating the amp with componets rather then with a processor .

Correct. IINM, they use mosfet transistors - which respond in many ways like valves do - arranged in a similar topography as the amp they are modelling. I used a Sansamp as a throw-in-the-case backup for an amp for years. IMO, they are generally better at copping the "feel" of an amp than digital, but are not as accurate at getting the tones.

Heath

i am sure the math can be translated to componets , and the circuit designed to behave a certain way under certain conditions .

Bob-Dubery

singemonkey wrote That's what I was thinking. But I don't understand how it'd be possible to get the level of complexity you find in a tube amp and speaker. I mean, isn't that essentially just an overdrive pedal then? When it actually reacts differently at different volumes - even compressing at max gain, don't you need some maths to be running to make that happen? And those little sansamp boxes even emulate a range of unique amps in each unit. My electronically challenged mind can't figure it.

The give away is that there's a whole range of those Sansamp boxes. They are, if you like, themed. There's an "oxford" and a "liverpool" that all offer a different basic sound that you can tweak. It's like having AN amplifier in a stomp box. The "blonde" seems to be a Fender emulator, the "california" a Mesa-Boogie emulator and so on.

A true modeller (think of the line 6 stuff as an example) would offer all those basic amp emulations and the means to tweak them in one unit.

Perhaps these reviews may help you decide if this device is going to do what you need....
http://www.tech21nyc.com/reviews/images/CS_GP508.pdf
http://www.tech21nyc.com/reviews/images/GuitaristCSreview0608.pdf

singemonkey

Yeah, this is why I'm keen on them. When I use software modellers I tend to stick with one or two amps at most. I'm more a Fender guy than anything else (although I like the idea of a JTM45 Bluesbreaker that you can play at room volumes). So I really don't need, or even want, a big slab of multi-fx to be able to do 50 amps and 40 cabs. A great bassman or deluxe reverb emulator would do me nicely. I've got, or will get, stomp-boxes for everything else. These guys do do a better job from all I've heard than the Boss Fender Bassman and Fender Deluxe Reverb pedals, and now I'm starting to understand why.

For critical stuff I've got my bassman which I can get blackfaced and get two new speakers to replace the dodgy ones in the beautiful dawn when I have the loot. But this through my very first little solid-state practise amp that virtually fits in my glove compartment, seems the business. Or straight into the deck for when I just can't bear the horror of concertina-ing my spine with the bassman.

My question now is: if these pedals can make credible tube amp/speaker simulations with transistors, and they've been doing it for a long while, why don't they make solid-state amps like this?... *thinks - wonder what the tech21 amps are about then?*

Bob-Dubery

singemonkey wrote My question now is: if these pedals can make credible tube amp/speaker simulations with transistors, and they've been doing it for a long while, why don't they make solid-state amps like this?... *thinks - wonder what the tech21 amps are about then?*

Well one thing is that the amps have to deliver a reasonable number of watts output signal. These boxes don't.

And you know that although emulation is a technical accomplishment, there's a part of me that says emulation is easier than originating.

And maybe they DON'T sound quite like the real deal. Maybe they're close but no cigar. Why do so many players insist on carting around real amplifiers rather than just run one of these boxes into the PA?

singemonkey

X-rated Bob wrote
singemonkey wrote My question now is: if these pedals can make credible tube amp/speaker simulations with transistors, and they've been doing it for a long while, why don't they make solid-state amps like this?... *thinks - wonder what the tech21 amps are about then?*
And maybe they DON'T sound quite like the real deal. Maybe they're close but no cigar. Why do so many players insist on carting around real amplifiers rather than just run one of these boxes into the PA?

Just checked out the tech21 amps. They are, as I suspected, power amps with sansamp circuitry. Impressive demo.

Bob, there's no substitute for glowing vacuum tubes. It's analogous to photography - which is less conservative than guitar playing. In photography, there's so much hype about digital, but the real advantage of digital is not in ultimate quality, but in convenience - how easily you can get the best quality out of the tools. For static, set up pictures, pro photographers overwhelmingly prefer film; and it's possible to get a richness and colour balance that's sorely lacking in digital. But for a lot of pros, it's not practical to use, or you risk losing some shots that might be "the money shot," so you settle for digital - which isn't so bad because you get all excited about the tech and forget that the tonal richness isn't there.

These emulators are so that you don't get put off going somewhere to play because of the creaking of the floorboards under your tube amp, or because the sound guy screams at you to turn down long before it starts to sound decent. Also, many of us can't get as good a recording sound from our own mic/amp setup as we can from an emulator. You sacrifice some quality for a whole lot of convenience.

AlanRatcliffe

singemonkey wrote My question now is: if these pedals can make credible tube amp/speaker simulations with transistors, and they've been doing it for a long while, why don't they make solid-state amps like this?... *thinks - wonder what the tech21 amps are about then?*

Well they do and the Trademark amps are pretty cool little amps. Unfortunately, the moment you build it into an actual amp, the speaker in the amp becomes the limitation, for the most part limiting you to one type of speaker tone.

The original Sansamps were studio tools and we were all using them on everything from guitars to the drum overheads to give them some life, warmth and occasional grind. The multiple small slider switches were not conducive to live playing though. The PSA-1 was a cool programmable rack unit (I know more than a few guys were using them with the then top-of-the-line Roland GP-100 (the original modeller/multieffect), but had no effects itself and was limited to 49 patches. Then the PODs came along and everyone baled on the Sansamps, trading the response for the flexibility of dozens of amps/effects in a relatively small format.

Ultimately though, we all want a real amp behind us, moving large amounts of air. It's a visceral experience and can't be emulated.

BMU

I had the Sansamp GT2 before the real deal in modeling happened. For direct recording it sounded thin and buzzy just like you'd think a solid state amp emulator would. No comparison to today's digital modeling tech in my opinion. Moving from that to the first Line6 POD was a no-brainer decision.