Is time ripe for emulations of emulations ?

[Vivek]

Long time ago, many FET based pedals, pre-amps and Amp Sims were released by Pedal manufacturers and these schematics reached the DIY world

and many times, it was the other way around where DIYers came up with a FET based building block which the Pedal manufacturers readily accepted into their designs.

But now FET are getting harder to source,

and it was always known that FET pedal builds cannot be consistent.

Is it right time to redesign all those earlier FET designs like mu amp, BSIAB, Dirty little secret, JCM emulations etc and release modern Opamp versions :

Same gain per stage
Same frequency response per stage
similar dynamics
Same tone controls
Effectively same thing

In other words, a modern emulation of an older emulation


Would the DIY world be helped with release of a whole bunch of new schematics and PCB design of their favorite pedals/ pre-amps, only "modernised" to use Opamps, no hard to source parts like FET, no trimmers, no uncertainty, no inconsistency of each build ?

[Steben]

I do feel that anything that can be done with opamps will lead to proliferation.

[Fancy Lime]

Given today's state of DSP, your idea sounds a bit like building a fake steam-locomotive with a two-stroke diesel engine to run it on electrified tracks. I see the point of sticking with the fiddly old tech because it is a fun hobby. I also see the point of fully modern simulation because it is efficient. I don't quite see the point of doing the in-betweens, at least not for simulation. Building opamp circuits that sound good is good enough for me. Why try and make them sound like something they are not?

Andy

[marcelomd]

Cross posting, but...

This is what I imagine for "modern analog emulation": http://www.runoffgroove.com/thunderbird.html

I'm with Andy. It's a fun hobby.

[Vivek]

You have great points Andy !

Let me clarify, correct and redefine my starting premise

There are many FET based circuits doing the rounds in the DIY market. But FET are getting harder to source.

Would the DIY world be helped if these older circuits were redesigned with Opamps ?

[Vivek]

This is what I imagine for "modern analog emulation": http://www.runoffgroove.com/thunderbird.html

Interestingly enough, I have been working on this schematic on SPICE for the last 2 days.

[Steben]

I kindly refer to my input stage idea on my Park G25R where it is ment to replace a Fetzer.

+ it is generic design, you can choose an array of economical opamps instead of picking a certain jfet
+ no trimming
- no exact natural transfer curve

[Vivek]

Park G25R

Please post a link.

Thanks Steven !

[vigilante397]

A friend asked me a while ago if I could do a tube version of a Fender-voiced JFET preamp he had. So he wanted a tube emulation of a JFET emulation of a tube emulation.

[Steben]

A friend asked me a while ago if I could do a tube version of a Fender-voiced JFET preamp he had. So he wanted a tube emulation of a JFET emulation of a tube emulation.

Tubes suck in getting jFET tone 

[Steben]

Park G25R

Please post a link.

Thanks Steven !

https://www.diystompboxes.com/smfforum/index.php?topic=125146.20

[Ice-9]

A friend asked me a while ago if I could do a tube version of a Fender-voiced JFET preamp he had. So he wanted a tube emulation of a JFET emulation of a tube emulation.

[vigilante397]

Tubes suck in getting jFET tone 

Accurate. If you know you want JFET tone, you won't like tube tone.

[POTL]

This is interesting, of course. But it seems to me that analog pedals are becoming a very narrow niche. For the last month I have been playing through the Neural DSP plugins, it's fantastic. The sound is very, very good, feedback (you feel each amplifier differently, as it should be in reality). Volume knob response is excellent, impulse cabinets, etc. For a concert, it is enough to take a laptop and a sound card. Of course, the sound is not 1in1, the real amplifiers that I have sound more natural and feel more natural, but every year the plugins are getting closer to reality.

[POTL]

Now let's get back to your idea. To start designing, it's worth understanding what you want to create.

1) Is this an overdrive pedal that goes into the input of the amplifier? If so, do you need an equalizer in it, because it is in the existing amplifier.

2) Is this a preamp that is connected to the power amplifier by changing the preamp? Will you simulate the bass reflex and the power amplifier itself with their equalization (presense and resonance), as well as the saturation of the power amplifier lamas (as in the old Marshalls without master volume)?

3) This is a finished product that completely simulates the preamp + amplifier + cabinet (of course, this should be ir, and not an outdated analog circuit).

Also, do you realize that it is desirable for modern pedals to have presets?

A good modern example I can give is Dut Beardy islander MK2



1) This is the Mesa Boogie Mark series

2) It has 2 (!) Equalizers, as in a real amplifier

3) It has presets, the pedal remembers the position of absolutely all (!) Knobs

4) This is a compact body The only thing missing is the ir cabinet simulator. I think that at the present time only such pedals will be able to compete with modern plug-ins.

Even the tube amplifier market is changing. People understand that they don't need huge amplifiers of 100 watts or 50 watts. Almost the entire market, from large brands to boutiques, is actively promoting compact amplifiers of 15-30 watts, which are enough for playing at home and small concert venues. And prices are going down. You can buy the PRS MT15, with two excellent channels for less than $ 1000, a full tube unit. Big bands keep tube technology in their studios, use digital amplifiers at concerts and sound great.

I see that you are in a rabbit hole of amplifiers in a box, you create a lot of topics and post a lot of reports on the work done. But I think that trying to use op amps is doomed to fail. Look at Engl, Diezel, Friedman. These are large manufacturers of tube amplifiers, they make cool and modern devices and know how a tube amplifiers should work and sound. Now look at their overdrive pedals that mimic their own amps. They all have a slightly different approach with op-amps, but they all sound far from amps (in the 2000s Brian Wumpler tried to do this). I have not heard a single op amp based amp in a box that sounded good.

The problem is how distortion is generated, op amps use diodes that make the sound too compressed and unnatural. If you can manage to make op amps sound like a tube, you may be building a successful business. But I can say that in reality there are only 3 paths (in my opinion).

1) Master programming and make digital devices (there are many players on the market, but few good ones).

2) Look towards MOSFets, they are the most flexible in terms of tuning and creating distortion, definitely better than JFets, Bsiab, BJT, Op-Amp, ways of creating distortion.

3) Compact tube preamps, possibly in combination with LND150. For example, Synergy and Shift Line products.

[Steben]

Not sure the opamp and diode idea is bound to be compressed unnatural. It needs design.
There are loads of tricks. Of course a simple back to back diode clipper with germs will always sound dull and compressed. I can never go really clean nor will it be a tight high gain clipper unless you count on opamp clipping. Do not dismiss the last. Eventual opamp clipping might give a good spice.

[teemuk]

...And Tech 21 had a huge success utilizing mere opamp clipping distortion* intogether with carefully tweaked filtering. In the end, clipping distortion is just a tiny ingredient in amp/effect tone so it's super important just for a specific tiny nuance. Besudes, opamps and diode clipping can mean a multitude of different types of circuits, just like saying "FETs" or "tubes". It's practically indicating nothing.

*(They employ diodes more frequently today but that's another story).

[marcelomd]

I was thinking about this the other day.

Now let's get back to your idea. To start designing, it's worth understanding what you want to create.
1) ...
2) ...
3) ...

The most successful drive/dirt/base tone pedals, in terms of market share and pedal-board-share, are the ones designed to "enhance" existing amps. TS, Klon, OCD, etc. Generally pretty simple circuits.
The next wave is something you plug into a full range power amp, or directly into an interface. It's either digital or really complex.
Analog amp emulation in a box, right in the middle, seems a bit of a niche right now.

[teemuk]

This is what I imagine for "modern analog emulation"

I fail to see what's "modern" in the type of circuitry that was common already in the early 1990's. There's more sophistication in common ADA, Randall, Fender, Rockman and Ampeg/Crate preamp designs and they appeared already in the 1980's! Fourty years old stuff is "modern" to you because there's remotedly amp-like filtering applied and a few extremely simple clipping stages?

TransTube, Valvereactor, H&K Dynavalve, Roland Analog TubeLogic, Pritchard, Quilter, ADA D-Torsion, and alike must be scifi alien technology by these standards. Sometimes I wonder why guitar effect DIY scene mostly circulates around building half a century year old circuits modified with switches that choose between a dozen of diode clipping alternatives, all sounding alike. Then some posts drop me back to earth and I wonder no more.

[marcelomd]

This is what I imagine for "modern analog emulation"

I fail to see what's "modern" in the type of circuitry that was common already in the early 1990's. There's more sophistication in common ADA, Randall, Fender, Rockman and Ampeg/Crate preamp designs and they appeared already in the 1980's! Fourty years old stuff is "modern" to you because there's remotedly amp-like filtering applied and a few extremely simple clipping stages?

TransTube, Valvereactor, H&K Dynavalve, Roland Analog TubeLogic, Pritchard, Quilter, ADA D-Torsion, and alike must be scifi alien technology by these standards. Sometimes I wonder why guitar effect DIY scene mostly circulates around building half a century year old circuits modified with switches that choose between a dozen of diode clipping alternatives, all sounding alike. Then some posts drop me back to earth and I wonder no more.

Agreed.

I meant "modern" as in "opposed to ancient", not as in "cutting edge". Modelling stage by stage, using math and standard components, instead of subbing *FETs and tubes and leaving everything else the same. That's why the quotes.

Quilter & company are awesome. But I think about them as their own thing, not an emulation of anything, even if they started like that.

For the record, I do prefer what Quilter, Darkglass, etc. are doing. New things.