Any cab simulator circuit worth building?

[emosms]

Hi,
I am a bedroom hobby musician and I wonder if to try some cabinet simulator circuit.
Right now i use a valve preamp, some booster/od in front, then straight into the audio interface, adding reverb and cabinet simulator.
F.ex. Guitar Rig 4 controll room is pretty pretty much decent cab simulator and I like it.
Tried VST plugins (le cab) for loading IR and I cannot say I liked the result.
---
Is there any analog circuit that could match the GR cab simulation performance?
As far as I know, cab simultor outputs/pedals/DI boxes are not much than an EQ response.
I tried to mimick EQ curves in guitar rig, instead of using the cabinets there, and at least simulated it does not sound good.
---
The final point is to make a cab sim that I could plug into a mixing console and have some good result.

Regards

[Pojo]

I'm probably not the best guy to answer this, but if I were to build something in the analog realm I would try to clone a Palmer PDI-03. I've never used one myself but Joe Banamassa has been using those for his front of house sounds for a while now and it's hard to argue about the tones he gets. I remember trying to find a schematic for one some time ago but not having any luck, maybe you'll be luckier.

I put a RunOffGroove Condor on breadboard once but wasn't terribly pleased with it.

The best sims I've heard are digital, as you've experienced with you're GR 4. I believe the better ones take into count more than just EQ curves such as room characterists and small frequency dependant time delays...aspects that simulate actual sound waves travelling through the air which is tough to do in pure analog.

[pappasmurfsharem]

I'm probably not the best guy to answer this, but if I were to build something in the analog realm I would try to clone a Palmer PDI-03. I've never used one myself but Joe Banamassa has been using those for his front of house sounds for a while now and it's hard to argue about the tones he gets. I remember trying to find a schematic for one some time ago but not having any luck, maybe you'll be luckier.

I put a RunOffGroove Condor on breadboard once but wasn't terribly pleased with it.

The best sims I've heard are digital, as you've experienced with you're GR 4. I believe the better ones take into count more than just EQ curves such as room characterists and small frequency dependant time delays...aspects that simulate actual sound waves travelling through the air which is tough to do in pure analog.

There is a schematic floating around for the palmer, but it uses a custom wound transform as most palmer stuff does. IMO its probably THE best sound speaker sim, but not easily DIY'd.

I want one badly, but the cost is just too high.

[anchovie]

It will be easy for a bunch of people to jump on this thread and name all the DIY cab sims that they know, but it seems like you're very particular about the sound you like. You're correct, any projects will just basically be preset EQs. Pojo is right - if you want much more than just a filter takes out the preamp fizz and don't want to rely on your computer for it then you should look into a decent piece of digital outboard gear, and only your ears will tell you which is the right one!

[garcho]

Use a mic! No need to build/buy anything, just stop going direct - instant "cab sound". Guitarists forget how much famous "tone" comes from a $100 SM57. Build a low power valve amp and you can record in a nursery. Just sayin'.

[emosms]

Not really usefull after 10 o clock in the evening .
I am playing on headphones 99% of the time, except when I exercise something unplugged.
Ocasionally in our rehearsal room as well.
---
Some fundamental question - maybe the analog stuff might work well plugged into PA, relying that there are some real speakers at the end?
---
For direct recording, I would still like to have a non-pc peace of gear.
like for.ex. I could use a reverb as a seporate unit or from the mixing console's DSP.
Torpedo two notes - a bit expensive

[mremic01]

I really like Tonepad's Marshall Cab Simulator. It could really use a volume and blend control though, because I think the effect is a bit too much. Like G12-T75's, it's scooped and a bit woofy on the low end, a bit fizzy on the top end, but still sounds pretty good. I used it with my AxeTrak to help get the AxeTrak to sound a bit more natural. Straight to the board, it doesn't sound as good as some other options, but it's better than nothing.

I built an H&K RedBox Mark II, and it's ok. Between an amp and a cab, I've found that it just doesn't have the headroom for cranked 100W amps. I'm not sure how you would use it live, but at band volume, it seems like the amp's output gets distorted by the Red Box before it goes to the board. You've also got a line-in, so you can just plug your pedals/pre-amp right into it and run that to the board. It might work better at 12v that at 9v, but I haven't tried that yet.

The Radial JDX is similar to the Red Box, but quite a bit nicer. There's no line-in though. It's only meant to go after your power-amp. I haven't played around with mine too much yet, but I was able to get better tones out of it than I was with the Red Box. There's no schematic out there that I know off.

You could always build a Sansamp BDDI and use it for it's cabsim. It has a blend, which can help make it sound less processed and more natural. I like running the Sansamp US Metal into the BDDI instead of using the US Metal's built-in cabsim. The BDDI is less fizzy. I've also got a British, which has much better voicing for its cabsim and doesn't benefit by using the BDDI. Set clean, any of the Sansamps could probably act as your cabsim. You can think of it as running your pedals into a particular amp rig that's set clean. The other forum has a thread where they're looking at the different character series circuits and making schems for them.

If you're willing to go the route of isocabs for quite recording, the AxeTrak is the cheapest and quietest option out there. The only problem is that it doesn't sound that amazing, and a higher wattage amp can make the speaker start distorting before you ever get the power-amp distortion going. I use the Tonepad cabsim in front of my 5W amp to get a cabbier sound. Still, it's useable and better than a lot of other options. I recently got my hands on a Rivera SilentSister, which is expensive and massive and can still make the room shake, but it handles more wattage and sounds a lot better.

[emosms]

Thank you very much for the comprehensive response.
Sansamp seems promising, at least what I have watched as demos.
Could someone point me which part of the circuit is the cab simulator? (which opamps)
http://www.aresaudio.com/files/sansamp-schematic.jpg
I will research the other possibilities as well.
----
My idea is to integrate a cab sim (with bypass) into a booster/double driode preamp device.
The device to be able to get a decent sound into PA.
Moreover, I would like to try reducing the load on my computer, taking out modules to be processed .
(f.ex. reverb from small mixer or external unit, cab sim from external unit)
Still not sure if a better interface or maybe better computer could solve some of the problems - I got craclings playing in real time.
And after all, not sure at all if I can get at least comparable to the software cab sim sound or even better 

[Mark Hammer]

1) Several companies make speaker enclosures with the speaker inside a sealed, soundproof box, with a mic suspended inside.  I have no idea just how soundproof and baby/apartment-friendly they are, but the intent is to be able to play loud, mic it up, and still be able to talk over it if you want.

2) The Anderton-designed Stack-In-A-Box project at PAiA has a simple cab-sim.  Description and schematic found here: http://www.paia.com/proddetail.asp?prod=9210K&cat=14

[DougH]

Not really usefull after 10 o clock in the evening .
I am playing on headphones 99% of the time, except when I exercise something unplugged.
Ocasionally in our rehearsal room as well.
---
Some fundamental question - maybe the analog stuff might work well plugged into PA, relying that there are some real speakers at the end?
---
For direct recording, I would still like to have a non-pc peace of gear.
like for.ex. I could use a reverb as a seporate unit or from the mixing console's DSP.
Torpedo two notes - a bit expensive

Yes, with a PA system, the EQ is all you need. When going direct, your best bet is an impulse response algorithm along with an EQ. Not sure what your setup is, if you are always plugged into a computer, most DAW software have good cab plugins these days. I record direct using Reaper ($60 web download) and use its IR plugin along with an apple graphic EQ plugin to shape it like a speaker curve and it works great. Otherwise you'll need some sort of external box as others have suggested.

[mremic01]

1) Several companies make speaker enclosures with the speaker inside a sealed, soundproof box, with a mic suspended inside.  I have no idea just how soundproof and baby/apartment-friendly they are, but the intent is to be able to play loud, mic it up, and still be able to talk over it if you want.

2) The Anderton-designed Stack-In-A-Box project at PAiA has a simple cab-sim.  Description and schematic found here: http://www.paia.com/proddetail.asp?prod=9210K&cat=14

That Stack-In-A-Box looks really cool. I might have to get myself a rack enclosure and put one together. Not only is it cheap, but it's nice of them to provide the schematic.

Most isolation cabinets leak sound, and they tend to sound... well... not so great. They'll certainly cut a deafening roar down to the volume of a loud TV, but a loud TV will still piss off your neighbours. The speaker and mic diaphragm have some suction interaction going on due to the fact that they're in a sealed box. Randall and Jet City each make one, but they have mixed reviews. Randall just came out with one that looks like a 4x12, but it's new and there's not a lot of reports from users about it. Demeter's isocab is a step up, but also a bit more expensive. There was one on the market called The Dead Room by Grendel, but the guy building them couldn't keep up with demand and wound up taking a lot of people's money without being able to deliver on the cabs, and now he's out of business. The Dead Room was supposed to be the best isocab out there at the time. Now Rivera's got the Silent Sister, which has a labyrinth port to allow the iso part of the cab to breath. But it's 999$ and doesn't turn up on the used market too often. That says something for it's quality though: no one wants to sell theirs. The AxeTrak is unique in that it uses a smaller speaker and mic that you can't swap out, but it's smaller, lighter, quieter, and cheaper than all the others. It won't piss off your neighbours. The current production ones are useful, but nothing amazing. It's a great idea that needs some improvement. They're coming out with a new version soon, so I'm curious to see if it's worth trying out.

[Mark Hammer]

That Stack-In-A-Box looks really cool. I might have to get myself a rack enclosure and put one together. Not only is it cheap, but it's nice of them to provide the schematic.

You will note the presence of a 4049-based charge-pump voltage upverter to feed the 12AX7.  That's a handy circuit to turn to when your charge=ump chip drawer comes up empty.

[J0K3RX]

This is my favorite cab sim, period. I use it instead of impulses now also. I have built almost every cab/speaker sim you can think of and this one is "in my opinion" the best! There are no pots or switches, just straight up great sound! Russian design of course.. 



My second favorite is the Hot Line 2 which is a really close second with the Simple Cab Sim above but has a variety of tonal variations.. Russian design again..

http://guitar-gear.ru/index.php?p=proj&id=59

Sprint layout--> http://guitar-gear.ru/proekt/Hot_Line_SpSim2/hotline2.lay

Audio demo
http://rutube.ru/video/fd5bef825afdd000fa8cfeb8812d38a2/?ref=logo

They are both well worth building!!

[ggedamed]

I have to specify that JOK3RX is not russian  .

[pappasmurfsharem]

This is my favorite cab sim, period. I use it instead of impulses now also. I have built almost every cab/speaker sim you can think of and this one is "in my opinion" the best! There are no pots or switches, just straight up great sound! Russian design of course.. 



My second favorite is the Hot Line 2 which is a really close second with the Simple Cab Sim above but has a variety of tonal variations.. Russian design again..

http://guitar-gear.ru/index.php?p=proj&id=59

Sprint layout--> http://guitar-gear.ru/proekt/Hot_Line_SpSim2/hotline2.lay

Audio demo
http://rutube.ru/video/fd5bef825afdd000fa8cfeb8812d38a2/?ref=logo

They are both well worth building!!

For the SimpleCabsim2 what voltage do you run at, Did you use BC560C and BC550C as in the scheme? Would BC550B and BC560B available at tayda work?

Are there before/after clips anywhere?

[J0K3RX]

For the SimpleCabsim2 what voltage do you run at, Did you use BC560C and BC550C as in the scheme? Would BC550B and BC560B available at tayda work?

Are there before/after clips anywhere?

I run it at 9V or 18V.... Don't know about the BC550B and BC560B, I asked Sergey about that a long time ago and he seemed to think it was important to use the ones he listed, so I took his advice. I ordered a crap load of them from mouser.. I have some "after" clips but no before.. I will try to make a couple.

[teemuk]

There's nothing but followers in there so I assume any small signal silicon transistor should work perfectly.

You could probably eliminate about 1/4th of the components if you converted this to use opamp-based followers instead. I reckon the actual tone wouldn't change one bit.

[yeraym]

I built this yesterday and tested it with a punch amp which I have yet to box up, and this will definetly go inside the box with it, it sounds really good. I used my own vero layout:





I built it with 2N3906 / 2N3904 as thats the only PNP / NPN pair I have at hand right now, but I simulated it in LTSpice before. Here is the plot for BC560C / BC550C, 2N5087 / 2N5088 and 2N3906 / 2N3904 pairs.



As you can see, there is some difference depending on the pair series you use, mostly between 2N390X and the others. But teemuk's post got me thinking, if I replace the followers with opamp followers what would be the frequency response look like? I tried to simulate it, please if someone sees and error in my "translation" to opamp based version tell me as I'm not sure I did it right.



Here is the resulting plot:



It looks to me that the original BJT based design is making use of some transistor parameter but I fail to see what it is. Could someone who knows please stand up and explain it?

[pappasmurfsharem]

yerym,

So you built it 3904 and 3906? Can you record some clips?

It looks like from your sims that the 5087 and 5088 pair is almost dead on with the BC550 560c's

[slacker]

It looks to me that the original BJT based design is making use of some transistor parameter but I fail to see what it is. Could someone who knows please stand up and explain it?

The input impedance of the opamp buffers will be much higher than the transistors, so if the input impedance of the buffers plays some part in the filtering, that could explain the difference.
The blue trace on your transistor comparison shows a smaller peak near the upper roll off.