Now building Load-boxes with variable line out.

[TheWinterSnow]

WHAT DOES IT DO?:

It's simple, this stompbox sized box allows the end user to directly interface the output of a tube amp up to 120 Watts directly into an audio interface's line input with no other hardware. Featuring an analog speaker saturation simulator, which adds compression/limiting and harmonic excitement that a speaker imparts on the signal, the Loadbox is the most realistic silent recording solution on the market, and is the cheapest.

FEATURES INCLUDE:

-120W power at 16 or 8 ohms
-Automatic Switched Cabinet Out
-Active buffered balanced line out; 32dBu (max)
-No need for DI into Mic Preamp, the output its ready for A/D conversion
-20dB variable boost for smaller amps
-Hand Soldered, Built and Tested
-Built to order.
-Will ship worldwide. Order at Corvus-Audio.com or by email me at CorvusEngineering@gmail.com
-Comes with 1 year Warranty to the original owner

WARRANTY:

1 year warranty to the original owner, non transferable if sold. Warranty includes any faulty operation from manufacturing flaws. Owner agrees to pay one way shipping to Corvus Audio. Warranty void if opened, non warranty work repair is $30/hour plus parts replaced and shipping. Repair from damage caused by customer repair or modification is full price of a brand new unit. Corvus Audio is not responsible for damages caused by any device that is connected to the loadbox.

RETURNS:

Returns are only accepted if the unit malfunctions from manufacture flaws within the first month (30 days) and the owner does not want to have the unit repaired under warranty. Shipping and other fees are non refundable, owner agrees to pay shipping on returned units.

There is no money back after ordering and there are no discounts for defective units.

PRICE:

US: $140 USD
CAN: $155 USD
EU: $170 USD
AU: $170 USD

TURNAROUND:

Build time can range from 2-3 business weeks. Shipping times are inconsistent but average 2-3 days in the US and 1-2 weeks International.

AUDIO DEMOS

Audio Demos

Resistive vs Reactive loads

 

[TRUIE]

Pretty interesting !
Do you have any pictures of the unit ? (essentially to see the dimensions / how big it is).
What kind of loadbox is it ? (resistive, reactive... ?)

 

[TheWinterSnow]

It will be in an aluminum box 112x60x27mm (typical stompbox/DI pedal size)

http://www.hammondmfg.com/pdf/1590B.pdf

Unfortunately, the load will be resistive as reactive components required to make the reactive load aren't readily available and would have to be self produced which I do not have the tools to build my own capacitors. Inductors are one thing but making caps is another story. I could pick up the correct componets from specialty markets but that would require that I charge at least $300+ per reactive load as the price for those components would be extremely expensive.

 

[TRUIE]

Thanks for the details !
The great thing is that it's very small.
I need a loadbox, but I still can't make up my mind between one like yours (resistive, small) and something reactive based (like the TubeTown Tonehound, but it's way bigger, almost like a little cab and produce some noise).

I don't even know which technology would sound better... I've read everywhere that theoretically a reactive load is better, as it reacts like a real speaker does, but is a resistive load THAT worse ? And also, is the difference big enough to annoy yourself with a big noisy box, instead of a little stompbox thing like the one you sell ?
Do you ever have the chance to compare both technologies ?

 

[TheWinterSnow]

For starters the Tonehound is an actual voice coil without the speaker, so it will make some noise.

Reactive is better, if you could readily get the components it would be one thing, and to me, that massive cost increase would not be worth it. Still there will be a fairly large increase in the quality of the sound as the load will change with frequency, the amount of current being drawn and those various frequencies will effect the way the global feedback reacts, thus making the non-linearity of the frequency response of the amp to become more as if it where loaded by a real speaker. Due to the size of the inductors, they have to be hand manufactured which like I said, starts getting expensive.

Maybe in due time I will start experimenting with making my own components and will provide upgrades for a minor fee of price difference. I would still have to sell a few of the resistive loads before that could become an option. The more items I build/sell, the sooner I can come out with upgrades, newer products, and much larger products. Eventually, MIDI control systems, 5150 clean mod kits and my own line of tube guitar amplifiers, which have been in the wood-works for the past two years.

 

[TheWinterSnow]

Giving this a bump. I was quite expecting a little more responses from this. There are a few that did email me but I never got any replies back.

I also want to hear more opinions of features, pricing etc. What would you want/expect from the product.

 

[polifemo]

Interested, and some pics n´clips would be of great help!

 

[aortizjr]

Wow I think the price is totally fair.

I currently use a Ted Weber Load Line to do something similar. What I also use is a Behringer GDI for speaker simulation when tracking. That way I can do the whole thing with zero latency. IR's eat CPU making hard to have low latency when recording a full band. I still keep a "clean" version doing IR's when mixing though.

So if any feature I would like, it would be that. A built-in speaker simulated output. Now I have no idea what that would take. Not sure it would even be useful to anyone else. But I find it a great alternative to an Iso cab or excessive bleed.

 

[TheWinterSnow]

Wow I think the price is totally fair.

I currently use a Ted Weber Load Line to do something similar. What I also use is a Behringer GDI for speaker simulation when tracking. That way I can do the whole thing with zero latency. IR's eat CPU making hard to have low latency when recording a full band. I still keep a "clean" version doing IR's when mixing though.

So if any feature I would like, it would be that. A built-in speaker simulated output. Now I have no idea what that would take. Not sure it would even be useful to anyone else. But I find it a great alternative to an Iso cab or excessive bleed.

I could one up you and provide an impulse loader as well. I am actually looking at DSP chips, was also looking at other digital audio which brings me to another product that I could easily release within the week (8x8 channel ADAT optical preamp).

Anyway, with the impulse loader, there will be a DSP in the load box which will allow users to upload custom impulses via SD Card. I may even provide an SD card with all the common/standard impulses used around here and may try to work with some of the better Engineers here to make our own impulse libraries just for the loadbox. Unfortunately I do not have the DSP programming skills to implement impulses, so I would hope that an amp sim programmer or some other professional programmer from the forums would hit me up on the endeavour. I am offering royalties to all programmers involved. If I could also find programmers that could write drivers I could easily turn the 8 channel preamp into a firewire interface. That I could probably do on my own, but would take some time.

 

[sprack]

Would seem simpler to run and Arduino or Beagle board in line. You could read a USB key with IR files or have a slot for SD/CF and wouldn't need a DSP specialist.

 

[aortizjr]

Interestingly, I have been considering putting something similar together.

I have been wondering if an Arduino has enough to horsepower to handle the calculations. You might need something like that just to handle the interface.

My other thought was something like the Marvell Kirkwood ARM. That way you get low power, and it has A/D D/A built in.

I have done plenty of programming and have done some assembly and PLC controllers. But I don't know much about DSP.

The problem with going that route is the expense. Looking at speaker sims, they are just a few opamps, resistors and caps, essentially a low-pass, high-pass then a set EQ.

Going SHARC, ARM, Arduino, etc. is going to add up pretty quick. Especially in small runs.

We might start straying off the thread. But it would sure be a cool product and a fun project!

 

[TheWinterSnow]

Arduinos don't have the horsepower to handle that sort of processing. The larger audio based ones might be able to but the number of cores and the clock speed have me a little worried.

The Arduino chips themselves aren't bad (under $10) and the AD/DA ships are packet change it just comes down to the programming.

I wish I could find open source code of just the basic impulse loader and simplified audio .dll hosts for microcontrollers/DSP.

 

[drew_drummer]

I think I'm gonna be switching my live rig around soon. Gonna switch back to the Laney VH100R I reckon... and I'm thinking I may get another amp, use a load-box with it... and then run the send effects out of this second amp, into the FX loop return on my Laney - letting me use two preamps with one power amp and cab. I'm assuming your loadbox would be ideal for that... ??

It's just an idea at the moment.

 

[TheWinterSnow]

I think I'm gonna be switching my live rig around soon. Gonna switch back to the Laney VH100R I reckon... and I'm thinking I may get another amp, use a load-box with it... and then run the send effects out of this second amp, into the FX loop return on my Laney - letting me use two preamps with one power amp and cab. I'm assuming your loadbox would be ideal for that... ??

It's just an idea at the moment.

Yes that could be done. I could also have the inputs for two power amps into one cab and make them foot switchable so that you could switch power amps on the fly as well.

 

[drew_drummer]

Yes that could be done. I could also have the inputs for two power amps into one cab and make them foot switchable so that you could switch power amps on the fly as well.

You mean like the Radial Headbone VT? Is that safe to do, wont damage the amp??

 

[sprack]

The A9 can do it. Pandaboards aren't that expensive for dev boards either, $180 on Mouser.
http://www.mouser.com/pandaboardES/?cm_sp=homepage-_-newproducts-_-OMAP4460+Pandaboard+ES

There are also some custom libraries for the NEON instructions that substantially reduce utilization as well.

 

[TheWinterSnow]

The A9 can do it. Pandaboards aren't that expensive for dev boards either, $180 on Mouser.
http://www.mouser.com/pandaboardES/?cm_sp=homepage-_-newproducts-_-OMAP4460+Pandaboard+ES

There are also some custom libraries for the NEON instructions that substantially reduce utilization as well.

Now that may be a bit overkill. Still don't know how extensive and how powerful the chip itself will need. It will need at least a few KB or ROM and RAM, but its the processing power that I want to be fast enough, but without being overly powerful because that brings up cost. I am going to have to talk to some programmers if this feature will ever come to fruition.

 

[caneris]

so has anyone done any tests of the line-out from a load box vs the preamp line out into an impulse? i.e a line out including the power amp and a line out with just the preamp into an impulse (guitarhack etc).
i thought i would ask before i do my own test with my Weber

 

[TheWinterSnow]

You mean like the Radial Headbone VT? Is that safe to do, wont damage the amp??

It wouldn't be damaging, if it is done right. If the switching speed is quick enough the amp would never know that it even switched from the cabinet to the dummy load.

so has anyone done any tests of the line-out from a load box vs the preamp line out into an impulse? i.e a line out including the power amp and a line out with just the preamp into an impulse (guitarhack etc).
i thought i would ask before i do my own test with my Weber

I would love to hear it. The difference should be very large, as even when the power amp is not distorting, they still are coloring the sound that you just don't get out of the preamp alone. The big thing that needs to be done if more and more people start going this route is that impulse designers need to start using ultra linear solid state power amps to make their impulses.

 

[caneris]

I would love to hear it. The difference should be very large, as even when the power amp is not distorting, they still are coloring the sound that you just don't get out of the preamp alone. The big thing that needs to be done if more and more people start going this route is that impulse designers need to start using ultra linear solid state power amps to make their impulses.

That was my train of thought as well, ill do some tests later tonight with a few different impulses (hopefully i have a SS power amp impulse somewhere). I post the results back here once im done.