Another potential stunner from Greg Ball

[anatech]

Hi ShinOBIWAN,
No, I didn't know you sold your amps. The never ending search for better amps - or different flavours I guess.

I'd very much like to see a no value schematic as well. Just for technical interest. You never know what kind of ideas our members may have to improve it.

Ever curious, what characteristic of the sound didn't you like? I'm just wondering if it's a standard output mosfet thing, or something else.

-Chris

Edit: Did the cat come quietly, or did he make a break for it?

[suzyj]

Originally posted by anatech
I'd very much like to see a no value schematic as well. Just for technical interest. You never know what kind of ideas our members may have to improve it.

I have to confess to being annoyed when people promote kit amps without providing any details. If a design is any good, it should be able to stand up to scrutiny, I reckon. Hiding good designs does nothing to advance the tate of the art.

Sure, for the person selling the kit, they'd prefer people bought the kit rather than copying the design, but I'd think that publishing the design openly would lead more people to buy the kit.

Hey, Fender publish the schematics for their guitar amps, and it certainly doesn't hurt their sales.

Cheers,

Suzy (just bought an Ibanez guitar and a Fender amp, after checking out its schematic on the web)

[AndrewT]

Hi Suzyj,
Amp guru did post the schematic but with a couple of areas blotted out or with simplifications. Someone even came up with a temp compensation arrangement that he thought would mimic the missing part of the schematic and Greg confirmed it was similar.

He is trying to start up a business and was hoping that this Forum would give him access to a market to make a bit of money, but not a lot.

I believe the full schematic is released with the kit when one purchases it.
To date all purchasers have kindly refrained from making public the full schematic.

[Terry Demol]

Originally posted by suzyj


I have to confess to being annoyed when people promote kit amps without providing any details. If a design is any good, it should be able to stand up to scrutiny, I reckon. Hiding good designs does nothing to advance the tate of the art.

Sure, for the person selling the kit, they'd prefer people bought the kit rather than copying the design, but I'd think that publishing the design openly would lead more people to buy the kit.

Hey, Fender publish the schematics for their guitar amps, and it certainly doesn't hurt their sales.

Cheers,

Suzy (just bought an Ibanez guitar and a Fender amp, after checking out its schematic on the web)

Hi Suzy,

If someone really wants the circuit they're going to get it.

It's funny you mention Fender, because the original Marshall
JTM45 was, I believe, copied from a (Fender) Bassman almost
directly.

And I think Jim (Marshall) sold a few of them

Which Ibanez and Fender did you get Suzy?

I have an old Ibanez electric something from 20 years or so ago
that has a light Basswood body and Floyd Rose on it.

Swapped the pickups out for Bill Lawrence (humbuckers) and a
mini humbucker in the neck, built an active pre amp (buffer),
completely stripped the 1mm thick 2 pack finish, replaced the
scratch plate with a hand made (Jarra) one and it sounds pretty
good.

I also have a '63 (Fender) Bandmaster that is great.



Oh... did you get that SS amp finished?

Cheers,

Terry

[HiFiddle]

This new design is based on Greg's unique SKA topology and
I doubt he would want his schematics published until his patents come through. It does say Patent Pending for a reason.

There has already been a suggestion that his original design IP has been sold to China and I notice he has removed the conceptual design from his website.

Would you give your livelihood IP away by posting it on the internet, Suzy?

[suzyj]

Originally posted by Terry Demol
Hi Suzy,

If someone really wants the circuit they're going to get it.

Yeah, I agree. Especially with something as simple as an audio power amp, and especially if he's offering kits.

Originally posted by Terry Demol
Which Ibanez and Fender did you get Suzy?

It's an Ibanez SA160. A very pretty guitar, methinks. I was looking for a Strat copy, and was really impressed at the quality of the Ibanez for the money.

I've had "learn guitar" on the to-do list for the last couple of decades. It's really good now to finally be doing it, though my fingers are quite sore, and I really am hopeless at it It'll be quite a while before I'm a match for Mark Knopfler, methinks.

The amp is just a straight-forward 15W frontman (transistor) one. It's cheap and cheerful, and surprisingly loud. I toyed with making one, and did a bunch of simulations under LTspice, but in the end simply bought a cheap amp, as there was no way I could build an equivalent for the money.

Truth be told, the thought of deliberately designing distortion into an amp makes me cringe!

Originally posted by Terry Demol
Oh... did you get that SS amp finished?

It's on the go at the moment. I'm expecting PCBs back from BEC on Monday (actually Tuesday as I've taken Monday off). I've been working on a matching preamp as well (see http://www.littlefishbicycles.com/preamp/) which has been heaps of fun.

After I've put the power amp and supply boards together, I'll start on the enclosures. I'm thinking of having some nice machined front panels made to match my other NAD components (which will probably end up costing me an arm and a leg). Have you seen the emachineshop software? I've used it to design my front panels, and it's heaps of fun.

Originally posted by HiFiddle
This new design is based on Greg's unique SKA topology and I doubt he would want his schematics published until his patents come through. It does say Patent Pending for a reason.

There has already been a suggestion that his original design IP has been sold to China and I notice he has removed the conceptual design from his website.

A patent, huh? That would mean that there's something in there that's totally new. If he's really found something new, then he should publish his results for peer review.

Originally posted by HiFiddle
Would you give your livelihood IP away by posting it on the internet, Suzy?

Yes, I would (and do). As they say, publish or perish.

Regards,

Suzy

[pinkmouse]

Certainly in the UK, if you publicise your invention before the patent is granted, it is invalid. Patent Applied For means absolutely nothing in legal terms. If there is a patent, we will see it all when it's published. Until then all we can do is speculate pointlessly, or just buy the kit and find out.

[anatech]

Hi HiFiddle,
I feel for Greg, but as I told him, the first item you sell, the secret is out. Schematics with values will not make a successful rip off. Getting the entire device means you have the latest rev and a working model. It's only a copy job after that.

At least all of us know it's his IP. We can accredit Greg with the design (well, maybe. Since we haven't seen it). I don't understand how all the patent laws work. I do have the feeling they only give you the right to bring suite. Not that helpful for a small guy like most of us. Money then becomes the deciding factor.

Professional ethics are the only thing that maintain order. For those in the world who have none, they degrade life for the rest of us.

-Chris

[Sheldon]

Originally posted by pinkmouse
Certainly in the UK, if you publicise your invention before the patent is granted, it is invalid. Patent Applied For means absolutely nothing in legal terms. If there is a patent, we will see it all when it's published. Until then all we can do is speculate pointlessly, or just buy the kit and find out.

Not exactly true. In most of the world (UK included) you must apply for a patent before publishing. In fact, the patent office itself publishes the application before it is granted. In the U.S. you have a year from from first disclosure to file.


That said, it's still up to the discretion of the inventor as to disclosure of the invention prior to publication of the patent application. You may not want to give your competitors a head start on work-arounds. Also, people may simply ignore the patent. The inventor may not have the means to enforce the patent - it costs money, and lots of it. So why give them an early start? Also, at the time of application the inventor is obligated to disclose the best way to realize the invention. After that, the invention may evolve and become better. Even if the improvements are patentable, the inventor may chose to maintain them as a trade secret, instead of disclosing them in a patent.

Sheldon