A new type of tube guitar amplifier

[gonzo]

[webmaster edit] This post was reported as spam earlier, and we've cleared that up now. The OP would like to state that this is not a product of his and he has no connection with the builder. He was just attempting to point out this new product to his fellow TDPers. [/webmaster edit]




i just found this.
i thought it was fascinating, thought i would share.



A NEW TYPE OF TUBE GUITAR AMPLIFIER

(my apologies if this has been covered before)

Milbert GAGA-50


http://www.milbert.com/guitar

http://www.thegearpage.net/board/sho...1&postcount=42

[Tele-phone man]

Wow...very interesting. This is really something new! There's a lot here to read and think about.

[ThermionicScott]

That's fascinating!

[JohnnyCrash]

OT's and their "limitations and distortions" might actually be what some people like.

At the same time, this is completely fascinating to me... how does it work without transformers? Any wall voltage? 5 lbs.?!

I'll be at NAMM in a few weeks - I have to try this amp out!

[redstringuitar]

No transformers, any valve, auto biasing?? I'll be looking out for more on this baby...pretty sure it'll be way out of my budget though.

[MickM]

Figures, I'm just getting to the point where I have a slight understanding of how my Champ works.

[jefrs]

Apparently the ZOTL (sp?) system uses a RF transformer, not an audio-output transformer. It does have transformers. They must be very light. What does it do for mains?

[redstringuitar]

Originally Posted by jefrs

Apparently the ZOTL (sp?) system uses a RF transformer, not an audio-output transformer. It does have transformers. They must be very light. What does it do for mains?

Good question, it has to go high voltage DC for the power tubes to work, surely?

[ThermionicScott]

On second thought, I'm starting to wonder if the tubes do anything besides light up...

- Scott

[anacephalic]

these guys may have been the first to apply the technology to guitar amps but OTL amps have been around in high end audio for a while. It's been about 10 yrs +/_ since i first read about them. Never researched them much since i had a set of tube amps i was, and still am, in love with.

[rangercaster]

thanks, but i'll wait 'til the Chinese clones are available ...

[Zillinois]

Interesting idea, sort of sounds like the Marshall Vintage Modern, whihc uses KT-66s, or "totally lacking tube warmth".

[ruger9]

Originally Posted by Zillinois

whihc uses KT-66s, or "totally lacking tube warmth".

You obviously haven't heard a Docter Z Route 66...

[barkley]

Wow. I dont really understand how tube amps work, but I really have no idea how that one works!


Glad they work tho... :)

[Billm]

It appears to be a fresh combination of existing technologies. You can get off-the-shelf high voltage switching power supplies that are smaller and lighter than conventional power transformers. Output transformer-less (OTL) circuits have been around for decades, as Anacephalic points out. I think that many of the designs are engineering exercises--mental challenges, not necessarily a great leap forward in tone or audio fidelity.

Here's a page on OTL design for the curious:

http://www.tubecad.com/2006/12/blog0093.htm

This guy even sells a board and experimenter's kit so you can build your own OTL amp.

As Johnny Crash says, our ears are trained to the kinds of distortions produced by output transformers, however slight they might be. Audio transformers have been around for 100 years and have gotten rather good. It wouldn't surprise me if the Milbert amp had some voicing in it to tailor the frequency response to players' expectations. Compared to transformers, speakers impose far greater distortions and limitations, so I'm not all that impressed by OTL designs.

The hi-fi megasnob, however, could have a direct-coupled (no capacitors) OTL system driving planar electrostatic speakers for the ultimate in perfection. The technology is wonderful, but insanely expensive.

Today, power transformers, diodes and big electrolytic caps are still less expensive than a 400-500V switching power supply, but who knows, maybe it's time for that technology to trickle down. Ditto for OTL. A 35 lb. Twin Reverb would be pretty cool.

[Dan German]

Very interesting. I like the fact that they provide a lot of technical info (even if I don't understand half of it ) instead of the usual vague promises of "groundbreaking design" and "incomparable tone and warmth".

The copy, however, shows that letting engineers write their own copy is almost as bad as letting copy writers design amps. "Harshless alacrity" indeed...

I'm perfectly happy with the overweight, old school amps I have now, but I'd like to get the chance to play around with on of these, once they actually exist.

[klasaine]

That's definitely something I'll check out at NAMM.
The sound samples didn't impress me too much - sounded like 'modeling' cleans and dirtys - but I never rely on sound samples via dig recording and through a computer to really tell me anything.
We'll see - would be great if it's for reals.

[Billm]

Ready, fire, aim!

I just read their patents and tech descriptions and it's nothing like previous OTL designs... and my previous comments have limited applicability. This really is fresh. It strikes me as an audio-modulated switching power supply that incorporates the transfer characteristics of tubes in order to warm up the tone.

I'm looking forward to members' reactions when they get to play it.

[jhundt]

darn, will I have to sell my '55 Deluxe to buy one of these now?

[keithcc]

This basic design was done by David Berning almost 20 years ago and was discussed in the audio buff magazines, particularly <i> Audio Amateur/ Glass Audio</i> quite a bit. Using it for a guitar amp seems ridiculous since it will not generate any of the characteristic sonic modifications of an overloaded, undersized-transformer, undersized power supply conventional tube audio amplifier of the late 1940s.

But yeah, it works.