Tubelab Single Ended

[xecluded]

I've seen many 45, 2a3, 6BQ5 single ended tube amps outhere with only a few resistors and caps. How come the tubelab SE and simple SE have so many parts in them as I've always heard when it comes to single ended, simple is best. I am thinking about buying one of their kit but so many parts used gave me a reservation.

[Bas Horneman]

Just off the top of my head I think that is because most schematics are separated between psu and circuit. And the tubelab puts them both on one pcb so it appears as having a lot of parts.

[Bas Horneman]

Just had a look at the tubelab schematic. There is a little more complexity but it is where it counts.

Besides in the end urban legends should remain urban legends.

I mean simple is good. But sometimes complex is better.

[quikie22]

Simple circuits work well when the demands on it are low.

SE with small power requirements usually get by with the simplest of topologies.

However as power output demands on it increase, especially with larger tubes ( with larger capacitances), the driver stages become "saturated" or there is "blocking distortion". Tubelabs design ensures that all these problems are looked into to maintain power output and minimise distortion. So as a result, the circuit becomes slightly more complicated.

[xecluded]

Not sure if i am convinced with the responses yet

I did some google and found this: The road to nirvana

Looking at that schematics, there really only a few parts in the amp and i bet it sounds great. Too bad, i just don't have the skill to build it from scratch.

[bayermar]

Keep in mind, the tubelab SimpleSE schematic shows BOTH channels for stereo.
In addition (as Bas already stated), the PSU is shown - all in one schematic.
So, looking at one channel only, I don't see the complexity?!?
There are a few options (switchable if you like) shown, too. If you would look only at one possible configuration, the the urban legend rule would be satisfied - it's really a "Simple"SE in terms of layout (not talking about the work that went into it to optimize it, I guess).

Martin

[xecluded]

You are probably right. My reason for posting is just to learn and not out to say any bad thing about tubelab as I am newbie and clueless about how these things work. I am sure there are good reason as to why they design circuit as such. Thanks.

[pedroskova]

I've never known George to add anything superfluous to any of his designs.

[Mr. Zenith]

I'll have to agree with Bas and Pedroskova on this one. Besides, it's all in how you view the word "simple". I've built lots of stuff from scratch, and I can tell you that it's no small task to build an amp of even "road to nirvana" simplicity. Parts count is only a tiny part of the equation; sourcing those parts, ordering, designing the enclosure, mechanical issues and post-build testing all conspire to increase the complexity of any project. I'm not going to even think of delving into the issue of circuit design.

What Tubelab has done is take care of most of these issues, while giving folks a chance to experiment and customize. His are proven designs that are extremely well-documented and thoughtfully executed. I haven't yet bought one of his boards, but you can bet your buns I'm gonna buy one - or one of each, if possible - as soon as I'm a bit more certain of my employment status.

[kmaier]

Well, I don't it's the responsibility of the forum to convince you of anything, only to share knowledge / experiences

You should be able to find dozens of 45 SE schematics on the net without issue. I would recommend some basic reading here:

www.wavelengthaudio.com/bugle.pdf

This will give you yet another simple 45 schematic and the design methodology used including sidebars on how values are calculated. It really is a good read, even though I'm not a fan of SRPP.

Finally, while the schematic you posted is fine, the cost of the OPTs alone will be probably be more than everything needed to build the TubeLab circuit, which is a solid design.

As you're admittedly a newbie, don't expect to reach nirvana as a first project. Do think of it as a journey and have some fun along the way... and you'll learn lots. Best of luck on your first project.

Regards, KM