Is there a better amp kit????

[Jonny Hotnuts]

I am about to start a tube amp project and want a solid foundation to work from.


While I am sure the K-12 is a fine amp, I was hoping for a few more watts output and the kit looks a bit... rudimentary.

I would prefer a kit that has a moderate starting price (4-5 hundred) and allow me to choose higher performance components (torrids, better caps ect.) during, or after the build to improve performance.

I have seen kits around like the ST35-70, these seem like they are very much on target with output and complexity but don’t know how they perform. I would definitely prefer to spend a bit more IF the SQ justified the expense.

Is there any other amp kits out there that I should be considering….or is the K-12 a better option? The only kits I can find are the ones I mentioned….I know there are others out there….or is there?


BTW:
I want to build the case so a componets only kit would be better.


Thanks for any suggestions
-JH

[lousymusician]

The Tubelab Simple SE might be an option. It's not really a kit, Tubelab supplies a circuit board, wiring instructions and a detailed shopping list for parts. You can build it exactly as specified, or upgrade parts to your heart's content. Since you plan on building a chassis anyway, the board might be all you need to get rolling.

It can put out 5 or 6 watts as a triode amp, or double that with the outputs in ultralinear. Outputs can be 6L6, EL34, 6550, KT66, KT77, or KT88. Output transformers from $15 Edcors to whatever you can afford. I think mine came in under $400, with decent but not exotic parts.

With the right speakers, it can sound very good. Do be aware that the performance of low-powered single-ended amps generally depends on the speakers presenting a relatively easy load. Inefficient, multi-way speakers with complicated crossovers and wild impedance curves are not what you want with this amp.

Search around the board, there are several threads about this design.

Tubelab

No commercial interest on my part, just a happy customer.

Bill

[chrish]

I will second Bill's suggestion. I am another happy customer. What speakers are you planning to power? You might be surprised at how few "tube watts" you can get away with. I am powering my 92dB Ariels now with a new flea power amp that I am testing out before giving to my girlfriend. 2 watts and the kids are telling me to turn the music down!

Merry Christmas,

Chris

[ArtG]

The DIY-35, which is based on the Dynaco ST-35, is a fine sounding amp. It produces about 14W/channel, although Dynaco rated it at 17.5W. It's a simple but long proven design, and the kit lends itself to parts upgrades, since you supply everything but the board, 'though I guess, that doesn't really make a "kit". A number of these have been built on custom chassis, however a stainless steel chassis is available, specifically for this project, should you desire it.

[defect9]

Heres one I've found to be awesome:

http://www.engineeringvista.com/audi...el-1/index.htm

The model one full pack kit was about... $245 after shipping for me, if i recall, and puts out around 6 watts/channel stereo. Upgrades are definitely available (if you use really efficient speakers or headphones, I'd suggest a Hammond 193J choke or equivalent inductor/choke, but the C-R-C filter is good for a start), and you can always go through and upgrade all the resistors and caps with nicer stuff. Lots of options. seriously lots. Boris is always helpful in responding to questions as well (even at 3am my time, amazingly).

Jumper selectable NFB, Triode, Pentode and Ultralinear modes so you can see what sounds best for you. Power transformer can be bought shielded if you choose.

dang, I sound like I should sell these for a living

Also, another vote for the SimpleSE as well. Great option with lots of customizability

-Jared

[tubino]

There are the Decware offerings, or you can take the jump and really DIY.

Just today I unwrapped my pair of James OPTs from Euphonia Audio. VERY fast shipping, $215/pair, and you can use these for a good-sized single-ended amp. I will use them for an 845 run at a low voltage (for an 845), something like 600. I've done a LOT of scavenging over the years, so I don't think I'll have to buy much more than a few caps to build this.

[Ty_Bower]

I'd offer the idea of the DIY ST-35 as a suggestion. While the core of the product is really nothing more than just a printed circuit board to get you started, people are bundling the board with all the necessary extra components needed to build a complete amp. That includes chassis, transformers, discrete components and vacuum tubes.

Here's one example of such a kit. I think you may have already discovered other ST-35 kits on your own.
http://store.triodestore.com/diy35kit.html

It fits your price range perfectly. While I haven't built this exact kit myself, I have built amps using the DIY ST-35 board. I've been very pleased with the way they perform, and I wouldn't hesitate to recommend them to others.

Edit: ...oops. I see you're not really interested in a pre-fab chassis, preferring to build a case on your own. I'd recommend you talk to Matt at Triode and ask if he can offer just the parts. I think he'd be willing to sell you only what you need.

[Variac]

Does the engineering Vista include output transformers?

[w5jag]

There are the actual Dynaco replicas from Dynakitparts. I think they start at about $450-500 USD.

Count me as another vote for the SimpleSE, though.

Win W5JAG

[tubino]

A 2-stage single-ended amplifier is as easy as an amp can be. Any PP amp is more complicated.

But if you buy good output transformers (James OPTs are my recommendation for your budget), then you could make a GREAT single-ended amp with them. You would have something more special, IMO, than any PP vintage, kit, or new. Or at least you would have the iron on the output to do it, but it might take 3-stages to be great.