Decware SE84C-DIY VS. Tubelap Simple SE

MillerLiteScott

I have been doing some reading on different DIY amps for my next DIY project. At first I thought I would go with:

1. S5 16LS @ $ 250 for kit including tubes on a breadboard.
I think I have decided against this due to inherent problems with buzzing and weak transformers supplied.

2. Next was the Tubelab Simple SE. @ $ 42 for a PCB shipped. It is up to the builder to purchase all the components which allows you to pick and choose which brands and control the cost. Tubelab supplies a list and has different options for all the components. The simple SE can run 6L6, EL34, KT 88 with out any adjustments. I am guessing the estimated cost for my build would be in the $400- $500 range.

3. Just added to my list today is the Decware SE84C-DIY. @ $ 299.00 plus shipping/power cord/ Tubes (1) input 6922/6N1P/6DJ8 & (2) output SV83(6P15P-EP) or EL84. This is a PCB based version of their PTP version less the tube rectifier.

Anyone have any experience with these amps or have any opinions?

Scott

mhardy6647

I have a Decware SE-84B (factory assembled, point to point). It sounds pretty good, but was replaced instantly in my hifi when I built and tried a pair of Bottlehead Paramours (SE 2A3). The Zen has very low power; I could not listen to 'little girl with guitar" music at moderate levels on a pair of Klipsch Cornwalls without audible 'straining' by the amp. Realistically it is probably capable of less than 2 wpc (with "SV83" outputs) at reasonable levels of distortion into a reasonable bandwidth. Its other idiosyncracy (quite deliberately chosen by Steve Deckert) is 6 ohm secondaries on the output transformers. It sounds awful with 16 ohm speakers (e.g., Lowthers, Altec VOTs) as a consequence, which is too bad. If you have high sensitivity 4 ohm speakers, though, it should be well matched. The Zen would make an excellent MR/HF amp in a bi/multi-amp system. I've not heard the "C" version, but I suspect it is very similar.

I cannot vouch for the current S-5 amp, but the original one (we have the stereo version using PP 11BM8 output tubes) was astonishingly quiet (again, on the Cornies, which are in the range of 98 to 100 dB/W/m depending on what you read) and sounds quite good on the Cornies or many other speakers I've tried it on.




I cannot say anything about the Tubelab Simple SE. Does it run the outputs in triode mode? If so, the power will be quite low, too.

Did you consider the Bottlehead SEX?
http://www.bottlehead.com/et/adobespc/S.E.X./SEX.htm


Hope this is helpful.

EDIT:
There's also this little guy
http://www.sparetimegizmos.com/Hardware/Stereo_6t9.htm
or:
http://www.tubes4hifi.com/6T9amp.htm

And, from the late, great Fred Nachbaur:
http://www.dogstar.dantimax.dk/tubestuf/miniblok.htm

These (and the Single-Ended eXperimenter's amp from Doc Bottlehead) are what are sometimes known as "spud amps"... one tubers! :-)

MillerLiteScott

Thanks mhardy for all your input. I have yet to go to all your links but I will in a little while.

I am thinking about using this amp initially with my RTA 11t's because I think they are @ 94 db at 1 watt. After that I may look into some diy speakers.

My main concern is budget and ease of the build because I am still new to the game. This will also be for a secondary system of which I have no room for.

Scott

mhardy6647

www.dynakitparts.com
Save up for a few more months and get the ST-35 kit; it's good stuff (about 14 wpc, which ought to do if for genuinely 94 dB sensitive speakers).

fredv

Hi Scott,

I have no experience to any of the above that you listed, but based on what I have read so far, I will come to the same conclusion Decware or SimpleSE. Decware kit has everything that you need, and there are still quite a bit of shopping after you have the SimpleSE in hand. MRH: if I remember correctly, you can wire the SimpleSE is triode or UL if the OT has UL tap. Due to the flexibility of selecting better iron and components (also mean more costly :-)), I will choose SimpleSE if I am choosing from the 2. George is also very supportive, and you can find a lot of help from diyaudio.com. Many have built and love the SimpleSE, and I think it cranks out about 10wpc.

I have a RTA 11TL. I am not sure how much change was from the T to the TL, but mine really doesn't sound like 94dB speakers, more like 90-91. I used to connect the 11T to a Fisher X-100-3 (18wpc, using 7189, a higher voltage rating EL84). I could crank it to pretty loud but of not much sound quality at high level. So, how loud you play can also be a deciding factor.

I second MRH's suggestion to consider the ST-35. The kit has everything that you need and is proven to be good quality. This hobby is addictive :-) Therefore, it is inevitable that you will attack a bigger project (call that an upgrade) later once you get your feet wet. When that time comes, the ST-35 can be a nice bedroom amp!!

MRH: How's the Eico AF4? Does it see any action lately :-) Just curious, do you happen to the plan for you FE-207E handy? I have pair and looking for some plans.

mhardy6647

The AF4 is not in service; it really needs a spruce-up (although I think it, like the HF-81, has ceramic coupling caps, so they at least are probably OK).



The "plans" for the FE-207E enclosures I have are from Dave J. who posted them at the Bottlehead forum long ago.
http://db.audioasylum.com/cgi/m.mpl?forum=bottlehead&n=69799&highlight=Fostex

MillerLiteScott

Thanks for all the info Mhardy and Fred. I had not considered the Dynakit ST35 or ST70 because I thought you had to find an original one to make the new kits work. They are a bit more $ but probably worth it in the long run.

Fred, I need to e-mail you because I do not think I am getting enough gain with my RS amp. I have to turn the volume up to at least 3 or 4 o'clock to get some decent volume, and I am pretty sure the amp has more power available.

Scott

mhardy6647

Nope, the new Dynakits include everything and are very reasonable facsimilies of the originals (including the iron); for that, they are very fairly priced.

Good luck!

fredv

Hey Scott,
You have my email. If not, email me via the forum. There should be a lot more gain than that. I rarely turn the pot pass 11 before some one yells at me to lower the volume. We will figure out why.

DanielBartholom

Hi:mad:


:)Nope, the new Dynakits include everything and are very reasonable facsimilies of the originals (including the iron); for that, they are very fairly priced.

Good luck!

strider

The more I've been reading about these kits, I'm getting the feeling that, like mhardy said, the Decware kit just doesn't have the power.

I'm split between the Dynakit ST35 and the Simple SE, at least right now. I like the idea of EL84's in the ST35, but the Simple SE just has so many different build options. For a first time amp builder like me, the fact that I can build the amp in its simplest form and make sure it works before I start adding the cathode feedback switch and the UL/pentode (triode?) switches, etc etc really appeals to me. I was concerned at first with the fact I'd need to figure out what transformers to purchase and how that decision would effect everything else in the amp build. The more I read the directions on the Tube Lab site and the various posts on diyaudio, the better I feel. I've never seen a more thorough set of directions then the ones for the Simple SE.

Hopefully I'll be pulling the trigger on something soon, I'm getting there slowly.

MillerLiteScott

Ben,

Let me know which way you want to go and maybe we can save on some shipping cost.

Scott

jeff pants

if your speakers are only low 90's db then i doubt the decware amp will be enough.
they do sound nice though. i have the decware SEP amp, about 6 watts and it's just enough in my large room with some speakers around 94-95db sensitivity.

the amp does have more power with EL84 output tubes, SV83 are quicker to clip for sure but sound a little better.
also, a zen with 16ohm speakers is really not ideal, the amp puts out more power as the impedance drops. they have a mod to change the output transformers for higher impedance speakers but i've read that the amps don't have quite the same magic after that.