Help with Decware Zen EL84 SET

[rvrazvan]

I'm learning searching and gathering parts for my first amp. I had an SEP in mind in the first place but right now i'm obsessed with Decware's SET. The amp can be briged so starting from this ideea i want to make 2 of them(one for each channel) so i can have 5W per channel of sweet triode mode sound. The problem is that i don't want to use 4 transformer and i need some help here.
I'm assuming that it's more than just pulling one of the transformers out of the schematic.

http://www.decware.com/se84cschematic.pdf
Any ideeas?

[tinitus]

bridged ?

with 2 kits its 600USD
quite some money to get 2x5watt
and you still need enclosures
and shipping from US

you might just as well look at this kit
KT88 SE Basic or Master Kit

or Bottleheads new cheaper 2A3 Stereomour
http://www.bottlehead.com/store.php?...on=show_detail


whatever, why a kit
with tube amps Im not sure I like the "just connect A to A and B to B", without knowing anything about what is what
no need to be an expert, but may still be good to learn just some of the simplest basics
a bit more work, but maybe more rewarding in the long run

this simple EL84 drive EL84 looks like a fun project
but I have no idea if its good or not, but looks ok
and just lately there have been info on affordable trafos from EU
http://home.comcast.net/~jafix/SakumaEL84.html

[eeyore]

It is a lot of work together 5w, but 5w of SET is expensive. Have a look at http://diy-audio-blog.blogspot.com. Not efficient using two output TX in bridge mode. It becomes, I think a Class A PP. Or you can try the same design by with 2 EL84 in parallel, upping the currents, of both the PSU and the output TX and also half the impedance of the TX.

[Eli Duttman]

Originally Posted by eeyore

It is a lot of work together 5w, but 5w of SET is expensive. Have a look at DIY Audio Blog. Not efficient using two output TX in bridge mode. It becomes, I think a Class A PP. Or you can try the same design by with 2 EL84 in parallel, upping the currents, of both the PSU and the output TX and also half the impedance of the TX.

Strapping SE84s into monoblocks does not lead to something resembling Class "A" PP. The O/P trafo secondaries float. Therefore, strapping is a simple matter. You connect the I/P jacks in parallel and wire the O/P trafo secondaries in series. There is no cancellation of internally generated even order harmonic distortion products.

PSE is not without problems. To prevent current hogging, "fixed" bias, with individual adjustments, is essential. Close matching of tubes helps, but the remaining small differences require compensation.

[planet10]

If you want 5W with an SE build an RH84. My current RH84 monos started out as Decware "clones"... over about 7 major iterations they turned into th RH84 i have. RH84 has both more power &, in my opinion, sounds better. Using recycled primary iron, all new poly cap power supply, the amps still only cost ~150 (we ended up with a stereo & a pair of monobloks)

With the budget required to buy 2 Decwares you could end up with something a whole lot better.

dave

[rvrazvan]

Thank you for your input Dave. You are probabley right. But i have developed some sort of an obsession for the Zen. The cost will be low anyway. I've bought an old radio today from wich i will take the power and output transformers. I have 4 EL84 all ready.
As a compromise i might try to make a dual mode amp. But the main goal is to have 5w in triode mode. There must be a solution.

[Mosquito]

Hey! not exactly related, but it seems that the Jafix / Sakuma thing pointed by Tinitus can actually work.
I do have a bunch of japanese 16GK6 and now, I'm thinking to give it a try.
Some optimization is necessary though...

[rvrazvan]

Originally Posted by Mosquito

Hey! not exactly related, but it seems that the Jafix / Sakuma thing pointed by Tinitus can actually work.
I do have a bunch of japanese 16GK6 and now, I'm thinking to give it a try.
Some optimization is necessary though...

Well give it a go an then let eu know

[K.A.B]

I've looked at the various schedules also at one time who are here in the thread but I chose a completely different amplifier after I found this Japanese page Single Ended Amplifire D.I.Y go to the EL84.

I have used the opt from edcor xse-15-8-5K and a main transformer from Frag Jan zuerst --- Ask Jan First TRA200 with all the parts it cost about € 150.

How does it sound, very well indeed what impresses most is that the bass is very tight after a comparison with an Audion silver night we were all sitting there with a smile on our faces.

I highly recommend this amp.

Anders

[eeyore]

If you want 5W, and are happy with a triode strapped pentode, why not use EL34/KT88 instead, or even more exotic Russian NOS GU50?