Zen Triode amp by Decware

andrew Ivimey · Post by **andrew Ivimey** » Tue Nov 06, 2007 6:52 pm

I see there is one of these tiny amps on eBay right now.

Has anyone any experience of them?

I knocked one up this afternoon in the old chocolate box amplifier as it was using two el84s anyway.

There are so very few components and I used a solid state PSU just to get up and running. It is cunningly simple.

It sounds, nice and natural, whatever! through 208sigmas.

There isn't much to experiment with but I will try a few things. It sounds worth it.

Post by **Nick** » Tue Nov 06, 2007 8:06 pm

As it happens I have one here now, someone local asked me to change the mains TX from 120 to 240. I haven't listened to it yet, nut I can plug it in tonight if you are interested.

andrew Ivimey · Post by **andrew Ivimey** » Tue Nov 06, 2007 9:53 pm

Nick, can you tell what the resistors are? What is the coupling cap?

And that's about it because that's all there is. What do youmake of it? Right now, my PSU hums; easy to sort and easy to go valve as specc'd.

Oh yes, where are the output transformers? They must be tiny - any idea of the spec? I believe they are 10K. I'm using 5K (nominal) as that's what I have to hand.

bestest, Andrew

pre65 · Post by **pre65** » Tue Nov 06, 2007 10:44 pm

Hi-i found the build instructions,but no component list.

The only part i could see was a couple of 32uF+32uF LCR caps.

http://www.decware.com/newsite/mainmenu ... .htm&intro

andrew Ivimey · Post by **andrew Ivimey** » Tue Nov 06, 2007 10:51 pm

Thanks Nick, that's all very interesting. No expensive bits there!

I'm using el84s but have ordered SV83s just to see.

pre65 · Post by **pre65** » Tue Nov 06, 2007 11:41 pm

Hi-i have a circuit diag now,but its too big to attach.

I have sent Andrew a copy,any one else wants one PM me an e-mail address.

Post by **Nick** » Tue Nov 06, 2007 11:52 pm

Can I have a copy Phil?

Andrew, the TX's are small, but big enough (IYSWIM), coupling caps look like solens, seems a good build, tight on space (as you would imagine), but its using nice bits, Sprage (sp) Atom caps, and dale resistors, and what may be AB resistors as well. I suspect its gojng to sound good, I can't tell, as I have both the mainx TXs out and I need to get some more heat shrink to extend the leads.

andrew Ivimey · Post by **andrew Ivimey** » Wed Nov 07, 2007 7:57 am

weeeeeeeeeeeellll I'm using Dale resistors too, because they came to hand. RS coupling caps till the 5th cavalry arrive in the shape of Obligattos or Russian teflons and I will do a valve rectifier to smooth things over, in that dept.

'IYSWIM' oh yes, that took a little thought.

Well 'spose you don't need huge trafos as the kind of speakers to be used have to be v.sensitive. But are they tiny nickel molibdenum alloys, mined on Mars, wound with the pubic hair of 72 virgins, round the 14th vertebra of the ravenous bugblatter beast of Trall, IYSWIM (!)

Mine are $19 Hongkers trafos.

Decware ain't cheap.

pre65 · Post by **pre65** » Wed Nov 07, 2007 9:51 am

Nick wrote:Can I have a copy Phil?

Hi Nick-has been sent.

andrew Ivimey · Post by **andrew Ivimey** » Wed Nov 07, 2007 6:17 pm

I cranked the B+ up to 330volts this afters, and cut the heater voltage on the 6N1P to 6volts. It was 12, glowing very nicely indeed and I hadn't thought to alter that where had been an ecc83 in that socket a few hours earlier.

Better! much better. Louder, more top.

I will be interested to hear what you make of the real Decware harticle when you have the UKvoltagetransformer sorted, Nick.

Post by **Nick** » Thu Nov 08, 2007 12:14 am

I should have it done tomorrow hopefully.

Post by **Nick** » Thu Nov 08, 2007 10:53 pm

Finished transfering the TX over this aft. Sounds very nice. Maybe a bit thicker than I would prefer myself, but I can see why people like them.

I think the shared ouput cathode resistor is creating a slightly wider than reality sound stage. But in this one, unlike Phil's diag, its bipassed with a cap.

I think the designer has made the best of the little thing. Not dissimiler in sound frwom what I remember of the dod special.

andrew Ivimey · Post by **andrew Ivimey** » Fri Nov 09, 2007 6:58 am

hm, easy enough to split cathodes and add caps, even use ultrapath! all tone control stuff really and then it changes from being 'Zen'.

As for maybe sounding like the Dodd, I have built quite a few tiny amps and several recently I am beginning to think that all these amps no matter what brew, sound the same; its just what valves do.

I need a holiday (so I havetime to concentrate on a big amp, again!)

Darren · Post by **Darren** » Fri Nov 09, 2007 9:06 am

Yes that was my conclusion some time ago. That is, the type of valve you use has the biggest influence on the sound.

Sure, changing parts and topologies will alter it some, but the valve has the biggest influence.

audio-talk

Zen Triode amp by Decware

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