I`m looking forwad to burning in as stock with the Tung-Sols which are liked by many. Then later on I have 6L6`s that run at nearly the same bias. I`ll have some extra power/grip V the Rachaels and can run without the CSP2+.  The new fidelety is something I`m keeping a lid on as I know it`ll be there but what shape/form it will be is like wondering what your getting for xmas.  :)

You may or may not know this but you have serial 001, the first production TORII JR to go out the door.  Naturally I'm listening to it right now as I read the forum.  Using a worse case scenario - that being an amplifier with about 5 hours on it and pairing it with the one pair of speakers in the world that acts like kryptonite on a TORII.  Just enjoying how good it sounds despite my attempts to handicap it with a worse case scenario which btw completely failed.  

This is a technique I find useful because when an amplifier rises above the handicaps and sounds great when it clearly shouldn't, you can be far more certain it will sound incredible when it's taken more seriously.

I'll probably be ready to let this one go by Wed or Thursday.

Steve  :)

OK, Great News!  I've taken the main photos of the amp and more importantly I have finished the owner's manual!

Your can read the owner's manual here:

https://www.decware.com/newsite/TORIIJRownersmanual.pdf

001 is in the shipping room now and I'm doing the QC on 002.  003 & 004 are in testing, 005 is on the bench... well you get the idea!



We should just call it the TORII UFO.  And yes I glued mine to table this time.

Anyway, I fully expect the 20 page owner's manual to answer all your questions.  Please read through it and post your comments or questions I missed or only partially answered here.

Now the only thing left is to make the web page

Steve

Steve said:
"We should just call it the TORII UFO."

I like "TORII UFO" better than TORII Jr.

Brian

I downloaded and read ( and enjoyed! ) every word in the owner's manual.

What is interesting is the (really) fixed bias approach to using only EL34 tubes.

I wonder if it would be possible to implement a toggle switch to handle different output tubes?

I'm sure Steve has valid reasons for his choice of output tubes in his amp design.
But a chronic tube roller like myself just can't help wondering what if......

For my Torii MK4, in my set up, I do prefer EL34s over KT66s.

Cheers !

I expect my Torii Jr. to be shipped within the week so I, too, have studied the manual. I fired an email off to Steve to ask some questions about the impedance switch which I didn't see covered. If you are curious, the rear position is HI and the forward position is LO. The switch is meant to be used "on the fly" so you can judge the best setting for your speakers.

So did I but it doesn't address the question of which position is HI vs LO. A minor point no doubt since your ears will determine the "best" setting but it is still nice to know.

LAST MINUTE CHANGE OF HEART...

So far only 001 has shipped out, I pulled 002 from the shipping room.  

During my listening tests when I tried all the possible output tubes (EL34, 6L6, KT77, KT66, 7027) I found the EL34 to be the best sound and the most power of all of them in this amplifier.  

Part of the reason for this is because when biased at 40 mA the high voltage in the amplifier is at the perfect point of 333 volts feeding the UFO output transformers, and the OA3 which feeds the input stage.  Anything lower than this amount will drop power.  So even though a KT66 may have more power than an EL34 in some amplifiers, in this amplifier it is the other way around.  

The reason for this is because biasing at 50mA drops the high voltage by several volts which changes the power output of the amplifier.

Well sadly the range of tube specs ( in today's current production, with Tungsol, Mullard, EH, JJ, Genolex, and all the Chinese offerings not to mention NOS tubes of yesteryear) is too great to make the bias non-adjustable like I had hoped.

For example, an EL34 that measures 22 mA at 400VDC on the tester would bias up at the target of 40mA just perfect. However, an EL34 that measures 30 mA at 400VDC on the tester would bias up at 50 to 55 mA.   This is why I was very clear in the owner's manual not to use different tubes, like 6L6's or KT66's because they will bias 10 to 20 mA higher!

Since the range of tube specs within EL34's can make the amp bias anywhere between 35 an 60 mA combined with the fact that you know someone will put a different tube in the amp regardless of what the owner's manual says...  I have decided to make the bias easy for the TORII JR owner's to adjust at home.



Here's is how you do it:  

To bias the amp for a new quad of output tubes (must be done every time you install new or different tubes) simply remove the two input tubes and turn the amplifier on.

You will see a center hole in each of the 9 pin tube sockets.  These holes are for your volt meter leads.  The left one is ground (black lead) and the right one is DC voltage (red lead).  Stick your meter probes in these two holes and adjust the bias pot located just in front of the on/off switch.  Let the tubes warm up for several minutes and then adjust the bias pot until the voltage on the meter reads 0.825 Volts DC.  This equals 40 mA.  1.023 volts equals 50mA and is too high.   0.606 volts equals 30mA and is too low.

Amp #001, you have my apologies as your amp is non adjustable. Your upgrade is of course on the house including shipping should you decide to add the mod.

Steve

"It's in the owner's manual on the picture that shows what everything is.  But to answer the question, towards the back is 8 ohms and towards the front is 4.  Sadly, now that you know it will forever change what you hear."

Oops. Hadn't thought of that. I believe a botched Vulcan Mind Meld will cause partial amnesia but its risky and hard to arrange. Maybe I'll have someone (like my long-suffering wife) flip the switches back and forth a bunch and leave them in a random position for a blind comparison.

Hi Steve, just curious ...

1. Does the Torii Jr. produce the even order harmonic distortion similar to the bigger Torii?  

And

2. By now having the bias adjustable ~ we are now able to try other tube compliments such as KT66 (as long as we do the bias adjustment with a multi-meter) and without having to send the unit back to the Decware factory ... am I correct about this?

Thanks.

Lin wrote on 09/02/15 at 00:31:55:


Thanks Lin, I just re-read the new manual reflecting that!

Hi, even though I haven't decided which Zen amp I'm going to buy until I come to ZenFest, how are you guys even seeing the shopping cart for the Torii Jr -- I don't see the webpage for it.  --thanks

Steve sent out a notice with a purchase link in mid July. It went to everyone "on the list" (regular repeat customers maybe?). That's how I  bought mine. It ships tomorrow.