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Decware Mini-Torri single-ended 6V6 stereo amplifier


erik2A3

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I've watched Decware come a along way over the years since its first introductory amplifier. Over those years I've built a number of both lower powered, single-ended triode designs with 2A3s, 45s, and 300Bs (parallel/shunt feed, Ultra-path, etc. versions, too) as well as modified and rebuilt a number of higher powered push-pull pentode designs. OTLs have been another area of great interest, and the Transcendent Amps have been really great with all Klipsch Heritage.

My wife gave me an absolutely fantastic little amplifier built by Decware, a small company of which I know some of you are aware. It's probably the first amplifier I haven't built myself (or had to fix or repair), and it is a marvelous amplifier with, in particular, our La Scalas and Lowthers. All of my amps are quiet with clean output, but the Mini-Torri, which uses a single 6V6 per channel wins in terms of power supply rejection with our most sensitive and notoriously transparent speakers, the crossover-less (thankfully) Lowthers. I was very, very impressed.

I've heard lots of inexpensive output tubes that in specific circuits sounded incredible, and have heard many in other designs that bordered on unlistenable. At a handful of watts and not in the high power category, I will say it sounds much, much larger than its small weight might suggest. Well-built in the United States, a real gem of an amplifier that has been fantastic with our usual musical diet of acoustic jazz, classical Baroque, solo guitar -- and does truly surprisingly well with heavier program material, too.

If looking for an all-tube design and you're not too hungry for power (some here understand that), and you're not trying to pressurize a really large listening space you might have a look!

erik

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Ski bum: I don't take it the wrong way, and if there is one thing in life I'm sure of (lots I'm not!) it's that. She collects hand made Teddy bears, I tube amps and old radios...and we support one another. I used to dislike putting ANYTHING on top of speaker cabs, particulalrly plants (still refuse that one), but these neat stuffed bears, as 'uncool' as they may look to some as far as a 'serious' audio system appearance, arguably provide some very good room dampening effects. It's a good match!

Tube regulators have been used for a long time and certainly don't 'sound' out of place in this true, dual mono amplifier. Of the other amplifiers we have, the sound of the Mini-Torii is probaby most like the Baldwin organ amp I rebuilt for another forum member....just less powerful.

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Hi Erik- Just wondering if you have poked around under the chassis to see if Deckert is using variable degeneration for the treble roll-off feature that he discusses in the promotion:

"Finally there is
a treble control that has been carefully crafted to take edge off the
top end, from barely detectible to substantial so that you can enjoy
listening to sub-par recordings or internet streams without going nuts
as well as trim the shout right out of your single driver crossoverless
speakers in bright rooms."

Also, have you by chance measured the filament, bias, plate, and screen voltages if tubes like the 6Y6 are swapped in as he says is reasonable to do? As you know, the filament draw of those is far greater than that of the 6V6, so I'd imagine that the voltage to the filament string sags a bit if they are used. I'm also scratching my head about the different impedance requirement of the 6Y6 vs. the 6V6 as well as the fact that the tube can't be run at the same voltages as the 6V6.

Anyway, enjoy the amp! It sure is gorgeous. Hope you can indulge my curiousity. Regards--- Maynard

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The new Tori boast a lot of tube options

1944 RCA Gray Glass 6Y6G

1949 Raytheon 6V6GT

1951 National Union 6V6GT

1950 Sylvania Gray Glass 6Y6G

1950 National Union 6V6GT

1955 Sylvania JAN-CHS-6V6GTY

1959 Tung-Sol 6L6WGB

1960 Canada G.E. 6L6-GB

1961 Raytheon 6V6GT

1962 Ken-Rad 6V6GT

1964 Sylvania 6V6GT

1970 Sylvania 6L6G

1972 RCA / Amperex 5881

1979 Philips JAN-6L6-WGB

1961 CBS-Hytron 6L6WGB

CEI 6L6GB

5881

International

6V6GTA

Ken-Rad Black Top 6Y6G

Sylvania Gray Glass 6Y6G

Westinghouse

6V6GTA

Tung-Sol Type41 6K6

RCA

6K6GT

G.E.

6K6GT

1940 RCA

Type 41 6K6

Sylvania

6F6GT

1961 G. E.

6F6 Metal

USSR

6F6M-1

Ken-Rad

6F6 Metal

6L6 Black Plates

Shuguang

6L6

RCA

Metal 6L6

RCA-Tung-Sol

6L6

Amperex EL37-6L6

Ken-Rad

6L6 Metal

USSR

6L6

1957 G.E. Black Plate 6L6-HP

G.E. Double "00" Getter 6L6GC

Tung-Sol

6L6

G.E.

5881

Sylvania JAN-CHS 5932 Black Plate

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The new Tori boast a lot of tube options








1944 RCA Gray Glass 6Y6G

1949 Raytheon 6V6GT

1951 National Union 6V6GT

1950 Sylvania Gray Glass 6Y6G

1950 National Union 6V6GT












1955 Sylvania JAN-CHS-6V6GTY

1959 Tung-Sol 6L6WGB

1960 Canada G.E. 6L6-GB

1961 Raytheon 6V6GT

1962 Ken-Rad 6V6GT











1964 Sylvania 6V6GT

1970 Sylvania 6L6G

1972 RCA / Amperex 5881

1979 Philips JAN-6L6-WGB

1961 CBS-Hytron 6L6WGB











CEI 6L6GB
5881

International
6V6GTA

Ken-Rad Black Top 6Y6G

Sylvania Gray Glass 6Y6G

Westinghouse
6V6GTA











Tung-Sol Type41 6K6

RCA
6K6GT

G.E.
6K6GT

1940 RCA
Type 41 6K6

Sylvania
6F6GT











1961 G. E.
6F6 Metal

USSR
6F6M-1

Ken-Rad
6F6 Metal

6L6 Black Plates

Shuguang
6L6











RCA
Metal 6L6

RCA-Tung-Sol
6L6

Amperex EL37-6L6

Ken-Rad
6L6 Metal

USSR
6L6











1957 G.E. Black Plate 6L6-HP

G.E. Double "00" Getter 6L6GC

Tung-Sol
6L6

G.E.
5881

Sylvania JAN-CHS 5932 Black Plate

Not sure I understand why Deckert is mentioning brand and year of manufacture?????

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Not sure I understand why Deckert is mentioning brand and year of manufacture?????

I think on the brand names its a smart thing to do. Reason is that I find different brands of tubes have different internal resistance and as a result, behave differently..and sometimes are even difficult to bias correctly. For example I have an amp that was designed around the Sovtek 6550, american 6550's are to hot for it, asian 6550's are too hot for it. It will run any EL-34 and only EI KT-90's, EH KT-90's are too hot for it.

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Not sure I understand why Deckert is mentioning brand and year of manufacture?????



I think on the brand names its a smart thing to do. Reason is that I find different brands of tubes have different internal resistance and as a result, behave differently..and sometimes are even difficult to bias correctly. For example I have an amp that was designed around the Sovtek 6550, american 6550's are to hot for it, asian 6550's are too hot for it. It will run any EL-34 and only EI KT-90's, EH KT-90's are too hot for it.

Interesting point. I haven't run into all that much variance among the US made NOS tubes. I've never used modern replacements (too stubborn not to stay with what I have always used!), but have read that they can perform quite differently. Guess from a marketing standpoint it's a plus in case someone happens to have any of the tubes Deckert mentioned.

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Anyone with experience with their SE84C ("Zen Triode") amp? I was thinking about building out 2 of the mono kit versions for my recently-acquired Heresy's.

Lou

I saw a few in the garage sale section....I think they were sold...but the owners can surely provide insight.

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Tubefanatic

I honestly have resisted analyzing and measuring anything -- nothing, which has never been the case with me. It was a gift, and sounded very right just out of the box, and I wanted to enjoy it that way without the usual dissection and analysis.

But you do have a point. I have some of the tubes that can be used with it, which I can yank out of some old radio chassis I have. The circuit has evidently been optimized for the 6v6, and as I mentioned I'm just sort of inclined to use it this way -- though I do want sometime to check operating parameters. Over the years I have spent so much time experimenting that I often neglect music listening. Our system has also at times been so complicated -- switchable battery bias, standby switches, remote power supplies, etc, that my poor wife was so confused by the insanity that she was afraid to play a record unless I was at home so I could show her the fifteen switches that had to be thrown, and the order to throw them in, before music would come out of the speakers. I have two organ amp rebuilds to look forward to, so can leave this little amp as it is as the gift it was and will continue to be. I don't have a schematic for it, and don't know if they aremavailable. If need be, I can draw it out by hand if I get motivated enough. Erik

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Over the years I have spent so much time experimenting that I often neglect music listening. Our system has also at times been so complicated -- switchable battery bias, standby switches, remote power supplies, etc, that my poor wife was so confused by the insanity that she was afraid to play a record unless I was at home so I could show her the fifteen switches that had to be thrown, and the order to throw them in, before music would come out of the speakers. Erik

Tell your wife that she isn't the only one who has had to live with the insanity that you outlined above! My wife won't even go near the equipment that I use as she doesn't want to be responsible if something blows up (we have a small system in the living room which she uses- tube amp with 1 switch, a tuner, and a pair of KLH 20s.) And I won't even get into the antique radio insanity which is almost as bad. At least she's not afraid to use those. Perhaps a new forum can be started for spouses of insane audiophiles.................... Regards-- Maynard

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Maynard

:) sounds like we share a coomon ground node! Imout together a small system for my wife, as well, though we have another, which is actually comprised of two, with a dreaded system A and system B switchbox . And like you I love old radios -- Crosly, Atwater Ken, Philco, etc. What I have to get my hands on sometime is an AK breadbaord style receiver, but those things, particulalrly if they have their original 01As, can bring a very dear price! But they are so cool! And then there are the Hallicrafters, Hammarlunds, etc. And for some strange reason, old radios sparked an interest in old clocks. After completely destroying a movemnt by taking it apart with the main springs still wound up (the parts flew all over my work room), have since been able to take them apart and get them back together again. It's interesting that I've ran in to a few people who experienced the same valve amp or radio craze who also got into old time pieces. Maybe it's because of how that vintage stuff smells, and I say that knowing you know exactly what I mean. I enjoyed your post!

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Thankfully, I haven't gotten into clocks!!! Given how much I spend on the amplifier and radio stuff I'd get brained with the frying pan if I even brought it up. Vintage communications receivers are amazing and I've restored dozens over the years, mostly for ham operator collectors, many of whom keep at least one vintage station set up. The modern digital ham equipment can of course do many things that the old "boatanchors" can't, but their performance is still breathtaking especially when considering their age (The Hammarlund HQ-180 is still one of the best receivers ever made imo.) I have a friend who has a huge collection of radios from the 20s, including many breadboards, which he's slowly liquidating. If he has an AK breadboard with the 01As for sale, I'll email you with the particulars. And to me nothing compares with the smell of an old wood cabinet radio on a cold winter night when the tubes are nice and warm (my wife has caught me many times with my nose near the back of the radios inhaling the fragrance!!!) Guess I really am nuts.................

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Hi, Maynard

Just got home, but will check in a bit. You mention receivers with which I'm very familiar. I grew up in a family of expert class radio operators,and though I had memorized code to take the test (which I don't think is required now), the bug mever really got me. My dad is thenone Iearned most of what little I knowmaboutmallmof this, and Imused to hate electronics when I was little. But it's how I learned to solder when I was five, making little animals out of pieces of tin can. My dad used to drag me to Radio Shack when it was a store that sold somepretty cool stuff.

Thanks for sending that message about the AK breadbaord. I'll check it out!

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