Oblivion | UltraSonic Studios
Feb 20, 2021 at 5:34 AM Post #1,246 of 1,401

UntilThen

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I've got many good friends on Head-Fi and though we don't get in touch much, help is just a pm away. Yes it's a joy to talk to gibosi or Ken as I know him.

Tomorrow I'm picking up a GZ34 from another friend. A very good price for a tube that tested new. This is the start of my buying rectifiers for Odyssey.

Mullard BVA GZ34 DD getter code LIJ 1961 Bruxelles Mazda, Made in Holland.
Mullard GZ34.jpg
 
Feb 20, 2021 at 5:41 AM Post #1,247 of 1,401

UntilThen

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Anyway as I told you some post ago, you will also have to do a real Odyssey to find all the matching combination Driver / Otuput / Rectifier...
I did not have to wait for Odyssey to find that out. Elekit combo use similar tube configurations. It is also my test bed for getting the hours into these NOS tubes in preparation for Odyssey. I'm already getting a glimpse into how each of the KT66, KT88, KT77, 6L6GC with Brimar 12au7 long sound like. Not forgetting EL12 spez. When Odyssey lands I would have already known how each of these tubes sound like.

With rectifiers, I've first hand experience for a year on GEC U52, Cossor 53ku, Mullard GZ34 in the Studio Six and Woo Audio Wa22. The tones carry through Studio Six to Wa22. I could actually suss out how each of those 3 rectifiers sound like even though other parameters are different.
 
Feb 21, 2021 at 8:34 PM Post #1,248 of 1,401

DecentLevi

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There will be no 3rd rack that I can assure you. Some of my present amps will go. Eventually only Elekit combo, Oblivion and Odyssey will remain.... and v280 as my only solid state amp. I might change that to v281 because I like that shape better. I know it's been discontinued but that won't stop me from owning it.

I have let the cat out of the bag. The next amp will be call Odyssey, my logon in my local forum. This amp will be special because I even get to choose my own name for it and it will be on the badge. Odyssey will sit on the top of the 2nd rack because it can get hot with KT120, KT150. Yes those tubes are in addition to what I have stated before. Power will be aplenty to drive speakers and hard to drive headphones. He6se and Susvara will be too easy peasy for it. Oblivion will slot below because it's hardly hot and I don't need to change tubes in that amp.

I wasn't going to give out more details but since @OctavianH ask, I just might volunteer some info but do remember this is the concept phase and things can still change. The main idea is that because I already have Oblivion which sound very clear, full of micro details, 3D wide soundstage, Odyssey will be a classic old school tube kind of design. It will be SET, ie transformer coupled and using good specialised transformers with taps of 8 and 50 ohms for headphones and speakers, Mundorf S/G/O caps and maybe Visnay resistors. It can be use with KT88, KT77, KT66, 6L6GC, 6550, 5881, 807, EL34, EL12 SPEZ, KT120, KT150, etc. With the last 2 tubes, output power will be plenty to drive speakers and certainly any headphones, including He6se and Susvara and any other power hungry headphones.

I don't like the chassis to be as big as Infinity. Even Oblivion chassis will work but it's most likely I'll opt for a special chassis that has a Viking look haha. It will have triode and ultralinear modes and I've ask for a 'keep it simple and stupid principle' in looks. I.e no manual adjustments of bias. Maybe 2 settings that will be accomplished with the flick of a switch.

There will be speakers banana plugs out and preamp out. xlr and rca input even though it's not a balance amp, purely to cater for my 2 inputs - Yggdrasil via xlr and turntable via rca. 2 beautiful meters - I don't care what it does as long as it dance in time to the music lol. Tomas will have given up by now lol.

Headphone out will be 1/4 inch jack and xlr balance out. Again I repeat this is not a balance amp. Those xlr balance connectors are just for convenience as all my headphone cables are terminated with 4pin xlr out and also in consideration of Yggdrasil balance out being better. I'll use primarily NOS tubes - drivers to be decided or I'm not talking about it in case ebay sellers watching jack up those tube prices. Power tubes are all NOS and will be source from my private 'friend' who will make me bankrupt investing in the likes of GEC KT88, KT77, KT66 and Philips Miniwatt 6CA7, Tung Sol 1960s 6550 (super rare), Radiotron 807 with the D^D logo, my own 5 pairs of NOS Telefunken and Tesla EL12 spez tubes. There's is a possibility that I might get a pair of GEC TT21 NOS tubes. I think that's enough. I won't be using 6V6 or 6L6 as those require less power which means another bias setting. Besides I want good sounding and powerful and sweet sounding tubes. This is when the odyssey voyage comes to an end, so it will be some amp but not overly over the top. There should be budget later for Susvara, He6se and Abyss 1266 phi TC.

After which I'll be spinning my vinyls and going through Tidal HiFi catalogue. Am I interested in a streamer later? Possibly but certainly a power conditioner, proper power cables, interconnects and speaker cables. After which I'll retire UntilThen and come back as TheEnd.

P/s as I type, I get a message from Tomas, suggesting a stylish wooden chassis. Now I'm getting a bit more excited. Either that or a stylish aircraft grade 10mm aluminium casing in gun metal grey or maroon red or gold. Now I'm getting over the top.
Interesting UT, sounds like a similar design as my Infinity amp but SET instead of the other special topology (forgot which?) used in mine. And yours will have auto bias. Would anyone know whether or not that is as accurate in biasing as optimally as with the manual bias option? If so, I wonder if there's any sonic difference between bias methods. And did you say you have yet to buy a power conditioner?
 
Feb 21, 2021 at 8:45 PM Post #1,249 of 1,401

UntilThen

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Interesting UT, sounds like a similar design as my Infinity amp but SET instead of the other special topology (forgot which?) used in mine. And yours will have auto bias. Would anyone know whether or not that is as accurate in biasing as optimally as with the manual bias option? If so, I wonder if there's any sonic difference between bias methods. And did you say you have yet to buy a power conditioner?
Elekit TU8200 is also auto bias and I hear no abnormalities with it. The Mchanson KT150 amp I audition yesterday is manual bias which I find cumbersome. Auto bias is a convenience I rather have and I won’t go nuts on tube rolling.

I have no intention on spending big on PS Audio power conditioning unit. I have a power filtration board similar to the Decmate and that is good enough for me. Besides power in my place is very stable and I have never any issues with.

Tomas told me Odyssey will sound different to Oblivion and I am aware of that and want it. I have 2 amps of contrast then.

Odyssey will be based on old school SET design of which the Mogwai Se is also. What that means is that tube changes will have significant tone changes. It will sound more tubey for want of a better word.
 
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Feb 21, 2021 at 11:07 PM Post #1,251 of 1,401

UntilThen

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Interesting UT, sounds like a similar design as my Infinity amp but SET instead of the other special topology

I would hardly call that similar. The only similarity there is some of the tubes used will be common. The amp design is different between Infinity and Odyssey. Not saying which is better but just pointing out that because the amp circuitry and design is completely different, they won't sound the same.
 
Feb 22, 2021 at 1:59 AM Post #1,252 of 1,401

hpamdr

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If so, I wonder if there's any sonic difference between bias methods. And did you say you have yet to buy a power conditioner?
@SonicTrance This is a question for Tomas, can you explain why do you prefer manual grid bias than auto-bias circuit for eternity/infinity....
Is there any technical issue or sonic reason to not implement auto bias circuity.
 
Feb 22, 2021 at 2:41 AM Post #1,253 of 1,401

SonicTrance

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@SonicTrance This is a question for Tomas, can you explain why do you prefer manual grid bias than auto-bias circuit for eternity/infinity....
Is there any technical issue or sonic reason to not implement auto bias circuity.
Less capacitors in the signal path using grid bias. Even if I'd use cathode bias in Infinity/Eternity you couldn't just roll tubes without adjustment. The gyrator is still set at a specific current.
 
Feb 22, 2021 at 3:00 AM Post #1,254 of 1,401

hpamdr

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Less capacitors in the signal path using grid bias. Even if I'd use cathode bias in Infinity/Eternity you couldn't just roll tubes without adjustment. The gyrator is still set at a specific current.
@SonicTrans Loud and Clear ! As the gyrator is working for "small/precise" range of current. It is better for grid bias current/voltage to stay pinned using precise manual adjustment.
For Odyssey, it is based on classic design (cathode follower ?) means that it is more suitable to get auto-bias circuit/module.
Thanks for clarification !
 
Feb 22, 2021 at 3:35 AM Post #1,255 of 1,401

UntilThen

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Even if auto bias is not optimal but near optimal, I’m willing to compromise by going with auto bias for convenience but fortunately for Odyssey my Rolls Royce will be automatic:wink:
No wonder Elekit Tu8200 on auto bias works like a charm. Makes Lewis Hamilton want to drive his F1 racing car in auto !
 
Feb 22, 2021 at 3:55 AM Post #1,256 of 1,401

hpamdr

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Even if auto bias is not optimal but near optimal, I’m willing to compromise by going with auto bias for convenience but fortunately for Odyssey my Rolls Royce will be automatic:wink:
No wonder Elekit Tu8200 on auto bias works like a charm. Makes Lewis Hamilton want to drive his F1 racing car in auto !
UT, you choose to go for R&R Phantom we go for Volvo XC40/XC60 Recharge. :wink:
If Hamilton want to have auto-gearbox, he will just run as the pace/safety car...
 
Feb 22, 2021 at 4:52 AM Post #1,257 of 1,401

UntilThen

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UT, you choose to go for R&R Phantom we go for Volvo XC40/XC60 Recharge. :wink:
If Hamilton want to have auto-gearbox, he will just run as the pace/safety car...
lol they use to mock Volvo as a old man's car.

Trust me. Hamilton drives an auto when he's not racing because he had enough of changing gears ! He probably have a driver to drive his cars on the weekends.
 
Feb 22, 2021 at 5:10 AM Post #1,258 of 1,401

UntilThen

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I have good news for the world. I am selling off my solid states because.... who need solid states. :ksc75smile:

Feel the curvy bodies of tube amps and you'll say goodbye to solid states.

So selling of Violectric v280 and Auralic Taurus Mk2.
 
Feb 22, 2021 at 6:22 AM Post #1,259 of 1,401

SonicTrance

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For Odyssey, it is based on classic design (cathode follower ?) means that it is more suitable to get auto-bias circuit/module.
Thanks for clarification !
Odyssey will have a triode gain stage which is RC coupled to the SET output stage. The output will have traditional series feed output which requires big and expensive transformers. It will be a contrast to my usual amps for sure!

Even if auto bias is not optimal but near optimal, I’m willing to compromise by going with auto bias for convenience
Cathode bias will be great for Odyssey! Don't worry about that! I'm really looking forward to build it! :)
 
Feb 22, 2021 at 6:35 AM Post #1,260 of 1,401

UntilThen

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Odyssey will have a triode gain stage which is RC coupled to the SET output stage. The output will have traditional series feed output which requires big and expensive transformers. It will be a contrast to my usual amps for sure!


Cathode bias will be great for Odyssey! Don't worry about that! I'm really looking forward to build it! :)
Yes to both replies. When you’re as enthusiastic about building Odyssey, I’m just as enthusiastic as well. All along the way when we discussed Odyssey in private I was supported by your helpful replies. Never once did you take a day longer to reply. I just want to say thanks and I have all the confidence in you turning out a great amp in Odyssey.
 

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