Oblivion | UltraSonic Studios
Aug 15, 2021 at 8:43 PM Post #3,001 of 4,282

leftside

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Some guys say these 1956 Footscray (KB/FB) CV455's are extremely close to the CV4033...for less than half the price from Langrex. I haven't tried one myself.

https://www.ebay.com/itm/274128808004?hash=item3fd359a844:g:5AgAAOSwBbhg7ZkR
Ah. See you already posted :) Yes these are excellent. Was running them when one of my Mullards blew recently.

I have a lot of 12AT7/CV455 tubes - about 2 big boxes full. Not buying any more though - unless one dies on me. Not using the GECs any more either. Another set of tubes that have been moved to "collectors corner" due to the prices. Plenty of other good 12AT7 out there.
 
Aug 15, 2021 at 9:35 PM Post #3,003 of 4,282

mordy

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Some guys say these 1956 Footscray (KB/FB) CV455's are extremely close to the CV4033...for less than half the price from Langrex. I haven't tried one myself.

https://www.ebay.com/itm/274128808004?hash=item3fd359a844:g:5AgAAOSwBbhg7ZkR
I am not so familiar with the 12xx7 tubes but wonder if this CV4033 with the flying leads is the same or similar to the one selling for $131 that was converted to an octal coin base:
1629077136877.png

https://www.ebay.com/itm/274043492242?hash=item3fce43d792:g:CoAAAOSwVSpdnHpe
For $9 + shipping it seems a good deal. Then, of course, you will need an octal base and have to solder in the leads.
What year is this tube from?
Here is the Footscray special edition tube:
https://pulsetubestore.com/products...play-ready-to-use?_pos=3&_sid=169a59abc&_ss=r
 
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Aug 15, 2021 at 9:54 PM Post #3,004 of 4,282

UntilThen

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Houston, my 5U4G rectifiers have landed and that means EL12 spez, EL39 and 807 are ready to launch. :)

Berlin, here we come !!!
 
Aug 15, 2021 at 10:05 PM Post #3,005 of 4,282

UntilThen

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Came in a Havana Cuba box and proudly GE. :)

IMG_2924.jpg

Mullard 5U4G - Made in USA ? @gibosi what's happening here?
IMG_2925.jpg
 
Aug 15, 2021 at 10:17 PM Post #3,006 of 4,282

Maxx134

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Yes, I love the 12ax7 family, haven't tried the 12au7 or 12at7, I must get on to that!

Try the 12au7 first. 🙂
Remember in the "little dot mk6" threads, I must have rolled every 12 pin in existence (almost) on that amp.
That amp (ironically) had the "advantage"(?) of very noticable tube rolling differences, by not being "biased" in the optimal linear range.

Spent thousands rolling both 12 pin & then 6pin (with adapter), searching for that next euphoric thrill.. What a money pit! 🥲


Also: "...The Philips Miniwatt series, usually made in the same Heerlen, Holland factory that produced the Amperex Bugleboy tubes, are a great alternative to the increasingly rare Bugleboy. They are identical internally, carry the same factory code markings, and sound the same."
I have bugleboy & yes they are great, but I never thought to consider their sound to be very similar to the Philips miniwatt. Yet, who knows which specific tube they talking about.

My guess too. It's not like they made production runs of "medical grade" tubes --
I only ever heard "military tubes", which makes me highly doubt any company would think of using the word "medical" for making improvements.
Never even seen light blue painted tips that color. Guess you learn something every day, lol 🤥😁

Thank you for helping to spend my money ! I have to trust you as I have trusted you with giving me the right iron or wood. Will try this Footscray. Do they have a Bumscray?
Those are fitted bases on Special Grade "Flying Leads" tubes (tubes with long Leads & no base, for military= different sound). Custom Thermo setting Bases installed.

They probably sound very good, but being a military grade, they may also not have usual brimar sound.
Being military, the internals also look like a collaboration design, as you see triple mica design, compared to the standard version tube.

I've now gone through all of 12au7, 12at7 and 12ax7 in Odyssey and I'm satisfied that they are splendid as drivers in the amp.
Satisfied with all those 12pins?
Look!😯
Screenshot_20210815-213209.jpg
Maybe Try this? 😄
 
Aug 15, 2021 at 10:25 PM Post #3,007 of 4,282

UntilThen

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Aug 15, 2021 at 10:31 PM Post #3,008 of 4,282

UntilThen

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Finally the realization of a dream, 3 years in the making. Berlin and I'm listening to 'Take My Breath Away'. :relaxed: :relaxed: :L3000:

This combination has to be the best I've heard so far but I've yet to try EL39 and 807. Tomas, why are the meters hovering below 65 mA?

IMG_2927.jpg
 
Aug 15, 2021 at 11:37 PM Post #3,009 of 4,282

leftside

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Try the 12au7 first. 🙂
Remember in the "little dot mk6" threads, I must have rolled every 12 pin in existence (almost) on that amp.
That amp (ironically) had the "advantage"(?) of very noticable tube rolling differences, by not being "biased" in the optimal linear range.

Spent thousands rolling both 12 pin & then 6pin (with adapter), searching for that next euphoric thrill.. What a money pit! 🥲



I have bugleboy & yes they are great, but I never thought to consider their sound to be very similar to the Philips miniwatt. Yet, who knows which specific tube they talking about.


I only ever heard "military tubes", which makes me highly doubt any company would think of using the word "medical" for making improvements.
Never even seen light blue painted tips that color. Guess you learn something every day, lol 🤥😁


Those are fitted bases on Special Grade "Flying Leads" tubes (tubes with long Leads & no base, for military= different sound). Custom Thermo setting Bases installed.

They probably sound very good, but being a military grade, they may also not have usual brimar sound.
Being military, the internals also look like a collaboration design, as you see triple mica design, compared to the standard version tube.


Satisfied with all those 12pins?
Look!😯
Screenshot_20210815-213209.jpg
Maybe Try this? 😄
When I was going through my 12AT7 spending spree, I also picked up a few 12AU7 as my DAC at the time could use them. I also picked up a pair of 6085 (E80CC) gold pins, pinched waist, D getter. Not with as nice lettering as that one you show though. I remember them being very good in that DAC.
 
Aug 15, 2021 at 11:51 PM Post #3,010 of 4,282

UntilThen

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They are expensive ! This one has red tip and says 'special quality'. :relaxed:

s-l1600 (30).jpg
 
Aug 16, 2021 at 1:49 AM Post #3,011 of 4,282

SonicTrance

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Tomas, why are the meters hovering below 65 mA?
The EL12sp bias differently than the KT88's and will draw less current, about half. This is also why you need to use the 5U4 with EL12sp. When drawing less current, and the power supply not being regulated, the high voltage supply (B+) will rise substantially. The EL12sp will run like they supposed to in Odyssey.
 
Aug 16, 2021 at 2:11 AM Post #3,012 of 4,282

UntilThen

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The EL12sp bias differently than the KT88's and will draw less current, about half. This is also why you need to use the 5U4 with EL12sp. When drawing less current, and the power supply not being regulated, the high voltage supply (B+) will rise substantially. The EL12sp will run like they supposed to in Odyssey.

Cool. Despite that, EL12 spez sound louder at the same volume knob turn. Running with EL11 in triode mode with no feedback.
 
Aug 16, 2021 at 2:20 AM Post #3,013 of 4,282

SonicTrance

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Cool. Despite that, EL12 spez sound louder at the same volume knob turn. Running with EL11 in triode mode with no feedback.
I dont remember what the gain is for the EL12sp when triode strapped, but it must be a little higher than the KT88's then :)
Have you tried the EL12sp in UL mode?
 
Aug 16, 2021 at 4:05 AM Post #3,014 of 4,282

UntilThen

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I dont remember what the gain is for the EL12sp when triode strapped, but it must be a little higher than the KT88's then :)
Have you tried the EL12sp in UL mode?

I've been listening in UL mode with EL12 spez for the last hour. Powerful and authoritative. Super quiet with He1000se. So much headroom with this amp. Volume knob is only at 9 o'clock. I've no doubt Odyssey will drive Abyss and Susvara very well.

Telefunken tubes are known for their sparkling high end and EL11 and EL12 spez exhibit that but still present a very lush tube tone that is a touch liquid. This combination is outstanding with tight bass that hits with impact.

@DecentLevi this is to alert you that EL11 and EL12 spez finally presents themselves in their glorious tone. This is the best I've heard these tubes. A far cry from what is happening with them in Euforia. Now another picture and I even put in a matching color RCA 6SN7gt grey smoke glass. :)

IMG_2940.jpg
 
Aug 16, 2021 at 4:23 AM Post #3,015 of 4,282

baronbeehive

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