[Zachik]

We're lucky to have builders like Mischa.

100% agree!!

 

[raindownthunda]

Been rolling with the Telefunken 6080's lately. The Telefunken's sound great with all of the drivers I've tried in the BH+. Today I went full on German with an early RFT ECC82 (foil getter) in the driver seat. Absolutely dreamy soundstage and timbre with with the AC - that bass!!


(Pins were cleaned before using!)

 

[raindownthunda]

It's been quiet here... hope 1101 amp owners are enjoying their gear. Last few weeks I've been listening to the Atrium Closed with the BH+ and 12AU7 and 12BH7 tubes via 6SN7 adapter. 12BH7 have been interesting to try. These CBS-Hytron black plates have a very airy and open stage, but are somewhat thin sounding on their own. Adding a pair of 6J5 (Fivre 6J5GT gray plates) and running as a driver triplet seems to add the thickness/density that was missing.

For power tubes, so far I've tried the Telefunken 6080, Bendix 6080WB, and Raytheon 6336B. All have slightly different qualities with this set of drivers. Bendix is the warmest and smoothest listen. Telefunken 6080 is balances things out a bit and is very enjoyable. My favorite combination currently is with the Raytheon 6336B. It brings the most clarity, immediacy, and spaciousness. Probably the most "life like". The Atrium Closed sounds SO good with the BH+ in general, I don't think I'd be able to say one combination is objectively better than another. They are all very enjoyable - just different flavors of the week.

edit: for those in the BH+ queue, I highly recommend the upgraded power tube regulators! The 6336 and especially 6528 are something special.

 

[Zachik]

It's been quiet here... hope 1101 amp owners are enjoying their gear.

Absolutely!
My Solar Flare makes EVERY headphone sound great.

 

[raindownthunda]

Really enjoying this combination with the Atrium Closed tonight. Power tubes are Chatham 6520 that seem to have similar construction to the 6AS7G. At first I tried the Russian 6S5S (6C5C) as drivers and the synergy was not there. As an aside, 6S5S sounded pretty great on their own in BH mode (goes to show how much synergy matters!). Not many tube combos in this amp drive me to make an immediate change, but this was one of them. Thumpy and congested sounding. Bring on the the G-73R which is totally hitting all the right spots. The stage opened up massively in all directions and there's now an enormous amount of detail and clarity. Awesome bass texture. The smoother 6520's add warmth and decay that compliments the Telefunken in all the best ways. Currently in Knight Rider mode with the black coated glass tube and K.I.T.T. style VU meters - had to turn the lights up a bit to take this pic:

 

[smodtactical]

Any internal pictures of the blue halo+ and blue halo stock

 

[raindownthunda]

Tube rolling journey chronicles continue. I have been trying out the 6J7 -> 6J5 adapters made by 1101 Audio. These adapters are very high quality. I think they are nicer than any other adapter I have tried (including ones made by a certain head-fi'er).

First up: EF37A

After trying 4 different tubes with the signature "Mullard Red" coating, I found only 1 to be silent, 2 to have noticeable noise floor, and 1 to be totally dead. Bummer. Fortunately I had this gray coated NOS pair that are dead silent.

Sounding very nice! Smooth and detailed with great soundstage. Remind me of some of my favorite L63.

Next up: KTZ63!

Having some fun playing with the new iPhone 15 Pro camera settings/lighting:

 

[triod750]

Awesome photographies.

 

[raindownthunda]

I'm having more trouble than I thought I would moving on from the EF37A family. I had forgotten about these Cossor OM5B and OM5C tubes. They are based on Mullard's design and electrically identical to the EF37A. Likely manufactured by Mullard (read more here). Not going to win any beauty contests but man do they sound good. They make for a killer combination using Blue Halo mode with the VC. Has anyone else tried these or the EF37A before in their amps?

 

[maxpudding]

I’d like to try these tubes if I could get my hands on the adapters. Currently still rolling a bunch of different 6J5 tubes in my BH+ amp whenever I have the time for a little R&R. They sound fantastic.

BTW, thanks for the recommendation @raindownthunda !

 

[raindownthunda]

Continuing to roll through tubes that use the 6J7 adapters in the Blue Halo+:

Left to right: Brimar 6J7G (these say foreign made, I wonder if they are USA manufactured?), Osram 6J7G (AnM logo barely visible), Marconi KTZ63


Marconi KTZ63. These had excellent clarity and were very incisive. Lacking in sub-bass in BH mode. When used in BH+ with 6x 6BL7 they were no longer lacking bass (especially with the Atrium Closed). Vocals really shine.


Osram 6J7G. These didn't have the clarity I was expecting. Not bad sounding, but nothing special. I may try letting these run for a few more days to see if the sound changes over time.


I didn't take pictures of the Brimar 6J7G (foreign made) in action, but they were my 2nd favorite of the 3 British labels. Excellent detail while having nice weight/slightly warm. Very smooth. Nice all-arounders.

Visseaux 6J7MG. Not pictured: Neotron 6J7MG (pretty sure they are also made by Visseaux).



I think the Visseaux 6J7MG are my absolute favorite of the bunch. Amazing clarity and sweetness. Really comes alive using BH+ mode with these 6BL7 power tubes. This is a special combination. They look quite funny towering over the 6BL7.


My favorite power tubes with this family so far. 6x Sylvania 6BL7GT (flat plates). The stage becomes expansive, lush and holographic. Great timbre, adds a slight softness/lush quality, but still punchy with excellent bass and slam. I'll have to come back to this family and try some more power tubes some other time.

I’d like to try these tubes if I could get my hands on the adapters. Currently still rolling a bunch of different 6J5 tubes in my BH+ amp whenever I have the time for a little R&R. They sound fantastic.

BTW, thanks for the recommendation @raindownthunda !

I'm continuing to enjoy the 6J7G/KTZ63/EF37 family very much. I definitely can recommend these adapters Almost all of these were incredibly resolving, they remind me of very good 6J5G/L63, though pricing seems to be a bit lower on average (KTZ63 being the exception). Most have been very low noise or noise free (even in BH mode).

Next up: 12J7

 

[mordy]

Continuing to roll through tubes that use the 6J7 adapters in the Blue Halo+:

Left to right: Brimar 6J7G (these say foreign made, I wonder if they are USA manufactured?), Osram 6J7G (AnM logo barely visible), Marconi KTZ63


Marconi KTZ63. These had excellent clarity and were very incisive. Lacking in sub-bass in BH mode. When used in BH+ with 6x 6BL7 they were no longer lacking bass (especially with the Atrium Closed). Vocals really shine.


Osram 6J7G. These didn't have the clarity I was expecting. Not bad sounding, but nothing special. I may try letting these run for a few more days to see if the sound changes over time.


I didn't take pictures of the Brimar 6J7G (foreign made) in action, but they were my 2nd favorite of the 3 British labels. Excellent detail while having nice weight/slightly warm. Very smooth. Nice all-arounders.

Visseaux 6J7MG. Not pictured: Neotron 6J7MG (pretty sure they are also made by Visseaux).



I think the Visseaux 6J7MG are my absolute favorite of the bunch. Amazing clarity and sweetness. Really comes alive using BH+ mode with these 6BL7 power tubes. This is a special combination. They look quite funny towering over the 6BL7.


My favorite power tubes with this family so far. 6x Sylvania 6BL7GT (flat plates). The stage becomes expansive, lush and holographic. Great timbre, adds a slight softness/lush quality, but still punchy with excellent bass and slam. I'll have to come back to this family and try some more power tubes some other time.



I'm continuing to enjoy the 6J7G/KTZ63/EF37 family very much. I definitely can recommend these adapters Almost all of these were incredibly resolving, they remind me of very good 6J5G/L63, though pricing seems to be a bit lower on average (KTZ63 being the exception). Most have been very low noise or noise free (even in BH mode).

Next up: 12J7

It is very likely that the Brimar Foreign are US made. Any codes? I have had luck looking at eBay or Google Images for similar items in order to identify the tubes.
Some people feel that the best sounding 6BX7/6BL7 tubes are the flat plate (parallel plate) Sylvanias.

 

[mordy]

I'm having more trouble than I thought I would moving on from the EF37A family. I had forgotten about these Cossor OM5B and OM5C tubes. They are based on Mullard's design and electrically identical to the EF37A. Likely manufactured by Mullard (read more here). Not going to win any beauty contests but man do they sound good. They make for a killer combination using Blue Halo mode with the VC. Has anyone else tried these or the EF37A before in their amps?

There is another version of the EF37A made for laboratory equipment called ME1400. Supposedly it runs on dual voltages (4.5V and 6.3V) but it works fine at 6.3V in my amps.
http://www.r-type.org/exhib/aad0185.htm
Found this tube for much less than the pricier EF37A.

 

[raindownthunda]

It is very likely that the Brimar Foreign are US made. Any codes? I have had luck looking at eBay or Google Images for similar items in order to identify the tubes.

No only other marking visible is the 6J7G imprint on the glass envelope. The only potential clue is the "6J" on 1st line, "7G" on 2nd line.

There is another version of the EF37A made for laboratory equipment called ME1400. Supposedly it runs on dual voltages (4.5V and 6.3V) but it works fine at 6.3V in my amps.
http://www.r-type.org/exhib/aad0185.htm
Found this tube for much less than the pricier EF37A.

Nice! I remember we were discussing this at some point as there was conflicting information on the datasheets, that's good to hear it's confirmed working as a suitable replacement

Speaking of suitable replacements, I've been rolling through some 12J7's using the 12V switch in the BH+. The two types I've picked up are the Brimar 12J7GT's and Five 12J7GT's. These were both dirt cheap, I guess it's a pretty oddball tube. Billington sells NOS/NIB Fivre 12J7GT for 5 GBP each(!). If you buy 80 or more they reduce the price to 3.50 GBP ea Billington seems to think these were made by Fivre in Italy with RCA tooling.

Initial impressions of the Brimar 127JGT are just OK, not great. I had gotten 4 of these. I think the Brimar 6J5G, 6J6GT, and 6C5G all sound wayyyy better. One seems to be totally rusted internally, despite having no visible damage to the glass envelope... something I have never seen before. Another one the base was completely undone and a mess, currently attempting repair using clear nail polish. Overall a disappointing haul.




In contrast, the Fivre's from Billington were an absolute delight to unbox - all four in perfect condition. Three have a black base and one brown base. The emobssed base is quite unique, love the design flair. Fivre were clearly proud tube makers



Fortunately these don't just look great, they also sound great! Absolutely loving these with the 6528 power tubes. Fantastic bass. Engaging, enveloping full bodied sound, lovely warmth and decay, while still having fantastic treble detail and texture. One of the best tube rolls I've heard with the Atrium Closed so far.

 

[mordy]

No only other marking visible is the 6J7G imprint on the glass envelope. The only potential clue is the "6J" on 1st line, "7G" on 2nd line.




Nice! I remember we were discussing this at some point as there was conflicting information on the datasheets, that's good to hear it's confirmed working as a suitable replacement

Speaking of suitable replacements, I've been rolling through some 12J7's using the 12V switch in the BH+. The two types I've picked up are the Brimar 12J7GT's and Five 12J7GT's. These were both dirt cheap, I guess it's a pretty oddball tube. Billington sells NOS/NIB Fivre 12J7GT for 5 GBP each(!). If you buy 80 or more they reduce the price to 3.50 GBP ea Billington seems to think these were made by Fivre in Italy with RCA tooling.

Initial impressions of the Brimar 127JGT are just OK, not great. I had gotten 4 of these. I think the Brimar 6J5G, 6J6GT, and 6C5G all sound wayyyy better. One seems to be totally rusted internally, despite having no visible damage to the glass envelope... something I have never seen before. Another one the base was completely undone and a mess, currently attempting repair using clear nail polish. Overall a disappointing haul.




In contrast, the Fivre's from Billington were an absolute delight to unbox - all four in perfect condition. Three have a black base and one brown base. The emobssed base is quite unique, love the design flair. Fivre were clearly proud tube makers



Fortunately these don't just look great, they also sound great! Absolutely loving these with the 6528 power tubes. Fantastic bass. Engaging, enveloping full bodied sound, lovely warmth and decay, while still having fantastic treble detail and texture. One of the best tube rolls I've heard with the Atrium Closed so far.

Re the identification of the first pictured 6J7G tubes I looked through a lot of stuff but could not find tubes with the denomination in this layout.