6SN7GT & 6F8G - An exploration of WWII-era octal tubes

[Ranger Ron]

Looks fantastic as well!

 

[spydrwebb44]

I own the Freya+ and have the Ken-Rad 6f8g (VT-99) rolled into the Gain Stage and Psvane Treasure CV181-Z aka 6SN7 in the Buffer stage. Fantastic combo! Modern mixed with vintage is some awesome synergy

Midrange: Rich & expressive with a balance of vintage warmth, Lush and modern clarity. You get that vintage analog feel

Soundstage: Wide, deep and immersive due to the Psvane tubes

Treble: Smooth, extended, non-fatiguing and not rolled-off

Bass: Full, rounded, textured, not boomy

Dynamics: Great slam with natural transient response, not overly aggressive

Have a TUNG-SOL (NOS) Made in USA matched pair en route, should be installed by next week.

Hoping they're less microphonic than my Raytheon 6F8G matched pair I've been running in the gain stage. When they're quiet, they're amazing but the 6SN7/6F8G adapters are also crazy sensitive and that doesn't help.

Planning to try the Raytheons in the buffer stage once the TUNG-SOL arrive. Will post an update when available.

I definitely feel the soundstage, in particular, benefits from the 6SN7 to 6F8G upgrade.

 

[PioneerDoom17]

Have a TUNG-SOL (NOS) Made in USA matched pair en route, should be installed by next week.

Hoping they're less microphonic than my Raytheon 6F8G matched pair I've been running in the gain stage. When they're quiet, they're amazing but the 6SN7/6F8G adapters are also crazy sensitive and that doesn't help.

Planning to try the Raytheons in the buffer stage once the TUNG-SOL arrive. Will post an update when available.

I definitely feel the soundstage, in particular, benefits from the 6SN7 to 6F8G upgrade.

Nice! I heard the Tung-Sol 6f8g are very good sounding hopefully they work out for you. Not many pairs for sale of them right now that are even an OK deal. I noticed the adapters are sensitive to noise and giving off the fuzz through the speakers but what i have done that has really helped with noise issues that has worked great is cleaning the sockets of the freya+ with DeoxIT D100L-16BX or soaking the pins (tubes and adapters) in 99% isopropyl then scrubbing lightly with a stiff Grout brush. Also, i always let the tubes warm-up for 25 minutes before powering on my power amps. Yeah so far I really am enjoying the performance of the 6f8f tubes. Keep us posted on the ken-rads in the Gain stage and Raytheon's in the buffer

 

[larcenasb]

[Edit: Sorry, meant to write this as a reply to PioneerDoom17's post w/ Freya pics]

Hi there, glad you're getting some of that vintage sonic bliss! But is the rear gain stage tube a Ken-Rad with the flat plates? The front one looks to be a Raytheon with T-plates. Or is the rear one branded Ken-Rad but also with T-plates? Just wanna make sure you're getting the same tube sound for each channel! I love the simplicity and easy tube rolling with the Freya. Cheers!

 

[PioneerDoom17]

[Edit: Sorry, meant to write this as a reply to PioneerDoom17's post w/ Freya pics]

Hi there, glad you're getting some of that vintage sonic bliss! But is the rear gain stage tube a Ken-Rad with the flat plates? The front one looks to be a Raytheon with T-plates. Or is the rear one branded Ken-Rad but also with T-plates? Just wanna make sure you're getting the same tube sound for each channel! I love the simplicity and easy tube rolling with the Freya. Cheers!

Yep i did realize the next day that i grabbed the wrong 6f8g tube from the wrong set when i was doing a swap out of the gain stage it pays to flick on the room lights when rolling tubes lol

 

[larcenasb]

Yep i did realize the next day that i grabbed the wrong 6f8g tube from the wrong set when i was doing a swap out of the gain stage it pays to flick on the room lights when rolling tubes lol

Hehe, glad it's all good now! Every time I go to the Ken-Rad flat plates, the bass tightness and lifelike realism of vocals really stands out to me. Happy listening!

Context: Chord Mojo 1 -> fully-modded Bottlehead Crackatwoa w/ RCA 6AS7G -> AKG K240 Sextett w/ Brainwavz hybrid angled pads

 

[PioneerDoom17]

Hehe, glad it's all good now! Every time I go to the Ken-Rad flat plates, the bass tightness and lifelike realism of vocals really stands out to me. Happy listening!

Context: Chord Mojo 1 -> fully-modded Bottlehead Crackatwoa w/ RCA 6AS7G -> AKG K240 Sextett w/ Brainwavz hybrid angled pads

The Ken-Rad’s are awesome! They have that fantastic bold and dynamic sound especially in the low-end great slam/weight. The Vocals, instruments like you said are so real/organic with good sense of space and body. They really give off that vintage magic and emotional engagement.

 

[larcenasb]

BTW, I'm glad to see some life in this thread. Since starting this back in 2018, I've put together two systems with octal tubes and enjoy one or the other pretty much every day.

1) Chord Mojo 1 DAC -> fully-modded Bottlehead Crackatwoa headphone amp w/ RCA 6AS7G -> AKG K240 Sextett headphones w/ Brainwavz hybrid angled pads or Senn HD 800 S
*favorite 6F8G tubes: RCA VT-99 smoked-glass (just like in my original post, I love the warmth and scale of this tube), National Union round plates (less dynamic than RCA, but decadently lush), Ken-Rad staggered-plates (powerful, bass tightness, natural vocals)

2) Systemdek IIX turntable w/ Rega RB330 & Ortofon 2M Bronze -> Tavish Design Vintage 6SL7 phonostage -> Cyrus Integrated 8vs2 amp -> Mission 751 speakers in rosewood + Outlaw LFM-2 sub
*favorite 6SL7 tubes: RCA VT-229 smoked glass (same general sound sig as the 6F8G version, lush but still with good bite and energy), RCA 5691 red base (more warmth and smoothness than the smoked glass, good for relaxing, not the best for excitement), Sylvania 6SL7WGT brown-base (not lush, more neutral, good for bloated or overly smooth pressings)

Cheers all and happy listening!

 

[Ranger Ron]

BTW, I'm glad to see some life in this thread. Since starting this back in 2018, I've put together two systems with octal tubes and enjoy one or the other pretty much every day.

1) Chord Mojo 1 DAC -> fully-modded Bottlehead Crackatwoa headphone amp w/ RCA 6AS7G -> AKG K240 Sextett headphones w/ Brainwavz hybrid angled pads or Senn HD 800 S
*favorite 6F8G tubes: RCA VT-99 smoked-glass (just like in my original post, I love the warmth and scale of this tube), National Union round plates (less dynamic than RCA, but decadently lush), Ken-Rad staggered-plates (powerful, bass tightness, natural vocals)

2) Systemdek IIX turntable w/ Rega RB330 & Ortofon 2M Bronze -> Tavish Design Vintage 6SL7 phonostage -> Cyrus Integrated 8vs2 amp -> Mission 751 speakers in rosewood + Outlaw LFM-2 sub
*favorite 6SL7 tubes: RCA VT-229 smoked glass (same general sound sig as the 6F8G version, lush but still with good bite and energy), RCA 5691 red base (more warmth and smoothness than the smoked glass, good for relaxing, not the best for excitement), Sylvania 6SL7WGT brown-base (not lush, more neutral, good for bloated or overly smooth pressings)

Cheers all and happy listening!

I had to try my staggered plate KenRad’s after all this talk. I agree with everything said. I’m also enjoying the very low noise floor these particular tubes have. Always a bonus.