[rnros]

Thanks Mordy.

Running Mullard ECC31 with Cetron 6336b. Very quiet combination in the OTL. Very good tone. I can give the 5998 a rest now.

I've been listening to that combination since I acquired the ECC31 on your recommendation.
Fantastic.

 

[Xcalibur255]

That is true. At some point all this tubes buying must stop.

It's tempting to buy a Utopia but I have another itch I need to scratch. I am going to buy a super monitor. The Axis VoiceBox S. Heard this 3 months ago in my system and it's the most ham fisted, tight bass, ultra revealing top end and a sound if you close your eyes, you would never have guess it's coming from a pair of small speakers.

And if you need ECC33, please do talk to Stavros, a fine gentleman.

What does a pair of those VoiceBox S speakers cost? It looks like they're using a custom RAAL ribbon tweeter.

 

[2359glenn]

That is true. At some point all this tubes buying must stop.

It's tempting to buy a Utopia but I have another itch I need to scratch. I am going to buy a super monitor. The Axis VoiceBox S. Heard this 3 months ago in my system and it's the most ham fisted, tight bass, ultra revealing top end and a sound if you close your eyes, you would never have guess it's coming from a pair of small speakers.

And if you need ECC33, please do talk to Stavros, a fine gentleman.

I will be talking to Stavros tomorrow morning on Skype
Will tell him to get in touch about the ECC33.

 

[UntilThen]

What does a pair of those VoiceBox S speakers cost? It looks like they're using a custom RAAL ribbon tweeter.

$2500. In US, distributor is colleencardasimports.com. It is using a custom ribbon tweeter. The designer, John Reilly brought a pair to my home for me to hear it about 3 months ago. I was very impressed.

There are some reviews.
http://www.6moons.com/audioreviews2/axis/1.html

http://www.theabsolutesound.com/articles/axis-voicebox-s-loudspeaker/

 

[UntilThen]

I've been listening to that combination since I acquired the ECC31 on your recommendation.
Fantastic.

The seller replied that he will post to Sydney but has to wait to Monday to find out the shipping charges. Bet it cost more than the tubes !!!

However I'm excited and looking forward to the 6528 tubes. I had just purchased 4 Svetlana 6n13s power tubes.

 

[UntilThen]

I will be talking to Stavros tomorrow morning on Skype
Will tell him to get in touch about the ECC33.

Tell him I say 'hi'. Stavros has supplied me with some really good tubes.

 

[JazzVinyl]

ECC31 seems a bit 'darker' to me in Glenn's GOTL than what it sounded like in Elise. It does pair well with 5998 in the GOTL.

But, it also does well with 4x 6BL7's (which I think are a tad less bass heavy than 6BL7's).

ECC31 has more gain than 6SN7, so use 4x instead of 6x BX's...

 

[gibosi]

Nice win, Mordy.
Look forward to your impressions when you get the GOTL.
Always IMHO, but there is a difference with these for me, on my gear.
IME, CTN 6336B needs 60 hrs to reach full potential and total consistent quiet.
I do have 3 matched pairs of the Raytheon, nice tubes, especially for the $40/pair price.
There are a lot of tubes to love with the GOTL : )

I have been wondering whether Raytheon actually manufactured the 6336 and 6528 or simply rebranded them. Based on your experience, among the US manufacturers, it is beginning to look like Raytheon, Chatham and perhaps RCA manufactured these tubes in the 1960s. But by the 1980s, only Cetron (which purchased Tung-Sol, which purchased Chatham) was making them. But this is still just a guess on my part.

 

[UntilThen]

Sound similar to the 6336B, but IMHO does not surpass them in any way.
(However, only 30hrs on 6528s vs hundreds of hours on 6336Bs.)

Hi Ros again. You said that 6528 sounds similar to 6336b? Kind of surprising as the 6528 transconductance is so much higher at 37,000 umhos and a mu of 9. Btw the seller is offering the A version and there are 6528, 6528A, 6528B versions.

Here's some data 'borrowed' from another source.

6AS7G/6080 (et al.) u = 2.0 Gm = 7,000 umhos, Pd = 13 W/sect.
5998 u = 5.4 Gm = 15,500 umhos, Pd = 13 W/sect.
5998A u = 5.4 Gm = 15,500 umhos, Pd = 15 W/sect.

6336 u = 2.7 Gm = 11,000 umhos, Pd = 30W/sect.
6336A u = 2.7 Gm = 13,000 umhos, Pd = 30 W/sect.

6528 u = 9.0 Gm = 37,000 umhos, Pd = 30 W/sect

 

[UntilThen]

So I am in line for an OTL amp.

What configuration?

I've come a full circle. I started loving 6 x 6BX7 the most but now I realise that I like the other power tubes just as much. Tung Sol 5998, Gec 6as7g, Gec 6080, Bendix 6080wb, Svetlana 6h13c, Cetron 6336b. Plus all my favourite drivers.

 

[gibosi]

...transconductance....

I don't know that transconductance has any relationship to sound.

In this case, rnros has 6336 and 6528, both manufactured at the about the same time and in the same factory. And in my experience, this is more important than transconductance, gain or any other measurement....

 

[whirlwind]

What configuration?

I've come a full circle. I started loving 6 x 6BX7 the most but now I realise that I like the other power tubes just as much. Tung Sol 5998, Gec 6as7g, Gec 6080, Bendix 6080wb, Svetlana 6h13c, Cetron 6336b. Plus all my favourite drivers.

Six power sockets
C3g
6/12/25 driver switch
Lundahl with 42EC4/PY500 rectifier
Gold Point Stepped Attenuator

It is very hard not to like all of the different tubes and enjoy them when you have many and you have many great ones.

Have you tried four 6AS7 power tubes with your LCD 2 ?
If so, how did you like the impact compared to a pair of 6336B powers ?

Like you, I could live with just a couple of my favorite combos, but it is very nice to be able to hear something a little different at times.

I may have to buy a few of the Svetlana 6H13C power tubes to lay around with...the price is right.

When I first started listening to headphones, I really liked the top end of the spectrum the most..it provides so much detail.
I have come to like the warmer sound as the years pass and I tend to love the bottom end of the spectrum more than ever before.
I like the bottom end of the warmer sound a lot now, as it seems to blend in seamlessly with a lot of my blues music. Glenns OTL is so transparent to tube rolling
and the bass it provides has impact and detail

It is hard to not go down the tube rabbit hole if you own one of Glenns OTL amps.

This amp is also great for people who are just getting into tubes. Glenn makes sure of that by making it use some very great sounding and cheaper tubes.
Heck if you want you can just grab six 6BL7/6BX7 and a pair of C3g and a rectifier of choice if needed and be done.
This combo will be a good as about anything you can buy tube wise for this amp, and will save a person "oodles" of cash.

My son and his girlfriend may just be living a couple of blocks away from us.
If this is the house they choose, then I know my wife will want to go over often. I can just take a pair of my headphones over and my son and I can both plug into his amp, pretty cool.

My son has the Senn HD650 and a Grado 225i.
I may grab a SE to 4 pin XLR adapter and I can use my HD800 when over there.

 

[2359glenn]

The best deal on tubes is the 1633 and Svetlana 6H13C.
This combo sounds great and might have a total cost of $25
For those that use a 5U4 type rectifier the Svetlana 5U3C is a great rectifier for a couple of dollars and the 3DG4 for a couple of dollars.

 

[2359glenn]

My headphone amp uses two #27 drivers and 6H13C
A 5U8C rectifier that can handle the large filter capacitor inrush. I use
massive filtering for B+ and the 2.5 volt DC for the #27s.
No noise is the most important thing that is why I exclusively use the 6H13C outputs.
And have a pair of noise free 27s hard to find.
Hard to believe I am not a tube roller.

 

[JazzVinyl]

What configuration?

I've come a full circle. I started loving 6 x 6BX7 the most but now I realise that I like the other power tubes just as much. Tung Sol 5998, Gec 6as7g, Gec 6080, Bendix 6080wb, Svetlana 6h13c, Cetron 6336b. Plus all my favourite drivers.

Yes, I have found 6x 6BL/BX7 require very quiet driver tubes.

Less quiet drivers appreciate the much lower gain 6AS7/6080's...or 5998's by themselves. My Chatham 6AS7's sound really dandy, paired with my Mullard 6080's.

My quietest drivers are the 12AU7, a Raytheon 12SN7 and the 1633 and some Raytheon and Sylvania 6SN7's.

Noisy drivers for me are C3g (mine are _very_ microphonic) FDD20 had development a lot of noises. Many vintage 6SN7 are pretty noisy, too, as are my 2x ECC31's, all these are best used with the lower gain power tubes.

But Glenn's amp makes sure you can find a tube combo to suit every driver....