[Renderman]

After the MLTL HT sub was built into the house, its lower half, as I'm sure you can visualize, looked like a wall. The upper help, however, had a pair of 18" woofers peering into the living space. A grill was mandatory. I went with Boring Beige fabric. Black looked too Hi-Fi.

I think I can visualize that, would be very interested to see a picture though! 

 
I had some time and decided to re-do my isolation transformer/noise suppression, took a picture of the isolation transformer with a 6SN7 next to it for scale

 
While at it, also took a picture of my current setup with the Elise and the 2 monoblocks powering my speakers:

 

[mordy]

Hi Renderman,

Back in the Little Dot days somebody claimed that the hum he had disappeared with an isolation transformer, and that it also added clarity to the sound.

I bought a used isolation transformer that had been used in telecommunications. Unfortunately it did nothing for me - hope that yours works well.

 

[Renderman]

Hi Renderman,

Back in the Little Dot days somebody claimed that the hum he had disappeared with an isolation transformer, and that it also added clarity to the sound.

I bought a used isolation transformer that had been used in telecommunications. Unfortunately it did nothing for me - hope that yours works well.

Hi Mordy,
 
Thanks! Not all isolation transformers are created equal. This one was specifically designed and built to reject noise. The shielding rejects noise that would normally be capacitively coupled to the secondary windings. This way (mostly common mode) noise is rejected. I also wired it so it can be used in either balanced mode or entirely floating, with the ground lifted from mains earth. It has worked very well for me so far and particularly tube amplifiers seem to benefit from it. There are some extra noise filtering circuits before and after the transformer that I did my best to try and optimize for the different loads, dac, pre-amp, power-amp.
 
I know curiosity killed the cat but... do you have any more info on the telecom transformer or how it was wired?

 

[hpamdr]

I got a new single power tube, It seems to be a  Mullard 6080 built in Mitcham  the 3th week of July 1961 labelled for UK Army on  September 1961.
 
I have seen some other mullard that have two O getters does the one i get can be paired with the other and wich one sound the best ?
 
 

 

[gibosi]

  I got a new single power tube, It seems to be a  Mullard 6080 built in Mitcham  the 3th week of July 1961 labelled for UK Army on  September 1961.
 
I have seen some other mullard that have two O getters does the one i get can be paired with the other and wich one sound the best ?
 

 
I don't know for sure, but I suspect that they sound the same. In the first line of the tube code, "AJ1", "AJ" = 6080 and "1" = revision 1. The 6080 with two O-getters I have seen also have "AJ1" on the first line. My take on this is that tubes with one getter or two getters are simply not that different. Otherwise, they would have incremented the revision code to "AJ2". But again, all this happened many years ago, and our knowledge is very incomplete, so this is just a guess on my part.

 

[hpamdr]

   
I don't know for sure, but I suspect that they sound the same. In the first line of the tube code, "AJ1", "AJ" = 6080 and "1" = revision 1. The 6080 with two O-getters I have seen also have "AJ1" on the first line. My take on this is that tubes with one getter or two getters are simply not that different. Otherwise, they would have incremented the revision code to "AJ2". But again, all this happened many years ago, and our knowledge is very incomplete, so this is just a guess on my part.

Thanks gibosi for the info.
Once ECC31/NR73 will cross the channel next month, i will try to find another one with a similar date code and mesurement in order to make a pair....

 

[Shaffer]

I think I can visualize that, would be very interested to see a picture though! 

I'll do my best to post some pics. The room is going through a bit or remodeling, so keep that in mind.

BTW, your amps look very sexy side-by-side. The scale is just right.

It's almost hard to believe how much of the sound was obscured by the noise in the WA6. I rolled a complete Tung-Sol setup tonight - 6CY7 up front and a 5V4G rectifier - and the sound is solid class-B. It's enjoyable. In essence, forget everything I've said about the amp; we're starting from scratch.

 

[Renderman]

I'll do my best to post some pics. The room is going through a bit or remodeling, so keep that in mind.

BTW, your amps look very sexy side-by-side. The scale is just right.

It's almost hard to believe how much of the sound was obscured by the noise in the WA6. I rolled a complete Tung-Sol setup tonight - 6CY7 up front and a 5V4G rectifier - and the sound is solid class-B. It's enjoyable. In essence, forget everything I've said about the amp; we're starting from scratch.

 
Looking forward to those pics, I can see through the remodeling
 
Hey thanks! Did my best to make the monoblocks look in style with the Elise.
 
Would you say that, in general, the WA6 is now on par with the 336SE? Do you have a preference between the two?

 

[Shaffer]

Just tracked the 6SN7 adpater for the Woo an miraculously they're in the US. That's less than a week!

Each of the WA6's signal tubes supposed to be max'd at 1.2A within the confines of the circuit. A 6BL7 draws 1.5A. I realize the transformer winding for the rectifier and the signal tubes are not the same. Still, on a purely intuitive level, I keep thinking that lessening the rectifier's electrical needs may allow me to run a 6BL7, at least for a few hours. What do you guys think?

 

[Shaffer]

Would you say that, in general, the WA6 is now on par with the 336SE? Do you have a preference between the two?

I like the Woo more. It took much more work and aggravation to get there. The Woo, sans the noise, can produce some fine sound. It's not an Elise by an stretch of the imagination. The latter's transparency, alone, sets it apart, not to mention its extension, its resolution if space, texture and detail, how quiet it is. Totally different class. To give the DV its due, the bass weight is quite something, as are its dynamics with high-z cans. It's tube needs aren't nearly as finicky as the Woo's - but what is - $50 or less will get superb sound, given its limitations. The Woo? Get ready to open your wallet. I did it on the cheap, and still it's over ~$200+ (minimum) by Woo's prices. I paid about 40% of that for exactly the same thing or better. The Elise sounds very good with stock tubes and another ~$40 or so will yield a nice NOS pair, as per one's taste. The Woo with stock tubes is utter dookie, as is the DV. It's almost a contest as to which sounds worse in that config.

 

[Renderman]

I like the Woo more. It took much more work and aggravation to get there. The Woo, sans the noise, can produce some fine sound. It's not an Elise by an stretch of the imagination. The latter's transparency, alone, sets it apart, not to mention its extension, its resolution if space, texture and detail, how quiet it is. Totally different class. To give the DV its due, the bass weight is quite something, as are its dynamics with high-z cans. It's tube needs aren't nearly as finicky as the Woo's - but what is - $50 or less will get superb sound, given its limitations. The Woo? Get ready to open your wallet. I did it on the cheap, and still it's over ~$200+ (minimum) by Woo's prices. I paid about 40% of that for exactly the same thing or better. The Elise sounds very good with stock tubes and another ~$40 or so will yield a nice NOS pair, as per one's taste. The Woo with stock tubes is utter dookie, as is the DV. It's almost a contest as to which sounds worse in that config.

Thats a nice, concise summary of your three amps This is the kind of information we need, thank you for putting in the effort!
 
Read quite a few Impressions similar to these and it makes me just that more comfortable in choosing Elise. I makes me think I really lucked out without spending a fortune on amplifiers and tubes. My first tube headphone amplifier was the Little Bear P8, at $150 not bad at all for the price and at least it got me on the path to tube amplifiers
 
As you mentioned, the Elise already sounds very good with the stock tubes and even with tubes quite a few people regard as some of the best (ECC31/GEC 6AS7G) the price is still under $1000. Granted, not a small amount of money but a price I'd gladly pay for the best sound I've heard from headphones to date (Using the T1 or Fidelio X2).
 
Rolling tubes has been quite an adventure, had a lot of fun experimenting. Already sold the C3gs and will sell most of my 6SN7s. The only other tube I would like to hear now is the 7N7, not sure why but the 6N7 does not appeal to me, let alone the FDD20 with external power supply. The ECC31/GEC 6AS7G combo is all I could want.
 
Have 2 pairs of ECC31's now (Philips Miniwatt ECC31 and Mullard ECC31) which sound identical to me. It's nice to have a backup pair and I will be keeping an eye out for a somewhat affordable set of ECC32s (If there ever will be). If I ever come across a nice set of affordable ECC33/35 I would not hesitate to buy those either.
 
Very happy with the Elise and her current tubes. Now to get back to what it's all about... the music.

 

[gibosi]

Each of the WA6's signal tubes supposed to be max'd at 1.2A within the confines of the circuit. A 6BL7 draws 1.5A. I realize the transformer winding for the rectifier and the signal tubes are not the same. Still, on a purely intuitive level, I keep thinking that lessening the rectifier's electrical needs may allow me to run a 6BL7, at least for a few hours. What do you guys think?

 
I doubt that rectifier selection will make any difference. The rectifier's function is to supply at most 0.125A DC (it's probably less than that... I'm guessing here) to run the amp. That is, this is the DC signal current that actually runs through the tubes, cathodes, grids and plates. The heaters require about 2.4A, so the transformer has to be able to provide a total of about 2.5A. Two 6BL7 heaters plus the current to run the amp would pull around 3.1A. Wild guessing here, but it seems reasonable to assume that the transformer is rated for more than 2.5A to provide a comfortable margin to handle surges and what not. So the question is how much more? 10% (2.75A)? 50% (3.75A)?  As best as we were able to tell, our Little Dots used transformers that could handle up to 50% more. But I have no idea about the Woo. If you can remove the transformer cover, you might be able to read the power rating on the transformer.

 

[Shaffer]

I doubt that rectifier selection will make any difference. The rectifier's function is to supply at most 0.125A DC (it's probably less than that... I'm guessing here) to run the amp. That is, this is the DC signal current that actually runs through the tubes, cathodes, grids and plates. The heaters require about 2.4A, so the transformer has to be able to provide a total of about 2.5A. Two 6BL7 heaters plus the current to run the amp would pull around 3.1A. Wild guessing here, but it seems reasonable to assume that the transformer is rated for more than 2.5A to provide a comfortable margin to handle surges and what not. So the question is how much more? 10% (2.75A)? 50% (3.75A)?  As best as we were able to tell, our Little Dots used transformers that could handle up to 50% more. But I have no idea about the Woo. If you can remove the transformer cover, you might be able to read the power rating on the transformer.

IIRC, it's a 75w transformer.

 

[gibosi]

As on the LD, I would hope that there would be a current / voltage rating printed on the transformer.....

 

[gibosi]

  I've been swapping back and forth between the ECC31 and CNU 6SN7GT.. (GEC Powers) they actually sound very close in performance on the T1s, Philips Fidelio X2 and my speakers. The ECC31 go deeper and have a larger base fundament but other than that they sound quite alike! Anyone able and willing to confirm this? (gibosi?)

 
This morning found some time to compare the ECC31, the National Union 6SN7GT and the Sylvania 6SN7W. Of course, neither of the 6SN7s match the ECC31 on bass, but otherwise, they are very similar. I find the Sylvania to be the most similar to the ECC31 in the mids and highs, while the NU is just a bit darker.
 
On a side note, I modded my HD700 last night and I am very pleased. The edge is gone and the treble is much smoother.