Feliks Audio Elise Tube Rolling Guide 6SN7/6AS7G/6080/5998
Nov 1, 2015 at 10:41 AM Post #346 of 384

Renderman

100+ Head-Fier
Joined
Jan 1, 2015
Posts
296
Likes
38
Wouldn't be surprised if the chassis and the parts, alone, can cost more than 150 euros. They're beautifully proportioned amplifiers. Once my kids are gone, I hope to use one of their bedrooms as a second, smaller audio room - SET-based.

I have to admit to really enjoying the use of non-audio tubes in a good sounding component. There's something mildly sinister about it.

Couldn't sleep last night, so I did the only natural thing, and surfed ebay for tubes. Mostly to pass the time. I guess I never looked that closely, it's astounding just how many 5U4-type tubes are for sale in every price range imaginable. So, I buckled and picked up a trio of NOS 5U4GBs for $7.25 shipped. Couldn't just leave them there. One is a high-grade Raytheon, a RCA, and an early-60s GE labeled as a Zenith. That's less than $2.50 each! To my mailbox.

Also picked up a TS 5V4GA and a duo of 5V4G. The 5V4 tube is like a gift that keeps on giving. Specific synergies aside, it's one of the better rectifiers I've heard, not too far away from the GZ34 that I love and really need to get a backup for before the guitar players destroy the remaining stock, and there's usually a nice light show to go with the sound. It's not a very big tube, physically, so the Woo can fit on the same shelf as my other HP amps. Total win-win-win. At least that how I rationalize buying tubes that I really don't need.

All this said, I need to stop buying tubes. But, they're just so much fun. Help me! lol

Wow that's a very nice deal on those rectifiers! That being said... I'm trying to help you (at least a little), I'll be sending you a package with several tubes and other components to play with, within a few days. I think they will keep you busy for a while! :)
 
Any plans on when you will be modifying the DV? I'll be at your service if you need any help or information.
 
Yeah, the monoblocks are very cute, and they sound far better than they should! Really happy with them after the mods, the only mod I might want to do now is replace the output transformers for better quality ones. The stock transformers work ok but do get a little hot and I can't help but feel their (under rated) power might be constricting the sound.
 
If I ever get the funds together for a more serious amplifier (Elise XL with speaker terminals?) I will certainly think of you. In a smaller room with good efficiency speakers these amps really shine.
 
Nov 1, 2015 at 12:31 PM Post #347 of 384

hypnos1

Headphoneus Supremus
Joined
Apr 26, 2013
Posts
4,307
Likes
1,381
Location
Suffolk, UK
[Mod Edit: Removed. Why quote something that you find unpleasant?]
 


 
Notice the labelling '6N7G' on three of the tubes which are beyond any doubt 'ECC31s'
 
Thirdly, to make definitive comments on a tube setup you have not even personally tried and assessed objectively is rather misinformed, to say the least.
 
Lastly, to assume what Lukasz thinks of the experimentation that has been carried out with tubes is again misinformed, and insulting to everyone...I suggest you ask him directly for his actual thoughts on this matter.
 
Nov 1, 2015 at 1:13 PM Post #348 of 384

gibosi

Headphoneus Supremus
Joined
Oct 18, 2012
Posts
5,899
Likes
2,982

 
I have one of these as well. Pretty neat I think. :)
 
Note that 10E/453 tells us that this is indeed an ECC31.
 
http://frank.pocnet.net/other/ServiceTypes/OldStores.html
 
The fact that they were labeled 6N7G suggests to me that back in the day, the ECC31 and 6N7G were considered to be interchangeable in most applications. Either one would do the job.
 
Nov 1, 2015 at 1:33 PM Post #349 of 384

Shaffer

Headphoneus Supremus
Joined
Sep 7, 2013
Posts
2,740
Likes
272
The fact that they were labeled 6N7G suggests to me that back in the day, the ECC31 and 6N7G were considered to be interchangeable in most applications. Either one would do the job.


Is that the same reason why the newer 6BQ7A were joined by other designation on its box?

I recall something similar about the 5AS4-A that later included a slash-delineated 5U4G to indicated a substitution option. As a side note, I scored my first 5AS4-A in the big $7.50 trio purchase. Kinda excited to hear it.
 
Nov 1, 2015 at 1:44 PM Post #350 of 384

Shaffer

Headphoneus Supremus
Joined
Sep 7, 2013
Posts
2,740
Likes
272
Wow that's a very nice deal on those rectifiers! That being said... I'm trying to help you (at least a little), I'll be sending you a package with several tubes and other components to play with, within a few days. I think they will keep you busy for a while! :)


To say that I'm more than curious would be an understatement.

Any plans on when you will be modifying the DV? I'll be at your service if you need any help or information.


Hopefully, in a month or so. Once it starts snowing and I'm forced into boring cars. Now I'm taking advantage, or trying to, of every day. We get a lot of snow, which comes with layers of highly corrosive salt courtesy of the city. That's why many car folks in this area put their machines away for the winter. We'd like to move somewhere less severe, weather-wise.

I'd like to formulate a plan, with your help, and take the mods one step at a time. Slowly. With pics. :)

Yeah, the monoblocks are very cute, and they sound far better than they should! Really happy with them after the mods, the only mod I might want to do now is replace the output transformers for better quality ones. The stock transformers work ok but do get a little hot and I can't help but feel their (under rated) power might be constricting the sound.


I bet a better set of output transformers would make the Woo sound better, too.

If I ever get the funds together for a more serious amplifier (Elise XL with speaker terminals?) I will certainly think of you. In a smaller room with good efficiency speakers these amps really shine.


Lukasz sells a small SET for ~$1100, as you likely saw. I'd really like to use that amp with the right speakers, but it's years away. Doesn't mean it won't happen, though.
 
Nov 1, 2015 at 1:55 PM Post #351 of 384

gibosi

Headphoneus Supremus
Joined
Oct 18, 2012
Posts
5,899
Likes
2,982
Is that the same reason why the newer 6BQ7A were joined by other designation on its box?

I recall something similar about the 5AS4-A that later included a slash-delineated 5U4G to indicated a substitution option. As a side note, I scored my first 5AS4-A in the big $7.50 trio purchase. Kinda excited to hear it.

 
Some tubes have more than one "name". Why, I do not know. In some cases, there is a European designation and an American designation. But why 6BQ7A is the same as 6BS8 is the same as 6BZ7, I have no idea....
 
6BQ7A = ECC180 = 6BS8 = 6BZ7
 
http://www.radiomuseum.org/tubes/tube_6bq7a.html
 
In the case of ECC31 being labeled as a 6N7G, my guess is that during the war effort, with the large amounts of American equipment being shipped to the British, this told British radio personnel that it was perfectly OK to use a ECC31 in American equipment originally supplied with 6N7G. But again, this is just a guess on my part.
 
Nov 1, 2015 at 2:00 PM Post #352 of 384

Shaffer

Headphoneus Supremus
Joined
Sep 7, 2013
Posts
2,740
Likes
272



I use a Niles switch box with my amps, which I'd really like to upgrade one of these days. For now, it doesn't seem to leave much of a sonic mark. It sits way in the back of an Oppo105, on a lower shelf, so it's essentially invisible. As you can see, the Niles comes with a round knob. Plastic, but good quality. The thing is, if I don't remember exactly where I left it set, I have to go through all the positions of the selector switch to find the amp I want.



The solution. Now, simply by feel, the exact position of the output selector can be identified. Plus, the milled aluminum feels better. I'm thrilled with this little mod. Sometimes it's the little things....
 
Nov 1, 2015 at 2:36 PM Post #353 of 384

Renderman

100+ Head-Fier
Joined
Jan 1, 2015
Posts
296
Likes
38


The solution. Now, simply by feel, the exact position of the output selector can be identified. Plus, the milled aluminum feels better. I'm thrilled with this little mod. Sometimes it's the little things....

I love little mods like those! I have replaced many a knob, pot, switch and feet... very little effort and a lot of satisfaction! :)
 
To say that I'm more than curious would be an understatement.
Hopefully, in a month or so. Once it starts snowing and I'm forced into boring cars. Now I'm taking advantage, or trying to, of every day. We get a lot of snow, which comes with layers of highly corrosive salt courtesy of the city. That's why many car folks in this area put their machines away for the winter. We'd like to move somewhere less severe, weather-wise.

I'd like to formulate a plan, with your help, and take the mods one step at a time. Slowly. With pics. :)
I bet a better set of output transformers would make the Woo sound better, too.
Lukasz sells a small SET for ~$1100, as you likely saw. I'd really like to use that amp with the right speakers, but it's years away. Doesn't mean it won't happen, though.

Patience is truly a virtue :) You will find out soon enough and, I'm almost as curious as you to find out what you think of them. :wink:
 
Less severe weather? Dry air such as in Texas or Arizona seems to be ideal to keep machines from oxidizing :p The human body might prefer a warm climate with some more humidity like in Florida?
 
I've got that plan mostly worked out in my head, just let me know when you're ready. I'll be less active outside and more indoors in about a month as well, leaving me more time to collaborate on projects like these. Just let me know when you want to start.
 
Yes I'm very much aware of the Arioso amplifier that Feliks audio makes. Ideally I would like an amplifier that looks the same as the Elise, although maybe wider. Using ECC31 (natively) as driver tubes and 2 or 4 6AS7G as output tubes. As I already found which tubes I like and have plenty to supply another amplifier. I'm sure Feliks Audio would be able to build it for me but i'm slightly afraid the cost would be too high for me.
 
Thinking about it, I should really try hooking up some output transformers to the headphone output of the Elise to discover if I like the sound. I would probably need 100:1 transformers, anyone here have a good suggestion which ones to use for an experiment like this?
 
Nov 1, 2015 at 7:55 PM Post #354 of 384

Shaffer

Headphoneus Supremus
Joined
Sep 7, 2013
Posts
2,740
Likes
272
Wish I knew the transformers to recommend. For a turntable, sure.

It's been a fairly uneventful audio day. The Woo is sounding pretty decent now, as the tubes got sorted and the buzz is gone. Not an Elise, but quite enjoyable. I mostly used the DV with a 7AF7 driver and an extra tall, triple mica CBS 6AS7GA. Not really sure if I like the CBS tube. It sounds a bit muted and a little veiled. Quite a pleasant tone, though. It's like a mid-line Magnepan speaker. Not the most exciting thing around, but after a while one gets used to it.

On a completely different note, what is the idea behind low-loss bases. A low loss of what?
 
Nov 1, 2015 at 9:26 PM Post #355 of 384

gibosi

Headphoneus Supremus
Joined
Oct 18, 2012
Posts
5,899
Likes
2,982
On a completely different note, what is the idea behind low-loss bases. A low loss of what?

 
That's a good question. These are the brown micanol bases typically found on tubes destined for harsh operating environments, such as a factory floor or in a military theater - tanks, battle ships, military aircraft and so forth. Some claim that these bases are more heat-resistant than standard black phenolic bases, that they are resistant to mold, mildew, and fungal growth, and that they are more resistant to vibration and shock resulting in lower noise and microphonics. And some claim that they provide superior RF insulation. All that said, I have no idea where the term "low loss" comes from. But in the end, these bases were more expensive to fabricate, and therefore, they were likely used only when a customer deemed them necessary.... for some reason or another...
 
Nov 1, 2015 at 11:18 PM Post #356 of 384

Shaffer

Headphoneus Supremus
Joined
Sep 7, 2013
Posts
2,740
Likes
272
That's a good question. These are the brown micanol bases typically found on tubes destined for harsh operating environments, such as a factory floor or in a military theater - tanks, battle ships, military aircraft and so forth. Some claim that these bases are more heat-resistant than standard black phenolic bases, that they are resistant to mold, mildew, and fungal growth, and that they are more resistant to vibration and shock resulting in lower noise and microphonics. And some claim that they provide superior RF insulation. All that said, I have no idea where the term "low loss" comes from. But in the end, these bases were more expensive to fabricate, and therefore, they were likely used only when a customer deemed them necessary.... for some reason or another...


That's an excellent explanation. I think I'll start looking at the tubes with micanol bases more seriously, if only for the possibility of lessened microphonics and greater RF rejection.
 
Nov 2, 2015 at 8:32 AM Post #358 of 384

Shaffer

Headphoneus Supremus
Joined
Sep 7, 2013
Posts
2,740
Likes
272
Nov 2, 2015 at 3:36 PM Post #359 of 384

Renderman

100+ Head-Fier
Joined
Jan 1, 2015
Posts
296
Likes
38
  Here is some interesting reading about tube bases and their materials.
 
The Vacuum Tube by Ludwell A. Sibley
Tube Bases and the Asbestos Hustle
http://www.antiquewireless.org/uploads/1/6/1/2/16129770/10-the_vacuum_tube.pdf
 
[From http://www.antiquewireless.org/article-on-line-archives.html]

Interesting read indeed! Gobbled it all up over breakfast :D
 
The more I think about it, the more I want to know what the Elise would perform like driving my speakers. Their efficiency should be high enough that I can get away with about half a Watt for reasonable listening levels.
 
I figured a 10:1 ratio might be a little to ambitious, 5/6:1 is probably more realistic. The transformers in the old Stax SRD-5 seem about right! Makes sense as those were actually meant to do the reverse of what I'd like to try. If anyone has or knows of these for sale, I'm looking to buy! :)

 
That being said, I do have a set of transformers that have a 8:1 ratio, those might just work at least for a first test!
 
Ok this might sound like an outlandish design by a mad scientist but wouldn't it be cool to discover Elise is actually capable of driving high efficiency speakers? :D
 

Users who are viewing this thread

Top