My DIY Altec Lansing A7 - Voice of the Theater

[santhosh]

Received my KenRad 45 tubes. Got these NOS off eBay, made in the 40s. It was a special feeling to open a ~65 year old packing - something that has waited so long to be used, to do what they were made for

Have listened to the system for only about 5 hours after changing to the new tubes. So far, here is how they sound comparison to the Shu Guang 2A3s. Straight out of the box, LF has more detail and heft. Mids have lesser density compared to the 2A3 tubes but sound more familiar, more real and believable. The 2A3s have an almost magical tone color - more lush and romantic. HF on the 45s sounded very feeble initially but has improved within the first hour. The 2A3s had very smooth and delicate highs, will wait and see how these turn out to be.

Took some pics.

Packing reminded me of how light bulbs are packed, they can be tested without removing the tube from the packing.

The 45 STs are smaller compared to the 2A3s. Stevieboy has a pair of RCA Cunningham 45 tubes which are almost the same size as the 2A3s but are very rare and cost more than twice, sometimes even thrice on eBay. They also sound better across the spectrum, have more air in the highs and are hence sought after. Some day!

 

[santhosh]

I need help in finding the exact year of manufacture - just curious . The box does not have any manufacture date or code. I did not see if the tubes themselves had a code on them, was too eager to listen to them. But I can check. This is a radio tube used in radio communication. Interesting how they sound so nice in an audio application.

Historically, KenRad (Kentucky Radio) was taken over by GE and GE did not make any changes to the design or continued to market them as KenRad until 1952.

As per this postcard, GE may have taken over KenRad circa 1947:
http://i138.photobucket.com/albums/q248/opalize/Ken-RadPostCard1947.jpg

Quoting from a discussion on another forum:

GE took control of engineering, and moved on from Ken-Rad designs and processes. In my experience, I've found the sonic character of various tubes from that plant to have also changed, beginning in '52 or so.

Between '45-'52, I'm sure many, if not most, of the same Ken-Rad employees continued to do their fine work, in the same manner. I'm also supposing the machining and processes remained the same as in the true Ken-Rad days.[\quote]

Link: http://www.thegearpage.net/board/archive/index.php/t-993874.html

 

[corElement]

I am very jelly of your 2a3 and tube rolling.
I wish I had some more time in India to get on the tube bandwagon with lyrita gear and explore tubes.

Your account of the Shu Guang 2A3s is interesting. Because perhaps what I noticed of my audition of the 2a3 at viren's place and it lacking bass control and depth (and my theory that better transformers will correct the bass issue) is perhaps not a transformer related issue but rather the nature of the Shu Guang itself. The thick fat density of the Shu Guang is stuck to my mind. But highs and lows are probably not it's strong points since you're noticing a difference with this Ken Rad.

 

[prem]

Hi Corelement

45 tube is more linear than a 2A3 tube. Hence extremes will be better. However Mids will sound a little lighter. Better transformers in both cases will improve everything across the spectrum.

 

[viren bakhshi]

Hi corElement,

(Please don't take this personally - I'm trying to direct this in a more general way, in response to the comments I see frequently in this forum).

This is a misconception that the Shuguang 2A3C sound is "thick fat, lacking bass control and depth". Remember, most of what you heard here was in a system using your Jamo speakers - speakers, with their lower sensitivity and uplifted treble, which were certainly not a good match for the low powered 2A3 SET amp. What you heard is correct - the sound that comes out of a system with mismatched components!

Sorry to belabour the point, but it needs oft repeating. When you listen to recorded music, you are hearing the sound of a system. When the system is put together well, you are rewarded with good sound. Each component contributes. Put a mismatched component in, and the sound falls apart. What's to blame? Can you definitively pin it to a component (part) within a component?

When you listen to a particular component in different systems, and environments, it becomes almost impossible to make definite judgements. And, over time, can you remember absolutely the sound you heard in a completely different context? Perhaps, we are falling too easily in the footsteps of mainstream reviewers - who are so eager to pronounce differences, and absolutes, in grand hyperbole, to every new product that comes their way.

There's a danger of making wrong conclusions in listening this way, that can be quite agonizing. Often, differences are subtle, and are evident only with listening over an extended time. And, it behoves to think of music in a wholesome way, rather than breaking it down to frequency components. And, in having a reference in you memory as to what music actually sounds like - which comes only from listening to live concerts.

Regards,
Viren

 

[sachu888]

Sorry for OT.I am looking for tube output transformer for SE amp input impedance of 5k to 10k.Please suggest me any Indian source.

Regards,
Sachin

 

[santhosh]

Sorry...Posted by mistake while still drafting....

 

[corElement]

Hi corElement,

(Please don't take this personally - I'm trying to direct this in a more general way, in response to the comments I see frequently in this forum).

This is a misconception that the Shuguang 2A3C sound is "thick fat, lacking bass control and depth". Remember, most of what you heard here was in a system using your Jamo speakers - speakers, with their lower sensitivity and uplifted treble, which were certainly not a good match for the low powered 2A3 SET amp. What you heard is correct - the sound that comes out of a system with mismatched components!

Sorry to belabour the point, but it needs oft repeating. When you listen to recorded music, you are hearing the sound of a system. When the system is put together well, you are rewarded with good sound. Each component contributes. Put a mismatched component in, and the sound falls apart. What's to blame? Can you definitively pin it to a component (part) within a component?

When you listen to a particular component in different systems, and environments, it becomes almost impossible to make definite judgements. And, over time, can you remember absolutely the sound you heard in a completely different context? Perhaps, we are falling too easily in the footsteps of mainstream reviewers - who are so eager to pronounce differences, and absolutes, in grand hyperbole, to every new product that comes their way.

There's a danger of making wrong conclusions in listening this way, that can be quite agonizing. Often, differences are subtle, and are evident only with listening over an extended time. And, it behoves to think of music in a wholesome way, rather than breaking it down to frequency components. And, in having a reference in you memory as to what music actually sounds like - which comes only from listening to live concerts.

Regards,
Viren

Hi Virenji! Don't worry I didn't take it personally at all I'm still learning here and you brought up 100% valid points.

But I feel there is some confusion/misunderstanding here, when I mentioned about "lack of bass control and depth" in this thread it was relative to Santosh's statement of the 45s where he said the 45s

LF has more detail and heft

it wasn't a blanket statement . I'm only trying to hear other people's view about it because I question my own conclusions all the time. Prem's reply answered it for me when he mentioned

45 tube is more linear than a 2A3 tube. Hence extremes will be better. However Mids will sound a little lighter. Better transformers in both cases will improve everything across the spectrum.

And in the previous thread it was relative to only the Jamo's, if you check the thread you'll see I mentioned the same thing you said here, about how the Jamo's were a very bad match. And how the 2a3 would be an extremely good match with for higher efficiency speakers with sensitivity of 96db+ and higher impedance. I entirely, completely agree with you! That's why I feel there's a misunderstanding.

And The amazing midrange tonality and delicate highs of your 2a3 is no misconception at all!!!!!!!
I just used the terms thick and fat in this thread relative to Santosh's expression of the 45's "Mids having lesser density compared to the 2A3 tubes." It was not a derogatory statement Infact the lush sound of your 2a3's is undeniable and addictive! Even Santosh finds the 2a3 to have a magical tonality as he mentioned and prem mentioned it's one of the best amplifiers he's ever heard in his thread . Others on this forum and other forums have also mentioned similar things. Even on my badly matched bright Jamo's I utterly loved the 2a3's! To be entirely honest... I actually crave it!! :licklips: Alas I should not get one right now

 

[stevieboy]

Enjoy the 45s Santhosh! I switch between the ST tubes and the globes. To my ears the STs have more crunch and drive and the globes are more easy going relaxed and spacious. Good to have both!

 

[santhosh]

Today afternoon, member Vin_eme dropped by and we listened to the system. We played several tracks and I especially loved the way rock music sounded on the 45s, I could hear more detail in the guitar, the snare drums had more weight, cymbals had more energy. I was telling myself..Wow! there is so much more detail and microdynamics that were not present with the 2A3s. I simply loved the 45s. Then I swapped back to the 2A3s and played the same tracks. I thought I would start missing the 45s and would want to go back to them very quickly. But no, the 2A3s had a different presentation, I seemed to actually prefer how some tracks/genres sounded. Some tracks sounded better, some sounded special and the rest were still quite good. Listening to the same rock tracks on the 2A3s, the electric guitar was so addictive and involving. The tone was so rich and enjoyable that I did not seem to care about the detail.

To summarise my impressions thus far, both tubes have their own characteristic sound, their strengths and weaknesses. I find it very difficult to choose between detail v/s tone. I seem to want detail in some genres/tracks, tone in some and both in some other. This A-B-A comparison has helped me understand my system better. I am glad I have two good different sounding tubes and Viren's design allows me to swap whenever I want. In a few days, I hope to be able to understand my own tube preferences for different genres and plan my listening sessions\playlists accordingly .

 

[corElement]

Today afternoon, member Vin_eme dropped by and we listened to the system. We played several tracks and I especially loved the way rock music sounded on the 45s, I could hear more detail in the guitar, the snare drums had more weight, cymbals had more energy. I was telling myself..Wow! there is so much more detail and microdynamics that were not present with the 2A3s. I simply loved the 45s. Then I swapped back to the 2A3s and played the same tracks. I thought I would start missing the 45s and would want to go back to them very quickly. But no, the 2A3s had a different presentation, I seemed to actually prefer how some tracks/genres sounded. Some tracks sounded better, some sounded special and the rest were still quite good. Listening to the same rock tracks on the 2A3s, the electric guitar was so addictive and involving. The tone was so rich and enjoyable that I did not seem to care about the detail.

To summarise my impressions thus far, both tubes have their own characteristic sound, their strengths and weaknesses. I find it very difficult to choose between detail v/s tone. I seem to want detail in some genres/tracks, tone in some and both in some other. This A-B-A comparison has helped me understand my system better. I am glad I have two good different sounding tubes and Viren's design allows me to swap whenever I want. In a few days, I hope to be able to understand my own tube preferences for different genres and plan my listening sessions\playlists accordingly .

Thats exactly what happened with me too!!! I wanted detail in some genres and the 2a3 magic in others. Certain notes on the 2a3's sound is really addictive! In some songs I liked my solid state and others the 2a3's rich lush presentation.

Good luck with future tube explorations and keep updating us!

 

[GeorgeO]

Santhosh

Welcome to the world of tubes..

Having owned amps using KT 88s, 2A3s( Class A) and EL 34s, my personal preference is for the last named.

George

 

[prem]

Hi Santhosh


In my system i do not find details missing in the 2A3 presentation.

 

[santhosh]

Hi Prem,
Your system is in a different league (higher) and the difference in components surely is extracting more out of the 2A3s . Will be interesting to see how the 45s sounds in your system.

In my system with the 2A3s, the details are there but woven into the music. IMO, the extreme frequencies play at a lesser level (dB). It is a different presentation, very enjoyable too.

Viren's choice of tubes in his SET amp and DHT Pre is such that the Russians, the Americans and Chinese all make music instead of war like in the real world

 

[corElement]

Hi Prem,
Your system is in a different league (higher) and the difference in components surely is extracting more out of the 2A3s . Will be interesting to see how the 45s sounds in your system.

In my system with the 2A3s, the details are there but woven into the music. IMO, the extreme frequencies play at a lesser level (dB). It is a different presentation, very enjoyable too.

Viren's choice of tubes in his SET amp and DHT Pre is such that the Russians, the Americans and Chinese all make music instead of war like in the real world

I was about to write a post to prem saying exactly what you wrote about how the details are woven into the music rather than separated. It is just as you said, the airy notes are blended in making the presentation very "harmonic". With prem's custom transformers no doubt it is extracting a higher degree of performance to top up the already musical sound. Even Virenji himself mentioned it earlier i believe.

 

[santhosh]

With prem's custom transformers no doubt it is extracting a higher degree of performance to top up the already musical sound. Even Virenji himself mentioned it earlier i believe.

Yes CE, I guess we are on the same page. I have very little experience with tubes but understand from others that with better transformers, the sound can scale up.

When I was getting my amps made, I did consider and discussed with Virenji about going in for Hashimoto or Lundahl transformers but cost of transformers + shipping to India was more than the amp itself. Since I could not afford it at that stage, I decided to go with the stock transformers and revisit it later.

 

[stevieboy]

Now enjoy the sound for a few months then get a couple of rectifiers to roll. They make as big a difference as the power tubes. I put in the GZ 34 variety when I want a tight extended sound and the 5V4G variety when I want a relaxed airy presentation. Currently put the 2A3s in for a while. Darn good to have all three options at hand to roll at will

 

[Dr.Bass]

Today afternoon, member Vin_eme dropped by and we listened to the system. We played several tracks and I especially loved the way rock music sounded on the 45s, I could hear more detail in the guitar, the snare drums had more weight, cymbals had more energy. I was telling myself..Wow! there is so much more detail and microdynamics that were not present with the 2A3s. I simply loved the 45s. Then I swapped back to the 2A3s and played the same tracks. I thought I would start missing the 45s and would want to go back to them very quickly. But no, the 2A3s had a different presentation, I seemed to actually prefer how some tracks/genres sounded. Some tracks sounded better, some sounded special and the rest were still quite good. Listening to the same rock tracks on the 2A3s, the electric guitar was so addictive and involving. The tone was so rich and enjoyable that I did not seem to care about the detail.

To summarise my impressions thus far, both tubes have their own characteristic sound, their strengths and weaknesses. I find it very difficult to choose between detail v/s tone. I seem to want detail in some genres/tracks, tone in some and both in some other. This A-B-A comparison has helped me understand my system better. I am glad I have two good different sounding tubes and Viren's design allows me to swap whenever I want. In a few days, I hope to be able to understand my own tube preferences for different genres and plan my listening sessions\playlists accordingly .

Hi Santhosh, to me the situation is rather simple, I would stick to the 2A3 and add to the "detail" by other means, especially at the source level (improving your TT and getting to a better cartridge (likes of TSD15 or SPU Silver Meister) and of course upgrading the internals of your amp (better caps, output transformers etc). I am sure you will reach a point where detail will never be a concern any more.

 

[prem]

Completely agree with you Dr Bass.

 

[santhosh]

Prem/Abhi,
This definitely crossed my mind as I have observed how both of you use a good/powerful source to drive rest of the chain. My findings are based on both my sources - the Lenco L75 as well as the Marantz CD-94 to isolate the changes that I keep making to the Lenco. For the Lenco, I plan on getting a 12 inch arm and a better cart in the new year, also make a better plinth.

If I am able to get the best of the 2A3s and 45s, I will be a happier man. Prem, I need your help in understanding what the 45s do in your system with better transformers et all. I'll send you my Ken-Rad tubes as soon as I receive my other pair of 45s in December (Actually I bought a pair of used Silverstone 45s first and then managed to get the NOS Ken-Rads too).