[jonchard]

I have some russians inbound I might have found unobtanium My searches were diligent!

 

[jonchard]

I keep reading all these conflicting tube thoughts, and I think it's because we all have different gear aside from the HA300MK2.

I posit one other consideration. We are ALL relying on Auto Biasing. Can anyone offer an explanation of how this is determined? Surely an amp cannot be expected to be 100% the consistant with every tube and power fluctuation etc? What are the influencing factors? Can Autobias every get it wrong? What would the tell-tale signs be? I read stories of requiring more or less voltage to hear a tube sing its best... sureley automation isnt ALWAYS right?

 

[trollbearpig]

Comparison reviews I feel should be identical tbh even with different equipment assuming two people are comparing the same tubes. How can someone think one set of tubes is brighter than another and someone else find the exact opposite.

I don't think the Cayin would bring in such a deviation of opinion, that would be a complete failure on the amp design imo if different units are providing two completely different presentations of the same exact tube. I think the more likely scenario is maybe we are talking about different tubes. Can't it vary depending on how well they are matched, what year they where made, what factory etc. Do we really know we are talking about the same set of tubes here? Looking at Langrex for a GEC L63 and their are a a number of different variations of that tube for example

 

[krude]

Comparison reviews I feel should be identical tbh even with different equipment assuming two people are comparing the same tubes. How can someone think one set of tubes is brighter than another and someone else find the exact opposite.

I don't think the Cayin would bring in such a deviation of opinion, that would be a complete failure on the amp design imo if different units are providing two completely different presentations of the same exact tube. I think the more likely scenario is maybe we are talking about different tubes. Can't it vary depending on how well they are matched, what year they where made, what factory etc. Do we really know we are talking about the same set of tubes here? Looking at Langrex for a GEC L63 and their are a a number of different variations of that tube for example

Indeed, tubes vary a lot. Production year, construction, measurements etc. but not sure it would affect the outcome to such an extent, that's why I think it's more likely DAC and transducers, plus maybe a bit of preference / expectations that can make a difference. Idk. I had a similar view on KenRads in the beginning but they did sharpen up a lot with burn in. Im actually surprised how much they changed.

 

[krude]

I also burned in JJ 6SN7 and sadly these lost a lot of sharpness in the process and became dull. I don't recommend these even at the price they are sold.

 

[jonchard]

Comparison reviews I feel should be identical tbh even with different equipment assuming two people are comparing the same tubes. How can someone think one set of tubes is brighter than another and someone else find the exact opposite.

I don't think the Cayin would bring in such a deviation of opinion, that would be a complete failure on the amp design imo if different units are providing two completely different presentations of the same exact tube. I think the more likely scenario is maybe we are talking about different tubes. Can't it vary depending on how well they are matched, what year they where made, what factory etc. Do we really know we are talking about the same set of tubes here? Looking at Langrex for a GEC L63 and their are a a number of different variations of that tube for example

There are many 7193's and Kenrad had multiple designs .. i saw at least 4 different designs of 2c22 by National Union so i expect similar from Kenrad. What we dont know is how warn our tubes are. I know my CV6 well and i know their values. I dont know the values of my kenrads. I compared them to 2c22 and CV6/det20/cv1135 and whilst they are all very similar, MY Kenrads were definately rounded off. The signature was very similar, but it was destinctly NOT BRIGHT. Everyrthing in its right place. Put in strong Red prints and the exapnsion in staging blew my mind. Im still holding a candle for Whiteprints, from a sheer value and availability standpoint they cannot be beaten and for my ears are more refined than Reds. I have 4 sets of whiteprints.

Im now chasing 6c5g and 6j5's. Initial impressions are favourable, the Fivre are beautiful to look at, the pinnacles were great for the cost. I have some Raytheon Mesh plate bottles on their way and some Russian 6c5c's coming! Exciting times.

We should certainly be able to identify "traits" between different tube sets, but synergy will be down to the actual set and your amps chosen biasing / Rectifiers / DAC / Headphones etc etc.

Ive had two quads of Kenrad 7193. I also had the National Union 7193 and 2c22 and they were markedly different. I never listend to one quad of Kenrad vrs the other sadly. Both quads were inoffensive, and i enjoyed both! They just arent white prints.

I'm still interested from someone who have a clue about Autobias, how it might be different from one machine to another, or why it might actually be consistant.

 

[Wes S]

Indeed, tubes vary a lot. Production year, construction, measurements etc. but not sure it would affect the outcome to such an extent, that's why I think it's more likely DAC and transducers, plus maybe a bit of preference / expectations that can make a difference. Idk. I had a similar view on KenRads in the beginning but they did sharpen up a lot with burn in. Im actually surprised how much they changed.

Exactly my thoughts as well.

 

[Wes S]

There are many 7193's and Kenrad had multiple designs .. i saw at least 4 different designs of 2c22 by National Union so i expect similar from Kenrad. What we dont know is how warn our tubes are. I know my CV6 well and i know their values. I dont know the values of my kenrads. I compared them to 2c22 and CV6/det20/cv1135 and whilst they are all very similar, MY Kenrads were definately rounded off. The signature was very similar, but it was destinctly NOT BRIGHT. Everyrthing in its right place. Put in strong Red prints and the exapnsion in staging blew my mind. Im still holding a candle for Whiteprints, from a sheer value and availability standpoint they cannot be beaten and for my ears are more refined than Reds. I have 4 sets of whiteprints.

Im now chasing 6c5g and 6j5's. Initial impressions are favourable, the Fivre are beautiful to look at, the pinnacles were great for the cost. I have some Raytheon Mesh plate bottles on their way and some Russian 6c5c's coming! Exciting times.

We should certainly be able to identify "traits" between different tube sets, but synergy will be down to the actual set and your amps chosen biasing / Rectifiers / DAC / Headphones etc etc.

Ive had two quads of Kenrad 7193. I also had the National Union 7193 and 2c22 and they were markedly different. I never listend to one quad of Kenrad vrs the other sadly. Both quads were inoffensive, and i enjoyed both! They just arent white prints.

I'm still interested from someone who have a clue about Autobias, how it might be different from one machine to another, or why it might actually be consistant.

If you haven't already, I would give those Red Prints a good 50 - 60 hours of burn in, and they just might get better. I thought the same thing you mentioned about the white vs. red initially as well, but now that both my sets have a bunch of hours on them, they are both so amazing I can't decide which one I like better.

 

[jamato8]

Yes, the tube is a circuit and you have to give them time and just let them run.

And an auto bias is a circuit. It controls the mA that a tube gets by using feedback. I like manual bias but that is not very common any longer. I have found different tubes to perform at different points at their best. But auto bias is the most convenient.

 

[jonchard]

Yes, the tube is a circuit and you have to give them time and just let them run.

And an auto bias is a circuit. It controls the mA that a tube gets by using feedback. I like manual bias but that is not very common any longer. I have found different tubes to perform at different points at their best. But auto bias is the most convenient.

So similar amps can sound different potentially if an amps autobias isnt quite up to scratch? Im not suggesting anyone has an issue at all, im suggesting even the same brand amp can sound different.

 

[jamato8]

So similar amps can sound different potentially if an amps autobias isnt quite up to scratch? Im not suggesting anyone has an issue at all, im suggesting even the same brand amp can sound different.

The circuit would be dialed in. I really doubt that there is an issue with the bias. We all hear differently, and there differences with everything upstream and even the voltage to the amp. There are so many variables. On lower quality amps, there very well could be differences but when using the same parts and testing, even if an auto bias was off a little, I don't think you would hear a difference. But tubes can make a difference and often as mentioned, tube runs can vary, metallurgy can change, vacuum for the tube can change. And for tubes, that is why it is nice to be able to test tubes. I test for micro ohms and for the current draw and do a life test, which is reducing the heater voltage to see how the tube responds.

 

[jonchard]

The circuit would be dialed in. I really doubt that there is an issue with the bias. We all hear differently, and there differences with everything upstream and even the voltage to the amp. There are so many variables. On lower quality amps, there very well could be differences but when using the same parts and testing, even if an auto bias was off a little, I don't think you would hear a difference. But tubes can make a difference and often as mentioned, tube runs can vary, metallurgy can change, vacuum for the tube can change. And for tubes, that is why it is nice to be able to test tubes. I test for micro ohms and for the current draw and do a life test, which is reducing the heater voltage to see how the tube responds.

Im asking the question so i have abetter understanding. That was helpful thank you! How much is a tube tester worth its salt Jamato8?

 

[jamato8]

Im asking the question so i have abetter understanding. That was helpful thank you! How much is a tube tester worth its salt Jamato8?

They are expensive now. Few are made now and they are real expensive. A TV7 modified to also show the current draw of the tube is around 1000.

 

[jonchard]

They are expensive now. Few are made now and they are real expensive. A TV7 modified to also show the current draw of the tube is around 1000.

Ouch! Nothing in this hobby is cheap lol! Thank you.

 

[jamato8]

Ouch! Nothing in this hobby is cheap lol! Thank you.

You used to be able to get them for a few hundred. TV7 B, C or D, not and A, they aren't made as well. I use the Hickok 539C, two of them, calibrated and use digital meters with them. they are bigger and cost more but not really any better than the military TV7.