[Escott1377]

I threw this question @ The Lab, not sure if it should posted here or there, but hopefully someone can help w/ my ?...Sorry for the laziness of just copy and paste.

"Hopefully you guys will help w/ this - I know you are typically geared more towards DIY and there is some content here.

So, I bought this pre amp and assembled...

http://www.transcendentsound.com/Masterpiece.html

The stock 300B's are white base EH's, which is about as bottom of the barrel as you can get.

I talked to a KR Audio dealer me that their quality has really gone down hill and recommended Emission Labs product.

I looked thru their offerings and their 300B Mesh gets really god reviews, but it operates at about 70% of a standard 300B tube.

http://www.emissionlabs.com/datasheets/EML300B-mesh.htm

With this being a pre amp design, I would essentially be limiting the load that the pre amp can drive w/ using the mesh option?

I'm not sure and like I said, you guys are spot on when I have asked for advice.

Thanks -"

[ClefChef]

The stock 300B's are white base EH's, which is about as bottom of the barrel as you can get.

I talked to a KR Audio dealer me that their quality has really gone down hill and recommended Emission Labs product.

I looked thru their offerings and their 300B Mesh gets really god reviews, but it operates at about 70% of a standard 300B tube.

http://www.emissionlabs.com/datasheets/EML300B-mesh.htm

With this being a pre amp design, I would essentially be limiting the load that the pre amp can drive w/ using the mesh option?

I'm not sure and like I said, you guys are spot on when I have asked for advice.

Thanks -"

You are making some statements here that would suggest you know little about analog electronics, tube audio, tubes or 300B in particular and you base your opinion mostly on the price of the tube. Having said that I suggest a pair of WE 300B.

I personally would keep EH 300B - they are excellent at this pricepoint.

[Escott1377]

You are making some statements here that would suggest you know little about analog electronics, tube audio, tubes or 300B in particular and you base your opinion mostly on the price of the tube. Having said that I suggest a pair of WE 300B.

I personally would keep EH 300B - they are excellent at this pricepoint.

Thanks, but you really did not answer the question that was asked.

I respect your opinion on EH tubes, but my decision to upgrade the tubes is mine and mine alone.

If you can ADD to the technical question that was posed, please do so.  Otherwise, please move on.

[ClefChef]

OK. This is the preamp, right? 300b here would operate at less than 1/100 of its current driving capacity. Your fears of 70% mesh tube capacity are unfounded.

[sfox7076]

Buy Tak 300Bs and move on.  Just don't touch those toroids...  And, well, there is a lot to learn here.  I have to tell you that plate dissipation is a different beast than turning up the volume on the preamp to drive the amps...  I cannot imagine you would ever push a 300B to a plate dissipation of 26 watts in a preamp, but I didn't design it.  You have to ask the maker about how the preamp runs the tube...  You should read about tube theory.  Especially if you are going to be building amps. 

Shawn

[sfox7076]

OK. This is the preamp, right? 300b here would operate at less than 1/100 of its current driving capacity. Your fears of 70% mesh tube capacity are unfounded.

Agreed.  But, well, he should talk to the maker, otherwise he will have to learn more on how tubes work.  It's like talking to someone who thinks that a tube will work in place of another just because the heater voltage is the same.

[Escott1377]

OK. This is the preamp, right? 300b here would operate at less than 1/100 of its current driving capacity. Your fears of 70% mesh tube capacity are unfounded.

Now we are getting somewhere.  Any 300B will operate ts less than 1/100 of its current driving capacity in a pre amp capacity?

With power = volts x current, then 70% output on a mesh option vs. standard, that should very well impact the performance of the pre amp.

[Escott1377]

Buy Tak 300Bs and move on.  Just don't touch those toroids...  And, well, there is a lot to learn here.  I have to tell you that plate dissipation is a different beast than turning up the volume on the preamp to drive the amps...  I cannot imagine you would ever push a 300B to a plate dissipation of 26 watts in a preamp, but I didn't design it.  You have to ask the maker about how the preamp runs the tube...  You should read about tube theory.  Especially if you are going to be building amps. 

Shawn

And I can't spend $2k on tubes.  Will not get the OK from the wife.

[ClefChef]

With power = volts x current, then 70% output on a mesh option vs. standard, that should very well impact the performance of the pre amp.

You are confusing tube max plate dissipation with tube power at given parameters. We are still talking about a preamp, right?

I recommend Boylestad and Nashelsky.

[mca]

I replaced EH300B with JJ300B tubes in my integrated and they were a big step up without spending insane money.

[Escott1377]

You are confusing tube max plate dissipation with tube power at given parameters. We are still talking about a preamp, right?

I recommend Boylestad and Nashelsky.

I looked that up on Amazon and I kept no reference books when I left Clemson with an electrical engineering degree and don't need to start building a library.

I think I'll just post this to the designer and get his thoughts.

Thanks all -

[h00hbt]

What exactly did he mean about KR´s quality going down hill?  If you say or post such a thing you need to explain your self or wise people won´t take notice. KR produce the finest of tubes these days and so do EML.