Best line stage tube?

[Allen Wright]

What do you all think of the line stage in this link?

I think it is old fashioned and not very good. A basic CF as he uses is called "Miss Piggy" in my "TubePreamp CookBook' because of it's sound.

A CF must have a CCS cathode load, and ideally a bootstrapped anode connection.

This makes the CF tube run at constant voltage and near constant current, greatly reducing distortion and greatly improving sonics.

Why not build the line stgae of my FVP-5A from this link?

http://www.vacuumstate.com/index.tpl?rubrik=8&lang=2&a=%DC%CC%D6%1E%7B%E5%C6%EF&b=734329.6480487392

I promise it will sound far far better.

Regards, Allen

 

[analog_sa]

Anyone used Kiwame resistors?

Yes, they are great if you have a horrible digital source. And if you insist on using them, they are available at 10% the cost as KOA Speer. At the time i bought hundreds without having the opportunity to hear them (net buzz) and now use them in non-audio projects where they perform amazingly 🙄

 

[DougL]

I agree with Allen,.
I have a more basic question: Do you really need a line stage with that much gain?

Doug

 

[Alastair E]

Personally, I was never much of a fan of the small-all-glass ECCxx dual-triodes...

I prefer the the old favorates, the 6SN7 and 6SL7, depending on what I needed from a particular stage...
--Look nicer too!😉

 

[M Gregg]

Hi,

What do you all think are the best resistors for tube circuits?
In the past I have used old carbon film.

I have a problem with floating the heaters on the HT due to the Heater DC and the HT DC having the same earth. I only wanted to bring DC into the line stage from an external source.

Does anyone know a way of lifting the heaters without a seperate Tx or winding?

Regards
M.Gregg

 

[athos56]

You would happy if u have tried Tube 26, 76 that available @ Tube Audio Lab

Ha, yes! I just finished a similar one based off the 56 tube (same tube, different heater), actually the filament is selectable for both the 56 and 76. I just picked a configuration from the Resistance coupled amplifier chart from the RCA RC-15. Sounds great! (180v, 100 kohm Rp, 4500 ohm Rk, 100 kohm Rg, 300 ohm grid stopper, 4.5uf coupling cap, 100uf Ck)

Athos

 

[M Gregg]

Next question,

What do you think of regulation on the HT supply?

Valve regulated HT or FET regulated?

Regards
M. Gregg

 

[Joshua_G]

Shunt regulators are the best.

 

[Wavebourn]

Personally, I was never much of a fan of the small-all-glass ECCxx dual-triodes...

I prefer the the old favorates, the 6SN7 and 6SL7, depending on what I needed from a particular stage...
--Look nicer too!😉

I have diametrically different preferences: 6N2P VS 6SL7 and 6N1P VS 6SN7. And GU-50 VS 807. They look nicer and work better. 🙄

For voltage stabilizers I prefer MOSFETs.

 

[analog_sa]

What do you all think are the best resistors for tube circuits?

Dark green.

 

[M Gregg]

Dark Green?

Do you have a link?
New to me!

Regards
M. Gregg

 

[Glowbug]

What do you all think are the best resistors for tube circuits?

Metal films get my vote, if possible 🙂

 

[athos56]

I got a bulk order of 1 watt metal films from overseas for dirt cheap, I think they were factory seconds or surplus. Not one has failed and most were within 5%. The pack came with a wide assortment from fractions of ohms to a couple megs. If your going to build, get one of these from the ebay.

Athos

 

[fdegrove]

Hi,

Yes, they are great if you have a horrible digital source. And if you insist on using them, they are available at 10% the cost as KOA Speer. At the time i bought hundreds without having the opportunity to hear them (net buzz) and now use them in non-audio projects where they perform amazingly 🙄

Audio, just like cooking, is not a science but an art, isn't it? 😀
Great chefs use passive components as filters. Active components are filters with a twist..........

Vuvuzela Africa, 😉

 

[serengetiplains]

My vote? Transformer-input push-pull triode with separate loading transformers and a single B+ supply. All components are matched as closely as possible. B+ is tube regulated. Output transformers are cross-wired on their secondaries for balanced output. All wire, including transformer wire, is silver.

This is real-time Aikido PSU noise cancellation with a few additional spices thrown in. Ahh, what a meal.

 

[SY]

Hi,
Audio, just like cooking, is not a science but an art, isn't it?

No, it isn't. It's science. The creation of the music (and the associated software) is art. Making an electrical signal bigger is science.

 

[Joshua_G]

No, it isn't. It's science. The creation of the music (and the associated software) is art. Making an electrical signal bigger is science.

Yet, different amplifiers with the same amplification sound differently. I'm not sure that science has all the answers as for the sound quality of different amps. For sure, science has some answers, like distortion, SNR, dynamic range and drive capability. Yet, sometimes there are differences in sound quality which aren't reflected in the above data.

 

[SY]

... distortion, SNR, dynamic range and drive capability. Yet, sometimes there are differences in sound quality which aren't reflected in the above data.

True, if those are the only things you measure, there can be audible differences. But that's an extremely limited set of data that you propose.

It is VERY easy to do a relatively simple measurement suite and accurately predict if a line amp will be audible.

 

[Joshua_G]

It is VERY easy to do a relatively simple measurement suite and accurately predict if a line amp will be audible.

Like what set of measurements?

 

[mach1]

It is VERY easy to do a relatively simple measurement suite and accurately predict if a line amp will be audible.

We’re spellbound….