Natural Sound

[DasguteOhr]

The preamp I'm playing at home can drive +10dBm, which is to say +10VU into a 600 Ohm load and does that with direct-coupling; no transformers or coupling caps.
The Khozmo is a very nice unit. We have a motorized version here in the shop.

That's why I recommended the combination: passive TVC with tubebuffer stage. The 6sn7 version has a 0db or +9db gain switchable, ~200ohms output.detailed, clean sound amazing timbres.
Exsample how it look

Passive tvc full balanced

P.S they have really good class d amps too

 

[Atmasphere]

That's why I recommended the combination: passive TVC with tubebuffer stage. The 6sn7 version has a 0db or +9db gain switchable, ~200ohms output.detailed, clean sound amazing timbres.

Where is the 6SN7 located?

 

[DasguteOhr]

Where is the 6SN7 located?

When you order it with 6sn7 version looks like this, too big for the housing. Ecc82 version inthere

 

[Atmasphere]

When you order it with 6sn7 version looks like this, too big for the housing. Ecc82 version inthere

Is the buffer before or after the 6SN7s?

 

[DasguteOhr]

Is the buffer before or after the 6SN7s?

The tube buffer is a simple impedance converter that is connected after the passive TVC preamp. It uses either a noval pin socket, e.g., an ECC82, or an octal socket, e.g., a 6SN7 tube. One stage only. Switchable 0dB gain or +9dB gain 200ohms output
This makes it more flexible. You can run long cables or drive two power amps, which would otherwise cause problems than with a purely passive solution.

P.S
The playingfield is large. You can use it, for example, for DAC output to change the sound.

 

[morricab]

The tube buffer is a simple impedance converter that is connected after the passive TVC preamp. It uses either a noval pin socket, e.g., an ECC82, or an octal socket, e.g., a 6SN7 tube. One stage only. Switchable 0dB gain or +9dB gain 200ohms output
This makes it more flexible. You can run long cables or drive two power amps, which would otherwise cause problems than with a purely passive solution.View attachment 159798

P.S
The playingfield is large. You can use it, for example, for DAC output to change the sound.

Having tried many passives, both transformer (even with silver wire!), shunt resistor and ladder resistor, I find a simple well executed active preamp to sound the best overall.

 

[Salectric]

Having tried many passives, both transformer (even with silver wire!), shunt resistor and ladder resistor, I find a simple well executed active preamp to sound the best overall.

A “simple well executed active preamp” still needs some means of controlling volume. What do you use?

I agree that a very well executed active sounds best to me, and I use an Alps Black Beauty pot in all my preamps.

 

[DasguteOhr]

Having tried many passives, both transformer (even with silver wire!), shunt resistor and ladder resistor, I find a simple well executed active preamp to sound the best overall.

That's why the Hattor concept is so exciting. You can find out whether you like a passive preamp or whether you want to add an active gain stage. Then you have an active preamp with TVC volume control in two housings.

 

[bonzo75]

That's why the Hattor concept is so exciting. You can find out whether you like a passive preamp or whether you want to add an active gain stage. Then you have an active preamp with TVC volume control in two housings.

That is not how it works. You still have the Hattor circuit. You will just have to compare the best passives to the best actives.

 

[DasguteOhr]

That is not how it works. You still have the Hattor circuit. You will just have to compare the best passives to the best actives.

Why not works?
You can't think in black and white. If you can improve the characteristics of a passive preamp, then do it. I don't know of any other product that offers this option for the price and sounds this good.

 

[bonzo75]

Why not works?
You can't think in black and white. If you can improve the characteristics of a passive preamp, then do it. I don't know of any other product that offers this option for the price and sounds this good.

If the passive preamp here works better than the active it can only mean Hattor active is not as good, or vice versa. Does not mean a better active or passive preamp will not be better.

If someone wants to know which preamp suits them the best, I would keep a Slagle passive preamp, an excellent active preamp depending on valve or solid state requirement, and compare the two to the same brand preamp as their amp

 

[microstrip]

Having tried many passives, both transformer (even with silver wire!), shunt resistor and ladder resistor, I find a simple well executed active preamp to sound the best overall.

Although I feel the same - and surely use an active preamplifier in my system - I can't justify it technically. Most active preamplfiers are simply a passive preamplifier followed by an active amplifier. Why can't manufacturers include this amplifier function in the power amplifier? Is it an industry conspiracy to force us to spend more money?

 

[DasguteOhr]

If the passive preamp here works better than the active it can only mean Hattor active is not as good, or vice versa. Does not mean a better active or passive preamp will not be better.

If someone wants to know which preamp suits them the best, I would keep a Slagle passive preamp, an excellent active preamp depending on valve or solid state requirement, and compare the two to the same brand preamp as their amp

It's only active when you select the +9dB gain setting. Otherwise, it's an impedance converter that makes the passive preamp immune to load or high capacitance from long or high-capacitance cables. You can improve your passive preamp. You'll only find out what works better by trying it out. If you have a passive preamp, I highly recommend trying it out.

 

[morricab]

A “simple well executed active preamp” still needs some means of controlling volume. What do you use?

I agree that a very well executed active sounds best to me, and I use an Alps Black Beauty pot in all my preamps.

The preamp I have uses a relay switched resistor ladder.

 

[bonzo75]

It's only active when you select the +9dB gain setting. Otherwise, it's an impedance converter that makes the passive preamp immune to load or high capacitance from long or high-capacitance cables. You can improve your passive preamp. You'll only find out what works better by trying it out. If you have a passive preamp, I highly recommend trying it out.

I tried a Hattor passive both with analog and digital I did not like.

 

[microstrip]

The tube buffer is a simple impedance converter that is connected after the passive TVC preamp. It uses either a noval pin socket, e.g., an ECC82, or an octal socket, e.g., a 6SN7 tube. One stage only. Switchable 0dB gain or +9dB gain 200ohms output
This makes it more flexible. You can run long cables or drive two power amps, which would otherwise cause problems than with a purely passive solution.View attachment 159798

P.S
The playingfield is large. You can use it, for example, for DAC output to change the sound.

Are you addressing this unit? https://hattor.com/product/tube-stage/

We can assume that it works as a cathode follower or as inverting amplifier - no way it can be considered just a "simple impedance converter".

Cathode followers have a sound signature - if we change the tube the sound changes. Usually they have low THD, mainly second and even order harmonic, increasing with level.

 

[DasguteOhr]

I tried a Hattor passive both with analog and digital I did not like.

Which one did you have? There are 6 different versions. It's weird. Do you like the lampizator? They also use it.
If I'm not mistaken, this is the 64-step OLED display version from Khozmo. If not, I apologize.

 

[DasguteOhr]

Are you addressing this unit? https://hattor.com/product/tube-stage/

We can assume that it works as a cathode follower or as inverting amplifier - no way it can be considered just a "simple impedance converter".

Cathode followers have a sound signature - if we change the tube the sound changes. Usually they have low THD, mainly second and even order harmonic, increasing with level.

Yes. But not negative in my opion gain 0db buffer

 

[bonzo75]

Which one did you have? There are 6 different versions. It's weird. Do you like the lampizator? They also use it.
If I'm not mistaken, this is the 64-step OLED display version from Khozmo. If not, I apologize.View attachment 159808

I like the dac, prefer with an external pre. I don’t know the model of Hattor I tried, will check, was probably basic

 

[Atmasphere]

Although I feel the same - and surely use an active preamplifier in my system - I can't justify it technically. Most active preamplfiers are simply a passive preamplifier followed by an active amplifier. Why can't manufacturers include this amplifier function in the power amplifier? Is it an industry conspiracy to force us to spend more money?

If you have monoblocks that becomes really inconvenient.

If you can drive long cables then you can place the preamp with the front end of the system in a location where airborne sound won't affect it as much.

The tube buffer is a simple impedance converter that is connected after the passive TVC preamp.

So does its output use a transformer or a coupling capacitor?

Transformers (and autoformers) introduce distortion via hysteresis. This issue causes any tube amplifier using one at its output to have an elliptical load line. This causes the plate Voltage and current to be out of phase which increases distortion of the tube (in addition to that of the transformer itself). If there is a transformer (or autoformer) used to change signal level, it too has hysteresis and so will make distortion. This is unavoidable even if the transformer is properly loaded; its a function of transformer operation. All transformers have cutoff frequencies both low and high which introduce phase shift (which is why a resistive volume control is more transparent and wider bandwidth).

Coupling capacitors don't have the hysteresis problem, but they cause the output impedance of the circuit to vary with frequency as they will have a low frequency cutoff (which introduces phase shift; in the bass region the ear interprets this as a lack of impact despite the cutoff going lower than the ear does). At the output of a preamp, this will cause the 20Hz output impedance to be quite a bit higher than it is at 1kHz. This effects bass impact and varies with the load of the amplifier input impedance its driving. This is one reason amplifier input impedance in home audio is quite high, such as 100kOhms so to try to get around this issue.

One might think these issues are minor (perhaps only 'measurable') but IME they are quite audible. The additional transparency and bandwidth gained by direct-coupling at the output of a preamp isn't trivial.