[rockadanny]

Both my tubed preamp and my tubed amp have volume control. I've tried two scenarios:
A. Amp at full volume while using the preamp to adjust the volume level.
B. Preamp at full volume and using the amp to adjust the volume level.

I THINK I can hear a difference. (More careful listening required.)

1. Is there a scientifically objective correct or preferred method as to which way to use?

2. Am I hurting anything one way or the other?

And a follow-up question ...

I seem to prefer 1/2 - 3/4 volume knob set on my amp and using the preamp to adjust the volume level.

3. Anything wrong with doing this?
(Am I causing any undue stress on any gear by doing this?)

And finally ...

4. Is it feasible that I really do hear a difference in sound with regards to which method I use?
(Or am I just imagining?)

[FullRangeMan]

I had this same situation in the late1990s, after some tests my personal preference was skip the power amp vol control, I had to solder the pre-amp interconnect cable direct inside the power amp, I was happy as I could hear a sound improvement in midrange and bass freq.

I would get nervous if I had to use an amp or preamp at max volume.

[mix4fix]

My main system:
1. The phono pre-amp has a volume knob
2. The pre-amp has a volume knob
3. The integrated amp has a volume

I eliminated one volume knob by upgrading the phono pre-amp.

Second system building is gonna have similar issues. Using that same phono pre-amp I just de-installed!

----------

I knew somebody who had a CD deck feeding a tape deck in his mini-truck back in the day (early 90s). He bought CDs but still wanted to enjoy tapes.

----------

It's all about being modest with the volume, keeping it at sensible setting(s). I would never max out a volume knob. Put the amplifier at one-half during testing and find a spot around two-thirds and under three-quarters. Always be mindful of your pre-amp volume during use.

[rollo]

Both my tubed preamp and my tubed amp have volume control. I've tried two scenarios:
A. Amp at full volume while using the preamp to adjust the volume level.
B. Preamp at full volume and using the amp to adjust the volume level.

I THINK I can hear a difference. (More careful listening required.)

1. Is there a scientifically objective correct or preferred method as to which way to use?

2. Am I hurting anything one way or the other?

And a follow-up question ...

I seem to prefer 1/2 - 3/4 volume knob set on my amp and using the preamp to adjust the volume level.

3. Anything wrong with doing this?
(Am I causing any undue stress on any gear by doing this?)

And finally ...

4. Is it feasible that I really do hear a difference in sound with regards to which method I use?
(Or am I just imagining?)

  Yes there is. Run Amp at unity gain. No not hurting. Nothing wrong. Yes absolutely hearing what you are hearing.
    Try pre at unity gain and adjust at Amp. Then opposite. Have fun

charles

[mix4fix]

  Yes there is. Run Amp at unity gain. No not hurting. Nothing wrong. Yes absolutely hearing what you are hearing.
    Try pre at unity gain and adjust at Amp. Then opposite. Have fun

charles

I always understood that amplification distorts at a cranked volume.

Set amplifier as I stated and use pre-amp to adjust for various source or media levels.

[opnly bafld]

I always understood that amplification distorts at a cranked volume.

Not necessarily, too many variables.

[opnly bafld]

1. If you hear distortion or if it just sounds bad, you are doing it wrong. 
2. No
3. No
4. Yes

[RDavidson]

There’s actually a lot to consider here if you really want to dive down the rabbit hole of optimizing everything as best possible.

What makes & models are your gear? Also what are your speakers?

1. I would look at the input sensitivity of the amp. Also what’s the amp’s full output rating?
2. I would also look at the output voltage of the preamp.
3. What are your speakers’ sensitivity and what kind of load are they? 8 ohm nominal? 4 ohm?

But if you want to keep things simple, I’d generally aim to control the volume on your preamp such that normal/comfortable listening levels are at about 12 o’clock on your preamp’s volume knob. I’m assuming it has a smooth type potentiometer. By their nature, smooth pots lack precision between L and R channels the more attenuation is applied. So if you can keep them “open” past the 9 or 10 o’clock mark or so, they tend to work MUCH better.

[FullRangeMan]

Its not enough use only 1 pot or reducing the pots from 2 to 1, both interconnects cables have to be soldered directly into the circuit at the amp and power amp for better sound quality, otherwise there will be no improvement in the sound.

As a option I would prefer a integrated with a good input stage.

[mix4fix]

There’s actually a lot to consider here if you really want to dive down the rabbit hole of optimizing everything as best possible.

What makes & models are your gear? Also what are your speakers?

1. I would look at the input sensitivity of the amp. Also what’s the amp’s full output rating?
2. I would also look at the output voltage of the preamp.
3. What are your speakers’ sensitivity and what kind of load are they? 8 ohm nominal? 4 ohm?

But if you want to keep things simple, I’d generally aim to control the volume on your preamp such that normal/comfortable listening levels are at about 12 o’clock on your preamp’s volume knob. I’m assuming it has a smooth type potentiometer. By their nature, smooth pots lack precision between L and R channels the more attenuation is applied. So if you can keep them “open” past the 9 or 10 o’clock mark or so, they tend to work MUCH better.

Is that assuming that min is "7 o'clock" and max is "5 o'clock"?

I try to put amplifier's volume to "2 o'clock" and pre-amp's volume will adjust accordingly to source and media levels.

[Early B.]

Keep it simple -- eliminate extraneous parts from the signal path, especially volume pots many of which are notoriously noisy. Disconnect the volume pot in your amp.

[Rusty Jefferson]

Is your amplifier with volume an integrated with multiple source inputs?  If so, why are you using a preamp? If only 1 input, have you tried a single source direct to the amplifier to listen without the preamp? Do you need the combined gain?

[avahifi]

With our SET 120 Control Amplifier, we recommend running it when using the amp only as a basic amplifier to set the Alps volume control all the way up (on). .

This takes the volume control out of the circuit.

Frank

[Tyson]

Keep it simple -- eliminate extraneous parts from the signal path, especially volume pots many of which are notoriously noisy. Disconnect the volume pot in your amp.

Agreed, amps almost always sound best when the volume pot is removed.  And since most volume pots are on the front while the line level signal is on the back, this also gives you the chance to remove a lot of excess wiring. 

[mix4fix]

Keep it simple -- eliminate extraneous parts from the signal path, especially volume pots many of which are notoriously noisy. Disconnect the volume pot in your amp.

Given we are using a integrated as an amplifier, and a pre-amp as the selection and control, there should not be talk about modifying anything and just run it smartly so it doesn't sound terrible.

We all agree that we should upgrade to a dedicated amplifier.

[ArthurDent]

Maybe a little clarification of equipment will help, here's rockaD's system from the gallery   https://www.audiocircle.com/index.php?action=systems;area=browse;system=623

[mix4fix]

Are we sure that isn't a gain versus a volume?

[rockadanny]

Preamp: Mapletree 2A SE Linestage - NOS 6SN7 Tung-Sol grey T plates; separate power supply; NOS Raytheon JAN-CRP 6X5WGT rectifier; Black Gate filter capacitor. Gains: 10dB, 10dB, and 18dB. Two outputs.
Power Amp: Whammerdyne DGA-1 Stereo Amp - NOS Sylvania 2A3 power tubes; NOS Amperex BB 6DJ8 input tube; optional wider band output transformers.
Speakers: PAP Trio15 Horn1 - Verastarr Illusion JR Series Copper Foil cabling. Leonidas crossover: replaced green 5.6 ohm resistor with a Path resistor; replaced Mundorf M Cap with Clarity CSA capacitor.

[rockadanny]

Stereo amp circuit document shows "Autoformer Volume Control".

[rockadanny]

Preamp Output Impedance: 450 ohms
Amp Input Impedance at 20Hz: 30k ohms, Input Sensitivity for full power: 1.3v rms.