How phono preamps work inside preamps or integrated amps?

[canonken]

Would it be correct to assume in a preamp or integrated amp, the phono preamp is basically a separate module that does its job...then passes its fixed output to an internal input?

Where I am going with this is could you build a specialized integrated amp where the phono signal was booted right up to the level needed for the amplifier section, with a volume control in-between?  The idea being you shorten and simplify the signal path.

Instead of: phono pre---preamp (with volume)---amp

Could you: phono pre (with volume)---amp

 

[Adrian]

Seems to me you are describing a passive preamp section.
A passive preamp has no "active devices" (no gain) with just inputs and attenuator for volume control.  Remove the inputs and your passive preamp only has an attenuator to adjust the phono stage input to your amplifier.
For comparison, I utilize the BH Submissive preamp (passive) that takes whatever input I provide it (CD, DAC, phono) and then has the signal attenuated for output to the amplifier.
For my system:  EROS - Submissive - Paramounts.

I think you can do this by installing the proper attenuator between the phono stage output and the amp input.
You can experiment with the value of the attenuator (50K, 100K, etc.) or get advice for a place to start with your current devices.

 

[canonken]

That could work.  It would be built to have full output (equivalent of volume being at max), and you would have a (passive) volume control to drop it down to where you wanted it.

Could you do that with just one set of tubes?  I am not sure what the output levels are of a standard component (be it a phono pre or a DAC) vs. the output from a preamp to an amp.

 

[Adrian]

I use no active preamp with no additional gain into the amp.
Most amps do not require any additional input gain to deliver sufficient power to the speakers or headphones.
The signal level from most sources (cartridges and phono stages, CD players or transports, DACS) are at a level good to go directly into the amp.
If you find that the source signal strength seems too low (not enough volume), then perhaps an intermediate preamp is needed to supply additional gain into the amp.

All I have is the phono stage feeding into the attenuator that adjusts the signal into the amp for volume control.
Basically, yes you can use only the output of the phono stage directly into your volume control device.
If you are using a MM cartridge, then the output of the MM cartridge should have sufficient output to the phono stage.
If you use a MC cartridge, then you will need  step up transformers to raise the cartridge signal to a level comparable to a MM cartridge before input into the phono stage.

 

[Paul Birkeland]

Would it be correct to assume in a preamp or integrated amp, the phono preamp is basically a separate module that does its job...then passes its fixed output to an internal input?

This is usually the case, but not always.  Counterpoint preamps come to mind where the line level inputs are padded down and sent into the phono preamp after the EQ.

Where I am going with this is could you build a specialized integrated amp where the phono signal was booted right up to the level needed for the amplifier section, with a volume control in-between?  The idea being you shorten and simplify the signal path.

An Eros and a Stereomour is exactly that.

 

[canonken]

Thanks!  Makes sense.

I read about these $10-50k phono preamps that then go into a complex preamp that then go into a big, complex amp.  The signal is being passed through so much between stylus to voice coil - how much can you gain (or more accurately, preserve) by simplifying the chain.  And I think that is exactly why things like what Bottlehead sound so good!