Newbee--well said. Steve is waving his arms excitedly but not making any sense, at least not to me.
- 80 posts total
- 80 posts total
Virtually all active external preamps have the source connected to the selector switch, then to the attenuator, then to the active gainstage, and then output to the amp.
Now, take the selector switch, attentuator, and gainstage and install it in an amplifier. Now we have an integrated amp, the preamp is incorporated with the amp on the same chassis.
So now, some don't want the active gainstage of the incorporated preamp to be called a preamp stage? Interesting. And now they call the volume control a passive preamp/stage? Interesting marketing technique/hype.
>>"Other than a phono pre-amp stage, I'm not aware of any other gain stages in a pre-amp that occur before the attenuator.">
Like you refer too, there is a phono section that uses a "head amp", sometimes called a "pre-preamp".
Like you stated, preamp active stages are virtually always after the volume control. If there is a source/cathode follower between the volume control and active gainstage in an external preamp, both are part of the preamp. When installed in an integrated, both active stages are still part of the preamp.
Look, it has already confused you into thinking you got away from a preamp gainstage. But you haven't.
Wonder how many others have been taken in by this marketing technique.
Okay - I swear this is my last post (he says for the 20th time...)
I've read your posts over and over Steve and here's my final conclusion and, granted, I seem to have had the order of some things wrong...
Like you said (I'll even quote...) "Virtually all active external preamps have the source connected to the selector switch, then to the attenuator, then to the active gainstage, and then output to the amp."
"Now, take the selector switch, attentuator, and gainstage and install it in an amplifier. Now we have an integrated amp, the preamp is incorporated with the amp on the same chassis"
Right, got it - this is 99% of the integrateds out there. MY understanding, and everything I can find research wise fleshes this out, is that the Portal and Creek 5350SE take a selector switch, attentuator, and install it in the amplifier - NO GAINSTAGE in the pre-amp SECTION of the integrated amp - and that's it.
So these are DIFFERENT in that they eliminate the gainstage in the pre-amp section of the integrated amp.
I presume there are some separate pre-amps out there too that are passive in design as well, so that there would be a selector switch and attentuator in the preamp that would connect to the amp. I dare not go down that road of debate though and am officially done.
My final word - the Panache beats anything I've ever heard, but, hey - I'm no audiophile....
Again it is quite basic Drubin.
I will lead you through it step by step.
OK, you have a CD source. We start out with a Basic amp and it needs an external active gainstage preamp to drive it. All Basic amps do. If it doesn't need a gainstage preamp, then it is already an integrated amp. Clear so far.
Now you dissasemble the active preamp and install it, the
selector switch, volume control, and active stage(s), especially the gainstage, in the Basic amplifier. Afterall the Basic amp needs the gain from that stage. Is it clear so far?
Now you have converted the Basic amp to an integrated amp. The volume control is before the preamp gainstage added. The total gain is now enough for a CD player to drive the newly made integrated amp.
But wait, some are saying the newly installed active preamp gainstage, after the vol control, is now only a simple amp stage. They renamed it.
And, since we can rename the preamp gainstage a simple amp stage, well, then we can also rename the selector switch/volume control a passive preamp. How clever.
Real slick marketing. Do you grasp this so far?
Yet, the circuitry, looking at the integrated schematic, is the same as if we had separates. So why rename?
Ok, we just split the active preamp in two. The preamp gainstage is now just a simple amp stage. The selector/volume control is now a passive preamp.
How convenient to then claim only a passive preamp is used, and is very simple. Remember, the preamp gainstage had to be installed to make the Basic amp an integrated amp. So the amp is not as simple as even a Basic amp.
The preamp gainstage, after the vol control, was just relabeled so the volume control could be called a passive, and seem simpler. Slick marketing.
Do you still understand?
Now I hope you are honest and want to learn and improve on the integrated amp.
Here is one basic problem for you to work on. Hope you don't want to hide the problem but will try to solve it.
Integrated amps have feedback loops. (How many call their amps "no global feedback" amps when they aren't? Not by a long shot.)
With each new stage, all the other stages of the amp feed back to it, and visa versa, through the power supply (see RCA Radiotron Designers Handbook, 1940's, so over 50 years known).
So if we have two stages and add a 3rd stage, the first two feedback to the third and visa versa. The first stage also loops to the second and visa versa.
If we add a 4th stage, then we have three feedback loops to the 4th stage, and visa versa back to the 3. Remember, we still have the feedback loops when we added the 3rd stage, and the first two stages. This also includes output and interstage transformers connected, signal wise to the B+.
Wow, that is alot of feedback loops, which are frequency dependent, and each has a different and large phase shift.
If you are truly interested in music, start identifying problems and solving them, instead of just insulting people.
We need to build and help audiophiles with knowledge so they will be informed, not get scammed.