amplifier with volume control

I'll second the van alstine set 120...great reviews...I think I'll try one for sh*ts and giggles....

The best TVC sounds threadbare.
The Music First Reference tranny uses about a mile of copper wire!

And that’s the problem with TVC’s the mile of thin wire, they ring are coloured to the max, nowhere near transparent, even less transparent than active preamps.
A good passive kills them, and direct source to amp is even better, if they aren’t "bit stripping"

Cheers George

I used to be the one US dealer for the British TVC company Music First. Transformer Volume Control done to a high level with Stevens and Billington transformers. The Reference-$18k, Baby Reference-$8k and Silver-$10k are excellent. Especially the Silver. Surely, the transparency and clarity are superb. The Reference tranny uses about a mile of copper wire!
However, now use a top line Atma-Sphere MP-1. There is no comparison between great TVC and great active. The best TVC sounds threadbare. Only a great active preamp creates great music.

I keep forgetting that if you have a cheap passive with some suspect pot, all bets are off.

In the studio I used channel matched Penny & Giles. Don't recall the cost but it was a lot.

For my last HiFi stepped passive built a few years back, silver contact switches, precision, matched low inductance resistors, high quality internal interconnect and top flight connectors.

I would hope that, all things being equal, that having the attenuator built into the amp would be an improvement over a separate passive box with the additional interconnect.

Nope. Bypassed many an input level control in studio amplifiers because they are redundant and color the sound.

If wishes were horses, beggars would ride

Many thanks. I'm going to try an amp with the volume control built in (my tech has an amp for sale with this).  This is a passive configuration and I would hope that, all things being equal, that having the attenuator built into the amp would be an improvement over a separate passive box with the additional interconnect.   After I try this I do intend, based on the comments in this thread, of auditioning an active preamp and comparing to the direct connection.  My only experience with active preamps is with an audible illusions and sonic frontiers anthem, neither of which impressed me - in other words I have never owned a high quality preamp.  There were several comments here that there are active preamps that maintain the transparency of a passive  while  of course adding dynamics. Which are they - I know the 2 I owned did not. Thanks again. 

ieales865 posts08-13-2021 2:12am

The demands the input of an amplifier puts on a source is just like what a speaker puts on an amp

utter nonsense. This just flat out wrong. There is next to zero current required in the input of an amplifier. There is no dynamic impedance or flyback current. Like most of what MC says, PURE HOGWASH!

you will find out that a well designed pre amp will actually outperform a passive circuit with any type of dynamic music, something is lost going all passive

utter nonsense.
If the impedance and design are correct, a passive has less coloration than almost any active circuit. Some devices may not be capable of driving a passive, but that is not a fault of the passive.

+1
All the above is utterly correct, been saying it for years. And any audio technician will say excatly the same, so long as they DON"T have a vested interest in active preamps.

Cheers George

I lived with and loved my passive preamps for decades. So transparent!
But about 6 years ago I thought of trying an active. Man, I was missing so much drive and PRAT. And the active was just as transparent with so much more music. Now on my third active preamp that is a destination piece. I will never go back to passive.

This Conrad-Johnson CAV 45 should fit the bill!
https://www.tonepublications.com/review/review-conrad-johnson-cav-45s2/#:~:text=A%20long%20test%20dr....
Or this Van Alstine!
https://avahifi.com/collections/power-amplifiers/products/set-120-control-amplifier

check out Decware.com - they make tube amps with volume controls and also a pre-amp. Made in the USA too.

The demands the input of an amplifier puts on a source is just like what a speaker puts on an amp 

utter nonsense. This just flat out wrong. There is next to zero current required in the input of an amplifier. There is no dynamic impedance or flyback current. Like most of what MC says, PURE HOGWASH!

you will find out that a well designed pre amp will actually outperform a passive circuit with any type of dynamic music, something is lost going all passive

utter nonsense.

If the impedance and design are correct, a passive has less coloration than almost any active circuit. Some devices may not be capable of driving a passive, but that is not a fault of the passive.

Airtight or nice little integrated with a quality volume attenuator or best bet for your set-up (as mentioned prior) a DAC with quality volume control

It depends on the amp and the optimal level of gain required.  With an amp that is extremely sensitive, (for example Art Audio PX25 or Diavolo is driven to max volume at .5v input) a passive preamp is preferred.  With amps that are less sensitive, higher gain in the preamp and a higher output is preferred and will deliver a better sounding experience.  

The key is choosing the right option for the power amp in question.  There is no "best option."  There are best options for that particular amp and system.  

I’ve used passive preamps in the past but they’re quite limited in application due to loading effects. A power amp with volume control would also limit one’s choices. For my application, an integrated amp was a better choice.

I prefer the name of potentiometer for the volume switch.  It just makes it sound like it is holding all the answers.  This may sound strange but I have my "cheap system".  This runs a class D amp to some transmission line speakers that I built.  I only run through this through bluetooth.  So, should be a crap sound, not going to argue things could be much better.  To maximize this, I run the volume switch on the "integrated D amp" at 2/3 potential.  I then adjust the volume from digital source.  This makes the speakers much more alive and dynamic at all volumes.

FM Acoustics amps have gain control for each channel in the back panel and Vitus Audio used to have the capability for variable output or fixed for 2 sources (not familiar with current models). For example, the VA  SS 101 sounds great alone and there is no need for preamp.

The presumption that an amp with volume control built in will automatically yield superior sound quality is wrong. It may. It may not. Only comparison to other genres/systems would tell. 

NO one can tell you which configuration would be superior in any combination of gear; pre/no pre, passive/active pre; dedicated DAC direct/integrated DAC direct; dedicated DAC with integrated amp, etc. 

I have tried all these and the winner? It depends on the setup and gear. 
Anyone who tells you differently is simply stating opinion. You simply have to try combinations if your goal is to actually find the best method with the gear on hand. Short of that, just presume and pick; it's what most do. 

I have built a lot of systems using DAC direct, either dedicated DAC to amp with software attenuation, dedicated DAC to integrated amp, or integrated DAC with hardware (built in) attenuation. Again, results vary based on the equipment, cables, etc. used. One can have a favored setup, switch speakers and find that a different setup is preferred. 

It is nowhere near as simple as recommending one setup as superior. The more systems built, the less a simplistic setup recommendation suffices. Unless you build a bunch of rigs, you simply will not know which is best method with your gear, and neither will anyone else. 

I have an old Acurus DIA100, which was marketed as a Direct Input Amplifier. It is the first version. Whether or not it technically is a direct input amp without a pre-amp I do not know. I use it to drive my outdoor speakers and it still sounds great. Back in the day it was the center of my main system and a very flexible input/output device. Maybe you could check one of these out. Hope this helps. 

I have a Quicksilver Integrated Amplifier. It is a tube amp, it has a volume control, and it sounds great. It is rated at 20 watts. A simple no-controls JDS Labs+ DAC feeds the amp, and the amp feeds Focal Aria 906 speakers, specified 89.5 dB sensitivity. I listen at moderate volume; the control stays around 10:30 o'clock. Well, it is around 12:20 o'clock when the input is from a phono preamp.

Get an integrated amp. Easy. 

Like audioman58 I have a dac with an active volume (tube line stage): Monarchy nm24. I run my TT through the second input of my amp: LTA z10. Though marketed as a power amp it has a line stage with a volume control for the second input, so I guess it would count as an integrated. As have other owners of this amp, I’ve found it sounds better without a preamp (because it already has one built in). That said the Townsend passive seems excellent, so there’s many ways to skin the cat. 

There were a lot of vintage amps built with volume controls on them and a number of thx amps allow you to vary the gain to the amp. When you avoid the pre amp and extra stage it can be a good thing but at the same time you will find out that a well designed pre amp will actually outperform a passive circuit with any type of dynamic music, something is lost going all passive.

Buy a good quality stepped attenuator and a project box, 2 pairs of female RCA jacks and build your own. 

Buy a very good dac with a great true Analog volume control 
like in the Bricasti dacs, I have the M3 with streamer board 
and even vs any $6k preamp out there you would be hard pressed  just to = it.

I began my journey with an active preamp then switched to a placette passive which was more transparent but sucked the life out of my system (but I was using longer interconnects to monoblocks).

That was your problem long interconnects with a passives high output impedance, if you use only 1-2mt quality low capacitance interconnects you would have had a far better outcome.

computer with a usb dac) and am now running direct to my amplifier which sounds much better

Now going direct you have a low output impedance from the dac and it can drive those long interconnects.

My question is how is an amp with a volume control different - if at all- from a passive (simple pot in a box) connected with short interconnects to an amplifier?

It’s not, if both have the same make and value of potentiometer (pot) inside them.

Cheers George

  “Ultimate Attenuators” used to be offered by EVS. These were volume pots that at one end could be directly inserted into the input jacks of amplifiers and the other ends could accept cables from a source. Not all amplifiers rear panel arrangements were suitable, amplifier placement could become awkward, and typically required a somewhat inconvenient separate two step volume control procedure. Still, a rather clever if somewhat hair shirted approach, that deserves comeback consideration.

many thanks to all.  I appreciate the advice regarding an active preamp, but for now I have decided to eliminate the active preamp - I have tried several and have found a direct connection better - but that does not mean I will not try one in the future.  The narrow question I have is if I use one source and no active preamp, whether a volume control built into the amp (or as 2 left ears puts it a "control amp") is better than running to a passive and then an additional interconnect to the amp. By better I guess I mean will a volume control at the amp be less likely to constrain dynamics the way my  passive preamp did.  

Some integrated amps have fairly complex preamps incorporated in them, others have little more than a passive volume control built in.  Sometimes manufacturers call those latter control amps.  You might look for one of them.

I had a professional tech bypass the dual volume controls in my Parasound amp, and it sounds much better...though there are some here who much prefer passive preamps, I believe they are a very vocal small group...

I would also recommend heading back towards the main stream if you are interested in sound quality. Active preamps serve a function as Millercarbon points out. An integrated amp sounds like the right solution. 

Bryston makes amps with volume pots for their "Pro" market.

What you want is an integrated amp. Preferably one with an actual pre-amp and not just a trim pot. Which is what you are talking about. What you call a volume control is really nothing more than a variable resistor. 

Quality in audio is everything. There are lots of ways you can lose quality. One is lots of connections and circuits. That is the one you are focused on but it is only one. On a very long list. 

The signal coming out of your source, whatever it is, if all you do is measure it like one of these guys who thinks measurements uber alles, then it seems like you have plenty of volts to spare. You can easily turn the volume up and drive the amp real loud. Whoop-de-doo.

But the amp is to the source as the speaker is to the amp. In other words your source has to be able to provide current and voltage into that amp under all conditions of frequency and dynamic range. Just exactly the same way the amp has to be able to do that with the speaker. The two seem very different but electrically and definitely conceptually they are the same.

The demands the input of an amplifier puts on a source is just like what a speaker puts on an amp. 

So now think about your source. Think of it as an amplifier. Because that is what it is. How big a power supply does it have? Not much. Because it was designed to drive the input of a pre-amp, not an amp. Sometimes depending on the amp you luck out and it works pretty good. Other times you find the sound lifeless, no dynamics, or rolled off, or the bass is weak. Whatever. Same as a guy with a weak amp and demanding speakers.

This is why a pre-amp almost always improves on running direct. Using a pre-amp, now you are driving your amp with a power supply that is never gonna run out of gas. Now it is like having 200 tube watts on a speaker that never even needs 50. Now you are gonna have all the clarity and detail of direct, but with dynamic drive and powerful bass foundation too.

Makes sense, right? Got it?