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How to control volume on monoblock power amps?

louisjamesbanks

Novice Member
Hi,
Looking to buy a set of monoblocks. Most I've seen feature no pot or attenuator to control the volume level.
How is this achieved?
Note, the system I shall be adding them to features a stage which has no volume control on it either.
Thanks
 

Ugg10

Distinguished Member
You need a preamp between the source and the power amp. The preamp can have a number of functions - select the source if multiple, apply additional gain for turntable inputs, controls volume/attenuation, provide balance/treble/bass/loudness/mute controls, some have built in DACs.

These range from £50-£50,000.

If you only have one line level (about 2-2.5v) you may be able to get away with a passive preamp like the Tusbury Pre or SM Pro M-Patch (I have this), this colours the source the least as it is basically a switch and a variable or ladder resistor.

If looking second hand then rotel and nad have few to choose from, further up the scale Audiolab, naim and linn come into play. If you only have digital sources the a dac with a variable output may be ok - Fostex A3, beresford 7510/7520, dacmagic plus. And some have streamers built in , OPPO Sonica, Cambridge CXN/851N, Naim Unitilite.

So, what is your source(s) and budget and what are the monoblocks, that will help get a more precise answer.
 

louisjamesbanks

Novice Member
You need a preamp between the source and the power amp. The preamp can have a number of functions - select the source if multiple, apply additional gain for turntable inputs, controls volume/attenuation, provide balance/treble/bass/loudness/mute controls, some have built in DACs.

These range from £50-£50,000.

If you only have one line level (about 2-2.5v) you may be able to get away with a passive preamp like the Tusbury Pre or SM Pro M-Patch (I have this), this colours the source the least as it is basically a switch and a variable or ladder resistor.

If looking second hand then rotel and nad have few to choose from, further up the scale Audiolab, naim and linn come into play. If you only have digital sources the a dac with a variable output may be ok - Fostex A3, beresford 7510/7520, dacmagic plus. And some have streamers built in , OPPO Sonica, Cambridge CXN/851N, Naim Unitilite.

So, what is your source(s) and budget and what are the monoblocks, that will help get a more precise answer.
Thanks for the tips. So with my current little Project Phono Box (no volume knob), plugging the output from that into the power amps would yield what? really loud output or really quiet? Would I be able to get away with passive with that setup? I run a project elemental, the aforementioned phono box and will be running some b&w monoblocks. Cheers
 
D

Deleted member 781788

Guest
Thanks for the tips. So with my current little Project Phono Box (no volume knob), plugging the output from that into the power amps would yield what? really loud output or really quiet? Would I be able to get away with passive with that setup? I run a project elemental, the aforementioned phono box and will be running some b&w monoblocks. Cheers
Really LOUD!
Ugg10 reply is on the money.
 

Ugg10

Distinguished Member
As KenT says, really, really, loud. You speakers will get the full power of the amps and probably play at 110db.

B&W monoblocks, interesting, not heard of them. Are they the MPA1.
http://bwgroupsupport.com/downloads/manuals/bw/MPA1-OM.pdf
Look a nice piece of kit.

I think the Tisbury would work fine. (New £150).

Tisbury Mini Passive Preamp II | eBay

Or the NVA20 looks a good price at the moment (there are a couple of used going cheaper)

NVA P20 Passive Pre amplifier. | eBay

Or the m-patch that I have but this is designed for studio work so has xlr plugs but if you have the MPA1 then these have xlr inputs so you may need new cables. Bit more versatile with two variable inputs and two switchable outputs and if you plug it in it has a headphone amp. £120 new.

JBL M-Patch 2 Passive Monitor Volume Controller 691991003851 | eBay

Or you could match up your project box with their preamp.

Pro-Ject Pre Box S2 Analogue Pre Amplifier - Phono Amp PreAmp Analog ProJect 9120071658564 | eBay

Or trade you fixed volume project phono pre in for their variable volume pre if you only want one box. This also has usb output to put into a pc if you fancy digitising your vinyl collection.

PROJECT PHONO BOX III USB VARIABLE TURNTABLE PRE-AMPLIFIER (SILVER) | eBay
 

BlueWizard

Distinguished Member
Even Power Amps that have controls do NOT have Volume Controls, they have Input Level Controls. That is, those knobs are their to scale the Input Level so it is within the working range of the Power amps. They do not work well as volume controls.

You have nice equipment but we absolutely have to ask, how much money do you have to spend?

If you don't have a pre-amp or some way to control the volume, then why are you buying Power Amps and not a Integrated Amp?

So, you have source equipment and by that I mean devices that source music - CD Players, Turntables, Network Players, etc... - and you will have Power Amps. So, you need something in between to control the volume and select inputs, etc....

How much money do you have to spend on just this aspect?

Next, what is your source equipment, and what features do you need to accommodate that equipment?

For example, if you have a Turntable, then likely you need a Phono Equalization Pre-Amp, that can be a stand alone device, or it can be built into the Pre-Amp.

Do you have a CD Player? Do you have other disc players? Do you have a Turntable? Do you have a Network Player, and if not, then do you want one?


There are DACs and Network Players that have limited Pre-Amp capability. If you want to go the low cost route (relatively speaking), the something like the Cambridge CXN or the more expensive Cambridge 851N, are DACs, Pre-Amps, and Network Players all in one. But the Pre-Amp aspect is somewhat limited.

The Parasound Halo P6 Pre-Amp is an all new upgrade of the original P5 Pre-Amp, though the cost is not cheap -

Parasound P6 Pre-Amp with New Upgraded DAC, Bass Management, MM/MC Phono - £1899 -

Parasound HALO P6 Pre Amplifier

Model Halo P 6 « Parasound

Again, how far do you want to take it and how many features do you need? Something like the Cambridge CXN is, relative to the Pre-Amp aspect, basically a Volume Control and some Digital Inputs. The above Parasound is a very full featured Pre-Amp.

Also, the Rotel RC-1572 Pre-Amp has a lot of features -

Rotel RC-1572 Pre-Amp, Phono, DAC, ... - £945 -

Rotel RC-1572 Preamplifier

ROTEL - RC-1572 Pre-Amp w/ DAC

Stepping down the scale even further, there is Emotiva -

Emotiva Black BasX Pre-Amp with DAC, MM/MC Phono - £399 -

Emotiva Black BasX PT-100 Integrated Stereo PreAmplifier - Emotiva - AudioVisual Online - UK Home Cinema and Hifi Specialists

Emotiva - PT-100 Bas-X Pre-Amp with DAC

Scaling it WAY DOWN, the Yamaha Network Pre-Amp -

Yamaha WXC-50 Network Pre-Amp, Optical, Network, AUX - £250 -


Yamaha WXC-50 MusicCast Stereo Streaming Processor - Streaming / Networking - AudioVisual Online - UK Home Cinema and Hifi Specialists

MusicCast WXC-50 - Overview - Yamaha - UK and Ireland

You can't get what you want until you know what you want, it terms of function and features. And we can't help you get what you want until we know what you want.

So -

1.) What are the components in your current system that will be transferred over to this new system?

2.) How much money are you willing to spend to have your Source Components connect to your Power Amps?

3.) Are there any particular features you need this new system to have?


Knowledge is power.

Steve/bluewizard
 
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As others have stated, if you are going the separate power / pre amp route..... You do actually need the "pre" part of that set up as well.

I have a Cambridge Audio Azur 840W power amp with no controls. It's fed from a Cambridge Audio Azur 851E pre amp to which all my sources are connected to. Volume and some basic EQ is also controlled from here.
 
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