Preamp?

[Swerd]

You are correct. A big question I had was to find a phono preamp with a volume control, and whether or not I would need something with gain to drive the powered speakers. I have a Art phono preamp which sounds better than my Yamaha phono stage. It appears all I need is a passive preamp or a phono preamp with volume.

Any phono preamp will boost the very low voltage from a phono pickup (3-5 mV for a moving magnet pickup, less than 3 mV for a moving coil pickup) to the so-called line level voltage, about 150 mV. This is the same line level voltage as from any other audio signal source, such as a CD, DVD, BR player, TV, etc. Your Yamaha AV preamp will boost that signal further (to the preamp level) which is suitable for audio amplifiers like you have in your speakers.

Also, because your Yamaha AV preamp has a volume control, you do not need another volume control on your phono preamp.

I'd use the Art phono preamp you now have. It probably is not worth the substantial extra cost to get a phono preamp with a volume control. And I am quite certain it isn't worth any extra cost to get XLR connections for a phono preamp.

 

[PENG]

Any phono preamp will boost the very low voltage from a phono pickup (3-5 mV for a moving magnet pickup, less than 3 mV for a moving coil pickup) to the so-called line level voltage, about 150 mV. This is the same line level voltage as from any other audio signal source, such as a CD, DVD, BR player, TV, etc. Your Yamaha AV preamp will boost that signal further (to the preamp level) which is suitable for audio amplifiers like you have in your speakers.

Also, because your Yamaha AV preamp has a volume control, you do not need another volume control on your phono preamp.

I'd use the Art phono preamp you now have. It probably is not worth the substantial extra cost to get a phono preamp with a volume control. And I am quite certain it isn't worth any extra cost to get XLR connections for a phono preamp.

May be I misunderstood, I thought the OP's issue is not just the volume control, but also the length of the interconnects because the equipment are in different rooms. If length is the issue, then balanced connections are probably needed. If volume control is the issue because the CX5100 is in another room, then a small phono preamp with volume control (that can be placed near the turntable) is needed. Again, I probably misunderstood the issues. I don't know if the OP's turntable has balanced output, if not then it obviously needs a RCA to XLR cable to work with the phono preamp's XLR inputs.

 

[PENG]

You are correct. A big question I had was to find a phono preamp with a volume control, and whether or not I would need something with gain to drive the powered speakers.

Do you have the owner's manual or detailed specs of the powered speakers? That should tell you whether you need a power amp.

 

[ellisr63]

May be I misunderstood, I thought the OP's issue is not just the volume control, but also the length of the interconnects because the equipment are in different rooms. If length is the issue, then balanced connections are probably needed. If volume control is the issue because the CX5100 is in another room, then a small phono preamp with volume control (that can be placed near the turntable) is needed. Again, I probably misunderstood the issues. I don't know if the OP's turntable has balanced output, if not then it obviously needs a RCA to XLR cable to work with the phono preamp's XLR inputs.

What i am trying to do is use the turntable as a stereo setup direct to my powered speakers. I do not need does. The Yamaha will have all sources connected to it, and be in another room. The turntable will be next to the speakers, and phone preamp. My current Art phono preamp has no volume control. I am looking to hook up the phone preamp directly to my powered speakers. The powered speakers (DIY) have B&O amp modules, and a mini dsl 2x4 crossover.

 

[ellisr63]

Do you have the owner's manual or detailed specs of the powered speakers? That should tell you whether you need a power amp.

The powered speakers are DIY k402 horns with B&O amp modules, and a minidsp 2x4 crossover. I hope this helps. The drivers in the horns are EV DH1A, and rated at 114db.

 

[PENG]

The powered speakers are DIY k402 horns with B&O amp modules, and a minidsp 2x4 crossover. I hope this helps. The drivers in the horns are EV DH1A, and rated at 114db.

You mean the modules linked below?

https://www.parts-express.com/bang-olufsen-icepower-250asp-power-amp-module-1x220w-at-4-ohm--309-250

If those are the ones you use to power both the horns and woofers then I don't think you need a power amp. Just make sure the phono preamp can output about 2 V rms and you should be fine. That also means you can run long XLR cables from the CX5100 outputs to the B&O modules XLR inputs. Try it!

 

[Swerd]

What i am trying to do is use the turntable as a stereo setup direct to my powered speakers. I do not need does. The Yamaha will have all sources connected to it, and be in another room. The turntable will be next to the speakers, and phone preamp. My current Art phono preamp has no volume control. I am looking to hook up the phone preamp directly to my powered speakers. The powered speakers (DIY) have B&O amp modules, and a mini dsl 2x4 crossover.

Now I think I understand what you're asking. Do you want to hook up a phono preamp directly to the B&O amp in your speakers, without involving the Yamaha AV preamp?

My first thought is that you can't do that without an audio preamp between the phono preamp and the B&O amps.

Typical output voltages for phono preamps are about 100 to 200 mV. Typical output voltages of audio preamps are in the range of 0.1 to 8 V. And typical minimum voltage input requirements of home audio amplifiers are 1.4 V (unbalanced) and 2.8 V (balanced). And all that ignores the input impedance levels needed for the B&O amps. So to answer your question, you have to know the voltage output level on the Art phono preamp, and the minimum input voltage range and impedance for the B&O amps.

I don't know if that expensive Pro-Ject phono preamp with a volume knob that Peng suggested provides enough gain to directly drive the B&O amps. I doubt it, but I don't know for certain.

Instead, you might think of getting a stereo audio preamp with a built-in phono preamp section. That would provide the proper voltage gain and impedance levels for the B&O audio amps, as well as volume control.

Two examples of old school stereo preamps are (there are others):
https://avahifi.com/collections/preamplifiers/products/vision-rb-preamplifier
https://www.crutchfield.com/p_745C165BEE/NAD-C-165BEE.html

 

[ellisr63]

Now I think I understand what you're asking. Do you want to hook up a phono preamp directly to the B&O amp in your speakers, without involving the Yamaha AV preamp?

My first thought is that you can't do that without an audio preamp between the phono preamp and the B&O amps.

Typical output voltages for phono preamps are about 100 to 200 mV. Typical output voltages of audio preamps are in the range of 0.1 to 8 V. And typical minimum voltage input requirements of home audio amplifiers are 1.4 V (unbalanced) and 2.8 V (balanced). And all that ignores the input impedance levels needed for the B&O amps. So to answer your question, you have to know the voltage output level on the Art phono preamp, and the minimum input voltage range and impedance for the B&O amps.

I don't know if that expensive Pro-Ject phono preamp with a volume knob that Peng suggested provides enough gain to directly drive the B&O amps. I doubt it, but I don't know for certain.

Instead, you might think of getting a stereo audio preamp with a built-in phono preamp section. That would provide the proper voltage gain and impedance levels for the B&O audio amps, as well as volume control.

Two examples of old school stereo preamps are (there are others):
https://avahifi.com/collections/preamplifiers/products/vision-rb-preamplifier
https://www.crutchfield.com/p_745C165BEE/NAD-C-165BEE.html

Yes, sorry I was not good at explaining it...that is exactly what I was wanting to do. I will look at the ones you linked.

 

[Swerd]

Yes, sorry I was not good at explaining it...that is exactly what I was wanting to do. I will look at the ones you linked.

A follow up on what I said last night…

My guess that you need a stereo preamp is only my best guess. I could be wrong and it may actually be possible to hook up a phono preamp directly to your B&O driven speakers. I've never tried such a thing, nor have I seen others do it. If anyone else reading this does know, please chime in.

Is your present external phono preamp this one? If so, try to find out what its output voltage and impedance levels are.

I did find this inexpensive item on Amazon. It is an external volume control. It is NOT a phono preamp. If your phono preamp does have enough gain to directly drive your B&O amps, you might be able to use this downstream of a phono preamp to vary the volume.

Those two stereo preamps I mentioned last night are both, in my opinion, very good but expensive options. I meant them to be examples of what you might need. I have had direct experience with the AVA preamp – it is an excellent piece of gear. Note that it can be ordered with an internal phono preamp and a remote control. Both at extra cost. If you contact AVA and talk to Frank Van Alstine, he might be able to give you some expert guidance. There are other stereo preamps available, I hope less expensive, but I didn't list them. They are "old school" designs in the sense that don't operate digitally and cannot convert digital audio into analog.

Your Yamaha AV preamp is much more capable, it already has a built-in phono preamp, and it's paid for. It's existing remote control probably works by infra-red light – the remote control must be in direct line-of-sight to the preamp. There are devices you can buy that allow you to remotely operate that Yamaha while it's in another room or equipment closet. That may be a less expensive option than a separate stereo preamp. I don't know much about them other that they exist. Does any one else know?

 

[PENG]

I don't know if that expensive Pro-Ject phono preamp with a volume knob that Peng suggested provides enough gain to directly drive the B&O amps. I doubt it, but I don't know for certain.

That one has adjustable gain up to a maximum of 66 dB for balanced connections so even if the OP has to use an unbalanced to balanced cable the maximum gain will still be quite high at 60. As an example, the popular Ortofon 2M Red is rated 5.5 mV, 60 dB gain will get it up to 5.5 V, that's plenty for the B&O modules gain of 27 dB assuming the one I linked was the one the OP has. The OP's existing phono preamp does not have volume control so that won't work with the amp modules regardless, without adding external hardware.

I suggested that expensive one because of the balanced I/O requirement.

 

[Swerd]

That one has adjustable gain up to a maximum of 66 dB for balanced connections so even if the OP has to use an unbalanced to balanced cable the maximum gain will still be quite high at 60. As an example, the popular Ortofon 2M Red is rated 5.5 mV, 60 dB gain will get it up to 5.5 V, that's plenty for the B&O modules gain of 27 dB assuming the one I linked was the one the OP has. The OP's existing phono preamp does not have volume control so that won't work with the amp modules regardless, without adding external hardware.

I suggested that expensive one because of the balanced I/O requirement.

Thanks Peng. So it might be possible. The devil is in the details. It depends on which pick-up cartridge and which phono preamp the OP has. I hope he has a moving magnet pick-up.

Do you think this $39 stand-alone volume control could be useful?

 

[ellisr63]

I currently have the Art phono preamp, and a Sumiko Pearl cartridge.

 

[ellisr63]

I have also been looking at some classic used preamps with a phono stage.

 

[PENG]

I currently have the Art phono preamp, and a Sumiko Pearl cartridge.

That is a mm cartridge that has a rated output of 5 mV. It will work with the $999 Pro-ject phono preamp I linked. $999 seems like a lot, but it satisfies your requirement of balanced connection, and has enough output to drive the B&O amp modules directly, but again, you have not confirmed if the modules are the ones I linked. Until then, I am only assuming..

 

[PENG]

Thanks Peng. So it might be possible. The devil is in the details. It depends on which pick-up cartridge and which phono preamp the OP has. I hope he has a moving magnet pick-up.

Do you think this $39 stand-alone volume control could be useful?

I couldn't find much info about it. In any case, it would only work with the OP's existing phono preamp if that one is an active amp and has sufficient gain to drive the active speaker's amp modules. If that one is also passive, then obviously no. Also, in general, passive preamp is only good if the interconnect is not too long.

 

[ellisr63]

That is a mm cartridge that has a rated output of 5 mV. It will work with the $999 Pro-ject phono preamp I linked. $999 seems like a lot, but it satisfies your requirement of balanced connection, and has enough output to drive the B&O amp modules directly, but again, you have not confirmed if the modules are the ones I linked. Until then, I am only assuming..

I have the lower output 50w and 125w unbalanced ones, and I am purchasing some of the balanced ones. I can use unbalanced for the phono as I have the capability of switching amps after the crossover remotely via Insteon outlets. So if the 50w, and 125 w will work for phone, I will just get the balanced ones for the Yamaha preamp.