Need a Preamp/Amp!

[team_tsp]

As noted in my other thread, I recently purchased a pair of Dynaudio C1's as part of a new system I'm putting together I need a preamp/amp, or integrated receiver, to drive these, let me know your suggestions!

Requirements:

• I will be running the C1's in a 2.1 configuration with a subwoofer (SVS PB12-NSD), so I would really like bass management.
• System will be used 100% for music.
• Budget - preferably less than $2000 for preamp/amp or integrated receiver, though I'd be willing to spend a little more if there was a good reason to.

Options I have been researching -

Integrated Receivers:

• Parasound Halo Integrated:
  • A bit more than my budget, though this seems to have a lot of good features.
  • However, doesn't let me "geek out" as separates would.
• Any decent AVR would also work I suppose, though I wouldn't be using the extra channels, video features, etc. I'd like to get equipment focused on 2-channel.

Stereo Preamps:
The only stereo preamps I know that have bass management are:

• Parasound 2100:
  • Limited bass management but seems functional enough (high-pass line outs are fixed at 80hz)
    
  • More attractive price.
• Parasound P5:
  • Great feature set
  • However, multiple reviews/measurements show that the DAC implementation was not optimized (kind of a bummer for a fairly pricey unit).

Amps:
Monoblock amps:

• I think monoblock amps would be fun, but I seriously cannot find affordable ones other than the Outlaw M2200. Anyone have thoughts on these, or know of any other makes/models that are affordable?

Stereo amps:

• Parasound A23
• Monoprice Monolith 2 channel
  • Anyone have thoughts on how this compares to the Parasound A23?
  • Likewise how does this compare to the similar ATI amps?
• There are dozens of other amp makes/models in this price range, any other intriguing suggestions?

 

[Flint]

Get the Parasound 2100, I love mine. I don't use it right now, but I will soon. The C1s work well with a 80Hz crossover.

As for amps, the C1s like lots of power. Look into the Monoprice amps.

 

[Batman]

I was going to mention the Monoliths yesterday but while I was driving I kept waiting until I was stoppped to respond and then ultimately forgot to bring them up. I'm sure Rammis and Heeman can give you all the details you need on that product.

 

[TKoP]

Get the Parasound 2100, I love mine. I don't use it right now, but I will soon. The C1s work well with a 80Hz crossover.

As for amps, the C1s like lots of power. Look into the Monoprice amps.

Like this one? or this one?

 

[Flint]

More like this one:

https://www.monoprice.com/product?p_id=15595

 

[team_tsp]

Thanks for the input so far!

Another option I forgot to include in my original post is the Outlaw Integrated Receiver (RR2150), which has bass management. But for some reason that product has never quite appealed to me, not sure why. I mean logically it seems like a fine product, but I kind of want to go with separates for fun anyways (as mentioned before).

The Parasound 2100 and Monolith 2-Ch combo is definitely an option I've been considering.

A couple questions:

1. If I go with the Parasound 2100, I'll be using the line outs from my Squeezebox Duet as the source. The Parasound 2100 has analog bass management (BM) I believe. Are there any pros/cons of analog BM compared to digital BM, which is found in most AVRs? Or does it really just depend on the product, regardless of the approach (analog vs. digital)?
2. Regarding the amp, I don't listen to music very loud, typically 75-90 decibels. The Monolith falls within my budget, but sometimes I wonder if it's overkill, though I know it's better to have a beefy amp for sudden peaks in the music, etc. I was just wondering if there is another quality amp that meets my needs at a lower cost? But the Monolith does seem like a good product, and it's nice to know it has plenty of power for the C1's, or any other speakers I might use in the future too.

 

[heeman]

If you want to save $1K, buy the Monolith. If you have the money, buy a B stock Halo A21.

 

[team_tsp]

If you want to save $1K, buy the Monolith. If you have the money, buy a B stock Halo A21.

Yea, the Monolith is looking more and more tempting, especially since I can just order it online. I tried calling a few local audio dealers to ask about amps, pricing, etc. None of them picked up, or called me back when they said they would

 

[MakeMineVinyl]

Yea, the Monolith is looking more and more tempting, especially since I can just order it online. I tried calling a few local audio dealers to ask about amps, pricing, etc. None of them picked up, or called me back when they said they would

The Monolith is identical to one of ATI's main amplifier models. The only exception is the power management circuit, which is now microcontroller based (and a true work of engineering genius).

 

[team_tsp]

The Monolith is identical to one of ATI's main amplifier models. The only exception is the power management circuit, which is now microcontroller based (and a true work of engineering genius).

Just so I understand right, the Monolith has the genius designed microcontroller based power management circuit?

If so, is there a reason why that was implemented for the Monolith and not ATI's amp? Or is it that the ATI is just older?

 

[MakeMineVinyl]

Just so I understand right, the Monolith has the genius designed microcontroller based power management circuit?

If so, is there a reason why that was implemented for the Monolith and not ATI's amp? Or is it that the ATI is just older?

The Monolith is a newer amplifier which, like all of
ATI's new models takes advantage of microcontroller circuitry.

 

[team_tsp]

Hey everyone, so a quick update. Normally I'd elaborate on my new gear, but I do have question.

Chris (aka @Batman) reached out to his contacts and sourced me a Parasound 2100 preamp (thanks again Chris!). I also ordered the Monolith 2 from Monoprice.

Both arrived today, and I've been setting everything up. The Parasound seems to be working great, etc.

However, I have a question about the Monolith amp. It seems to be working correctly, and sounds clean, etc. However, the unit itself is emitting a noticeable hum (with slight buzz). I noticed this immediately when I powered on the unit to make sure it wasn't DOA (without any preamp or speakers connected to it).

The hum is noticeable even in my main listening position, which is about 7-8 feet away from the amp. Of course music covers up the hum, but during quiet passages I can still sometimes hear it. After about an hour of listening to music, the hum has stayed constant (not getting any louder or softer).

Do anyone have thoughts on whether this might be an issue, or are a lot of amps like this? I'm debating whether I want to live with it, or whether exchanging it is a worthwhile endeavor, or to return it.

This is bumming me out quite a bit since I really want to like the amp.

 

[Flint]

No, the amp should not be audibly humming from the chassis. I will wait for our friend Rammisframmis to chime in, but I would think the amp needs to be replaced. There is another member with a similar three channel version of that amp, and I spent a few days with it recently and never noticed any hum from the chassis.

 

[team_tsp]

Thanks @Flint for the quick response -

I noticed Audioholic's review (which has great measurements of the amp and was influential in my decision to purchase the amp) mentioned how humming can occur due to DC offset in your home's electrical system. He said an AC line restoration device (he referred to an Emotiva product) fixed the humming for him:
http://www.audioholics.com/amplifier-reviews/monoprice-monolith-7-channel-amplifier-review

Not sure if I should give that a try, though Emotiva's product costs $120...

 

[Flint]

I strongly recommend you reach out to Rammisframmis, or await his response here, before doing anything. Just enjoy it as it is for now.

 

[team_tsp]

I strongly recommend you reach out to Rammisframmis, or await his response here, before doing anything. Just enjoy it as it is for now.

Agreed, was just doing some research

 

[MakeMineVinyl]

However, the unit itself is emitting a noticeable hum (with slight buzz). I noticed this immediately when I powered on the unit to make sure it wasn't DOA (without any preamp or speakers connected to it).

The hum is noticeable even in my main listening position, which is about 7-8 feet away from the amp.

Normally an amp chassis should not emit an audible hum or buzz. If there is DC on your AC power line, this will cause an offset within the core of the power transformer and will usually cause an audible hum or buzz like what you are hearing. The cure for this is the back-to-back capacitor DC blocker you mentioned previously.

The usual cause for DC on your power line is that there is a heavy load on the transformer on the power pole servicing your house and your neighbors. This heavy load causes high even order harmonic distortion from core saturation which is manifested as DC. If this is the case, you could expect that the DC (and thus the hum from the amplifier) would come and go at different times of the day as the load on the pole transformer changes. If you notice that the hum does come and go at different times, there is nothing wrong with the amp and you would need to get a capacitor DC blocker if you listen at those times.

If the hum from the amplifier does not ever change, no matter what time of day (and thus load on your AC), I would contact Monoprice about a replacement.

The problem you are experiencing is not at all unusual, even with very, very, high end power amplifiers - any power amplifier with a transformer is vulnerable.

I should also mention that you should double-check that you are not hearing this hum or buzz from your loudspeakers instead of the amp itself. If so, this would be a simple ground loop.

 

[team_tsp]

Normally an amp chassis should not emit an audible hum or buzz. If there is DC on your AC power line, this will cause an offset within the core of the power transformer and will usually cause an audible hum or buzz like what you are hearing. The cure for this is the back-to-back capacitor DC blocker you mentioned previously.

The usual cause for DC on your power line is that there is a heavy load on the transformer on the power pole servicing your house and your neighbors. This heavy load causes high even order harmonic distortion from core saturation which is manifested as DC. If this is the case, you could expect that the DC (and thus the hum from the amplifier) would come and go at different times of the day as the load on the pole transformer changes. If you notice that the hum does come and go at different times, there is nothing wrong with the amp and you would need to get a capacitor DC blocker if you listen at those times.

If the hum from the amplifier does not ever change, no matter what time of day (and thus load on your AC), I would contact Monoprice about a replacement.

The problem you are experiencing is not at all unusual, even with very, very, high end power amplifiers - any power amplifier with a transformer is vulnerable.

I should also mention that you should double-check that you are not hearing this hum or buzz from your loudspeakers instead of the amp itself. If so, this would be a simple ground loop.

Thanks for the insight @rammisframmis -

I am sure that the hum is not coming from the speakers, as I heard it the first time I powered on the amp without anything connected (just to make sure it wasn't DOA or anything).

As for the hum coming and going, I feel maybe it's gotten a bit quieter, but I'm not sure. Based on research, it sounds like a lot of people have had luck with the Emotiva CMX-2 getting rid of amplifier hum. I might give that a try, unless anyone happens to know any comparable products (preferably cheaper and/or available on Amazon) that you'd recommend?

 

[Razz]

I just moved into an old house and found out I have a lot of DC in my lines. My ATI 2007 went nuts! The buzz I have comes and goes and can be very loud actually. Also, the buzz I get is more rhythmic. It goes up and down in frequency. I told rammisframmis about it and he new right away what it was. So I just now ordered that Emotiva CMX-2. I'll let you all know how it works for me.

 

[MakeMineVinyl]

I just moved into an old house and found out I have a lot of DC in my lines. My ATI 2007 went nuts! The buzz I have comes and goes and can be very loud actually. Also, the buzz I get is more rhythmic. It goes up and down in frequency. I told rammisframmis about it and he new right away what it was. So I just now ordered that Emotiva CMX-2. I'll let you all know how it works for me.

This is a good argument for 240VAC power, as it is balanced by its nature, and thus crap on the line will cancel out just like balanced audio cabling. But Noooooo, in the USA we're stuck with "unbalanced" 120VAC power so depending on which "half" of the AC line you are taking your power from, you may or may not have a problem. Also one half or the other is usually more heavily loaded and this causes line distortion and DC. With 240VAC, both halves are loaded equally by default, so no problem.

Make America's AC power great again......

PS: Like I mentioned to you when you were at the ATI factory, the DC blocker will introduce a small power loss because the capacitors cannot be infinitely large (at least for a reasonable price). However, its likely to be a rare occurrence when you will need more current than will be available.