Matching a amplifier to speakers

displayname

160 posts

04-29-2025 at 02:32pm 

Musical Fidelity pair well with Dynaudio.

I agree with that. 

Another good option would be Norma. https://tmraudio.com/components/power-amplifiers/norma-audio-revo-pa-150-stereo-power-amplifier-1/
That specific unit looks like an excellent deal. 

I looked at the specs and it appears to have a input impedance of 47k.

I'am trying to find a amp with a input impedance near 100k,to work with my mx110 preamp/tuner, as recommended by Mcintosh.

thanks

westcoastaudiophile

470 posts

04-29-2025 at 02:10pm 

Four output KTs are driven pretty hard to produce 180W of power, thus lifespan will not be great, likely below 2000h. 

I guess it all depends on one's listing habits .

I don't think I listen more than 10 hr's per week,so 2000 would be approx 4 years for me.

Thanks

@twangy57, hello, and I hope you are well, as you seem to be. A few questions...Have you had your MX110 overhauled, or is it stock? Have you used the Adcom amp with the new speakers, and what do you think? What sq characteristics are you looking for with an amp, as what has been recommended to you so far has been all over the place, and I am not trying to sound negative. People will generally recommend what they own, or like, which is fine. What I would also like to ask, what is your room like, acoustically, and what wall are the speakers set up on, the short wall or the long wall? In the meantime, if you changed the power cord on your Adcom amp (have a technician do it, if you never have) to a 12 or 10 gauge cable, your Adcom amp will become a new amp, for the better.....I promise you this. I have my own ideas on power amplifiers...tubes vs ss, and brands / models (been around the block with this for a very long time). Take your time selecting a power amp. Keep in mind, this. The same exact system, down to the cables, will present differently to every listener, and this same system will sound different from one room to another. Something to think about. My best, MrD.

Musical Fidelity pair well with Dynaudio.

I agree with that. 

Another good option would be Norma. https://tmraudio.com/components/power-amplifiers/norma-audio-revo-pa-150-stereo-power-amplifier-1/
That specific unit looks like an excellent deal. 

Four output KTs are driven pretty hard to produce 180W of power, thus lifespan will not be great, likely below 2000h. 

Does anyone have a Rogue amp with KT=120's

I'am looking at a pair of M-180 mono-blocks with 180 watt's per side.

Do these tubes have a decent lifespan?

Are they  readily available at a affordable cost?

I also Imagine with 8 power tubes these amps will put out some heat.

Thanks

ditusa

1,973 posts

04-28-2025 at 12:09pm 

@twangy57 Wrote:

The only other amp I have found so far that has a impedance close to what I need  is the Parasound Halo 21+

Parasound Halo 21+ Input Impedance (SE): 33 kΩ see specifications below: 

That's strange I could of swore it was 100k bal and 84 un bal.

I must have been thinking of another amp.

Thanks

Amplifier input impedance should be at least 10x (I have had good luck with at least 20x) the output impedance of your preamp or source (whatever is driving the amplifier).  To determine power requirements, you can play with the this (linked) calculator as a starting point.

@twangy57 Wrote:

The only other amp I have found so far that has a impedance close to what I need  is the Parasound Halo 21+

Parasound Halo 21+ Input Impedance (SE): 33 kΩ see specifications below: 

’’Specifications

Power Output (8, 4, 1 Ohm): 300 W, 500 W, 1,000 W

Inputs: Stereo RCA, stereo XLR, DC trigger

Input Impedance (Bal., SE): 66 kΩ, 33 kΩ

Gain: 29 dB

Dimensions (WHD): 17-5/8" x 7-1/8" x 20"

Weight: 71 lb.’’

Mike

I’ve owned Dynaudio speakers and like them very much.  Yes in general they will sound best with an amp capable of delivering more power and current.   Sounds like tube amps have been correctly ruled out for this case so I think you are on the right track. 

84kohm+ amp input impedance should work well with most any pre-amp.

Update.

Upon talking to several audio shops,they tell me the 40k impedance of my preamp would work fine just about any amplifier,as long as I wasn't running speaker cables over 10 ft.

Sound right?

I have found 2 amps I like,but both are older.

They both have the input impedance I need to get the best results from my Mcintosh mx110,(at least I think so).100k

First one is a Conrad Johnson 350sa -input impedance 100k

the second is a Audio Research 150m-input impedance 100k

I going to call around to make sure these can be repaired still if needed .

Would anybody not buy these because of their age?

My thinking is because they are solid state,they would be easier to maintain. 

The only other amp I have found so far that has a impedance close to what I need  is the Parasound Halo 21+

It;s impedance is 84k,close to the 100k Mcintosh recommends.

Thanks

blackbag20

545 posts

04-28-2025 at 05:32am 

@mike4597 Plus one ... Klaus is amazing.  I have the Kismet Amp and it's never leaving the house ... do yourself a favor and check this guy out!!

https://odysseyaudio.com/

They look nice ,and very reasonably priced,but I need a input impedance of around 100k to work with my Mcintoch mx110.

Thanks.

@mike4597 Plus one ... Klaus is amazing.  I have the Kismet Amp and it's never leaving the house ... do yourself a favor and check this guy out!!

https://odysseyaudio.com/

emergingsoul

1,246 posts

04-27-2025 at 11:37am 

Frankly very few people understand how to match amps and speakers. Most of the components these days get along pretty well.

Just make sure you’re speaker sensitivity makes sense when you buy amplifiers.  Highly sensitive speakers don’t need as much amp power rapidly ( can consider a low power tube amplifier which I think is something I wish I would’ve done earlier).  Also, Crossover design impacts Power usage within the speaker that’s a whole Nother issue.

Seek advice of the dealers selling the products and get their thoughts on how components match with each other. They have experience using the components and that’s the best source of info.

I thought I was doing that,but I was not aware of the impedance mismatch between some tube pre-amps and most solid state amps.

I new the speakers I was buying liked high currant and a lot of power,and I thought I would have no problem getting a amp to deliver that a reasonable (under 5000$) cost.

I’am sure I will find something that will fit the bill.

thanks

squared80

178 posts

04-27-2025 at 09:35am 

There is no such thing as ’matching’ amps and speakers. All you need to worry about is power handling, since all amps are literally going to sound the same (save for tube amps).

They sound different to me,and I guess I'am the only one that it will really matters too,

thanks

Frankly very few people understand how to match amps and speakers. Most of the components these days get along pretty well.

Just make sure you’re speaker sensitivity makes sense when you buy amplifiers.  Highly sensitive speakers don’t need as much amp power rapidly ( can consider a low power tube amplifier which I think is something I wish I would’ve done earlier).  Also, Crossover design impacts Power usage within the speaker that’s a whole Nother issue.

Seek advice of the dealers selling the products and get their thoughts on how components match with each other. They have experience using the components and that’s the best source of info.

There is no such thing as 'matching' amps and speakers. All you need to worry about is power handling, since all amps are literally going to sound the same (save for tube amps).

For what it is worth:

My Futtermans are notoriously fussy about load. Since I am married to the Futtermans, speaker choice comes second: find a pair that matches up to the Futtermans. 

Except that I already owned the Altec 694Cs. 

Which, coincidentally, paired up magnificently with the Futtermans. Pure luck. 

"100boardwalk

17 posts

04-26-2025 at 07:05pm 

I know you’re thinking SS, but if you consider tubes, the MC 275 would likely play nicely with the MX110. My ancient McIntosh XRT 20’s have comparable sensitivity to your new Dynaudio 360 speakers, and my 275 drives them admirably.I purchased my very low hours MK VI 275 from Audio Classics for $4999."

I originally planned on going tube,but from everything I have read and what people on here that have owned the Dynaudio focus 360’s have told me is,they need at lot of power and a lot of currant.

I also think with the warm nature of the mx110,my system might benefit from some clarity offered  by the right ss amp.

I have been looking at the Mcintosh amps,just need to think on it some more.

I just know some people have said these speakers seem to like at least 200 watts per channel.

Thanks

I know you’re thinking SS, but if you consider tubes, the MC 275 would likely play nicely with the MX110. My ancient McIntosh XRT 20’s have comparable sensitivity to your new Dynaudio 360 speakers, and my 275 drives them admirably.I purchased my very low hours MK VI 275 from Audio Classics for $4999.

I’am starting to think I should maybe switch my pre-amp to a Conrad Johnson or another pre that has a lower output impedance.

I wonder why the MX110 has such a high output impedance,as the C-22 is only 220 ohm’s?

Is it a result of the FM tuner?

Lots of variables involved.

Thanks

ditusa

1,969 posts

04-26-2025 at 12:46pm 

@twangy57 Wrote:

ditusa

I looked at the schiit tyre,but it has a input impedance of 47k.

I'am looking for something near 100k or more as Mcintosh recommends for my MX110 tuner/pre-amp

thanks

Why not buy a McIntosh Amp?

Mike

Which one?

All the solid state amps have a low input impedance around 20k ohm's,which means they won't match well with my preamp's output of 40k ohm's

 If you mean tubes, which one has over 120 watts that I can get for 5000,or less?

Thanks

knownothing

1,667 posts

04-26-2025 at 11:58am 

@twangy57 I might suggest this:

https://www.audiogon.com/listings/lisbdfg8-audio-research-vt200-mkii-power-amplifier-silver-pre-owned-tube

I have no connection to this seller, just seems like it would fit the bill.

kn

I was looking at that one.

16 power tubes.That scares me.

How often would they need to be changed at 10hrs listing a week?

I know it's getting hard to get nice NOS el-34's for my guitar amps.

Thanks

@twangy57 Wrote:

ditusa

I looked at the schiit tyre,but it has a input impedance of 47k.

I'am looking for something near 100k or more as Mcintosh recommends for my MX110 tuner/pre-amp

thanks

Why not buy a McIntosh Amp?

Mike

@twangy57 I might suggest this:

https://www.audiogon.com/listings/lisbdfg8-audio-research-vt200-mkii-power-amplifier-silver-pre-owned-tube

I have no connection to this seller, just seems like it would fit the bill.

kn

I have been looking at the spec’s on many of amps recommended here,and few have a high enough input impedance to work well with my mx110.

McIntosh states a 40k output on the mx110,and a minimum 100k input on the amp it is to be going into.

The Parasound Halo 21+ comes close at 84k unbalanced .

The Rogue Audio stereo 100 is 200k

I was trying to go solid state for less maint.,heat and tighter bass.

Would the Rogue st-100 have enough power for my speakers(Dynaudio focus 360 4ohm)?

Would  the 84k input impedance on the Parasound be alright with my Mac mx110?

I’am wondering if the older Conrad Johnson 350sa,could be repaired if needed down the road?

Thanks

ditusa

I looked at the schiit tyre,but it has a input impedance of 47k.

I'am looking for something near 100k or more as Mcintosh recommends for my MX110 tuner/pre-amp

thanks

@twangy57 you’ve gotten some good suggestions so far.  I don’t hoe you could go wrong with a Pass Labs amp.  Some solid state amps that I suggest pair well with Dynaudio speakers include amps from Moon, Primare and Plinius, and can be found used for reasonable prices. The comment on impedance matching is important no mayter what you choose.

kn

@twangy57. Remember: Schiit Tyr Mono Amps see here. 

Mike

In my search for a high impedance amp,it seems most of the Conrad Johnson SS amps have a 100k ohm input spec.

I found a old one for sale on the Audiogon site..It is a 350sa SS amp.

It has the power I need and is in my budget.I have heard CJ tube amps,which I thought sounded great.

Would any of you consider buying a amp over 20 years old ?(I think).

Thanks

incorrigable

ThanksI will look a the wired 4sound amps,they might be a good candidate,as they have like a 91k ohm input impedance.

My Mac mx110 is recommended to be used with amps of at least 100k ohms,and there aren’t many solid state amps that have that.

I might have to go tube if I want to keep the Mcintosh pre-amp.

That could get expensive with the high currant these speakers like.

Does anybody know of any good solid state amps with input impedance of at least 100k.

Thanks

@twangy57  - I recommended the JC5 since you initially suggested a budget of $5000. Less is understandable (although I never seem to be able to come in under budget). lol. But the close out price on a new silver Parasound JC5 is nearly the same as recent used ones. If you’re considering Parasound, this is a pretty good deal. 

@twangy57 

I would highly suggest the Anthem STR Power Amp. It'll power any speaker you hook to it (see reviews with measurements and you'll see it's actual power output), looks awesome with the meters (which you can turn off if you don't like them) and it has a fantastic sound.

Not my ad

https://www.usaudiomart.com/details/650203087-anthem-str-amplifier-mint-mint-mint/

mike4597

Thank you,I will take a look at Odyssey Audio.

Take a look at Odyssey Audio.  Klaus makes some very good amplifiers.  I replaced my Rogue Audio 100 wpc tube amp with two 200 watt monobloc amps, and the improvement was quite significant—I consider these amplifiers to be “keepers.”   Odyssey offers both stereo and monobloc solid state amplifiers, made here in the U.S., and with a 20-year warranty.  www.odysseyaudio.com. 

incorrigable

I will see what I can find on them.

Thanks

mbarrett635

I saw them,but I'am trying to stay around 4,000 or less.

Probably not going to find those used for awhile either.

Are they that much better than the Halo?

Thanks

Wyred4Sound SX 1000R monoblocks ($3300) will make your Dynaudios sing. Headroom is what I refer to. Like a powerful car where you set the cruise control but the transmission doesn't kick down, even in the mountains. 

You asked about the Parasound A21+. If you are willing to stretch your budget just a little bit, you can get the Parasound JC5 in silver for $5499. I’ve had Parasound amps for years and just recently bought a JC5 (but in black). I find it really neutral, and at 400 watts/channel into 8 ohms, it should have no trouble driving your Dynaudio 360s. 

petaluman

Thanks,sounds like good advice.
I'am very hesitant at this point to stray far from the amps I grew up listening too,so it would have to just blow me away in order for me to make the change now.

mike_in_nc

Ok,but I know that every single piece of guitar gear I have tried that was claimed to be better than that old stuff has never worked for me,

Most of the digital modeling stuff sounds good when you demo it,but once there is competing instruments involved it falls on its face,and sends me running to a 64 Fender amp.

I will try though,as it would be nice to just once,like something that doesn't cost a bunch.

Thanks

salc

Ok,good to know.

I have been focusing on high currant,and damping factor.

I will do some reading on the input impedance ratio.

I have a old McIntosh MX110 tuner/preamp.

I will check this against the Pass amp,just to see what it looks like.

Thanks

@twangy57 - Future Audiophile has reviewed quite a few Class D amps. I can think of worse places to start your reading.

As you do your reading, I hope you'll consider two things: (1) Class D has improved a LOT in the last 10 years, and some people (including me) think it rivals Class A sound; and (2) a lot of audiophile prejudice is out there, based on who-knows-what (maybe the Class D of 20 years ago, maybe just that it's called "D") against Class D. IMO that is rubbish. I have heard and owned some Class D amps that I've preferred to more expensive class AB amps, including some very highly regarded ones.

Trust your own ears.

bluethinker

I hear you,That is the one thing that I see in most reviews of the Dynaudio's.

I will write That down in my notes.

Any thoughts on the Parasound Halo 21+?

Thanks

soix

Either,depending on condition,price.

Thanks

mike_in_nc

Thanks,I know nothing about class D.I will have to read up on them.

lordmelton

Thanks,I think I have heard that they do go well with Dynaudio speakers.

II’ll add them to my list.