D’Agostino amp with Spectral preamp

@carey1110  

I used to have 2 pairs of D'Agostino Momentum M400 monoblock amps driving the Wilson Alexx at the time and was using the ARC Reference 10 linestage preamp at the time. They paired really well together between the Dag Momentum M400 monoblocks and the ARC Ref 10 preamp with the Wilson Alexx speakers I had at the time. I highly recommend pairing the Dag amps with the ARC Ref 10 or Ref 6 linestage preamps. Before using the ARC Ref 10 preamp I was originally using the matching Dag Momentum linestage preamp but I preferred the ARC Ref 10 pre paired with the Dag Momentum M400 monoblock amps on the Wilson Alexx speakers. They sounded better together IMO. 

Spectral designs are ultra-wide bandwidth and really optimized when used in a system wide approach with their matched electronics and recommended cabling. It's more than an attempt to sell more of their gear, but with the instrumentation grade circuitry involved the networked cables are pretty much a requirement for their electronics to perform as they were designed and maintain stability. You will hear some reports of users who match a piece of Spectral gear with other brands but that's not the way to get them to perform at their peak level.

Thanks guys for you input. Sounds like I should tread carefully here. 

There shouldn't be an impedance mismatch.  If I recall correctly Spectral preamps can work well with non-Spectral amps, but Spectral amps should always be used with Spectral preamps (and interconnects).  Spectral believes in wide bandwidth performance which can unsettle some equipment.  Good luck.

The rule of thumb is the  input impedance of an amp should be at least 10x that of a preamp. It looks like there should be no problem!

1++ Spectral has a weird or rather very different way of designing its stuff and should only be used together. Although it is not death to use a Spectral preamp with a Dag amp you will need another preamp in time as you plan. It is death to use a Spectral amp with most other preamps. A friend fried his amp this way. He returned it to Spectral for repair and they asked him if he had used it with another preamp. He had not told them what had happened. Consequently I do not bother with Spectral Gear. It is great sounding stuff used correctly and very well made but I also lean to the warmer side of things.
Daniel D'Agostino is not someone you want to buy anything from. When a potentiometer in a 7 year old Krell preamp (this was way before he left Krell,) went south he personally informed me face to face at the NY show that the potentiometer was a custom device and he does not stock them and he is not going to have another batch made. He recommended getting one from Radio Shack and mount it to the top of the preamp which was a very slender unit thus the need for a custom pot. The marketing literature said "Built to last a lifetime." My ass, gold screws and all. Most people buy his stuff because they are impressed by the looks. I personally think his stuff looks silly. Don't waste money on gold screws. It is the stuff inside you want to spend money on. 
If you like the warm sound go with PassLabs. If you like the sterile, clean sound go with Boulder. I'm sure there are others that are fine also but I have experience with these two and I can vouch for them. Both have great service and back up their stuff even after the warranty is up. 
When one of my Krell KMA 100s finally toasted its output stage at around 20 years of age I gave them to the friend of a friend who though he might be able to fix it for himself. They were wonderful amps and the very last D'Agostino products I will ever purchase. 

Spectral recommends that its amps and preamps be utilized together. i agree with Audiotroy in that mixing Dag and Spectral will get you the worst of both worlds. Go all Dag or Dag amp with tube pre, a combo I have heard in my home which I thought was fabulous. Spectral is fast and clean. If you like that, go all Spectral. Anything else will ruin its presentation, not complement it.

How do you know if that is a match or not

Pre-2k ohms,  amp 100k ohms

Personally we can't think there would be any reason why these two couldn't work together. 

However in our opinion you can get better sound for less money than the Dagastino gear with the T+A electronics they make an extraordinary 300 watt per channel power amp which competes with the much more expensive Dag amp. 

As per sonic flavors these are two totally different sounds, the Spectral is super clean and fast, the Dagastino is more traditionally a warmer more laid back sounding product. 

If you like the sound of Spectral go with Spectral if you like Dag go with Dag gear.

Hope that helps.

Dave and Troy
Audio Doctor NJ

What's the output impedance for the preamp and the input impedance for the power amp?  I could look it up, but so could you.

How can you tell if there is an impedance miss match?