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Newbie needs help on Audio Research and DynAudio Quality


Hello all,

 

I am a newbie to high end home audio and need help from all of you audiophiles out there. I was actually into high end car audio back to when I was younger so I kinda understand what sound quality level can be considered at audiophile standard. I bought this set up (2 mono amps Audio Research Classic 120, Audio Research LS22 preamp, Dynaudio Contour 1.8 mkII, Rega Planet CD player) 4 years ago and did not have time and room to put them up to enjoy until recently. After setting them up last week, I was very disappointed at the performance. The sound was harsh and I would get tired after listening to 2-3 songs. I remember when I picked up the speakers, the previous owner played a couple of songs using his turntable and it was warm, clear and enjoyable (I could not remember what equipment he had back then). I have another set of solid state stuff to play around which includes Luxman M-12 amplifier, Sansui CA-2000 preamp, JBL 4311B, and same CD player Rega Planet. The sound quality is much better compared to ARC set. I expect that the ARC set at least has to be at entry level of audiophile but what I got out from it is disappointing. I need help from you experts to point out what is wrong or what I should expect from Audio Research.

Best Regards,

Dan


sqlover
mapman's avatar
mapman
22,211 posts
 
Almarg how would you reconcile the manual indicating same power into 4 8 and 16 ohm with doubling down power into the same? It is a hybrid design so that would bode well in terms of having low output impedance for a tube based amp.

Those amps were introduced in 1990 and not used for several years. It's  possible they are not operating up to spec.

I suspected the larger models would be an easier drive but did not check the specs. Good catch! Dynaudios in general seem to get the rap of being towards the power and current hungry end of things.
almarg's avatar
Ag insider logo xs@2x
almarg
9,670 posts
 
Almarg how would you reconcile the manual indicating same power into 4 8 and 16 ohm with doubling down power into the same?

Tube amps providing multiple output taps typically have the same or similar **maximum** power rating when a 4 ohm load is connected to the 4 ohm tap as when an 8 ohm load is connected to the 8 ohm tap, and likewise for a 16 ohm tap if one is provided (as it is here).

However as long as the amp is operated within the limits of that maximum power capability, how much power is delivered as a function of the speaker’s impedance vs. frequency variations depends on the relation between the impedance of the speaker at each frequency and the output impedance of the amp. It does NOT depend on the amp’s **maximum** power capability, as long as that capability is not exceeded. That’s a point which is often not recognized. And as I mentioned the output impedance of this amp comes very close to being in solid state territory, and to being almost negligible in relation to the impedance of the speaker at all frequencies.

Best regards,
-- Al
mapman's avatar
mapman
22,211 posts
 
Yes the multiple outputs for various impedance levels does cover that.

The speaker specs indicate bass range impedance down to 3.8 ohm. Not natural turf for a tube amp. The speaker specs are fairly detailed for a product manual but specs still leave grey areas. Plus the current operating condition is not clear. It is very hard to say without actually being able to hear what the op hears. I’d give the Luxman a shot for comparison if not done already. Perhaps the ARC amps just need a tune up. They look pretty beefy like they should be reasonably up to the task. Still 4 ohm and less in the bass region and most tube amps are not a natural match from a low distortion perspective.
mofojo
2,297 posts
 
When I had Dyns they did not sound good at all with tubes. That was with a Cayin A100T with kt120s. They sounded great with high current ss amps. 
mapman's avatar
mapman
22,211 posts
 
Hey Al the way the manual is written the 45 damping factor may only be when used with 16 ohm speakers. The amps input stage is semiconductor based, the output tube. Could this tube amp similarly produce a damping factor of 45 into a 4 ohm load?  Maybe but do you see in the specs where that is indicated?
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