2. amps-preamps
  3. 1404294640

Active vs Passive Pre amps

I know this is'nt a new subject, but I would appreciate your views folks. At the moment I am using a Passive Pre, equivelant to the Music First Audio baby reference, but built by an independent engineer. I use it into my ARC Reference 75 power amp, into Daedalas DA-RMa speakers. To be frank, I am very happy with it. The only drawback is the dual volume pots only have about 18 stops available, so you tend to go from too soft to too loud. When the dealer delivered the ARC power amp, he used it briefly with an ARC Ref 3 Pre and I preferred the passive, but it was a limited listen with a new, non run in Power amp.

The passive seemed more neutral and detailed, the ARC a little rich and lush. I know you are supposed to lose dynamics with a passive pre. The question I suppose, is whether it is worth trying to get hold of an ARC Ref 3 or maybe an LS 26/27 and comparing again? Do you think ARC power amps should sound better with an active ARC Pre, which are'nt cheap, even second hand? If I am going to stick with a passive pre, are there better options than the MFA baby reference?

Thanks
david12
david12 OP
1,454 posts
 
Thanks for your comments everyone. As to the dynamics issue, if there is one, some of you dispute that, I thought there was a difference between resistor and transformer based passives. My unit uses the same transformers as the MFA Baby reference. Again, my understanding is that transformer based units have less limitation on dynamics and headroom.

It sounds like I am going to have to spend a lot to improve on my passive unit, which only cost me about $1400 second hand, less than the cost of the transformers themselves.

Has anyone any comments on the quality hierachy of the ARC pre's. My understanding is that it would be in this order LS27>Ref3>LS26, I may be wrong.
raymonda
855 posts
 
I would just replace the pots in your passive with 42 Stepped Ladder type.....or you might try the more recent smd type pot. I'm using one now and prefer it to ALPS. With a resistor based stepped ladder you can choose the type of high end resistor you like....Dale tend to be faster while Takman seem to be more romantic. I think from what you have described you'll prefer Dale.

So, keep your passive and just replace the pots......you'll save a bundle while upgrading your preamp and providing you the gain control you desire. This is a simple solder job...if you are not comfortable your local repair shop should be able to do it for under $35. The cost of the pots should be around $70.00. Remember to order the correct impedance for you pots to match your amp.

Thanks me later!
raymonda
855 posts
 
Oops.....I should have done my research on this passive before wading into these waters. Your pre is transformer based and pot replacement is not as simple as a non transformer based pre. There are other passives that have 48 gain settings...you might try them. Akustyk is a great option....and can be customized to your needs.
stevecham
3,340 posts
 
The resistance range on the volume pot is not appropriate for your system. Also, do you know what taper the engineer put in there? It could be swapped out for another pot and solve your problem, that is if you like the sound of it.
plasmatech
77 posts
 
Stick with an ARC preamp. The amp is voiced that way and there is good synergy.
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