2. amps-preamps
  3. 188598-170624

Use of Y connector rather than passive preamp

I get way better sound when my DAC with volume control is directly cabled into my power amp than when it goes through my preamp. I also like the sound of my phono pre directly cabled rather than going through the same pre (though the choice is not as clear). I basically need a switch with volume control on only one input. A passive pre could do the trick, but there is a lot of discussion re qualities of different designs, and I imagine directly cabling the DAC to the amp would beat interposing any switch/volume controller. To minimize impact on the DAC route, can I use a simple Y connector at the power amp, with a volume control on the phono pre side? Is there a danger if I accidentally have both inputs on at once? Perhaps the impact on sound quality will be minimal if I use a passive pre and just turn the volume to full when using the DAC? (RME ADI2 DAC, Parasound JC3+ phono pre, McIntosh 462 power amp, ARC LS25 II pre, all balanced connections). Thanks a lot for your help!

arhgef
arhgef OP
55 posts
 

Just in case anyone checks this later: It can be ok to split an upstream signal so that it feeds into two amps, not ok to feed two upstream signals into the same amp input. If  they are on at the same time, bad things can happen. I thought maybe by turning on only one this could be ok, but that is begging for an accident. I think that some circuits can be damaged even if they are not powered on.  

koestner
664 posts
 

There are some inexpensive passive preamps that accept more than one input. I think Schiit has one, and also look for a used Tortuga as they come with remotes.

arhgef OP
55 posts
 

Have been looking into this. Some brands to check: Schiit, Mapletree, Goldpoint, Khozmo, Little bear/Nobsound, This covers a variety of prices and quality for stepped attenuators and potentiometers. You can also look into some based on transformers. It is important to keep the cable between the pre and power amp short, or the cable capacitance combined with inductance of the pre can produce high frequency rolloff. I have been trying these and they sound wonderful for some sources (eg my DAC with its higher power). Great improvement in clarity over my ARC - the detail in orchestral pieces is impressive. Bass is tighter. Depending on source you can lose some “fullness” in the bass (frequency response is fine). I hear this with the phono pre. I will definitely use a passive for my DAC, and may keep the ARC for the phono, Choice there depends on the recording (do you want clarity versus richer bass?). The impedance match between your amp and the pre is important for good sound. They say a rule of thumb is ratio of 100 or better. 

arhgef OP
55 posts
 

Just to be clear, the DAC has good output and a volume control, so you could say it has a preamp built in. When using the DAC I will just set the volume on the passive pre to max. I hope this will sound essentially like cabling directly into the power amp. Buying a passive pre instead of a switch gives me the versatility of using it either as a passive pre, or as a high quality switch with a different pre/buffer on one of the sources. 

scm
313 posts
 

The Tortuga Audio LDR has an adjustable impedance feature.

The remote is pretty nice too. 

My listening is about 99% vinyl 

The Tortuga will allow you to hear what`s going on without adding anything to the mix. 😎 

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