How to Improve Gain for RCA on Preamp. Can it be done?
I own a Schiit Freya+ which I use as a preamp to my active speakers. I use the balanced XLR from my Freya+ to my actives (which have balanced XLR).
The Freya+ has XLR inputs and RCA inputs but I have noticed a large difference in gain between the two. Specifically, I have looked at the following two scenarios:
A) source > balanced XLR in Freya+ > balanced XLR out > actives
B) source > RCA in Freya+ > balanced XLR out > actives
I observe a large difference in gain between (A) and (B) even when using the tube stage of the Freya+ (I almost always use the tube stage as it sounds the best and gives best gain).
For source, I have used my ADI-2 DAC FS which has both XLR and RCA out.
The problem comes with my TT. When I connect the phono stage by RCA to the Freya+, I have to turn the Freya+ all the way nearly to the limit to get satisfactory dB. But directly connecting my phono stage to the actives (which also support RCA) gives excellent dB.
The problem is I am purchasing new actives (Genelec 8351B) which support XLR but not RCA. Therefore, my question is as follows:
Is there a way to improve gain on a preamp using RCA? Is this problem that I am experiencing specific to the Freya+ or is this a general loss of gain (I am guessing 15 dB) that always accompanies RCA. Are there preamps that would mitigate this? I am willing to buy another preamp if so. Let's say 3K for a new preamp as a round number.
There are several ways to interpret your comment; just so you know, Atma-Sphere built the first balanced line preamps offered to home audio back in 1989. We got a patent on the technique we used since we didn't use an output transformer and the preamp was all-tube. At the time it didn't occur to not support the standard; as others entered the field we were dismayed to see that very few supported the standard- to this day. |
@millercarbon Just so you know, this isn’t how its supposed to work. In a balanced system, the signal is not generated with respect to ground; ground is independent of the signal. So the RCA and XLR outputs should be the same voltage! Think of a phono cartridge, which is a balanced source. Its output does not change if you run it balanced or single ended. The ground is the tonearm tube; its independent of the signal. Think of an output transformer, whose secondary can drive either single-ended (with one side at ground) or balanced (neither side at ground; ground is merely chassis with no other connection to the transformer). The output voltage is the same in either case. When you see the gain difference as described, what is happening is that the inverting and non-inverting aspects of the balanced line are generated with respect to ground rather than each other. IOW, each is a single-ended output, with one out of phase with the other. This type of connection does not support the balanced line standard, since the ground connection is essential for its operation to complete the circuit. So its not ’always like this’ as you say, its just like that if the equipment isn’t supporting the standard.
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