Please recommend preamp


I'm new at this but am trying to put together a nice system primarily for a large vinyl collection that can also play CDs and probably either a tuner or cassette player. I will have speakers in two rooms, neither very large. I started with the JBL 4312 speakers from my youth for the bedroom and then bought JBL L150As for the living room for $950.  I just got a QSC RMX2450 amp in excellent condition for $300. I think my next step is a pre-amp. What would be a good bet for around $1000?  I'm hoping to get it right the first time rather than test-drive and buy and sell; really, I just want to listen to my records.
takeum0ut

Showing 3 responses by almarg

Mesch makes an excellent point. Dorkwad has recommended a very nice product, that is in your price range, but unfortunately I don’t think it would be a good match for your amp. As is often the case with tube preamps its measured output impedance of around 1800 ohms (unbalanced only) is much too high to be a good match for the input impedance of your amp (10K unbalanced, 20K balanced). And I note that the manual for your amp recommends that it be used with a preamp having an output impedance of 600 ohms or less. Also, its gain is probably too high to be optimal for use with your very sensitive and very high powered amp, especially when playing CD’s. Gain that is too high in relation to the sensitivity and power capability of the amp (with the efficiency of the speakers also being a relevant factor, that apparently being moderate at 89 db/1W/1m for the L150A) would force you to use the volume control too close to the bottom of its range. Finally, although your amp can accept unbalanced inputs in certain ways, it does not provide RCA input connectors, and it appears to have been designed with the expectation that it would be likely to be driven with balanced signals.

IMO your chances of success would be greatest if you were to choose a solid state preamp providing both unbalanced (RCA) and balanced (XLR) outputs. Some of the older Classe preamps such as the CP-50 and CP-60, with the optional built-in phono stage, may be findable in your price range or for not much more, and should be fine choices. Some of the lesser models in that range, though, such as the CP-45 and perhaps the CP-30 and CP-35, may have line-stage gains that are somewhat higher than would be optimal for use with your amp.

Good luck. Regards,
-- Al

I took a look at the specific listing you referred to for the CA-7A. It’s possible that it would work out ok but I wouldn’t recommend it.

First, the CA-7A dates back to around 1986, which raises concern about condition-related issues surfacing eventually if not sooner. I’d also be concerned about the possibility of condition-related issues because in this particular case I’d have less than complete confidence in how thoroughly it might have been tested and checked out, given that the seller appears to be a high volume business not necessarily specializing in audio equipment.

Also, the 1K output impedance of the unit, while perhaps marginally ok, exceeds the 600 ohm max recommendation that is stated in the manual for your amp. And it can be calculated from the specifications that are provided that its gain is probably too high to be optimal for use with your amp and speakers. Finally, it doesn’t provide balanced outputs, so you would have to connect it to your amp using adapters or adapter cables (although in itself that would be a relatively minor downside).

Regards,
-- Al
Regarding the NAD C-375BEE, if you haven’t already seen it you’ll want to read this review, which glowingly praises its sonics aside from those of the optional phono stage and the built-in headphone amp. Which of course, given that reviews should not be taken as gospel, is not to say that you or others wouldn’t be pleased with the phono stage. But you might want to consider the other 375BEE that is presently listed at Audiogon, apparently without a phono stage but with a manufacturer’s warranty. It could of course be used with a separately purchased standalone phono stage.

Regarding the HK units, as I said in connection with the Nakamichi preamp you mentioned earlier I personally would be hesitant to go with a 1980’s product, as I would expect that eventually if not sooner capacitors would need replacement, and there would be significant risk of other condition-related issues. Especially in the case of a solid state product, for which both the availability of replacement parts and the difficulty of their installation often tend to be more problematical than in the case of tube-based products.
I had looked at the NAD C165BEE on this site...my QSC amp would "melt" it?
Since Elevick has not yet responded, I’ll take the liberty of clarifying his comments. The QSC amp would not have any adverse effects on the C165BEE or any other preamp. He was referring to NAD and other home-oriented power amplifiers, which he had found could not stand up to the rigors of commercial use. And he was implying that in contrast QSC amps were designed with ruggedness rather than sonics as the main priority. And that you may therefore do better in terms of sonics with an amp designed for use in the home.

I have no experience with QSC or other such products, so while that strikes me as certainly being a legitimate concern I can’t comment specifically. I’m just offering an interpretation of his comments.

Regards,
-- Al