Upgrade to a outboard Phono Preamp?

[jvm051]

Just recently I purchased a Rega P1, and upgraded to the Rega Bias Cartridge, and a glass platter. Now when I play it in Direct mode, using my Integra DTC 9.8 preamp, it sounds great. Only problem is when it is in direct, the Sub is not active. If I switch to Stereo mode, the bottom end is basically missing. I am using Audyssey Multi EQ XT, and it does a great job, with CD's and movies, but not with the Analog Phono stage of the Integra. So my question is, would adding a outboard phono preamp possibly help, by adding more gain? This is my first Turntable so I am still learning.

[Otto]

Hi there jvm,

I can't promise that a phono preamp will fix your complaint, but you can give it a try.

As I understand it, the RIAA equalization curve requires that the phono preamp stage reintroduce bass frequencies into the signal. I think they cut bass from the phono signal because it makes the groove too wide (thereby reducing the amount of time you can have on one side of the record), or because it causes the needle to move too much (thereby causing it to jump out of the groove sometimes), or perhaps a combination. Check that if you're curious, I could be off on that description, but that's what I recall.

Anyway, if the Integra doesn't do the RIAA curve well, your problem could well be solved by using an outboard preamp, since it may do a slightly different job of EQing the low end. I'm using an NAD PP-2 (picked up on AudiogoN for something like $75) for my phono preamp, and it seems fine. I happily admit that I'm a newb to phono as well. FWIW, my preamp is the Cary Cinema 11, and I was considering buying the Integra 9.8. I've read in Stereophile and AVS that the 9.8 really shines in digital application, and less so in analog ones. I think its phono stage isn't its strong suit.

I also have the problem of no bass when using a stereo signal. I got around that by using a mixer and another preamp to mix, select and control which signals are going to my sub. If you're interested, I can describe better what I did to always have a sub signal of my choosing.

Good luck!

[jvm051]

Yes I am very interested in how you did this.

I just wonder, even if I add a outboard preamp, I will still have to go through the Analog inputs on the preamp, and if the better qualities of a outboard will be noticed. May try the NAD.

[Otto]

Yeah, you'll still have to go in the analog section of the Integra. Whether or not you will hear a difference, who knows? I would guess "yes," but it might be somewhat subtle. OTOH, maybe it'll be vast. Like I said, I'm a newb with vinyl myself, but I sure do enjoy it when I have the time.

As to how I did the sub thing for two-channel listening -- I used the "other" pair of L/R outputs on my preamp. I'm using the single-ended RCA outputs to feed my amp, so I wasn't using the balanced outputs. I sent those balanced outputs to a little Peavey mixer, and mix them to a single channel. That is then fed to a BFD for sub EQ on one channel of the BFD. The other channel of the BFD is fed by the sub out of my preamp. I then EQ either side of the BFD for the application at hand -- one for about an 80 Hz cutoff and the other for about a 40 Hz cutoff. From there, either channel of the BFD is fed to an input of a second little preamp. In general, any old preamp will do, and I happen to be using a Rotel RSP-960AX that I picked up last week for $150. I had to create a special cable that breaks the balanced signal to a "left" and "right" RCA so that I can feed the Rotel (it doesn't have balanced inputs). I can then select which input I'm using on the Rotel, and it chooses which side of the BFD to be used. The BFD isn't really necessary in this picture, but it's there. Actually, I do use the BFD to impose a low-pass filter on the L/R mixdown, so, yeah, it's somewhat necessary (unless you have some other means to LPF).

I know it sounds complicated, but if you draw it out, it's not that bad. Basically, I'm just using the Rotel to select which input will be fed to my sub: 1) the "normal" sub output from my preamp, or 2) the L/R outputs mixed down to a mono track.

Anyway, I hope that makes sense, and I hope it's somewhat helpful. Try out a little phono preamp first and see what you think. There are lots on eBay and AudiogoN for not that much money.