cartridge output level

Yes, there is a difference in output level based on record speed. Most manufacturers use either 3.5 or 5 cm/s. The higher the speed, the higher the rated output. I have an Audioquest AQ7000Fe5 cartridge with an output of 0.5 mV at 5 cm/s and I have a phono stage that has 62 dB of gain. My preamp has 26 dB and my amp 26 dB of gain. Your Colibri is a first-rate cartridge, so my suggestion is to buy an outboard phono stage with more gain than the gain in your preamp, and run the output of the phono stage into the line stage inputs of your preamp. If you buy a cartridge in the 1-5 mV range you will probably lose resolution and it won't sound as good, so I would get a phono stage instead. Your preamp manual should show how much gain it has but obviously it is not enough. Also, you might call or e-mail Hovland and see what they recommend. Perhaps you could send your preamp to them to have the gain increased. I think you will need about 55-60 dB of gain minimum for the phono stage. I also had this problem with my CAT preamp not having enough gain and buying an outboard phono stage made a huge difference in sound.

The overall gain of your system is what is really most important. With a 0.45 mV cartridge output, I don't think your 46 dB phono and 14 dB linestage gain are enough. You also need to know the voltage gain of your power amp and the voltage sensitivity of your speakers. You can actually figure out how much overall gain you need since most power amps need about 2 volts input to drive them to full power. Each 20 dB of voltage gain multiplies the voltage by a factor of 10. So if your overall phono and preamp gain is 60 db, you are multiplying your 0.45 mV by 1000 to give you 0.45 volts, not enough to drive your power amp IMO. Changing the impedance load won't affect the gain much if at all. I would see what Hovland has to say--if they cannot increase the phono stage gain I would look for an outboard unit. My Aesthetix Rhea has all-tube gain and goes up to 75 dB but I run mine at 62 dB. Again, you have a great cartridge, so I would be a lot more inclined to find a way to increase gain rather than changing cartridges.

Yes, I now understand that you have 77 dB of gain prior to your power amp. That should be enough gain (77 db gain of 0.45 mV is a gain factor of almost 8,000, so your preamp output should be close to 3.2 V) which should be way enough gain for your power amp. Unless, of course, your power amp has low voltage gain, which I doubt, and/or your speakers have low voltage sensitivity. To get the dB from input and output voltages (output/input=gain) you use the formula dB=20 log (Vout/Vin). In your example your dB is 77, Vin is 0.45mV. If you solve for Vout you get 3.2 volts. This should be plenty of voltage to run your power amp to full power assuming it has a normal gain of 20-30 dB. Something does not add up here so maybe Hovland can shed some light on your problem. Let us know what they say. Again, I think you said it right, you probably have a voltage gain problem, not a cartridge output problem.

I agree with your statement that your CD output of 2 volts will lead to about 10 volts output from your preamp using the linestage. But 3 volts output from your preamp should still be enough. The only thing I can think of is that the taper on your volume control is such that the gain is low until 12:00 or so and increases rapidly after that, but still, it should not be encountering much noise in your preamp unless the tubes themselves are noisy. I have never tried the 75 dB gain position in my Aesthetix Rhea, but even with 62 dB I had to buy some low-noise tubes from Upscale Audio to minimize tube rush because the phono stage uses tubes for all of the gain. One time a tube was going bad and causing big thumps through my speakers and subwoofer. Going to 0.65 mV will help, so that is a solution, but there are a lot of solid-state phono preamps that go above 60 dB. Again, I think Hovland should be able to help you.

Thekong: I have never set my Rhea phono stage at 75 dB gain but I guess I should try it and report how it does. Again, since the Rhea uses tubes for all the gain, the choice of tubes is extremely important. The stock tubes worked fine but didn't sound nearly as good as some NOS Mullard 12AX7's that I bought from Upscale. 0.2 mV cartridge output and 85 dB speaker sensitivity is a tough application since it requires so much gain but it seems as yours works. I still am scratching my head as to why Cptaz is having such a large gain issue with his rig since he has 0.45 mV output and more sensitive speakers with similar phono and preamp gain as yours. Gregm: I am not sure what you are asking, but I am using a Rhea with 62 dB of gain going into my CAT linestage preamp which has 26 dB. My Essence power amp also has 26 dB of gain and my Wilson WP7's have 92 dB voltage sensitivity. I have also tried the 56 dB of gain from the Rhea but I like the sonics of the 62 dB setting a little better. BTW, I have tried various cartridge input load settings with my Rhea and the differences are only sonics, not gain. I like my AQ7000Fe5 cartridge run wide open at 47K ohms.

Did you speak with Hovland about possibly increasing the gain in either the phono or line stages? I was able to have this done on an earlier phono stage I had. Sometimes this cannot be done due to limited phono overload. Another thing is the volume control taper, although it probably won't change the tube rush problem. Or even your power amp manufacturer may be able to increase the voltage gain. Just alternatives to increasing your cartridge output, which sounds expensive to me.

I have a CAT tubed preamp and the owner also discourages the use of NOS tubes, and it certainly is not sonics as NOS tubes are way superior in that piece. My take is that the builder cannot guarantee a supply of NOS tubes, only current production versions. I am not buying the statement that the preamp was optimized for current production tubes. NOS tubes are almost always superior sonically, and remember that it sometimes takes time for them to reach their optimal sonics. The reason for the particular volume control taper where the steps are small initially and increase after 12:00 is to give smaller volume steps for line-level inputs. Clearly you need a faster taper, but again, your problem sounds like one of noise. The gain of any piece of equipment can be increased or decreased through the use of different resistors and/or power supply, but it may degrade sonics due to overload, noise, or other factors. So it appears as if your choices are a higher-output cartridge like that mentioned by Thekong, a phono stage with more gain, another preamp with more gain, a power amp with more voltage gain (the power may or may not be affected depending on how the current amplification is affected), or perhaps some higher sensitivity speakers.