cartridge output level


Hi all,
This is Marco from Italy, I have a question about how a cart output level relates to volume knob position.

Let me explain: my VdH colibri is rated .45mv@5.7cm/sec, it goes into the mc phono stage of an hovland hp100 tube preamp, no complaints for the sound but the preamp volume knob is often in the 3 o'clock position, and anything below 12 is not enough.

Now this preamp phono stage is quiet enough up to 1 o'clock, above that the tube noise is audible, not to a level to ruin the listening pleasure, but is there.

I would like to be able to play with the volume knob between 10 and 2, the question is, if i could get a new cart, how do I know the correct output level to achieve that goal? I wouldn't want to end up not being able to go beyond 9 o'clock either.

Also, is there a difference in output level at 5.7cm/sec as per VdH spec compared to 5cm/sec of other manufacturers?

I know the simple answer is to try other carts in my setup, but unfortunately that is not an option here.

Any advice for a suitable cart is very much appreciated, I listen to jazz 60%, classical 30%, pop/rock 10%, I like lively dynamic sound with huge soundstage but not dry or too bright.

Thank you all,
Marco
128x128cptaz
Rlawry, thank you, I think I understand your point, but I have to do some more homework to fully grasp the overall gain concept.
I now realize anyway, that I didn't previously make clear that the total gain of the unit is 77 dB, phono 63 dB, line 14 dB, as you can see in the Hovland web site http://www.hovlandcompany.com/products/electronics/hp100/specs.html.
That probably doesn't change the substance, and I agree that increasing gain would be a good solution, I'm now waiting for a reply from Hovland.
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.
As an aside from the current discussion:
The Thor Cantantus has a fixed resistor that you can specify, is best for cartridges at .65mVolts but my Sumiko Celebration at .5mVolts works fine. My preamp lacks a phono preamp so it was necessary to get a separte piece.
Check and see if the SUT is in, a voltage reading should tell Hovland that info, let them instruct you just in case, working with live units is for people trained to do so.
As a former electronic tech, better safe than sorry
Rlawry, according to Marco's reports, he's getting ~0,9v at the output with the SUT in the circuit (63dB) -- before even hitting the active pre... and that's the reported overload ceiling of the phono.
Strange, as you & Marty note.
Rlawry, that formula made me think a lot, for example, based on that, if the SUTs were out of the circuit the total gain would be 60 dB (77-17), and the max preamp output 0.45 volts, so am I correct in ruling out this option?
I don't know the gain of my power amps, but I know that, in my room with my system, when I use the CD I'm happy with the volume at 12 o'clock. Now, this CD has an output of 2 volts, the line stage has 14 dB gain, that means according to the formula a max output from preamp of about 10 volts. Let's assume that, to make me happy, I need 3 volts out of the preamp, and that happens when the volume knob hits 12 o'clock in CD replay, it would make sense that, to get the same 3 volts in LP replay, I need to hit 3 o'clock, in the noisy area, being the max output from phono 3.2 volts as per your calculation.
Bottom line, to bring the voume back to 12 o'clock with LPs, I think I need to increase the voltage gain of the phono stage, just as you said, and to do so I only see 2 options:
1-Outboard phono stage with higher gain as you suggested, is your Rhea noisy @ 75 dB?
2-Cart with higher output level, a 0.6 mv one would give a max output of about 4.3 volts, would those be enough to bring the volume back a few clicks down?
Hmmm, decisions, decisions, life is hard...