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 [email protected]/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.
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.
Hi Marty, Rlawry, thanks for your prompt reply. There's something I don't understand, I checked that computer and looks like the optimum gain for my cart is 57db, my hovland phono stage has a total gain of 63db (46 of the phono + 17 of the built-in SUT), besides hovland states that it would overload above 0.9mv. The gain of the line stage is 14db, so that could be the problem, but I have no problem with cd either, the volume is where I want. Rlawry, maybe I should follow your suggestion and go for a solid state outboard phono stage like the Einstein, I can't imagine a tubed one with a gain higher than 63db. I was just hoping that a cart in the 0.6/0.8 mv range would do the trick, but based on your comments that would not be the case. Thanks again, Marco
Marco: Does the Hovland MC stage allow for adjustable impedance loading? If so, try some of the different load settings (particularly lower than your current setting, if possible) to see how it sounds.
Hi Hdm, the Hovland MC stage has a fixed impedance loading of approximately 530 ohm due to the built-in step-up transformers, as per instruction manual, with a "provision for reduced loading" by inserting resistors inside, but being the Colibri recommended load 500 ohm I thought that wouldn't be an issue. Anyway, as I said before, I have no complaints for the sound quality, just for the quantity, I even thought to have Van den Hul increase the output, or trade in for the 0.65mv one, but I'm not sure that would fix the problem. Do you think that reducing impedance loading would somehow increase the output level? I'm not much into tech stuff, I thought that would just affect tonality and/or frequency response.
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.
Hi Viridian, whoa, the SUT NOT in the circuit? That doesn't sound good!!! I just opened the Hovland, the input phonos on the rear panel are directly plugged into a metal box with a writing that says "HOVLAND MC7 high gain phono stage", from there a cable goes into the circuit board that has the tubes for the phono stage, maybe that box is empty and i was charged for the SUTs anyway. Well, I guess if such a thing can happen, it would happen here to me. It's definitely time for that e-mail to Hovland, thanks for the suggestion, I'll report back asap.
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.
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
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.
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...
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.
What I'm getting from all the above is that you SHOULD have plenty of gain/volume at 12 o'clock. There's an error somewhere. Call Hovland and make sure your Colibri is actually not a VERY low output version.
Since I am also using the Colibri, I would like to share my experience here. First, my system:
1, VDH Colibri (copper version @ 0.65mv., platinum version @ 0.2mv) 2, Herron phono stage (66db gain @ 47K ohm, but I am loading it down to 1000 and 200 ohm for the copper and platinum Colibri respectively, and I am not sure what the gains are with these loadings). 3, Herron linestage (14db gain) 4, Accuphase electronics crossover at 500hz (0db gain) 5, Sonic Frontier Power 2 for mid/treble, and Power 3 for bass (relatively low gain @ about 21 and 23db respectively) 6, Modified Apogee Duetta Sig. (I estimate it at about 85 db/w)
With the 0.65mv copper Colibri, I need to turn the volume to slightly over 12 oclock, and with the 0.2mv platinum Colibri, it needs to be at 2:30 to 3 oclock. Even though I dont really have problem with noise, I wonder if I can get better dynamics with a higher gain phono stage, such as the Rhea.
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.
Hi guys, thanks for all the inputs, I'm really learning a lot from all of you. Yesterday evening I got a phone call from Alex Crespi, VP Hovland company (WOW, he called me overseas, we're not used to that kind of customer care here), he very patiently explained to me that the 14 dB of gain of the line stage are for the most part located in the last part of the volume run (forgive my english, I hope you get what I mean) to give a better control, so it's not uncommon to have to work around 3 o'clock position. Besides, it could very well be that the 0.45 mv spec'd by VdH @ 5.7 cm/sec, are on the low side due to this slightly higher speed. He also said that the tube rush can be an issue at those volumes,I'm not the first to report it, and based on his experience, a cart output level in the 0.6/0.8 mv range should almost match the volume with CD. Now, I would like to point out, as I did in my original post, that this tube rush is not unbearable, I was just wondering how's life without any. Looks like, to find out I have to either change my beloved Colibri (Clearaudio anyone?) or go SS (hugh), or maybe the low noise tubes mentioned by Rlawry could do... Life's getting harder, please keep the inputs coming guys, I really appreciate it. Cheers, Marco
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.
Hi Viridian, yes I thought about that, looks like I cannot contact VdH directly as I did with Hovland, the way to go is through the italian importer, I can send the cart back for "retuning" and in the meantime submit this request, it's gonna take a while, I'll let you know. Hi Gregm, I'm sorry I also don't understand, the stated overload of the Hovland phono stage of 0.9 mv (millivolt) I thought was meant to be the maximum output level of the cartridge, am I wrong here? Hi Rlawry, looks like increasing the gain in the Hovland is not an option, and the volume taper (I don't know what a taper is, behind the volume knob there's a chunky thing full of resistors) has been designed that way for a reason, according to mr. Crespi. The power amps option sounds interesting though, I didn't know you could increase their gain, does that mean increase power? I'll try to talk to the manufacturer, that should be much easier being Mastersound an italian brand. I wonder though, if I could do that and fix the problem with LPs, woudn't I end up having the opposite problem with CDs, I mean not being able to go beyond 9 o'clock? Thank you all, Marco
There are some high quality cartridges out there with a higher output than the Colibre, but, if you like its sound, it is going to be hard to find a suitable alternative (the Colibre is a very dynamic, lively cartridge). A Decca London comes to mind, but it is a very touchy beast (difficult to get it to track correctly).
Since you like the sound, you probably should stick with your set up. Keep in mind that, the tubes that come with the unit are currenly manufactured tubes and pretty mediocre. A friend of mine replaced the tubes in his HP 200 with Amperex Bugleboys for a pretty dramatic improvement in sound.
Also, you might want to have your unit checked out by the dealer or Hovland. That same friend had issues with noise, particularly with LP playback, that turned out to be damage caused by some kind of power surge. I don't know if the Hovland is particularly sensitive, but this does raise an issue.
While I don't think VDH can increase the output of your particular Colibri, they offer a H.O. version of the Colibri with over 0.65mv of output. This is the one (copper) I have. So, if you really like the sound of the Colibri, you may consider this option.
Hi Larryi, I agree it's not going to be easy to find a suitable alternative to the Colibri, i read something about Decca London and I don't think it's for me, at this time I'm curious to hear about the Clearaudio Titanium (0.8 mv), suggestions are welcome. The tube rolling suggestion is indeed interesting, also Rlawry said something about that, he named Mullards, you Amperex, looks like my options are widening thanks to you guys. I know the stock tubes are mediocre, Hovland don't encourage rolling though, they say the unit has been optimized around those tubes. To their credit, I have to say that I tried putting some telefunken NOS, but i went back to stock tubes because, even though there was a very slight improvement in noise, I felt I lost some depth in soundstage. After that first experiment, I gave up tube rolling, but after your reports maybe I should try harder. I will also make sure the unit is not defective, thank you.
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.
Hi Thekong, yes since your first post I've been checking out VdH website and I saw what you're talking about, a trade-in would be very well worth considering. Rlawry, I think I'm gonna be pretty busy for the months to come to explore all the options, comparing costs and sonic advantages, one italian hifi magazine lately reviewed your preamp, the CAT Ultimate phono, plenty of gain and killer sonics but expensive, it kinda turned me on. Hi Piedpiper, yes that will probably be my first attempt, I just have to figure out how to start, I mean which tubes to buy first and where. Again, I want to thank all of you guys for all the inputs, I'll get back to you with my findings. Cheers, Marco
Marco (cptaz): what I meant is that, with the stated gain of 63dB, you'll get a "reference" 0,8?V at the output of yr phono. As you & Rlawry correctly note, I totally confused the issue... sorry guys. In fact, if yr preamp sees ~0,9v fm the phono compared to the usual ~2V fm the cdp, the difference is indeed considerable (~+7dB)...
As noted above by Rlawry, More efficient speakers might be needed with your setup.. I am not sure of the efficiency on those triangles, however I can tell you this... My system has 60 db phono stage, with 15 db line stage, and a .45mV cartridge. And with 101 db speakers and only 20 watt amps, well it sounds like 2000 watts pumping at only 10 o'clock on the volume knob. I have heard my rig with 90 to 93 db speakers and I can tell you that I needed to crank up to nearly 3 o'clock in moving magnet mode with a different cart. and with this cart in MC up to 12 o'clock just to get sound going good.. No matter what you are forcing the tubes to be exposed to high gain and hum at some point regardless how good the tubes are.
So speakers can make a huge difference, #1 no matter what tube you use none will be silent in most phono amps up past 12 o'clock anyway so not bringing the gain that high in the first place via more efficient speakers will help solve that problem, cause with a 26 db line stage also backing them, Tubes of a slightly quieter variety might help, but with that much gain none will be that quiet from what I have heard.
How do you feel about the digital through your system? Do you feel its a bit pushed too when you want to get gain cranking? Cause that should be a bit effected as well if you speakers are just not juiced enough by the rig. Otherwise I say yes your easiest way out would be to get a new high output cart. But to really solve it and keep the better .45mV cart. might take some speakers.
Hi Gregm, ok now I understand, it totally makes sense, it's those 7 dB that make me turn the volume so high. Hi Undertow, let's see, my triangles are 93 dB and my amps are 50 watts, I think those 8 dB difference on speakers outweight the 30 watt difference on the amps, so that makes sense too. I have to say though, that with digital I'm totally happy with the volume at 12 o'clock, I can't go beyond 1, and that's an area that, even when the phono input is selected, is pretty quiet. So, while I still want to try some more tube rolling, looks like one day I'm gonna have to get a new cart, one with a higher output that won't make me miss the colibri. Options are: -Another colibri @ 0.65 mv, would those be enough? -A Shelter 9000 (0.6 mv) or Air Tight PC1 (0.6 mv) same as above -A Clearaudio Titanium (0.8 mv) -You name it Thank you all, Marco
I would opt for the .65 Colibri or the Airtight PC1, rather than the Clearaudio even thought the Titanium would make more of a difference. It sounds to me like you don't need much of a boost. Have you considered the Benz Ruby H with a .7 mV @3.54 cm/sec which translates to 1.1mV @5.7 cm/sec or .98mV @5 cm/sec. I would take its warmth over the Clearaudio's brightness.
let's see, my triangles are 93 dB and my amps are 50 watts
So, if you get 93dB/ 1watt, you should get an extra ~17dB out of those amps before clipping -- which means that a 1kHz sine can be reproduced to ~120dB spl with yr spkrs... I doubt you listen to sine waves, though:)
Going fm 0,45mv to 0,65 will make ~3dB difference. The Titanium should fare better in this respect (amplitude) with ~5dB. Actually the Tita is very nice for the money -- I used one for a while on loan fm a dealer. However, there used to be s/thing strange with the suspension on certain samples -- it would "soften" considerably & the cartridge tracked really low... don't know if it's a problem or part of the engineering, and anyway this never happened with the one I used.