hissing sibilants

I'm having trouble with this hisssssing "esses" and sssibilantsss.
I have a Pro-ject RPM9.1x TT + 9cc tonearm, Lyra Delos cart and Electrocompaniet ECP-1 phono stage.
I may blame it on:
- alignment, namely VTA (it's set just correct, i.e. arm is horizontal, but some say Delos "likes" to be a tad higher than the tail of the arm, is that true ?)
- load impedance: ECP-1 does not allow regulations, they say it does all by itself; yes, but how, and what's most, which load is it set at ? I don't know.

what's your opinion ?
thanks, ciao
I think you need to adjust the VTA by ear. It is very difficult to get the optimal VTA alignment by just looking with the naked eye. Select a record with plenty of silibant sounds and adjust until it sounds right. If you have the same recording on CD that will give you a benchmark, so you are not trying to adjust something that was recorded too hot.
In my experience you can have cart. alignment (VTA etc.) and loading correct and still have problems due to issues with the electronics that you are using. You are dealing with a thorny problem for which there are no silver bullets. It will take some effort on your part to tease things out and resolve the problem. Good luck.
Just lower it and see if it improves the problem.
It happens to all recordings that you play? Some recordings are bad and inherently have lots of sibilants. Try the recording you know that doesn't have it and confirm if the problem still exists.

Otherwise, the VTA could be too high (tonearm tail higher than cart) or loading is too high. My system can't take 47k loading that makes the whole sonic picture too sharp.
I have a Delos and if you're having sibilance issues, it's definitely not the cartridge. As others suggested, do you hear sibilance on all records, or only some? Just to give you an idea, I have a few pressings of "Synchronicity" by The Police and one of the copies is unlistenable because of sibilance, while the other sound great.

If you're having sibilance with vocals on all records, I'd check the VTA to make sure it is in fact neutral, which is actually tricky to get, and if it is, lower it just a bit to see whether you can hear a difference.

However, I suspect your phono preamp is not the best match for the cartridge for a few reasons. The manual for the Electrocompaniet phono preamp states "Gain 1 KHz Moving Coil (source impedance = 10 ohm)," which would be very low if it is in fact input impedance. I have my Delos loaded at 200 Ohms, but I've heard of others who have it loaded anywhere from 100 to 500 Ohms with good results, but 10 ohms is certainly too low when loaded directly into the MC input. When I first got my Delos, I called the Lyra distributor to inquire about the loading, and the person I spoke with said that loading it at 5-10 ohms would "kill it" (his actual words). (It would of course be different for a step-up transformer.)

Further, the gain for your unit is stated as 73 dB, which is WAY too much for the Delos. Your line preamp's gain and your speakers' sensitivity also come into play here, but from my experience, a gain over 60 dB kills this cartridge (my words). At an output voltage of 0.6 mV, the Delos does not need more than 55 - 58 dB of gain at the phono stage level to perform its best. When I switched gain on my phono preamp to 63 dB, the sound became strident, shrill, and overall unpleasant. It did not matter much when I lowered gain on my line preamp; the sound was just not right until I lowered gain on the phono preamp. In fact, it sounded like serious sibilance amplified to an uncomfortable level. At 73 dB, I cannot even imagine how aggressive and un-musical the sound must be. Something to think about.
agree about the phono stage....it is the most forgotten art of vinyl, that you have to find the best match for your cartridge (either loading it properly or the best match step up transformer....)
How do you know its not something else like a metal tweeter? If the problem really is with your TT setup, how old is the Delos? Phono cartridges sound awful until they are fully broken in.
IMBW but I believe that the spec you are quoting is refering to the ECP1's gain if the internal or "self" impedence of the MC is 10 ohms. They do not actually state what the input impedence of the ECP1 is when using the MC setting. Delos recommends loading anywhere from 98 to 806 ohms so I can see how people are getting good results when loading the cartridge anywhere from 100 to 500 ohms. The ECP1 in MC mode must be directly coupled (no coupling cap between the cartridge and the first transistor) to the cartridge as the HI-FI choice excerpt on the Electro website states that some MC are effected by the DC voltage that it runs through the cartridge coils. Maybe Delos could answer how the DC would effect there cartridge... BTW when a dealer says 10 ohms would "kill" the cartridge he just meant that the voltage drops by half when the input impedence of your phone pre is the same as the internal or "self" impedence of your MC.
Btw, it is sort of obvious, but did you also check that your cartridge is properly aligned otherwise? You only mentioned the VTA, but even more important is the overhang, azimuth, proper offset angle, etc. I'd start there to exclude an improper set-up as the cause.
The gain value surely cannot be dictated by the internal impedance of the cartridge. From what I understand it is dictated by the cartridge's output voltage. You want to use the lowest value that provides sufficient gain for the signal. Tools such as the KAB calculator are useful to approximate what that value is. My own personal experience with both MM and MC cartridges and several different phono, line and power amplifiers confirms that it is critical to use correct gain to match the output voltage of the cartridge for the cartridge to perform its best. Too little gain and the signal will be too low to provide enough volume, while too much gain (at the phono level) will result in a sound that is shrill and strident, and it becomes all but impossible to adjust the volume to get the sound right.

My concern about using this particular phono preamp with a Delos seems to be confirmed by this review that's reprinted on the preamp's page:

"The only test result that might be significant is the very high (in context) current it passes through a cartridge's windings, up to 0,2mA. It certainly won't do any damage, but with some cartridges might affect the sound. That apart, this is an extremely fine piece of kit and is strongly Recommended."

I thought the current went from the cartridge to the phono stage where it gets amplified, rather than the other way around, which the above-quoted text would suggest. It's possible that it was incorrectly translated into English, and it simply means that the preamp uses a very high voltage to amplify the signal, which might not be ideal for medium or high output MC cartridges such as the Delos.

I thank you all.
I don't have problems with CDs and I have it with many records, that's why blame it on my analog setup -I'd better say on how I have set it.
These days I'll try one or two different phono stages (North Star Phonostage and Whest 3.0RDT), then we'll see -no: hear- if the ECP-1 is guilty.
If not, I'll try and re-set VTA.
thanks again
IME (as well as the MC industry) finding the optimum load is by far the most important for achieving best sound performance of a MC. You yourself have found this out when you optomized your Delos with 200 ohms.. BTW there are strong advocates for 40 to 1 SUT not because they needed that amount of amplication but they get the best sound when the standard 47k input impedence of the phono pre is "reflected" down to about 29 ohms when presented to the cartridge. I myself have changed out the input resistor on my phono input to 3k to give my cartridge a 30 ohm load (as reflected through my SUT) which was the best overall sound from my Dyna.

As far as the .2ma of current that they are describing it's from the base of the transistors that are being used in the first stage of amplification. If you want to dive into it you can find threads on DIY forums as to which kinds of transistors, in what types of circuit topologies, that will present the lowest amount of current to the preceding stage, in this case the coils of the cartridge.