Phono Stage upgrade to complement Dohmann Helix One Mk 2

@rauliruegas

Yes, while playing the test record the P1 gain wizard started at 0db, while playing the test LP, then jumped to 5db, then 10db, then 15db, and stopped at 15db. It didn’t proceed to test any higher gain setting. I’m still listening at 25db, but perhaps I need to revisit, and listen the 15db gain more critically. At 25db, I think it sounds great, but I really should do a better job researching the differences, and I will over the next 3-6 months, but right now I’m just enjoying listening my LP’s with new ears.

With the increased gain settings, of course I can listen with a higher speaker SPL, but I try to keep it within realistic sound levels, but being closer to the front, the sound is louder than sitting in the middle of the concert hall.  With the gain set at 0, I had the volume on the pre-amplifier on maximum, but with the gain set at 25, I have the volume set right in the middle, but the SPL is louder with the increased gain, and decreased volume setting on the pre-, but possibly only up to 70 db SPL instead of 55-60 db SPL.  I don't know if they're related, but it is my understanding that the gain was selected based on the internal resistance in the MC cartridge, and not necessarily based on the SNR.  

There was minimal brightness with the other tonearm, but I lowered that one about 0.5mm, and there is no brightness with either tonearm presently. (Eventually, I ended up lowering the first tonearm by about 3mm, after first lowering it about 1mm.) I’ve also been playing with the azimuth a bit, and I do have the AnalogMagik software that I can plug in, but right now I’m just using my ears.
Thanks.

Dear @drbond : About speaker SPLs what I tryed to say is that in my case when I tests a new audio item in my system I try always that the measured SPLs coming from the speakers at seat position been evenly ( as I can. ) the SPLs during the listening test sessions before and after the test of new audio item. It’s healthy to do it that way because our ears are very sensitive to minuscle SPL changes and those little SPL changes could makes that the new item like it or dislike it more than the " old " one.

In the other side the nalizer inside the CH takes the new cartridge impedance parameter and after modeling internally tells you due to the overall characteristics of the CH quality design/performance which gain level is the better with that cartridge and obviously that does not takes in count if you like it or not. It’s a test/fact/objective.

Yes, the AnalogMagik tool can help you.

R.

@rauliruegas 

So, I set up the AnalogMagik software today, and it did help me adjust the azimuth.  I was able to get the Lyra Atlas cartridge to have a -28.4 cross talk in both L and R channels.  Oddly, the VTA didn't work with the Lyra Atlas, as it read 6-8%, and the software says that if the reading is above 5%, it might not work for that cartridge.  (The Koetsu was down around 2%).  Another oddity was the gain selector on the AnalogMagik software:  it selected 15db also, but that's only because the CLIP SIGNAL light went from green to red on the USB Phono Plus computer interface machine when I selected 20db. . . I suppose that's the same reason that the CH P1 software also stopped at 15db.  Would I hear anything adversely by having the gain so high that the clip signal light turns red on that computer interface machine?
Thanks. 

So here's some follow up on the CH Precision P1 (run in current mode) gain settings from the Analog Magik software:  at 15db gain, the SNR = 21db; at 20db gain, the SNR = 23db; at 25db gain, the SNR = 20.5db.  

At 20db gain, sometimes the CLIP SIGNAL light would flicker green, but was mostly red.  Apparently, Analog Magik favors a 20db gain. . . I'll have to play some more with this.  

Dear @drbond  : "  Would I hear anything adversely by having the gain so high.."

The best for you is to ask  directly to AnalogMagik.

In the other side that " oddly " VTA with the Atlas is something that you have to ask for too. I don't know if that could means that you have to " play " a little with the cartridge VTA till be inside that 5% range limit even that you set up the Atlas VTA where you like it the more.

R.