Phono Stage upgrade to complement Dohmann Helix One Mk 2

@jperry 

Thanks for the recommendation, but it appears that the Nagra phono stage only has one MC input, and one MM input. To accommodate the Dohmann, I would need two MC inputs

I just got an older VPS.
It has 2x MC inputs, but I jumpered one to work as a MM.

I assume that a classic also can be gotten in 2x MC, with some extra coins.
(Just standard is 1xMM and 1xMC.)

The Classic is likely a step up, but my pockets are not as deep as I would like them to be.

The MC section is a SUT and loading card section, with jumpers for SUT/no-SUT, loading card/or not… etc.

The Nagra Classic replaced the VPS in 2020 and is better than the VPS, which it replaced.

How is it better?

The web site says:

Total harmonic distortion (THD + N):

Please refer to the below graph

However the 2nd harmonic looks like it is 20+dB higher than the VPS.
Third harmonic looks the same,
And the noise on the Classic looks a lot lower on the Classic.

The ARC gear sound pretty good to me as well.

No @jperry - I had to draw the financial limit at the used model.

Many a reviewer has very specific loves/prejudices - Martin Colloms loves Naim and Linn - Roy Gregory anything stocked by Audiofreaks (he had to answer letters about this in hi fi plus) - Michael Fremer (anything new and stupendously expensive) 

And most reviewers will wax poetic as out the positives, or maybe “they” find the reviewer that will be positive.

So it is a bit of a feedback-loop as negative reviews, do not result in a negative reviewer getting more products to review that “could be” heavy on the negative side.

@drbond how do you like the Dohmann?

I'm not the most knowledgeable about different turntables, so my experience is rather limited.  I've only had a Rega P3, Rega P8, and then made a (very large) jump to the Dohmann Helix One Mk2.  The audiophile friend who's been in vinyl for decades was very impressed with the Dohmann.  Coming from the Rega P8, it's a world of difference:  a vast improvement in every aspect:  detail and clarity most obviously improved to my ears

@drbond I had the wisdom, luck, or just curiousity to stop by Dohmann HQ on Sat Feb 18th. (Mostly to see about a Schroder brass HS weight)

It was a wonderful couple of hours, and it is hard to find any fault with the TT as it was setup, and the music that was there was about a 50% overlap with what I have, so it was a good sign.

There are many “double negative” Australian sayings, and they can be subtlety different than without double negatives… but as the saying goes, “Dohmann makes it hard to not like him.”

I have a good cart, arm, phono stage and the SOTA rebuild is proceeding. But that Helix is really something else again.
I don’t think you will have much left to blame things on… but cartridge set up is an easy way to find a failure even with everything being good on its own.

well done!

Thanks for sharing! Was the Dohmann HQ in Australia, or Bulgaria (as I just read a Fremer article about Dohmann, Schroder, and another sound equipment manufacturer joining together to form a conglomerate in Bulgaria.)

The outskirts of Melbourne.

Yes, the alignment was tricky the first time, but I made all my mistakes on the Rega P8. I’ve only used the UNIDIN alignment on the SmarTractor, since I listen to entirely acoustic/classical/jazz music. Do you have any idea how the Baerwald or Loefgren alignment would affect the sound, if at all?

Well, I opined that IMO the spindle distance and overhang are about the least important things to get right, but the Azimuth, rake and Zenith are hard… and people get over anal to the Nth degree on the easy stuff and can miss the important stuff… and he seemed to concur.
(We talked at length and I’ll be getting a WAM Zenith disc when the TT rebuild is complete.)

Anyhow… for instance with the CB-9, I plug in the 222mm spindle difference I get baerwald having the Schroder recommended overhang.
I am visually within 0.2mm of 222.

The I go into the calculator and use Loefgren and get a number a couple of mm different.
On a lark put in a spindle distance a mm error, and got an overhang a bit different. 1mm error in spindle distance is heaps.

So we can get anal on that to save a small fraction of a degree of error and then can miss say a cartridge Zenith error of a handful of degrees.
And SRA and Azimuth are also difficult, but less so for Azimuth.

This is worth a watch IMO:

My opinion is that I would not stress at all about it, but Baerwald is a longer effective arm, and I believe should be better overall… to an anal fraction of a degree… but I have not done the maths and graphs yet.

How does the TT sound?
I missed which arm and cart you put on it?

And @drbond I am a bit envious… but my old table is a thing of joy.

Thanks for sharing your experience with Dohmann, and the details about cartridges that you discussed together! I’ll have to look into that WAM zenith disc, but I’ve been using the AnalogMagik software with decent results, and there is one aspect of that software, while not perfect, I’ve read can be used to help with zenith: apparently somehow the VTA measurement may actually do a better job at measuring zenith.

The WAM people mention their micro scope measurements and they a small USB microscope at the edge if the record to get SRA, and then shim the cartridge to get SRA to ~92 degrees.

Even with VTA at zero, many cart can have SRA be off by many degrees.

The azimuth adjustment with the AnalogMagik software seems to do a good job, getting the crosstalk to match between channels, but there’s no way to measure that SRA, so I’ll have to watch that video one weekend, and see if it’s worth it.

They have some 3-10 minute videos on the SRA and microscopes on the WAM site.

Presently, I just use electonic level in my phone camera, and use that to verify that the tonearm is level (0 degrees) when playing.

I guess I should try the Baerwald alignment now that I’ve been listening to the UNIDIN for a few months. . .

Others have said the Loefgren is better, so not having done the maths and graphs yet, I would not personally rush into it… But Frank (Schroder) designs it for Baerwald, and he also seems to know what he is doing.
Perhaps one late afternoon or evening you could try calling Nirvana Audio +61-3-… and ask Mark. He likes the Schroder arms and speaks highly of Frank, and would likely know.
As mentioned in the previous thread… personally I think that the Azimuth, Rake (SRA/VTA) and Zenith are more important… and Mark seemed to agree, and we quickly had moved onto the AudioMagic and talking about WAM and how they attack these versus how AudioMagic approached it. And he is involved with both, and carries both products.

@rauliruegas mentioned .04% RMS distortion, but I know what that is in angular space. I would be more worried about SRA and Zenith, and get a USB scope or the WAM measurement service and shims… to remove a potential “handful of degrees”, before stressing about smaller errors from Baerwald, Loefgren or UNIDEN.

I think that the turntable sounds phenomenal!

^This last statement^ makes me think that maybe it is good enough 😊

My setup was suffering some remaining sibilance on the hottest recordings, so I upgraded the arm and cart to try and ameliorate that. And the table rebuilt sort of snuck in there.
If it was not for sibilance on some hot pressings, I would have called it a day and just kept listening.
The Helix I heard at the HQ sounds like a similar set up to yours, but maybe a different cart. It sounded great…

1. Was it better than my old TT with the old arm and old cart?
   1. “Yeah it was, but not by miles on good pressings.”
2. Did it ever sound bad to the point where I was paying attention to tracking flaws or sibilance?
   1. Never (not like my old arm/cart sometimes can.)

Once one forgets that there is a system there, and the music just flows, then for me I have sort of “arrived”.

One aspect that I think stands out is the balance of the presentation: the music is just balanced, so that the instruments are distinct, clear, and yet communicative and musical. There isn’t one range that overwhelms another.

I have two Schroder CB 11 tonearms installed, and I’ve used four cartridges thus far: the Lyra Atlas, Koetsu Urushi Black, My Sonic Lab Ultimate Platinum, and Lyra Etna Lambda SL. Presently, the latter two are installed.

If you’re ever visiting central Florida and want to listen, send me a message.

I am unlikely to visit Florida, but if I do get to the area… then, in the double negative sense, “I wouldn’t say no.” 😉

Mark Döhmann runs Nirvana Sound in Australia, as well as having his own website. You could reach out to him and discuss. I’ve spoken to him about phono stage and cartridge recommendations in the past. He’s really responsive and a wealth of knowledge.

@mattn22 posted while i was typing… and said it more clearly. (Just call)

If I do not end up buying the Zenith disk, then the next time I am in Melbourne, I’ll likely stop by and drop off a “thank you” token. (Which is usually 750ml)
It is like a symbolic offering 😇

Thanks @rauliruegas .

I was using this:

I see it says effective length: 239.3 (but I have a CB-9 not Bond’s CB-11)

And then and here: 

I see it says effective length (IES/RIAA):

• Baerwald: 239.296
• Loefgren B: 239.749
• Stevenson: 237.418
• AP: 237.411 

I thought that Loefgren was 2mm different, but it is Stevenson and AP that are.
And whether it is DIN, IEC/RIAA etc changes things.

Using DIN I see it as:

• Baerwald: 238.336
• Loefgren B: 238.804
• Stevenson: 236.488
• AP: 236.531 

On IEC/RIAA, the 0.447 mm is about 20 thou, so it would be easy to end up Loefgren-B if one wanted Baerwald, but did not account for the drag pulling cantilever back and changing effective length to make it longer.

But going from IEC/RIAA to DIN, then everything jumps about a mm, so how important is all this stuff?
(One can basically get whatever one wants for effective length.)

Are there UNIDEN and other calculators?
And the calculator gives a graph with the Y-axis denoted as “distortion %age”… and the relationship between angular error a distortion becomes a bit obfuscated.

Thanks @rauliruegas 

@mijostyn that was a gentlemanly offer to Bond.

I have some taps and access to a milling machine.
So let me understand this…

The alloy piece with the 1 hole in the middle and then the 2 holes for the cartridge. It is that that you make out of brass?

And then maybe 2+ of them and have the cart all set on each, and then when it gets swapped on you adjust nothing but VTF?

And one still sets the Azimuth, Zenith, and VTA?

Or is the cart shimmed (Wally style) so that it is just set the height (VTA) and VTF, which witching carts?

It needs to be totally transparent in order to do no harm to the signal at all audio frequencies. Is there really such a thing?

One can it in analogue… there is not a requirement to do it digitally.

• If one’s glasses are thick, then the DSP makes sense.
• For people that like solder and capacitors, then analogue makes sense.

Not everyone would want a Vandersteen sub, but some do. And the crossover is a key part of it:
https://www.vandersteen.com/categories/crossovers

Dear @holmz ​@drbond : At the end digital tech is used in almost all today subwoofers through the DSP that is the one that can gives us ( comes with a microphone. ) where in position and to our " ears " makes the " best " system/room integration.

^All true^. However the analogue approach is well thought with the Vandy sub system.

It may not work in a system with a different filter in the speakers as the phase could be off.

And everyone one adjusts the subs with a microphone, and either potentiometers or S/W equivalent of a potentiometers.

At least knowing that there are non-DSP approaches, and mentioning it in a thread, is not a crime. We would need a way to compare that solution to the digital one☝️to be able to say whether it is better, worse, or the same.

If one is a purist then “High Pass Filtering” (HPF) the signal going to the main speakers is often a bit “on the nose” conceptually. I have no problem with DSPs, and streaming into and out of a DAC, and conceptually into and out of a DSP. But those that do, may want to know that they’re is a non-DSP approach.

And one can then use a DSP “ONLY” on the sub band without digitally touching the signal coming out of the L/R speakers.

Dear @holmz : A subwoofer is a complete solution where the crossover is only an inherent and important part of any sub ( a key like you posted. ) along the box, drivers and the like.

^Correct^. You are not the only fellow or lady that understands what a system is.

The crossover is not a second product but is part of the subwoofer it self that must has a low/high pass filters and several other functions.

The other stuff on that web-site has the subs which rely on the HPF.
(It’s part of a system)

Even this 32K dollars can’t even the Velodyne THD 0.5%. Well certainly maybe the best sub out there and you need 64K :

It is sort of important to note that the 0.5% is meaningless in the sub band…

But it becomes pretty important in terms up HD and IMD for the higher frequencies that attenuated from the filter, but still made be created in the sub itself, and then give away their location.

The subwoofer bass solution with good integration to the main speakers and room give you huge benefits. We can’t talk here of disadvantages in the same way we can’t say that a phono stage has the disadvantage of the RIAA eq. because it’s part of the phono stage in the same way that creossover is integral part of a subwoofer.

Btw, when we have well integrated subs in our system there is no come back, we learn that we can’t listen any more with out it due that helps to lower the distortions levels of not only the speakers but amplifiers too and several other advantages.

Again… you are not first to discover ^this^.

Lew, the high pass is made it at the input of my amps ( cap/resistor ) the low pass is made it by the Velodyne electronics. Maybe you can do the  same or look for a second hand Bryston croosver.

In the link I just posted you can read about 12"/15" drivers characteristics inside the same catalog models.

After last week’s talk about a system I find ^this^ humerous.

 Lastly, if you don’t have a subwoofer or preamp output on your amp or preamp, subwoofers such as the RELs we sell have a specific high level input which runs off your amplifier’s speaker binding posts.

There is a certain simplicity and elegance in running the sub input off of the speaker’s binding posts. Not sure if it is just REL and Vandersteen, or if there are others as well.

Is there a "best" approach for monoblock amplifiers with two sets of binding posts?

I’m not sure I understandI?

I am guessing that the speakers have bi-wire posts?
So it sort of depends on whether you 4 sets of wire pairs, or a bundled bi-wire and whether it is a single end at the amp, or if there are two set of ends… and whether they can splay wide enough to hit both sets of outputs.

Holmz, I am no fan of the REL approach, for the reason that if you drive the subwoofer off the main amplifier output, then neither the main amplifier nor the main speaker derives any benefit in terms of reducing the workload inherent to reproducing the lowest bass frequencies.

Well I am not sure what the REL approach is other than reading @Rauls words that it derives the input from line level rather than RCAs or XLRs. So it sounded like the it was similar to a Vandersteen, however the manual is a bit light light on specifics… other than that there are the speaker inputs.
But whether the main amp to speakers are high pass filtered did not pop out.
It was 30 pages and i skimmed it, so maybe I missed it… but it does seem like it is not the same as how the Vandy unit works. That unit HPF the main speakers, and then the sub rebuilds the bass back up to where it should have been without a HPF going to the main speakers.

Moreover, any distortion in the output of the main amplifier is presented to the REL subwoofer amplifier at its input. Unfortunately, I long ago concluded that you cannot obtain all the major benefits of subwoofing unless you’re willing to add a high pass filter on the main amplifier.

Well that is what I posted a while ago, and it was a high pass filter to derive that benefit that you point out.
Then the sub rebuilds the signal back to where it should be at.

One can roll their own capacitor, or use a host of HPF to do that at various price points from a capacitor to a Harrison labs one at $50 to ones at kilo$...

Holmz, was that "humerus" or "humorous"? And why did you find it humorous?

I read too much Homer in my youth, as I had a great 7th and 8th grade literature teacher. And hence the spell checker is Greek to me.

lewm : " I truly did wonder why you thought Raul’s quote was humorous. " . Easy, because he did not think in that way before. Seems to me that is his way of audio life kind of think because he posted twice something with no sense in reference to what I posted about sub’s, he said twice: " you was not the first person to said that " .

But where in hell posted I that " I was the first audiophile to said that " ?

You might be right… I agree that it seemed to you that it had no bearing on the topic,
Yet here we are talking about whether to use a capacitor and then how to hook the sub up, and it is a week later and you still claim that that post is not addressing some of the OP’s question on subs.

You choose to put in a capacitor, and others insert that HPF that I linked to… and then they use a powered subwoofer that is designed as a system.

At some point it is going to click as to it being a system and why I posted it.

Similarly that REL kind of clicked with me as being a bit incomplete in that is it not using the HPF between the preamp and the amp(s)… and the sub has no way to account for a dependable slope or crossover knee… so it is either too much bass or need a lot of TLC to make it blend.

Are you addressing me?

No @lewm .
It appeared that @Raul was using your quote, in a way that was oblique and directed at me.

I truly did wonder why you thought Raul’s quote was humorous. Along the way, I could not resist the anatomical pun.

@lewm I liked the pun. So you get a point.
(But let’s try and resist using digital in an anatomical pun please.)

The two best and most expensive electronic crossovers I know about are the Pass XVR1 and the Bryston.

I assume you mean “electronic” as in solder and parts?

The DEXQ is more like a MiniDSP, Lyngdorf or Trinov, but for more a 2-channel.
It is likely overkill, but subs, and bi-wire binding posts, then it has some allure that  could allow it to be used as a 3 way XO.
It is a digital solution and the pricing reflects it as being digital.

 

Hmmm…this subwoofer project is looking complicated:

often it does…
Many do it digitally, and that is a lot easier some ways.
However if the main analogue chain is nice, then we can complicate it with an analogue approach, which is in fact a bit simpler.
(But there are many ways to skin a cat)

it seems like an ideal approach would be an in line high pass filter after my pre-amplifier, but this would have to be an analog filter, correct?

That is one way, and usually it is the one that has the minimum detriment to the signal chain. And even with this HPF, one can use some DSP on the sub to flatten the response a bit.

(I can see myself reacting to a cello that sounds like it’s in one place for the higher notes, and another for the lower strings/notes…)

A cello sounds like it is in the same place as the higher notes of the instruments harmonics locate the cello, and low notes reinforce the fundamental tone.

When it is done right then it is not apparent that the sub is even on.
But if one turns the sub off, then it is apparent.

And it often sounds best when it is turned up to the point that it is apparent and backed off to the point where it almost seems like it is not contributing.

Set up well it is like PFM (Pure Magic).

…or replace my pre-amplifier, which I really enjoy listening to, with a digital pre amplifier that has filters built into it…which I am averse to do…

It is ^here^ where the in-line HPF is an elegant solution.
It sound great now, you just a bit more of low notes, and remove having to force the main speakers from trying too hard to play those low notes.

With the HPF, one just tapers off a major portion of the power to the main speakers, as the lion’s share of power is used for pushing air in the low notes. And then the sub takes that over and tapers off the power as the notes enter back into the main speakers in a smooth fashion.

And then all the IMD and Doppler distortion of the panels having to wave back-n-forth as the high note are also coming off of it… becomes reduced as most of that waving gets shed to the sub.

Doing this at a knee of 100Hz is not uncommon with a 1st order slope.
Some people go high with higher slopes.
And if the sub resonates or has harmonic, or noises, that locate it in the room, they they might cross it over lower.

If one fancies the idea biasing the dielectics, then the HPF get some extra stuff in it, but it behaves like a single capacitor.

I don't agree with Holmz in some cases, but for me to debate Holmz here would only confuse you further.

Or maybe it would not?

Suffice to say, as I said before, a properly integrated subwoofer will not give you the sensation that the cello is jumping from main speaker to subwoofer and back again.  On that score, Holmz and I agree.

And we both are advocating use of a high pass filter between the preamp and the amp. I just buy mine, and others use a capacitor.

On the other hand, I am not a fan of digital filtering or digital shaping of the response.

People with DACS and streamer, and CD players are alreadily heaving inverted in digital tech…

It is easier to tolerate a DSP on the sub chain side.
And the HPF solutions we are both talking about are on the main L/R channel side,.

I am still trying to figure out the difference other than manufacturers sticker.
It looks like you fancy the Velodyn and I like the Vansdersteen.

Unfortunately, the more I read about HPF, the less inclined I am to use them: everything that I’ve read so far indicates that their use does impact SQ.

Well is there a link to that?
And is it a digital or analogue HPF?

Additionally, here’s a paragraph about higher order HPF influencing signal moreso than lower order HPF (but it is just the internet, which could be wrong):

There is slower transcient response, but if you have a speaker with a crossover, then I am not sure one can be a purist.

Although there is no limit to the order of a filter that can be formed, as the order of the filter increases so to does its size. Also, its accuracy declines, that is the difference between the actual stop band response and the theoretical stop band response also increases.

I think you might be talking about speaker level XOs that have the inductors.

The ones with capacitors are not large, as they are RCA level. The big ones are the size of a couple packs-o-smokes.

drbond , you will hate any analog high pass filter.

^That^ is a bold statement.

And how do we reconcile the fact that most speakers have a crossover in them, and those are analogue?
(Or are we throwing that out because the ESLs may not?)

While I generally appreciate digital, when one has a nice analogue system, there is an allure in keeping the front end free of digital.

To operate a subwoofer correctly all filters have to be digital. The highest quality units now use 64 bit floating point processors and have none of the issues older units had like the volume control problem. Conversions in and out of 24/192 are invisible

The idea that a sample rate and bit depth used for recording bats and other high frequencies is “required”, starts to fly in the face of logic.
Couple that with people tolerating many % of distortion in the lowest registers makes that paragraph a bit absurd.

I like digital as much as the next fellow, but one could just about do the math with a slide rule or abacus and keep up, and the idea of 64-bit math for the signal that has the highest amplitude in the spectrum means with probably could do it with 8-bits and 500 samples/second.

But if you are saying that the HPF for the main speakers should be 24bit/192k or something like that, then I have no argument. One pretty much needs that to keep the HP stuff that is going to the main speakers sounding good at 20kHz and beyond.
 

… can a high grade analog capacitor (e.g. silver Duelund CAST) be used for the HPF to the ESL with good results? 

Of a battery biased HPF.
Is your connection from preamp to amp RCA or balanced?
(I am guessing XLR if you ran Atmasphere amps at some point.)

I cannot figure out a way to post a photo of the inside of my Vandy M5-HP (high pass filters), and I have the older RCAs as well. The XLR ones have a row of dip switches for matching to the amp’s input impedance, which then makes the knee of the curve exactly at 100Hz.

I am not overly “bowled over” with the battery biasing cables, but perhaps there is something to it. And the cotton and silk covered cables do not have the dielectric polarising issues… and people rave about them… so maybe it makes a difference.

What are the higher end passive sub woofers on the market? (I do have an extra couple of amplifiers (class A and AB) sitting around).

The powered subs are more of a system, and there is an allure to having a sub that either comes on when the rest of the system does, or has some efficient amp that can be left on.

Other than power outages, mine was on for 20 years in the old house.
I rarely even thought about it… it just sat in the corner.

While I am intending on some DIY jobs for the new house, a lot of that is for Feng Shui and WAF… and there not a lot of choice in my location nor places to find them in the wild or in shops. In FLA they should be “springing up” somewhere.

I would suggest that going a bit slow is not a crime.,, and doing it right can be a chin-scratcher.

You can call or find dealer and look at what is on offer.
And some manufacturers answer the phone.

I could not find Velodyne, but Martin Logan has a bunch of dealers around Sarasota, and Vandersteen in Miami or Atlanta.

My pre-amplifier has two outputs: RCA and XLR, so I can run the RCA to the amplifier and the XLR to the subwoofer, or vice-versa, as the amplifier has both RCA and XLR inputs.

That works if the sub needs an RCA input and has its own filtering scheme.
I have not been overly shy in liking the approach of pulling the signal off of the binding posts.

I was leaning towards a lower crossover for the HPF, something like 80 Hz, or maybe 60-80 Hz, to keep the midrange in the ESL’s

Again I have not been shy in advocating the 1st order (6 dB/octave) at 100Hz.

• You attach the HPF at the amp side of the cable.
• Attach the line level cables to the speaker posts.
• Turn some pots on the back to set the levels.

and then you’re I’m done.

I would suggest seeing what the fuss is about, and if you go with a Velodyne or ML, then you at least went in with the eyes open.
 

holmz , Not at all. You ever tried an analog crossover on ESLs? Wel I have, several ones and they all turned out to be awful in the end. You can do it but there are far superior ways

^Nope I have not.^

I have only tried the Vandy HPF and their sub… and it is the older one.
(not old when I got it, but it is now.)

But yes the three options are:

1. A Vandy like HPF cutting the main L/R and a sub that account for that
2. The same HPF (or a capacitor) and do the bumping up of the sub digitally using another cable from the preamp like RCAs.
3. A digital XO and the running the HPF to the main L/R and LPF to the sub(s)

In any case reducing the low frequencies to the main L/R is “always” beneficial - unless one never has low notes, DC offsets or subsonic rumble freqs.