RME ADI-2/4 Pro SE - RIAA mode measurements

[LTig]

and then good I would like to see the response curve in your system ... if it is better than 0.1db .

It is +/- 0.03 dB . Will add the plot later here.

.is the vinyl source so rigorous to justify this focus on this kind of thing?)

Well, you have to start somewhere. With MM pickups flat FR is difficult to reach because one needs the perfect capacitive load. It' s easier with MC pickups and I have one.

 

[morillon]

i talk about "in your room"...
not your phono amplifier etc
hihi...
ps lp test can t give you the possibiliy of mesureaments cartdrige prephono etc performant etc

sorry for my "english"

 

[morillon]

my point is just that the whole vinyl process does not allow you to focus on numbers anyway....
it's a bit out of place
then 0.03 or 0.1db... not really the subject...
;-)
pressing, dynamic compression ..noise ..weeping ..significant reduction in bandwidth during playback ..non-linear bp...crosstalk not to good.....
etc etc


so really the 0.03 against 0.1db!! of respect for the riaa curve..?
sinad
snr?
etc

;-))

ps i have ( not had) somes mc cartdriges , somes phono amplifier, somes sut or "prepre", somes turntables etc too...(just to explain that not a lawsuit against vinyl.....just facts ;-) )

 

[dlaloum]

It is +/- 0.03 dB . Will add the plot later here.

Well, you have to start somewhere. With MM pickups flat FR is difficult to reach because one needs the perfect capacitive load. It' s easier with MC pickups and I have one.

I beg to differ - the response of the cantilever and its resonance will drive the FR.
With MM you can tune this with both R and C loading (although it takes effort and time!) to achieve a decent approximation of flat FR- with MC, there is not much you can do in the analogue domain to compensate... Digital then provides a means.

 

[Gregg Hermetech]

Been spinning vinyl through the 2/4 all day, sounds great. Heavily modded Rega RP6 with AT150MLX cart. 2/4 ref level set to +26 dB, works well for most cuts, good level, no clipping. All the EQ/filter options are great for getting it to sound just right. Haven't tried it with my old phono pre into analogue ins instead, not sure I will as it's sounding great as is. Be nice if they added an option to monitor the analogue inputs pre ADC at some point, for people that want to do their own digital RIAA curves etc.

Not had the TT set up for three years so I've got lots of great listening ahead! Also been nice listening to some of the projects I mastered that went to vinyl over the last few years.

 

[levimax]

Those were the days when there were engineers in charge of product development who also know their environment. These days a) engineers are not component, b) they are working against a budget, c) the buyers are not knowledgeable, hence the manufacturers are not challenged.

Please explain why the explanation from RMI is false. To me it appears that the 20 dB or even 34 dB headroom requirement is nothing but a "myth". Engineers have always done as told by marketing and 40 years ago if 20 dB of headroom was "good" then 34 dB must be better. To me RMI is challenging one of the oldest and hardest to understand Hi-Fi myths of all time and I think they should be applauded if correct and corrected if wrong. So far their explanation makes sense to me but I would be very interested in the "other side" if there is one.

 

[Sonic-Wall]

Been spinning vinyl through the 2/4 all day, sounds great. Heavily modded Rega RP6 with AT150MLX cart. 2/4 ref level set to +26 dB, works well for most cuts, good level, no clipping. All the EQ/filter options are great for getting it to sound just right. Haven't tried it with my old phono pre into analogue ins instead, not sure I will as it's sounding great as is. Be nice if they added an option to monitor the analogue inputs pre ADC at some point, for people that want to do their own digital RIAA curves etc.

Not had the TT set up for three years so I've got lots of great listening ahead! Also been nice listening to some of the projects I mastered that went to vinyl over the last few years.

You are almost there! Just give it a try and plug in your phono pre.
We are curious to hear about your impressions

 

[levimax]

You are almost there! Just give it a try and plug in your phono pre.
We are curious to hear about your impressions

Maybe this helps. I have done TT to phono pre to ADC and TT to "custom balanced transmitter with correct loading" to ADC to FIR RIAA. Both worked fine but I had some "Wi-Fi interference" issues with the phono pre which went away when I switched to the balanced transmitter so I have stuck with that. I like the idea of digital RIAA and of course having the TT go through the ADC allows for all my DSP room and sub woofer corrections to be easily used. I also use FIR filters to dial in the cart FR response using a test record. Much easier than messing around with different resistors and capacitors and pretty much the only way to go for MC carts. YMMV but for me I will never go back to a phono pre-amp analog solution when a ADC and free software works better and is cheaper and more flexible.

 

[Gregg Hermetech]

Yeah I still need to to set the TT up properly, I have a test record I use with Pink Noise, so I can work out the corresponding EQ to get it back flat again. That'll be as easy as storing a preset on the 2/4.

 

[badboygolf16v]

Yeah I still need to to set the TT up properly, I have a test record I use with Pink Noise, so I can work out the corresponding EQ to get it back flat again. That'll be as easy as storing a preset on the 2/4.

I'm still waiting for my 2/4 to turn up. I remembered I've got a HiFi News & Record Review test disc somewhere so can use the pink noise on there to EQ my cartridge's frequency response. Are there some instructions on the web that you would recommend?

 

[sarumbear]

Please explain why the explanation from RMI is false. To me it appears that the 20 dB or even 34 dB headroom requirement is nothing but a "myth". Engineers have always done as told by marketing and 40 years ago if 20 dB of headroom was "good" then 34 dB must be better. To me RMI is challenging one of the oldest and hardest to understand Hi-Fi myths of all time and I think they should be applauded if correct and corrected if wrong. So far their explanation makes sense to me but I would be very interested in the "other side" if there is one.

I wasn’t commenting about a specific product. You may however may want to research how much the cartridge output peaks when the stylus goes over dirt on track or through a vinyl surface cut. Once you have the data you can decide what is myth and what is engineering.

 

[morillon]

I'm still waiting for my 2/4 to turn up. I remembered I've got a HiFi News & Record Review test disc somewhere so can use the pink noise on there to EQ my cartridge's frequency response. Are there some instructions on the web that you would recommend?

maybe only before, or even definitively..
is it more important to dig the cell position settings, weight, arm height etc..
;-)
especially since it directly influences the tonal balance of the result.
;-)

 

[Gregg Hermetech]

I'm still waiting for my 2/4 to turn up. I remembered I've got a HiFi News & Record Review test disc somewhere so can use the pink noise on there to EQ my cartridge's frequency response. Are there some instructions on the web that you would recommend?

Just set up an analyser to read pink noise as flat (I use SPAN Plus VST3 plugin, I think you need a 3 or 4.5 dB offset to get Pink to look like White, i.e. flat), play the test disc Pink Noise track, look at it on the analyser. Add a plugin EQ before the analyser and tweak until the Pink noise looks flat again. Adapt that EQ curve to the 2/4's EQ.

 

[LTig]

I beg to differ - the response of the cantilever and its resonance will drive the FR.
With MM you can tune this with both R and C loading (although it takes effort and time!) to achieve a decent approximation of flat FR- with MC, there is not much you can do in the analogue domain to compensate... Digital then provides a means.

My MC pickup is specced for 50 kHz (Van den Hul MC One Special) and although there are no +/- dB limits mentioned I'd expect it to reach 20 kHz with ease. Yes, you cannot do much to improve FR but I think you don't need to.

 

[Gregg Hermetech]

maybe only before, or even definitively..
is it more important to dig the cell position settings, weight, arm height etc..
;-)
especially since it directly influences the tonal balance of the result.
;-)

And yes, you TOTALLY need to have the TT setup properly before doing this: levelling, alignment, VTA/SRA, VTF etc. This EQ should be the last step.

 

[levimax]

I wasn’t commenting about a specific product. You may however may want to research how much the cartridge output peaks when the stylus goes over dirt on track or through a vinyl surface cut. Once you have the data you can decide what is myth and what is engineering.

My point was RMI in their literature for this product basically says 6 dB is enough headroom for a phono stage and they made some compelling engineering and measurement based arguments for the 6 dB figure. While I understand a loud "pop" will generate a high voltage spike I don't understand why having the phono stage accurately reproduce this large spike and send an overload signal to the pre-amp or power amp helps anything "sound better". Seems like the phono stage should handle the overload. Maybe I am missing something.

 

[sarumbear]

My point was RMI in their literature for this product basically says 6 dB is enough headroom for a phono stage and they made some compelling engineering and measurement based arguments for the 6 dB figure. While I understand a loud "pop" will generate a high voltage spike I don't understand why having the phono stage accurately reproduce this large spike and send an overload signal to the pre-amp or power amp helps anything "sound better". Seems like the phono stage should handle the overload. Maybe I am missing something.

The issue is clipping. Think what will happen when a 10dB peak is fed to an input that has 6dB headroom? The top 4dB of that peak will be saturated and turned into a square wave. What is the characteristic of a square wave: unlimited THD.

This is why the term “head” room exists.

 

[levimax]

The issue is clipping. Think what will happen when a 10dB peak is fed to an input that has 6dB headroom? The top 4dB of that peak will be saturated and turned into a square wave. What is the characteristic of a square wave: unlimited THD.

This is why the term “head” room exists.

If you read the RME explanation they said 10 dB peaks don't happen (6 dB is plenty they say) but lets say they do happen and lets say they were very big i.e. the 340 mV mentioned in the old amp specs. That would mean the phono stage would output over 18 volts and send it directly to the pre-amp which would most likely clip / overload and if not it would certainly overload the power amp. Why is clipping on the phono "worse" than clipping further down the line in the pre-amp or power amp? The whole 20 dB or 34 dB of headroom makes no sense to me. Let's say a MM cart with 5 mV output (maximum for normal music) drives a system to 100 watts then to have 20 dB of headroom for the entire system you would need 1,000 watts and for 34 dB 5,000 watts. Again maybe I am missing something but I don't see the old "minimum 20 dB headroom" for a phono stage to make sense.

 

[sarumbear]

If you read the RMI explanation they said 10 dB peaks don't happen (6 dB is plenty they say)

They are wrong. Even music has more crest factor than 2!

Again maybe I am missing somethin…

Yes you are but I failed to explain to you why. Sorry.

 

[levimax]

Yes you are but I failed to explain to you. Sorry.

Maybe you could start by explaining why the RME comments are incorrect i.e. why 6 dB is not enough headroom. Hopefully I could follow along. Thanks