Poor BASS with Dynavector XX2 +Sunilda + AudioNote

I recently bought a complete analogue set: Dynavector XX2 + DPS table with Reha RB300 arm + Prephono MM/MC Sunila (from Audio Valve). All of that connected to my Audio Note.
Tje results is fine (open, smooth, clear, depth ..) but lack of bass!! No sure if it is the prephono (I will change the 12AX7 by some NOS) or if is a mismatch between the cartridge and the arm ..

Any suggestion ?? Many thanks
This may be obvious, but are you sure the cartridge alignment and especially VTA are set correctly? Generally to increase bass you want to lower the back of the arm slightly below parallel.

I second what Bob said about the VTA... You'll know it when you hit "the spot."
Hello from a fellow DPS owner!

I know both the DPS/Rega combo and the XX-2 pretty well (although not together). I don't see a mismatch between the Rega arm and the XX-2 cart in term of a resonance/compliance match. A few things to check:

- Cartridge loading: What loading do you use? Does the phono use an step-up internally for the MC input? The XX-2 requires a pretty low loading (12-30 with a step-up, 30-100 Ohm into a solid state MC input).

- VTA: I would start with the arm parallel to the record.

- Is this a DPS modded Rega or a basic Rega arm? The rewired arm is substantially better than the stock Rega arm.

Best wishes,

According to cartridgedb.com, the Output Impedance/Coil Resistance of the XX2 is 6 ohms. Using the 25x rule (+/_ 50%) the optimal loading for that cartridge should be 25 x 6 ohms = 150 ohms. +/_ 75 ohms or in other words somewhere in the range of 75 ohms to 225 ohms.

To use this method, start at the lower end of the range (75 ohms or so) and listen to the bass. It will be strong enough, but a little sloppy (not tight.) Next, try 100 ohms, again listen to the bass. It should be tightening up (at least a little) and still be very strong. Now go up to 150 or 175 ohms, The bass will still be tight but deminished in power. The frequency balance will begin to seem mid-rangey, or even bright. You need to back down, probably to 125 or 120 ohms to recover a tight strong bass.

It's all about picking the right gear for the steepness of the hill you're trying to climb -- so you get the most out of your engine. With cartridges, you're trying to find the impedance match that delivers the most voltage to your phono preamp.
Yep, yep, yep -- Setup and loading.

I CAN guarantee you it isn't the carts fault.
My XX2 kicked rump!
Thanks for your input .... Some answers:

1/ This is modded arm .. so a bit better
2/ Cartridge alignment is perfect ...
3/ VAT ?? I do not know as I cannot change it on my DPS.
4/ Loading .. Intersteing. My prephono has 2 input: MM and MC. This latest allow different positions 47R, 100, 300 , 1K ... The best is on 47R although the difference is quite small. Surpizing enough, if I move it onto the MM position, I get (indeed) 20 less db .. but the sound is very similar ....

My conclusion so far ?

AA/ I am happy to know that there are no mismatch between my DPS and the cartridge

BB/ VTA can be theissue ... I will see what I can do ..May be add some LP to change the angle ??? (but will not be able to put it lower ..)

CC/ the issue can be my prephono SUNILDA. I will try to replace the 12AX7 .... then change my Sunilda for another product (although I am quite surprize, this product being quite expensive and well reviewed .....


Thanks again
Dear Patrick: As Restock point out there is no clear problem on the Rega/XX2 matching but I think it is not the best tonearm match.

I have a friend that have the same tonearm/cartridge in an Avid TT ( different electronics and Avant Garde speakers. ) and never really like it.
I owned the XX2 and I think s a very good cartridge with very decent tonal balance and certainly not a lack of bass not either in the other side but neutral.

I think that that cartridge deserve a precise VTA/Azymuth set-up in a better matching tonearm.

In the other side the Sunilda has a subsonic filter at 20Hz this makes that the roll-off in the bass start at around ( depend on the choose of filter order. ) 80-100 Hz.

So, IMHO ( at least ) you have these two different subjects where my experiences tell me " you are in trouble ".

Now, I don't know which speaker/amplifier you own and how good are integrated to your listening room, specially in the bass response subject.

If I was you first I will try to borrow ( somewhere ) a different tonearm and try in the audio system.

Regards and enjoy the music.
Thans for your comments Raul .. I feel so bad!!!

I can always add a VTA system on the arm. It exists and do not cost much ..... This will solve partially the problem.

I can also change the arm (the DPS is engineered to put other tonearms like the wilson B .... It will cost me additional 1500 $ but it will imprve).

But what makes me feeling bad is the subsonic filter on the Sunilda. If Bass starts ay 80 hz, I'm dead ...

My system is very well balanced with my AudioNote CDplayer + Dac + Preamp + Amplifier.... So I reamize my biggest problem is the prephono.

What can I do to tweak the subsonic filter (I do not know what it means ...)? If I put some NOS, will it change ??

Dear Stelma: Maybe you can by-pass, why don't you call to the manufacturer to they can give you information how a technician can do it.

Regards and enjoy the music.

you should be able to change VTA on the DPS: The Rega arm should be secured with a set-screw from the side; you can loosen the set screw and lift the arm a little bit; then tighten the set screw. I use business cards to measure the distance between arm and plinth to achieve repeatable and accurate VTA adjustments on the DPS.

The XX-2 is very sensitive to VTA changes from my own experience with setting up my friends turntable. How far is the tonearm tube from parallel to record?

My friend uses a loading of around 100 Ohm into his Pass XOno.

Just curious - where are you located?

Best wishes,

Thanks again ...

Sorry, I do not know how far is the tonearm tube from parallel to record ... I have not chechek.

What I will do is the following:

1/ To check my prephono Sunilda with my friend's turntable (which is well adjusted as he own very good arm). If I have strong basses, it will mean my Sunilda is OK. Otherwise, I will contact AudioValve and s what i can do.

2/ If Sunilda is OK (this is what I would prefer), I will purchase a VAT adjustment system (available for Reaga arms ..) and I will change it.

My feeling is that this is a VAT issue, as the rest of the sound is really nice ....

Curious? I am fom France .. in Grenoble.

Regards to all
Stelma - the DPS already is designed so that VTA can be adjusted (just simply via set-screw).

Most VTA adjustment system (e.g. Riggle, Incognito) would not work if the arm is correctly mounted on the DPS (i.e. set screw from the side rather than the counter nut usually used on the Rega arm).
I own a DPS table as well.

VTA is extremely easy to change with DPS/Rega arm.

It should of come with the proper sized hex screw to change it.

I used a deck of cards, and this made setting VTA very easy and repeatable.

For me it was usually between 5 or 7 cards depending on record thickness to get the best sound. I had a ZYX Atmos however.

Look on the arm side of the table, you should have a hole in the black acrylic plinth.

IF you are unable to adjust VTA with the hex screw in that hole, it is because you have the lug nut of the Rega arm tightened against the underside of the black acrylic and thus you have no freedom of movement on the tonearm. The lugnut should be towards the bottom of the Rega stub, only serving the purpose of preventing you from pulling the arm out of the hole completely. The VTA adjusting hex screw is what really holds the arm in place.
I have an XX1-H and have also found that the VTA seems to be very sensitive. I think as you get into better cartridges the VTA becomes more and more critical and harder and harder to easily identify without an on-the-fly adjustor. Far more so than my old 20X-H.

I completely agree with Soliver - you should have hex set-screw in place. Willi
(the DPS designer) makes a special one that has a flattened ball-point so that
the threads of the Rega arm are not damaged. For other arms (e.g. the
Schroeder No.2 arm) that one should be exchanged for a ball point hex screw.

I prefer the set-screw method combined with deck of cards (that you slide
between arm post and plinth to measure height and remove after set-up) to the
other Rega methods for VTA adjustment.
Ouah ... I'm impressed !

Many thanks for your valuable input. I will check that this week end (I am on business trip this week) and will let you know early next week if this has changed my life ....

BTW I do not have any doc on the DPS ... Is some one has an electronic copy he can send it to my email on stelma@sfr.fr

Many thanks again ...!!

Last week end, I have checked ... and hourra I founded the hole to tweak my VTA .. And the results was GREAT!! more basses and the sound still warm and charming !!!

I also tried with a prepre Acuphase C7 ... and it was even better !!! It means more basses, more volume .......

I will continue my investigations ... and update you later on !!!

MANY THANKS to all of you for your recoomendations.
Great to hear things have improved with something as "simple" as VTA adjustment ;) Try to play around with different VTA settings and keep track of it using a stack of cards. A change in as much the thinkness of a single card can make quite a bit of a difference for the Dyna XX_2. Good luck and enjoy!
I will continue playing aroud with cards ... but when I read the paper from Geoff, I do not understand why a single Business Card can make so much difference !!!!!

I think the single card analogy, "making so much difference", is a little extreme :)
I don't. I have an XX-1 and found it to be very sensitive to VTA. A single card is about the difference in thickness between a regular album and an 180g album. I can now see why some people adjust VTA depending on the thickness of the vinyl being played. You need on-the-fly VTA adjustability on the tonearm to do this though.