Re: Level mismatch solutions - fixed and variable attenuators

End of last year I made a passive box for my friends ff800 based on a quad GoldPoint stepped attenuator.  I convinced him to go RME, and so when he noticed the interface doesn't have a dedicated volume knob for output I jumped at the chance to keep him hooked, and to avoid the shortcomings of Mackie and TCe 'solutions'. His is much nicer than the one I built for myself around 2005 or so.
https://drive.google.com/file/d/1dNiu-bjXIqqxFDiofk_YU3bOiEqlF1Y4/view?usp=sharing
https://drive.google.com/file/d/1XK93ILbe0jxPZej1T_52Oi6kcad8HNaS/view?usp=sharing

My old trusty/dusty unbalanced version:
https://drive.google.com/file/d/1H2HCC4zWl-xZz4kgwj-gGNdQHcQOuwfL/view?usp=sharing

52 (edited by thesimulacre 2020-12-29 04:35:05)

Re: Level mismatch solutions - fixed and variable attenuators

Here's a couple more shots:
https://drive.google.com/file/d/1qOXPcw … sp=sharing
I tore up some Mogami cable to do the wiring and my friend with a laser CNC helped me with the Walnut panel cutouts. The case was a part from some kind of heavy-duty outdoor lighting that I hack-sawed in half, and the knob is a lid from a jar with a smaller knob glued inside.
https://drive.google.com/file/d/15Z8hDKU-RReNEyATaWhcmcQDVXQZ-Z8d/view?usp=sharing
I had used some off-cuts from the laser process to make a stand for vertical orientation, but it was too delicate for my friends heavy-handed music madness times.

Re: Level mismatch solutions - fixed and variable attenuators

what an amazing post !!! it solves several issues of mine by one.
Had a hiss in certain situations, always had to monitor at -30db main etc blabla.

I bought the JTS MA-123 (thomann German site https://www.thomann.de/de/jts_ma_123.htm)inserted directly between the balanced cables and the speaker input and voila !!!!!

...no hiss + monitoring up to 0 db with the speakers even cranked possible + cheap headphone out into the Fireface UFX I with a Y-cable creating a tinitus like sound....gone.

its just amazing !
best invest in my past 25 years !

Re: Level mismatch solutions - fixed and variable attenuators

Although not really needed I also bought this. I made the experience too often that good products come and go.
But once  needed they are not available anymore.. wink

BR
Ramses
X10SRi-F, E5-1650v4, Win10Pro21H2, Cub11Pro, UFX+, XTC, 12Mic, ADI-2 Pro FS R BE, RayDAT

Re: Level mismatch solutions - fixed and variable attenuators

Really interesting stuff. I'm having the same issues with my BFpro fs. Output is super hot, monitors turned down as low as they can go. It's workable until some random system sound blows them off their stands. So I took your sound advice and spent £40 on the JTS attenuators. All good.......
Then I had a skim through the manual and game to this little nugget tucked inside page 45

Setting the reference level of both XLR outputs is done by a sliding switch on the bottom of the device (+4 dBu or +19 dBu

I'd never seen that before so I flipped it over and holy shit there it was.
Switched it to +19 and problem solved. Gonna have to return the attenuators, that haven't even arrived yet.

WHY did nobody mention this switch in that whole thread? Is it a recent addition to the hardware?
Herr Carstens, you need to update your thoroughly informative post
https://forum.rme-audio.de/viewtopic.ph … 42#p120442

Re: Level mismatch solutions - fixed and variable attenuators

Cool.
That applies only to the Babyface pro or to which others  as well ?

57

Re: Level mismatch solutions - fixed and variable attenuators

The switch is a major feature of the BF Pro 'FS' update.

Regards
Matthias Carstens
RME

Re: Level mismatch solutions - fixed and variable attenuators

Now I don’t read manuals end to end until I need to but I always check out every physical switch,slider, socket, wheel on a device. Even then I’d check the manual and physically before I started spending money.

Re: Level mismatch solutions - fixed and variable attenuators

I don’t read manuals end to end until I need to but I always check out every physical switch,slider, socket, wheel on a device.

I know, I know...I should have spotted it. In my defense, it is a really feckin small switch.

Re: Level mismatch solutions - fixed and variable attenuators

Hi fellows! I wan't to build a simple attenuator between my Babyface and my Dynaudio Lyd5. I don't get it though, should I always use a "H pad" if I want connections to be balanced?
http://www.uneeda-audio.com/pads/

Thanks! smile

61

Re: Level mismatch solutions - fixed and variable attenuators

That link names the correct version as U, not H.

Regards
Matthias Carstens
RME

Re: Level mismatch solutions - fixed and variable attenuators

Oh thanks a lot for putting your pipe down and answering. I was a bit puzzled....

Re: Level mismatch solutions - fixed and variable attenuators

I'm having a variant of this issue, with my sennheiser hd600 conencted to my BFpro headphone out. All meters close to the bottom, the output meter on the interface never goes above 1 led. Any recommendations on how to resolve this issue?

64

Re: Level mismatch solutions - fixed and variable attenuators

Use a mini TRS to TRS connector so you can plug the Senn into the small TRS output. This reduces volume by 6 dB. If still too loud then you are an extreme case of low volume listener. But there is help: The attenuators described in post 1 are also available as low impedance headphone versions. Google 'headphone attenuator'. They don't change the sound, just take away volume.

Regards
Matthias Carstens
RME

Re: Level mismatch solutions - fixed and variable attenuators

Thanks for the post.  Does working at -30 dB have an impact on sound quality and resolution than at 0 dB or does it only matter to work better with a DAW?
Thank you.

Re: Level mismatch solutions - fixed and variable attenuators

There is a (theoretical) change to resolution, but not to "sound quality".

Regards
Daniel Fuchs
RME

Re: Level mismatch solutions - fixed and variable attenuators

Hey all,  I am new to RME and this is my first post so apologies if i got something wrong in this post.

I just picked up a BFP FS and i love this thing. Everything is working great but i have a couple of questions maby you could help me with if thats ok.

I have the switch set to +4dbu, my DAW output in Total Mix is set to -10db and Main Out set to -10db in Total Mix. So it's down -20db in Total Mix outputting to the BFP FS for good listening levels. This gives me good level into my Focals and my Output LED meter on BFP FS is hovering around half way, lit up 50% lets say. Everything sounds great.

My question is will this effect the sound quality at all in the unit with D/A etc working in this range, or should i get some JTS Mic attenuator MA-123 and set them to -20db to get everything to 0db across the board. I have no problem picking some up i am just after the best option.

Second question is. I replaced my monitor cables and i bought Mogami 2 Meter – Quad Balanced 2534 before I noticed most people recommend the Mogami 2549. My fault i should of checked.  Will a 2m length of 2534 quad going to each monitor be ok or should i grab some of the 2549. I like the sound of my 2534, I am just looking to optimize my set up and keep the output as true the BFP FS as possible.

Thanks all..

Re: Level mismatch solutions - fixed and variable attenuators

The signal level does not affect "sound quality" at all.

Regards
Daniel Fuchs
RME

Re: Level mismatch solutions - fixed and variable attenuators

... nor the choice of the type of cable.

ADI-2 DAC (with stock PSU) - Neumann KH 310 A monitors - Cheap USB and XLR cables

Re: Level mismatch solutions - fixed and variable attenuators

RME Support wrote:

The signal level does not affect "sound quality" at all.

Fantastic. Thanks for the response smile

Re: Level mismatch solutions - fixed and variable attenuators

N00b wrote:

... nor the choice of the type of cable.

Great,  thanks for the help smile

Re: Level mismatch solutions - fixed and variable attenuators

Hi,

I have an RME ADI-2 DAC FS used as a preamp with a Nuprime STA-9 power amplifier (home Hifi use)
Input Impedance: 47k Ohms
Input sensitivity: 232.8mV, 1W @ 8 Ohms; 1.4V to rated power
Gain: x 22

I listen music at low volume and use RCA cables, with
Auto Ref Level = ON  (so, always at -5dBu at my volume level)
Loudness = ON  (one of the reasons I have chosen RME ADI2...)


What do you think of
-20dB attenuator with a bridge of fixed resistors 10kOhms / 1kOhm (I can easily integrate this attenuator inside the amplifier)
Are there better resistance values for better compatibility with the RME ADI-2?
Are there any problems using this kind of attenuator between an ADI-2 DAC and my poweramp?

Thanks in advance.

Regards,

73

Re: Level mismatch solutions - fixed and variable attenuators

What is that added attenuator good for?

Regards
Matthias Carstens
RME

74 (edited by fafa44 2021-08-28 22:09:39)

Re: Level mismatch solutions - fixed and variable attenuators

Hi Matthias,

I listen music at low volume (I live in an apartment ...)
My source Bluesound node 2i is set to fixed output level. On the ADI-2 DAC, at -5dBu I have a -60dBr volume!
I am newbe, it seems to me that an attenuator would allow the ADI-2 DAC  to operate in a better range.
-20dB may not be enough ...

regards

Re: Level mismatch solutions - fixed and variable attenuators

Ok, what about this ? Switchable between -10, -20, -30 dB: https://www.thomann.de/de/jts_ma_123.htm

BR
Ramses
X10SRi-F, E5-1650v4, Win10Pro21H2, Cub11Pro, UFX+, XTC, 12Mic, ADI-2 Pro FS R BE, RayDAT

76 (edited by fafa44 2021-08-29 17:10:50)

Re: Level mismatch solutions - fixed and variable attenuators

Hi,

@ramses, I had read this possibility above. I keep this in reserve.
I am with RCA connection  yet: So, there is the Monacor ILA-1020 (limited to -20dB).

But, I have the possibility to directly insert a DIY resistor bridge inside my amp (I just need two 3-pin connectors and 2 resistors, resistor tolerance 1% or 0,1% ).
So, I would prefer this solution :
I will connect a  resistors bridge R1 + R2 between the RCA signal output and RCA ground
The amplifier input signal is taken from R2.
(Dac RCA output impedance = 100 ohms
Amp Input Impedance: 47Kohms)

I need to know the best value range of R1 and R2 for RME ADI-2 DAC output:
-20dB (ratio about 10)   - 4,7K/470ohms, 10K/1K , 47K/4,7K,   others?
-30dB (ratio about 32)    -4,7K/150hms,10K/320 ohms ? 47k/1,5K,  others?

Thanks for your help.

Regards

77

Re: Level mismatch solutions - fixed and variable attenuators

The ADI can be used with attenators down to 1k, so even the 4.7k/150 would work.

Regards
Matthias Carstens
RME

Re: Level mismatch solutions - fixed and variable attenuators

Mathias,thank you for this useful information .

Regards

Re: Level mismatch solutions - fixed and variable attenuators

Hi,

I have used the RME ADI-2 FS as DAC in my system since May 2019, with this gear and signal path:

AudioPC >> ADI-2 DAC >> Naim 202 pre-amplifier >> Naim HI-CAP PSU >> 2 x Naim NAP250 power-amplifier >> Audiovector R3 speakers. So 2 x NAP250s used to bi-wire the speakers.

With Naim's special way of connecting components the signal is routed through the HI-CAP PSU which provides power for the 202. With this set-up, Auto Ref Level ON, ADI-2 set to -10dBr volume and +7dBu reference level, the 202 volume control operates around 20% from start. The (vintage) Naim NAP250s, from what I can find out, has specification of 1.6V and 24dB gain.

While looking for tips regarding filters and PEQ I came across posts on using ADI-2 FS as pre-amplifier, and this discussion on level matching. Given the quirkiness of a Naim system I was wondering if the ADI-2 could drive the vintage NAP250s and the bi-amping configuration, and only way to find out was to give it a try!

Playing the first track was unsettling as there was a significant change in the overall sound, with first impression of 'something' missing. But then, after playing different tracks and genres came the realization that a significant amount of coloration was no longer there. With the Naim set-up, when listening at 'home concert level' (when wife is out) there is a certain compression-like feel to the sound which gets uncomfortable after a while. With the ADI-2 as preamplifier going directly to the NAP250s the sound is scaling to amazingly high volume with wider soundstage, higher resolution and better clarity and importantly, very musical overall performance. It is not often during 40+ years in hi-fi that I have had such a profound eureka moment!

So using the ADI-2 as preamp is the way to go, which brings up the balancing theme. Listening at normal level (music, TV), with Auto Ref Level ON, the ADI-2 volume setting is around -40dBr. When I listen to music at the home concert level the ADI-2 volume is in the range of -25dBr to -30dBr with reference level of -5dBu. The sound stage is rock solid and no distortion audible.

So the question is if this is ADI-2 operating within its high performance envelope, or if using attenuators will provide further optimization. The NAP 250 has 1x XLR connector which is connected to RCA out on the ADI-2. So RCA attenuators like the JTS MA-123 can only be connected to the RCA out on the ADI-2, while I understand from your initial post MC, that the MA-123 should be connected to the NAP250 input, which is not possible with current interconnect cables.

Input, advice and recommendations much appreciated!

Re: Level mismatch solutions - fixed and variable attenuators

I see that Rothwell Audio has what they call 'For Source' fixed value RCA attenuators (-10, -15, -20dB) for use at the output sockets of the source and not the input sockets of pre or power-amplifiers. Anyone with experience using this attenuator to reduce gain in the system?

81

Re: Level mismatch solutions - fixed and variable attenuators

KNedrebo wrote:

So using the ADI-2 as preamp is the way to go, which brings up the balancing theme. Listening at normal level (music, TV), with Auto Ref Level ON, the ADI-2 volume setting is around -40dBr. When I listen to music at the home concert level the ADI-2 volume is in the range of -25dBr to -30dBr with reference level of -5dBu. The sound stage is rock solid and no distortion audible.

So the question is if this is ADI-2 operating within its high performance envelope, or if using attenuators will provide further optimization. The NAP 250 has 1x XLR connector which is connected to RCA out on the ADI-2. So RCA attenuators like the JTS MA-123 can only be connected to the RCA out on the ADI-2, while I understand from your initial post MC, that the MA-123 should be connected to the NAP250 input, which is not possible with current interconnect cables.

The NAIM seems to have a very unusual unbalanced input via one XLR female socket. According to your numbers you could use the Rothwell RCA attenuators, the version for putting them on the outputs, with -20 dB attenuation. The MA-123 are fully balanced and no good match here.

Regards
Matthias Carstens
RME

Re: Level mismatch solutions - fixed and variable attenuators

Thanks for the confirmation Matthias. Rothwell 'for source' RCA attenuators have been ordered.
Best regards