Ordering integrating OG Analog preamps with Wiim Ultra as hub

[john61ct]

I am sure this is DUH! territory for them that-know-more-than-I

but thought it might be helpful to log my thought process and maybe get some feedback if I am off track.

I want to route all sources through a Wiim Ultra in order that (if I use DSP) its PEQs and Roomfit may help, and also the settable max gain / voltage to protect my beloved LS50s.

I also want to use a good Loudness Compensation preamp, several I will be testing both digital and OG analog, here I will use an OG Adcom GFP-555 as an example

This unit also includes the usual ad-hoc user controls - balance, tone, mono, a couple filters... And most importantly a Signal Processor loop as well as 2x switchable / bypass Tape loops!

So, given that I want both, in which order to chain these units?

The issue is, Wiim Ultra is itself a source of course, so if the preamp feeds it, I lose their ad-hoc volume / mute / loudness comp, balance, bass & treble, when using WU as source.

Solution to that, is Wiim comes first, but that means I use the preamp for "pass through" only, lose its Source Selector function

IOW must route all other inputs through the WU, or upstream of it if needed.

This is fine, I still have the three loops for easy AB testing in Signal Processing experiments.

Note this is all for such testing and learning, barely more than a thought experiment, not likely to be used in any final "production system".

What I'm specifically looking for constructive feedback on, is the logic of this ordering choice treating the components as given.

TIA

 

[john61ct]

Other preamp-alternatives to be parallel tested for Loudness functionality

Pre-amps with Loudness - OSD Pre-1 ?

Most of my source-switchers and volume controls are analog-only, which is my preference. I am also frugal, some months actually poor 8-( I like having physical tone controls, and miss the old variable loudness curve feature, ideally automatically coupled with the volume level, but I guess that...

www.audiosciencereview.com

 

[john61ct]

My current thinking: Adcom GFP-555 as initial hub

but really Wiim Ultra is primary, to ensure use of WU Volume Limiters
both maximum volume percentage +
analog line-level output maximum voltage
ALL sources into GFP-555 MUST get routed through Wiim Ultra using one of the preamp's "tape loops".

(USB out cannot be concurrent, both S/PDIF are, shoutout @harkpabst )

(WiiM Ultra analog output is concurrent → AudioControl Epicenter, "FR for Stereo Bass", separate remote)

...

WiiM S/PDIF out → Schiit Mimir + Forkbeard
(DAC, Master User Volume with auto Loudness Contour, alternative to Adcom GFP-555 own LC, more inputs, sample rate display, balance, plus some more PEQ)

Schiit Mimir (Analog Out) → Adcom GFP-555 (Tape 1 Input)

Tape 1 Wiim Ultra DSP / Volume Limiters Loop
Adcom GFP-555 (Tape 1 Output) → WiiM Ultra
(Analog Input) enables Wiim EQ/DSP for all inputs routed through the GFP-555, not just WU own direct inputs

...

Currently unused, preamp non-defeatable Signal Processor Loop, must be jumpered when not in use.

...

Tape 2 Loop for now testing Chase RLC-1 – in future "Modularised DSP ℠ " unit at the overall input Stereo layer, not to collide with Wiim's, comparing DRCs, likely RPi-based pass-through, but maybe another player source.

...

Leaves GFP-555 line inputs x3 – CD, Tuner, Aux

If I need more S/PDIF input to Wiim Ultra, can put a switcher on that, even those with lotsa ports are pretty cheap.

both units also have Phono input

Wiim adds WiFi / LAN streaming of course + BT, all both in & out. And both last & least, HDMI

...

All feedback welcome, especially any corrections of errors or misconceptions revealed 8-D

 

[Mort]

It's very hard to figure out what you are asking.

 

[john61ct]

It's very hard to figure out what you are asking.

No explicit questions asked, but some folk may spot foolish errors from this noob to (not just) loops.

If no one does then great I'm hoping I've cracked it for now, would give me lots of flexibility!

From the OP
> thought it might be helpful to log my thought process and maybe get some feedback if I am off track

 

[john61ct]

Found another advantage in routing the Wiim Ultra within the Tape Loop on GFP-555

besides

to ensure use of WU Volume Limiters

* both maximum volume percentage +
* analog line-level output maximum voltage

...

enables Wiim EQ/DSP for all inputs routed through the GFP-555, not just WU own direct inputs

I am testing / documenting three different
"Master User Volume with auto Loudness Contour" implementations

1. besides that built into GFP-555 (which I suspect will prove excellent, if not as adjustable)
2. WiiM (S/PDIF out) → Schiit Mimir DAC + Forkbeard (analog out) and
3. RLC-1 from Chase Technologies, likely "too strong" (but could act as a separate "bass boost" remote?)

(please discuss these and other LC possibilities here)

Pre-amps with Loudness - OSD Pre-1 ?

Most of my source-switchers and volume controls are analog-only, which is my preference. I am also frugal, some months actually poor 8-( I like having physical tone controls, and miss the old variable loudness curve feature, ideally automatically coupled with the volume level, but I guess that...

www.audiosciencereview.com

I have been interested for some time in "line-level audio distribution splitters", not switches not mixers, but mirroring the same (single) signal out to multiple destinations.

Wiim Ultra already does this across the FR analog stereo output, and either one of the S/PDIF (TOSlink and Coax) outputs (but not USB).

I plan to get a cheap distribution splitter, and use it between the Wiim analog output, feeding concurrently into the various analog inputs of GFP-555 - up to 5x at a time! choosing via its "listen" input selector knob.

(while the "record" output selector remains on the Tape 1 loop output)

This will allow for all kinds of ABX testing, not just the Contour implementations above, but

> AudioControl Epicenter, "FR for Stereo Bass", separate remote

and

> in future "Modularised DSP ℠ " units at the overall input Stereo layer, not to collide with Wiim's, comparing DRCs, likely RPi-based pass-through

maybe miniDSP as well.

...

> If I need more S/PDIF input to Wiim Ultra, can put a switcher on that, even those with lotsa ports are pretty cheap.

Since this distribution splitter also does video ("yellow coax" RCA) I can use it to do the same with S/PDIF digital RCA coax, which is exactly the same spec, up to 11x stereo output pairs at a time.

$42 delivered!

...

Of course for proper A/B testing, level matching is critical

? Behringer DS2800 ?

@dualazmak ?

other ideas, maybe stereo inline attenuators?

...

All feedback welcome, especially any corrections of errors or misconceptions revealed above 8-D

 

[john61ct]

It's very hard to figure out what you are asking.

Notice I did ask an actual question here (LOL)

 

[john61ct]

Just a thought note, but feedback and/or questions are welcome, especially to correct any noobish misconceptions!

This routing note is about positioning to test Schiit Eitr 2 for its Forkbeard preamp functionality, mainly to test as a user volume level control integrated with Loudness Contour.

Not as flexible as a Schiit's Mimir DAC + preamp, but $300 cheaper.

This specific idea came up as I learned about SMSL's SU-2 DAC, which features:

no volume level control, and

no USB

So thinking, from the Wiim Ultra USB Output → Schiit Eitr 2 DDC

which simultaneously outputs via 3x closely related transport formats:

AES/EBU → SMSL SU-2

TOSlink

S/PDIF Coax RCA

The DAC outputs both true balanced XLR and analog SE RCA, so I doubt there will be any need for further analog outputs at this "up front" stereo layer.

The latter two DDC outputs are available to be used for parallel digital routing downstream, DSP in general and especially crossovers / bass management, PC/RPi integration etc

TBC

...

More about Eitr 2

New Schiit - Eitr 2, not just a USB input DDC (Unison 384) but full digital preamp with Forkbeard

from 'WiiM Ultra Streamer Preamp Review' https://www.audiosciencereview.com/forum/index.php?threads/wiim-ultra-streamer-preamp-review.57342/post-2555025 For those wanting USB-C input from a host / PC Here's a new DDC to connect USB input cleanly to Wiim via your TOSlink input Schiit Eitr 2...

www.audiosciencereview.com

...

and my other Loudness Contour preamps in contention to be compared

Pre-amps with Loudness - OSD Pre-1 ?

Most of my source-switchers and volume controls are analog-only, which is my preference. I am also frugal, some months actually poor 8-( I like having physical tone controls, and miss the old variable loudness curve feature, ideally automatically coupled with the volume level, but I guess that...

www.audiosciencereview.com

..

At this stage I doubt clocking issues are relevant but if you disagree, please discuss here

Principles: Time of Arrival Delays, vs Phase tuning ?

I've been getting into the weeds on DSP for "speaker building", differences between using FIR from scratch to get linear phase crossovers vs using IIR to "correct phase" in already magnitude-working crossovers. I've seen members state that "time alignment" is a completely different topic domain...

www.audiosciencereview.com

...

 

[Ruediger]

This routing note is about positioning to test Schiit Eitr 2 for its Forkbeard preamp functionality, mainly to test as a user volume level control integrated with Loudness Contour.
Not as flexible as a Schiit's Mimir DAC + preamp, but $300 cheaper.
This specific idea came up as I learned about SMSL's SU-2 DAC, which features:
no volume level control, and
no USB
So thinking, from the Wiim Ultra USB Output → Schiit Eitr 2 DDC
which simultaneously outputs via 3x closely related transport formats:
AES/EBU → SMSL SU-2
TOSlink
S/PDIF Coax RCA

I have Ultras doing USB into various DACs and don't think there will be anything different with the Eitr 2?

It's a neat idea if you want max. savings and Forkbeard. $99 per box.

But know that for $199 you might also get the SMSL D-6s - same features, but with USB (and remote). One less box, same costs.

 

[john61ct]

D-6s looks good, thanks but does not further my goals this this configuration

As stated, its point is testing Eitr 2's Loudness Correction integrated Volume Control.

The point of the SU-2 (besides low cost and simplistic feature set) is just its unique (for the price) ability to convert from Eitr 2's AES/EBU jack to the two type analog pairs, leaving the two concurrent S/PDIF outputs available.

 

[Ruediger]

I think the SU-2 is a total steal. 9039, balanced out... $88 at smsl site. In a chain with no further need for usb, volume, remote it's perfect.

I wonder though how this will work out in terms of gain. The SU-2 is fixed at 100%, the voltages are listed in their specs. Will you put the Ultra at fixed output and just create some headroom with max. volume? That's a lot of power going to the amp. All reduction and volume control is with the Eitr 2 then.

When I do that the other way round - amp volume bypass 20db gain, DAC 100%, Ultra max. volume 92% and used for volume control - I get a suboptimal range of usable volume. 15-45%.

 

[john61ct]

Will need to wait and see.

That's a lot of power going to the amp. All reduction and volume control is with the Eitr 2 then.

The actual power amps - maybe a dozen or so - are several devices away, most of the devices have their own attenuation, and DSP will likely get involved, especially if phase / timing issues need tackling.

I need to learn more on measuring for the clipping level of each line level device in the chain, for those that don't have that built in. Maybe learn to use a volt meter?

Ideally the Eitr 2 could be the last device in the (full-range stereo front-end part of the) chain, but USB being the only input makes that difficult, and I doubt adding an extra (say RPi) DDC stage would be worthwhile just for that issue.

Really, since I want the Vol/LC to be upstream of all the multichannel signal splits & bass management, I think that's the right spot for Eitr 2 anyway, so I'm happy the Wiim Ultra even has a good USB audio output

 

[Ruediger]

I need to learn more on measuring for the clipping level of each line level device in the chain, for those that don't have that built in. Maybe learn to use a volt meter?

A meter with suitable range and test tones would be the scientific method. Personally I go by the specs + what was measured in the review and apply rules of thumb.

For the Ultra and it's EQ and RoomFit (both can add gain) I create the same headroom by max. volume reduction. The Ultra also does a pretty good clip prevention (explained in detail in the WiiM forum), but it's still an intervention and I chose not to invoke it.

DAC voltage output at 100% and what the amp likes/wants for it's buffer board or input sensitivity depends on the specs of these boxes.

F.e. 3e audio A7 3.5vrms sensitivity at XLR in. DAC max. 5vrms out, calculating by scale of the volume and the way the ESS9039 (in this case) handles the volume that means volume = 92 yields just short of 3.5vrms with a 0db signal fed.

Ideally the Eitr 2 could be the last device in the (full-range stereo front-end part of the) chain, but USB being the only input makes that difficult, and I doubt adding an extra (say RPi) DDC stage would be worthwhile just for that issue.

Really, since I want the Vol/LC to be upstream of all the multichannel signal splits & bass management, I think that's the right spot for Eitr 2 anyway, so I'm happy the Wiim Ultra even has a good USB audio output

The Ultra can also be a somewhat good input switcher. Remote, auto-inclusions, pre-gain and volume stored per input.. all the convenience in software is already there.

It's "just" optical, rca, phono, network and usb though.

 

[john61ct]

The Ultra can also be a somewhat good input switcher. Remote, auto-inclusions, pre-gain and volume stored per input.. all the convenience in software is already there.

Yes the Ultra is not just a source but my hub, a given. But volume control, multichannel and multi-sub crossovers will be handled downstream, lots of tuning via REW tbd, but maybe WU DSP and Roomfit will still contribute to some extent. I do p an to apply a global subsonic "rumble filter" which will only actually apply to the bottom-most mono subs.

> A meter with suitable range and test tones would be the scientific method.

SPL meter? or DMM?

> Personally I go by the specs + what was measured in the review and apply rules of thumb.

So not relying on my human ears' ability to perceive distortion?

> 3e audio A7 3.5vrms sensitivity at XLR in. DAC max. 5vrms out, calculating by scale of the volume and the way the ESS9039 (in this case) handles the volume that means volume = 92 yields just short of 3.5vrms with a 0db signal fed.

Above my current paygrade, but I'll get there.

That "92" what unit is that?

I realise just an example - as I said there may be many line level devices before reaching the actual power amp, the F-LR stack more so than Surround or mono subs for example.

 

[90sNintendoKid]

@john61ct I would use the WiiM Ultra for all my sources, usb output into Camilla DSP for EQ and loudness management and then to a dac.

 

[Ruediger]

Yes the Ultra is not just a source but my hub, a given. But volume control, multichannel and multi-sub crossovers will be handled downstream, lots of tuning via REW tbd, but maybe WU DSP and Roomfit will still contribute to some extent. I do p an to apply a global subsonic "rumble filter" which will only actually apply to the bottom-most mono subs.

I get some serious rumble when not using room gain compensation. But I guess a DSP could do the same.

> A meter with suitable range and test tones would be the scientific method.

SPL meter? or DMM?

I haven't measured for max. voltages. I just have a standard multimeter for electronic works. Checking for unwanted DC, proper resistance, shorts and such.

For better measuring of audio outputs a meter with ranges especially suited for these voltages would be better.

> Personally I go by the specs + what was measured in the review and apply rules of thumb.

So not relying on my human ears' ability to perceive distortion?

Absolutely not. When it's clearly present all the time things are already completely wrong. But when it appears at peaks - imagine home theater with a lot going on in loud scenes and with scenery switches - you'd have to be really paying attention. Not very scientific. In general I just want it to be ruled out. I assume that is what everybody wants?

> 3e audio A7 3.5vrms sensitivity at XLR in. DAC max. 5vrms out, calculating by scale of the volume and the way the ESS9039 (in this case) handles the volume that means volume = 92 yields just short of 3.5vrms with a 0db signal fed.

Above my current paygrade, but I'll get there.

That "92" what unit is that?

I realise just an example - as I said there may be many line level devices before reaching the actual power amp, the F-LR stack more so than Surround or mono subs for example.

Yes, you'd have to look briefly at every one of it. The example is the SMSL D-6s in my home theater. It has volume control 1-99 and uses the ESS9039 to adjust, not a volume IC.

Also the input sensitivity of amps is quite different.

The SU-2 with fixed volume can output 4.7vrms via xlr. That is 2.6db more than the 3.5vrms required for full amp power of my 3e audio A7. Would have to account for that before the DAC. The problem is only theoretical of course unless that power is really sent. Which is a problem of persons, knobs and apps. The Ultra as a hub makes it easy to cap things. Just need to do the calculations right (again just an example).

 

[john61ct]

For better measuring of audio outputs a meter with ranges especially suited for these voltages would be better.

Again to be clear, by "a meter" you are meaning a voltmeter? I believe a standard DMM lets you switch down to a 2V resolution, or up to 20V for the pro levels.

Here is a blurb from Gemini, anyone able to confirm?

 

[Ruediger]

For DC, yes. That's helpful, but not for everything. AC ranges are not good on mine to measure audio.

 

[john61ct]

I thought only the AC parts of the signal are of interest? Isn't all DC just noise wrt analog audio?

So I'm thinking rather than measuring with a DMM, maybe better to buy some (legacy, old obsolete secondhand so cheap) processor / mixer that clearly shows input dBV / dBu if not displaying voltage directly

and just use that at each line level output stage to adjust to below the spec'd clipping level of the following sink device.

RMS vs transient Peaks becomes a complication...

 

[john61ct]

TBC here

DMM reco, REW as dBu / dBV meter, test bench analyzer ?

Below is from Google, looking for human verification from anyone. My questions are embedded (?Q?...) Using my measurement interface E-MU 0404 USB ($36 delivered!) and software like REW as RTA, can act as an accurate AC volt / dBu / dBV meter! Still need a decent DMM capable of measuring true...

www.audiosciencereview.com