A VU Meter Amp/Speaker Selector Released by Fosi Audio

[solderdude]

As I posted on the other thread :
Bought one from Audiophonics. Seems to work fine but there are some reasons you probably won't want it.
When turned off, it automatically goes to input amp B and output speakers 2. You can keep using it when turned off that way but only in this configuration.
It does however remember the last inputs/outputs when turning it on. (you don't need power to use input B output 2, for all other configurations you need to power it on)
The VU meters are not buffered! Even turned off, VU meters keep on moving. One would think this is fine, but this means it does interfere in the signal path. It probably does not have a big impact but it might induce some distortion.
On the positive side, the remote did not interfere with my Topping D70s DAC.
The sensitivity of the meters actually is 250-300 watt-ish. That means you won't see much movement in normal use, unless you play loud or need a lot of power.
The sensitivigy-knob should be at max to give a more or less correct reading. Any lower setting and you won't see any reading at all. So the sensitivity knob is rather pointless.
Binding posts are ok but the holes are vertically. Diagonal would have been more easy.
So if you need a speaker/amp switch that can handle high power, it seems usable, but I would not use it in a critical listening environment.
If you want dancing VU-meters without using more than 25 watts, forget it.

Suggestions for improving would include a buffered stage that powers the meters, so any possible distortion (if any) caused by the components would be limited to a minimum and give the possibility for a better match with lower power setups by adding a "sensitivity switch" that eg can swap between the 250 Watt and eg a 25 Watt-scale. The extra cost would certainly be acceptable for such an improvement.

Your comments, most likely, are not about the meter discussed in this thread (LC30) ?

 

[JeyElDee]

Your comments, most likely, are not about the meter discussed in this thread (LC30).

They are. Added a picture.

 

[solderdude]

If you want dancing VU-meters without using more than 25 watts, forget it.

The meter should deflect to half the scale even with 0.2W so wonder why you say you can't use it with a 25W amp.
0.2W on normal speakers is just above average listening levels. 25W peaks should send the meter to half the scale.

When one wants dancing needles they should buy a meter that is connected with RCA and use that before any amp (and no volume control on the DAC)
This device is to show power levels.
The 'sensitivity' adjustment makes no sense unless you can have a calibrated setting for say... 2ohm to 8ohm speakers or so.
As it is now it is just dancing needles with some relation to the speaker amp output level.

The default connection of amp and speakers is weird indeed (with power off).

It's bling with an added speaker/amp selection possibility from the lazy chair.

 

[EJ3]

As I posted on the other thread :
Bought one Fosi LC30 switch with VU-meters from Audiophonics. Seems to work fine but there are some reasons you might not want it.
When turned off, it automatically goes to input amp B and output speakers 2. You can keep using it when turned off that way but only in this configuration.
It does however remember the last inputs/outputs when turning it on. (you don't need power to use input B output 2, for all other configurations you need to power it on)
The VU meters are not buffered! Even turned off, VU meters keep on moving. One would think this is fine, but this means it does interfere in the signal path. It probably does not have a big impact but it might induce some distortion.
On the positive side, the remote did not interfere with my Topping D70s DAC.
The sensitivity of the meters actually is 250-300 watt-ish. That means you won't see much movement in normal use, unless you play loud or need a lot of power.
The sensitivigy-knob should be at max to give a more or less correct reading. Any lower setting and you won't see any reading at all. So the sensitivity knob is rather pointless.
Binding posts are ok but the holes are vertically. Diagonal would have been more easy.
So if you need a speaker/amp switch that can handle high power, it seems usable, but I would not use it in a critical listening environment.
If you want dancing VU-meters without using more than 25 watts, forget it.

Suggestions for improving would include a buffered stage that powers the meters, so any possible distortion (if any) caused by the components would be limited to a minimum and give the possibility for a better match with lower power setups by adding a "sensitivity switch" that eg can swap between the 250 Watt and eg a 25 Watt-scale. The extra cost would certainly be acceptable for such an improvement.

Looks like the only use for me (where I plan to put it anyway) is at the BASS amp of my Tri-Amped system (unconventional: 1 NAD 2200 running at 4 OHMs for the pair of custom subs, [crossed over at 80 Hz] & one NAD 2200 amp for each Dahlquist M-905's carrying the duties from 80 Hz up).
It's true purpose for me is: BLING! Which bears some unknown resemblance to reality.

 

[Yorkshire Mouth]

I’d love to see this measured and reviewed.

We’ve had so many threads recently and discussion of (for example) whether certain measures of some Fosi Audio amps, Topping amps, and the WiiM Amp show issues which would be audible in real-world use.

I think with DACs we’re pretty much all agreed that they’re a solved problem. With amps we’ve maybe just a little tension. I think (and I may be wrong) that most of us think that any amp that’s not badly broken will sound much like any other, and there’s no need to spend a fortune. Others are maybe less convinced. This product, unless it significantly degrades the signal, gives us a chance to answer the question.

 

[Brian Hall]

I received one of these today. Added it to my main setup. It works great.

Makes it easy to switch between my stereo setup for music and the dolby atmos setup for movies and tv.

Main L/R speakers are the only speakers connected. It switches between my Dolby Atmos AVR and the Fosi V3 mono amps. Exactly what I needed. The VU meters are a nice addition.

 

[JSmith]

I received one of these today.

Nice, but a shame you didn't send it in for testing first.

Looks like Erin did some basic testing on this already actually.


JSmith

 

[Yorkshire Mouth]

Nice, but a shame you didn't send it in for testing first.

Looks like Erin did some basic testing on this already actually.


JSmith

I’d love to see Amir test this and see exactly what the difference is between (for example) the output from an amp and the output from an amp once it’s been through this.

 

[Brian Hall]

I’d love to see Amir test this and see exactly what the difference is between (for example) the output from an amp and the output from an amp once it’s been through this.

Nothing obvious enough to be noticeable. I'd bet any difference is inaudible.

 

[JSmith]

I’d love to see Amir test this and see exactly what the difference is between (for example) the output from an amp and the output from an amp once it’s been through this.

You will probably find, like other similar devices, that it measures ok and doesn't add too much in the way of distortion or noise, but limited to 250W of power (not that 250W is low at all). But as always, it's nice to see tested on the AP to be sure.


JSmith

 

[Brian Hall]

This device made me order some more banana cables. I've got some other speakers to compare and I'm also considering getting either Forte IVs or Cornwall IVs. No place close to try them out. Except maybe the Klipsch main office. They are closer to me than any dealer.

 

[Brian Hall]

In response to an audiophile fan's request, Fosi Audio created a VU meter amplifier/speaker switcher-LC30, and now brought it to everyone. It's now available on mainstream shopping platforms. See the link https://fosiaudio.com/pages/amplifier-speaker-selector-lc30

Members from ASR can enjoy a 10% discount by redeeming this promo code: FALC3010

Fosi Audio will keep co-creating new HiFi gear with audiophiles, which makes them become of unmatched value. Do believe another amazing stuff is coming soon this month!

I bought one of these to switch between my AVR and stereo amp while sharing the front L/R speakers. It is almost perfect.

It needs a single RCA in for each amp and a single RCA out for each speaker set to allow for sharing or switching an active subwoofer.

I added a separate manual A/B switch to handle the switching subwoofer outs, but it would have made things neater and easier if that had been included in the LC30.

Create another version, maybe an LC30-S that includes that capability for a little higher price, and I will buy it as soon as it is released. Most people who would be interested in this unit are probably running an active subwoofer.

 

[badie]

+1 for addition of RCA

I did a test of the FOSI LC-30 and compared its behavior against the VU Meters of an Accuphase E-405.
Made some videos for my (german) review (use translator if interested).
Fosi LC-30 review with videos of "dancing needles"

... LC-30 is just dancing needles

and without any attenuator (at least on one channel) useless for comparing speakers as soon as they have different sensitivity
Comparing amps works very nice though (as long as they have volume control)

 

[EJ3]

+1 for addition of RCA

I did a test of the FOSI LC-30 and compared its behavior against the VU Meters of an Accuphase E-405.
Made some videos for my (german) review (use translator if interested).
Fosi LC-30 review with videos of "dancing needles"

... LC-30 is just dancing needles

and without any attenuator (at least on one channel) useless for comparing speakers as soon as they have different sensitivity
Comparing amps works very nice though (as long as they have volume control)

But, you do not need to translate this to understand it:
All you need to do is watch the 3 videos badie presented for us to look at that are imbedded in the article and it doesn't matterwhat language that to cannot read the language, you will understand the problem.
I (being concieved in Charleston, SC USA but born in Salzburg, Austria [and spent lots of time there in my youth. making 9 trips to there from Charleston to Visit Opa & Omi for up to 3 months at a time] did not go to school there & formally learn to read German). At one time I could read things like the Max Und Moritz books and I was a translator for Porsche cars N. America in (with a German from the factory) training the USA people working at Porsche Cars North America (in the early 1980's) about the cars because I know the automotive specific technical language as that was/is a hobby of mine & when I was visiting Austria I always learned that stuff there.
But, as I haven't used my German since 1990, I could not read that & my computer is secured in such a manner that I could not get the translate app to work for me (someone with more computer knowledge could, I am sure).
But watching the videos made the issue clear:
These Fosi meters are but "dancing needles" unrelated to anything that is a real measurement objective.
As long as you know that the objective is to look cool (they do that well) then they are a fun but uninformative visual and may be fine as a visual gee-gaw in someone's system.

 

[badie]

Thanks @EJ3

Maybe better to post the videos here with a little translation.

Accuphase E405 routed into FOSI LC30.

First video: 1kHz Signal Tone from REW. Accuphase on -30db, regulated sensitivity on LC30 to show the same. Then slightly changing volume on Accuphase.

Second Video: 1KHz Signal tone from REW, this time all set to -10db (Accuphase VU as reference)

Third Video: Same story - this time -35db