Bose S1 Pro with Shure A85F Line Matching Transformer - Game Changer!

[rokdog49]

This is the same as the Shure:
https://www.sweetwater.com/store/det...edance-matcher

If you don’t have it, what you have is different.

[shufflebeat]

I'm not questioning the evidence of anyone's ears but there seems to be a measure of misunderstaning around mic vs line, how transformers work and how they compare with preamps.

I've not put my finger on the main issue yet, being only vaguely versed in the principles of electronics, but it seems to revolve around the idea that you can't create energy (gain) from nothing, only transform it in certain ways, none of which are 100% efficient so I'm struggling to see where the free gain comes from.

Again, not doubting anything but my own understanding yet but looking forward to enlightenment.

[MarkF_48]

Originally Posted by shufflebeat

I'm not questioning the evidence of anyone's ears but there seems to be a measure of misunderstaning around mic vs line, how transformers work and how they compare with preamps.

I've not put my finger on the main issue yet, being only vaguely versed in the principles of electronics, but it seems to revolve around the idea that you can't create energy (gain) from nothing, only transform it in certain ways, none of which are 100% efficient so I'm struggling to see where the free gain comes from.

Again, not doubting anything but my own understanding yet but looking forward to enlightenment.

You are on the right track. A passive device such as this transformer can not create 'gain', but what it does is step up the voltage through the ratio of the transformer windings so it appears to have gain. And this is dependent on the loading of the impedance/resistance of what it's plugged into. Line and instrument inputs tend to have a higher input impedance than a mic input and allows more voltage to be available to the preamp circuits in the amp, thus an increase in volume as everyone is seeing versus using a mic into the mic input. The line input impedance is also reflected back through the transformer so the mic sees a a higher termination loading. This tends to alter the frequency response of the as folks have noted.
This is kind of a simplistic explanation, but it really comes down to the workings of ohms law.

[shufflebeat]

Originally Posted by MarkF_48

You are on the right track... ...it really comes down to the workings of ohms law.

This is also my understanding, although I'm probably approaching the limits of my understanding with that.

So, my thoughts would be, I bought the s1 because it sounds good, plus it fills many small gaps for which a bigger mains speaker would be overkill - but only because it sounds good. I may not need extended bass for a duo stage monitor but it will make all the difference at a solo corner spot.

I agree that in most (certainly not all) cases some kind of preamping is necessary but there are more elegant and useful ways to do it than this. I've just invested in an "ART dual pre" battery powered preamp, not necessarily only for this but I think it will do that trick.

I used a line transformer many years ago to put a harmonica mic into a guitar amp so they have their uses.

[shufflebeat]

For those who are interested or those who were scratching their heads about basic laws of physics:

The ART Dual Pre, to my eyes and ears, is the perfect companion to s1 users struggling to get a decent level with a regular dynamic mic. 48db of gain means my Senn e935 clips the red at about 2/3 of the way up the travel.

At that point there is both a mix control blending the signal from the USB computer connection (yes, it's a USB interface as well) with the mic inputs (plural, there's two of them).

And that to the gain available on the s1 preamp and I reckon you could get a signal out of a house brick.

The presets on the s1 seem subjectively more effective and more defined than without the ART.

ART is externally powered via a PSU or power bank or internal 9v battery, 50hrs without 48v phantom power or 20hrs with (yes, it provides phantom power to two mics).

Highly recommended if you need one.

[rokdog49]

Looks like a winner and thanks for the suggestion. I see that device is primarily used for recording.
The Shure A85F works very well and for $20. On top of that, it plugs right in to the S1 with no need for additional cables. One less thing to plug in to my stripped down system.
I can also use my Yamaha mixer to add gain if I chose to go that route.

[Methos1979]

Originally Posted by shufflebeat

For those who are interested or those who were scratching their heads about basic laws of physics:

The ART Dual Pre, to my eyes and ears, is the perfect companion to s1 users struggling to get a decent level with a regular dynamic mic. 48db of gain means my Senn e935 clips the red at about 2/3 of the way up the travel.

At that point there is both a mix control blending the signal from the USB computer connection (yes, it's a USB interface as well) with the mic inputs (plural, there's two of them).

And that to the gain available on the s1 preamp and I reckon you could get a signal out of a house brick.

The presets on the s1 seem subjectively more effective and more defined than without the ART.

ART is externally powered via a PSU or power bank or internal 9v battery, 50hrs without 48v phantom power or 20hrs with (yes, it provides phantom power to two mics).

Highly recommended if you need one.

VERY interesting but how do you get the signals from both inputs to a single output? It seems the 1/8" output is the only thing carrying both mic channels out, right? So then you would need a 1/8" to 1/4" adapter to input into a single S1 channel? If that would work that would solve the second 'issue' with the S1 - not enough inputs for two mics and one guitar!

[shufflebeat]

Originally Posted by Methos1979

VERY interesting but how do you get the signals from both inputs to a single output? It seems the 1/8" output is the only thing carrying both mic channels out, right? So then you would need a 1/8" to 1/4" adapter to input into a single S1 channel? If that would work that would solve the second 'issue' with the S1 - not enough inputs for two mics and one guitar!

I hadn't considered that question, I'm happy enough with what it already offers, but now that you mention it - if I remember correctly the 1/8" input on the Bose sums the two channels (L/R) for playback so it will be interesting to see if that works, leaving both mic channels free.

Mics coming from the ART wouldn't be able to take advantage of EQ presets, however.

I'm also aware, as previously mentioned, that some b/t speakers display some latency on stereo channels, even if connected by 1/8" jack. I don't know if this is the case with the s1 but will investigate when time allows.

[leew3]

Originally Posted by Methos1979

VERY interesting but how do you get the signals from both inputs to a single output? It seems the 1/8" output is the only thing carrying both mic channels out, right? So then you would need a 1/8" to 1/4" adapter to input into a single S1 channel? If that would work that would solve the second 'issue' with the S1 - not enough inputs for two mics and one guitar!

it looks like this preamp has 1/4" outputs on the back for each channel that you could use without an adapter for this purpose. These outputs are labeled 'monitor' so I'm not sure what that means for running them as what are functionally mains.

[Methos1979]

Originally Posted by leew3

it looks like this preamp has 1/4" outputs on the back for each channel that you could use without an adapter for this purpose. These outputs are labeled 'monitor' so I'm not sure what that means for running them as what are functionally mains.

Yes, I realize that but this defeats the purpose of this initial thread looking to bump up the mic(s) volume and use the Bose S1's limited inputs. I need one of the S1 inputs for my guitar. So unless there is a way to combine these two mics into a single output, it doesn't get me anything better that what I get with the Shure A85F.

[shufflebeat]

Originally Posted by Methos1979

...it doesn't get me anything better that what I get with the Shure A85F.

Except for this point:

Originally Posted by MarkF_48

...This tends to alter the frequency response...

Which could be a plus-point from your point of view, of course.

I was imagining using only one channel of the DP for one mic input on the Bose. I wasn't really thinking to add channels, although I'm thinking that might be possible.

[shufflebeat]

Originally Posted by leew3

These outputs are labeled 'monitor' so I'm not sure what that means for running them as what are functionally mains.

The type of input the Dual Pre is expecting is pretty much exactly what the s1 pro is.

They are referring to active studio monitors, not stage monitors but these days they're all much the same, line level balanced input.

[leew3]

Originally Posted by Methos1979

Yes, I realize that but this defeats the purpose of this initial thread looking to bump up the mic(s) volume and use the Bose S1's limited inputs. I need one of the S1 inputs for my guitar. So unless there is a way to combine these two mics into a single output, it doesn't get me anything better that what I get with the Shure A85F.

Got it. I've used a Pignose 1/4" to 1/8" TRS cable when I've connected a preamp to the S1 Aux input for my mandolin in the past. I wonder whether that would accomplish your goal here?