SSM2141 or OPA2604

[conleycd]

Hey all,

I have to make some reasonably decent de-balancers (not transformers) and I'm wondering the best route. 

I'm caught between using the AD SSM2141 which is so self contained (less the power supply and some caps) or a standard debalancing scheme using the OPA2604.

The advantages of the SSM2141 is pretty simple self contained high common mode rejection.

I gather the only advantage of the OPA2604 is that it can run on a higher voltage rail and theoretically provide more head room.  The OPA2604 also requires much more around it to make it work.

I could almost use the SSM2141 like a dead bug layout instead of of a PCB board...

Thoughts?

CC

 

[radiance]

Did you consider using the THAT 1240  or the THAT 1200 ?

 

[ppa]

Hey all,

I have to make some reasonably decent de-balancers (not transformers) and I'm wondering the best route. 

I'm caught between using the AD SSM2141 which is so self contained (less the power supply and some caps) or a standard debalancing scheme using the OPA2604.

The advantages of the SSM2141 is pretty simple self contained high common mode rejection.

I gather the only advantage of the OPA2604 is that it can run on a higher voltage rail and theoretically provide more head room.   The OPA2604 also requires much more around it to make it work.

I could almost use the SSM2141 like a dead bug layout instead of of a PCB board...

Thoughts?

CC

you can use the ssm2141 in sbalancer confing. that attenuates the input signal of 2:1 to have 24 dBu on input.

 

[conleycd]

Hmmm....

Looking at the THAT series - the 1240 is about twice the price (when buyer smaller quantities - this all goes away at like 1000 pieces) of the SSM2141 and has slightly worse common mode rejection specs (90db vs. 100db at 60hz).  However, the 1240 can be powered by higher voltage rails - so higher headroom.

The input impedance is slightly different on both too.  The 1240 is about 18k and I think the SSM2141 is 25k.  Both should be ok for most low impedance sources up to about 2k (which I guess isn't super low impedance).

Can anyone comment on the advantage of 10db more common mode rejection?  Is this really that audible?

I'm inclined to think possibly the THAT series for my higher end debalancer I was thinking of making as part of an active summing box.  But... the SSM2141 may be helpful in some live audio situations where super high head room may not be as necessary.

?

CC

 

[kazper]

Buy the 1K quantity and I'll take 20 off you  



Small bear sells the Coolaudio SSM2141 clones, don't know what there quality is...

 

[emrr]

Can anyone comment on the advantage of 10db more common mode rejection?  Is this really that audible?

Do you have problems already?  If you don't, you'll never hear a thing.  If you have really bad troubles, you may hear a difference.  It's a bit esoteric, unless you have a definite problem to solve.    I have a lot of 50-60' unbalanced wire runs in my studio, with no problems whatsoever.  My runs ain't that pretty, either. 

 

[cuelist]

But... the SSM2141 may be helpful in some live audio situations where super high head room may not be as necessary.

???    ???

As an ex live sound engineer I can tell you that headroom is definitely very much necessary in live sound situations.

 

[conleycd]

But... the SSM2141 may be helpful in some live audio situations where super high head room may not be as necessary.

???    ???

As an ex live sound engineer I can tell you that headroom is definitely very much necessary in live sound situations.

Well... yes and no.  Most of the "professional" live sound I see are using DI boxes that were intended for doorbell transformers - not my idea of high headroom.

I'm not not going to put in a massive transformer for a bipolar +/- 50volts to get 30 some odd db compared to an IC that will run on +/- 18v to run a balanced signal from the sound board to be received and then unbalanced for a particular piece of gear.

I might run something with high voltage rails like that in a studio with a piece of gear that I'd make and would be an asset to the studio.

CC