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Ampeg SVT3 Pro PREAMP OUT Balanced or Unbalanced? NEED A DEFINITETIVE ANSWER QUICK!!!
- Thread starter BassYerFaceoff
- Start date
Lol. Ok best of luck I guess. I love these HELP ME WITH MY PROBLEM BUT I WON'T LISTEN TO ANYONE threads.
okcrum
in your chest
It will be unbalanced, due to the TS preamp out connection, presuming the cable is wired correctly. You need to get 2.8v out of the preamp out jack to drive the Crown to max power, not the 1.4v it would need if the preamp output were balanced.
The adapter cable should be wired like this:
People are trying to help you here. Don't be a Richard.
I'm not trying to be a "Richard"...But look at the aforementioned response. It's like the post wasn't read or someone was trolling.
Nevermind. Thanks for the help... Seriously...and Happy Holidays.
Not trolling, I read the post. The answer is your output is unbalanced. You can use a mixer in between. Maybe if you helped us understand why it's important to run through the crown we could help, as in, what actual problem are you trying to solve by doing this. Maybe there's an easier way.
Instead you took great offence at the attempts to help you. See ya.
Because the Crown pushes more Wattage than the Ampeg? (1400w @ 4ohms bridged rather that Ampeg at 450w @ 4ohms)
Running my cab AND FOH...
I'll figure this out...
The 3 PRO is notorious for sounding quieter than it ought to. You have to max the master volume and slide that fader next to the EQ controls all the way up, then use gain to control your overall volume level.
Unless you are running with way not enough cabinet, that thing should be plenty for any situation where you have FOH support. And it is much less likely to blow stuff up than running 1400 watts of funk into whatever cab is on the other end.
The Rane Sound System Interconnection Guide recommends the following
The cable shield is connected on one end to pin 1 of the XLR, and not connected (NC) on the other end.
See diagram 13 on this webpage: [Invalid or Expired Link Removed] Diagram 13 shows the shield much more effectively.
IMHO a better solution is to use an isolation transformer like an Ebtech Hum Elimator XLR
[Invalid or Expired Link Removed]
The Hum Eliminator XLR will handle 1/4" TR or TRS plugs, or XLR plugs. It's nice little problem solver.
Rane agrees that an isolation transformer is better than an adapter...see the section titled "The Next Best Right Way to Do It" [Invalid or Expired Link Removed]
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okcrum
in your chest
That'll work if you have shielded pair cable. Most of the adapter cables you'll find at the local GC don't. Either way will work; we're only talking a 3-4 ft. run with everything powered from the same circuit. The diagram I posted was from Radial, but it's really common to see in the wild.
EDIT: If we were talking long cable runs, then the Rane method or transformer would be better.
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okcrum
in your chest
To be fair to the OP, who's new to this, a quick search of the net shows there's a helluva lot of confusion as to whether this cable config is balanced or unbalanced. 
To be fair to the OP, who's new to this, a quick search of the net shows there's a helluva lot of confusion as to whether this cable config is balanced or unbalanced.
The preamp output is 1/4 TR unbalanced. The power amp input is XLR balanced.
The adapter you suggested is very clearly unbalanced because you ground one side of the input...I.E. pins 1 and 3 are linked, so the input becomes unbalanced, since pin 1 is ground.
The version I suggested is a little less unbalanced...I believe you may get some "pseudobalancing" along the length of the cable that improves noise rejection. I believe this occurs because the cable has impedance along it's length. It's a bit above my level of understand and probably varies somewhat with circuit design, so I can't say for sure.
okcrum
in your chest
Ultimately, if you ground one side of a balanced input, it becomes unbalanced. A few ohms' more wire to ground won't change that much, nor will it restore the common mode noise rejection of a balanced line. The biggest advantage of the Rane connection over the Radial connection is that it avoids ground loops on long runs. In essence, it's a ground lifter cable.
Pretty sure over a long cable run that there will be enhanced noise rejection with the Rane connection beyond what is gained by the ground lift.
See this article. Invalid Link Removed
FYI...The link opens to page 2 of the article which is the relevant part.
I believe these are equivalent circuits to our two adapters and a 30dB difference in rejection is claimed. The only difference is the shield is connected on both ends so there is no ground lift as suggested by Rane.
- Feb 12, 2006
- 60,984
- 5
- 220,760
- Disclosures
- Development Engineer-Mesa Boogie, Development Engineer-Genzler (pedals), Product Support-Genz Benz
I predict damages speakers in your future unless you are very careful. An "accident" will destroy your speakers very quickly at that power level.
According to their website, the cabinet is 800 watts RMS, and is available in both a 4 and 8 ohm
version. Do you know which version you have? This may be more important than your preamp being balanced or unbalanced.
According to their website, the cabinet is 800 watts RMS, and is available in both a 4 and 8 ohm
version. Do you know which version you have? This may be more important than your preamp being balanced or unbalanced.
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- Apr 15, 2009
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- Sales and electronic tech/piano tech: England Music Center - Clinton IA - now closed
I used to run the DI output of my SVT 3 Pro into the input of a Carver PM 1.5 (XLR to XLR) and it worked fantastic until the power transformer in the 3 pro smoked (something they were known for doing) during a gig.
Watch how hard you push the speakers in your cabinet or you'll smoke them.
Do you know if you have a 4 or 8 ohm cabinet? That'll help us all out.
Watch how hard you push the speakers in your cabinet or you'll smoke them.
Do you know if you have a 4 or 8 ohm cabinet? That'll help us all out.
From Ampeg’s website:
For amplifier support or any questions concerning owner’s manuals or schematics please open a ticket here or call 818-575-3600 option 2
For amplifier support or any questions concerning owner’s manuals or schematics please open a ticket here or call 818-575-3600 option 2
This whole thing seems like a (risky) solution in search of a problem.
OP - One way to do this would be to use the DI out of your SVT3-Pro into the crown. Speaker out of the crown to input of a Palmer PDI. Out of Palmer PDI to input of your cabinet. The palmer then sends a line to your FOH. This way you'd have the balanced input for the crown with a different signal going to FOH. I do this currently with an Ampeg PF-50T, and have done it also with a V4B and an SVT. The palmer is not cheap, but sounds ridiculously awesome with a speaker connected after it. Might not be viable for your upcoming gig, but you could do it for the next one.
Good luck.
Good luck.
