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SVP-Pro into a SVT-4 Pro through the XLR jack

neckdive

neckdive

Oct 11, 2013
971
2,342
#1
I have recently acquired an SVT-4 Pro and a SVP-Pro. They both have great tone together and of course the 4 sounds clean and quiet by itself. Unfortunately, the SVP has the noise problem typical with some of these units (mid 90's blackface). I will eventually get around to trying different tubes sets but I want to try a different hookup first.

I currently run out of the SVP from the 1/4 inch preamp out and into the 1/4 inch power amp on the SVT-4. I would like to trying going out of the balanced out jack. (The SVP-Pro manual says I can also go from the XLR to an external power amp.)

Do I simply need a XLR to 1/4 inch cable to go from the XLR in the SVP-Pro into the 1/4 inch power amp input on the SVT-4? Are there short- or long-term issues with this setup?

This is probably a simple answer but I would just like confirmation from folks more experienced than me that this setup was ok and that neither or both are going to blow up immediately or otherwise cause expensive damage.

Thanks in advance.
 
#2
I don't think it will cause damage but still I wouldn't use the XLR output of SVP-Pro, because it bypasses the Master Volume pot which is the 5th tube and that gives additional tone coloring to the whole unit. I also have SVP-Pro and use the 1/4 output and use Master Volume past 12 o'clock to fatten up the sound a little bit more.
 
#3
No problem with a XLR to1/4 inch.
I also own a "black-face" svp-pro from 1995 (first serie). Which is humming permanently through the speakers.
I already changed the tubes. I can only imagine an design error in the circuit. I read a lot of comments - the problem is well known.
The 5 Tubes are more or less arrange in series. Probably the heating with DC instaed of AC could make a difference, but I haven't tried this.
I took away the earthing. Removed the lid. And used an ground loop isolator and also used the XLR but it only sounds good through the pre-amp out.
 
#4
capcom said:
I don't think it will cause damage but still I wouldn't use the XLR output of SVP-Pro, because it bypasses the Master Volume pot which is the 5th tube and that gives additional tone coloring to the whole unit. I also have SVP-Pro and use the 1/4 output and use Master Volume past 12 o'clock to fatten up the sound a little bit more.
Click to expand...

My particular unit was previously modified with a Jensen JE-MB-C transformer on the DI output. It is supposed to increase the output level of the DI, increase the bass response and lower the distortion. So I wanted to try it out through my amp since I don't have access to a PA. I expect the tone to be different but I am curious about the possibility nevertheless.

FenderOli said:
I took away the earthing. Removed the lid. And used an ground loop isolator and also used the XLR but it only sounds good through the pre-amp out.
Click to expand...

Which ground loop isolator did you use and was it effective at reducing the noise? I have read good things about the Behringer HD400 but I am always interested in people's experiences with other solutions. I have read about removing the lid but I can play with or without the lid and I don't notice a difference. What is "take away the earthing?"
 
#5
It was a cheap ground lift isolator called: Monacor FGA-35. It sounded dull and the noise was still there - I haven't got an solution. I removed the ground(earth) - it helps a bit - but its dangerous.
Now I play an second 12AU7 in V5 and the humm/hiss is better - but I its not as loud as before. I need the master-knob. The lid itself ratles when not screwed, but I don't notice any difference too.
I also tried shielded-powercord and pre-amp out cables.
I also read threads the past ten years - I still haven't got a clue.
 
#6
I had a gig tonight and wanted to run the SVP/SVT-4 combo for the first time but only if it was going to be quiet. So I decided to run it out of the Effects Send into the SVT-4 and darned if it didn't quiet it down by about 95%. The only drawback of course was that I was running only 4 tubes in the preamp and the Master was non-finctioning so the Gain on the SVP became my only volume control (besides the bass itself). Nevertheless it sounded fantastic through an Ampeg SVT 410 HLF.

Yes, it's a workaround but it gives me hope that if I can find a nice quiet tube for V5, I'm home free.
 

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