SVP Pro to power amp questions

[colinmk]

Hi all, just looking for a bit of advice on my new set-up.

I have an svp pro going to a behringer ep2500 power amp.
This is feeding a 500w rms 1000w peak ampeg 410 he.

I am looking to get the best possible sound from the rig at pretty high levels and the way I have tried so far is putting the power amp into bridged mono which gives me 1300watts at 8ohms going to the ampeg. I realise this is too much but I have never been putting the power amp gain past half way. This seems to give a fairly conservative overall volume though so does anyone think it would be better to just use one side of the power amp which would be 450w.

Also I can't find out if the svp pro is unbalanced outputs? I know there is a DI out witha balanced xlr but this gives me no sound when I connect it to the power amp so I have just been connecting with an unbalanced cable from the preamp output to the power amp. Any help would be appreciated.

[steve-soar]

Hi Col I use to own an SVP Pro and I still own a SVT IIP. I run the SVP Pro like this, unbalanced out from the phono outs, into the left hand side of the power amp (bridged into 4 ohms), then out into a 4 ohm cab.
Sounded great, what ohmage is your cab?
You should be getting a signal by using the DI out, the switch next to it gives either eq or no eq.
Here is a link to the manual.
[url="http://ampeg.com/pdf/SVP-PRO.pdf"]http://ampeg.com/pdf/SVP-PRO.pdf[/url]
Get in touch if you need any more help.
Steve.

[colinmk]

[quote name='steve-soar' post='354472' date='Dec 14 2008, 07:11 PM']Hi Col I use to own an SVP Pro and I still own a SVT IIP. I run the SVP Pro like this, unbalanced out from the phono outs, into the left hand side of the power amp (bridged into 4 ohms), then out into a 4 ohm cab.
Sounded great, what ohmage is your cab?
You should be getting a signal by using the DI out, the switch next to it gives either eq or no eq.
Here is a link to the manual.
[url="http://ampeg.com/pdf/SVP-PRO.pdf"]http://ampeg.com/pdf/SVP-PRO.pdf[/url]
Get in touch if you need any more help.
Steve.[/quote]

Cheers Steve, it's 8ohms. I'm going to try running it unbalanced into the power amp bridged and see what happens. It was distorting before at low levels but I might have set the power amp wrong. Off down now to try it out. Do you set the master on the SVP to maximum and then adjust the gain accordingly?

[ahpook]

i used to have exactly the same set-up and i always ran the power amp in bridged mono mode, using unbalanced cables from the ampeg to the behringer.

does the di produce any sound at all ? i just tried the DI out into my power amp and it was quiet, but there was a signal.

[colinmk]

[quote name='ahpook' post='354491' date='Dec 14 2008, 07:38 PM']i used to have exactly the same set-up and i always ran the power amp in bridged mono mode, using unbalanced cables from the ampeg to the behringer.

does the di produce any sound at all ? i just tried the DI out into my power amp and it was quiet, but there was a signal.[/quote]

Just tried it again, sounds like the valves might have gone, it's very crackly making some bad distorted noises and the like. Do you remember what sort of settings you had at all? I had the master turned up full and adjusted the gain on the svp accordingly, kept the ep2500 on about half gain and it wasn't sounding good. When I added more bass on the svp EQ I can hear slight crackly distortion. I'm going to try and test it the cabinet to make sure that's fine from another pre and then take it from there. I have another power amp I can try too.

[ahpook]

deffo try the switcheroo with the different power amp....certainly sounds like something's amiss.


settings-wise, i set the gain to taste, drive at zero, master vol on the ampeg at full and adjust the power amp to give the output volume i need. other than that i only ever use the ultra-low switch, everything else is set flat.

hope this helps

[Finbar]

I have the gain on about 9 o clock (it always clips), the drive on full and the master on about 12 o clock. I have to say I don't have any of the problems you mention, but the gain knob is VERY sensitive, and will change the nice musical clipping into horrid distortion at the slightest movement of the gain knob. Try laying off the gain knob a bit?

[colinmk]

Tried a different pre going to the power amp today and it sounded a lot cleaner, could get higher levels overall without clipping the power amp. I'm thinking there is a problem with the valves. When I adjust the drive about 2 oclock it gives me disgusting distortion then smooths out the more I add?! Seems to be distorting at random times too. does this sound like dodgy valves to anyone? Thanks.

[colinmk]

Using a crown ce1000a I got off ebay and it's sounding beastly now. Dunno what the problem with the ep2500 was but I've sold it now and it seems to be working OK for the buyer. Maybe it doesn't like unbalanced inputs? Just managed to get hold of four harma's and Jan 5814a too and going to put them in tomorrow to complete the set-up.

Interestingly the crown's input sensitivity is 1.4v and I'm not getting any issues with it however I have the option to change it to 0.775v if I mod it myself. According to my voltmeter the ampeg's pre out is around 0.7v so I'm thinking I might go ahead and do this for the sake of matching up the voltages. Don't want to break it now it's finally working though! Sounds fantastic at the moment too, really cutting through like I wanted and capable of gritty BRMCish tones like I wanted and a good amount of balls in the low end department too even though it's just a 4x10. My Rivoli's loving it.

[colinmk]

[quote name='colinmk' post='449008' date='Mar 29 2009, 09:59 PM']Using a crown ce1000a I got off ebay and it's sounding beastly now. Dunno what the problem with the ep2500 was but I've sold it now and it seems to be working OK for the buyer. Maybe it doesn't like unbalanced inputs? Just managed to get hold of four harma's and Jan 5814a too and going to put them in tomorrow to complete the set-up.

Interestingly the crown's input sensitivity is 1.4v and I'm not getting any issues with it however I have the option to change it to 0.775v if I mod it myself. According to my voltmeter the ampeg's pre out is around 0.7v so I'm thinking I might go ahead and do this for the sake of matching up the voltages. Don't want to break it now it's finally working though! Sounds fantastic at the moment too, really cutting through like I wanted and capable of gritty BRMCish tones like I wanted and a good amount of balls in the low end department too even though it's just a 4x10. My Rivoli's loving it.[/quote]

First jam with the new valves and interestingly I have to turn the gain much further up to get a good level now and it the pre doesn't start clipping until it's pushed very hard now. Not sure if I prefer these valves or not yet. The tone I got from the older ones seemed to be more gritty which maybe suits me better. Going to test it out a bit on my own tomorrow and see which are better.

[colinmk]

Not sure if anyone is interested or not but I have swapped my crown pa for a crest CA9 and my set-up is now complete. The tone I'm getting is better than I hoped for, the valves in the preamp are sounding lovely when overdriven and this crest is fantastic, such a difference from the crown. The sound is just so solid now even at low volumes it cut's through and you can still feel it. Only one gripe with the crest is that it is quite noisy but it's a small price to pay tbh. I am now putting less wattage into my cab too, had the crown going at 1100w bridged and now the crest is 600w single side and it is much, much louder. This would support the argument that the difference in input sensitivity makes a big difference with this preamp as the crest is 0.775 compared to the 1.4v crown. The crest cost me £400 but I'm delighted I spent the extra cash on it.

[Dood]

Good to 'hear' a great result!! Nice one! Now, can you turn it down, I have cracks in my walls from all that bass thunder!!!