Ampeg SVT-VR bridging channel 1and channel 2 impact

jose.romo.macie · #1 12-29-2010, 03:01 PM

I’m recently acquire a Ampeg SVT-VR, my first all tube amp. I remember a I a video about bridging channel one bright into channel two normal input. I test in in my amp and it makes a considerable improvement in the tone. But I can’t avoid thinking that it’s not the normal operation that the amp was designed for. There should be a lot of comments about this in TB but I could’t find anything.

Bridging channel one and Channel two has a negative impact in the amp?

This is the video I was talking about:
http://www.youtube.com/watch?v=L8bkCn14b6Q

coreyfyfe · #2 12-29-2010, 03:03 PM

Quote:

Originally Posted by jose.romo.macie

Bridging channel one and Channel two has a negative impact in the amp?

Shouldn't have any negative impact.

JimmyM · #3 12-29-2010, 03:19 PM

it's fine. might blow a preamp tube a little sooner than usual if you go for grindy hot preamp distortion. big deal. folks have been bridging two channel tube amps for decades. that's the whole reason amp companies started making amps with separate gain and master volumes.

jose.romo.macie · #4 12-29-2010, 06:11 PM

Thanks for your answers. I'll keep brinding my amp

rodl2005 · #5 12-29-2010, 06:25 PM

Interested!!! I'm using a VR > 8x10 at a Festval gig tonite. I own an old '92 SVTII- which I LOVE, but am pleased to be able to give a SVT-VR a WHOLE 3 set gig tonite.

Anyone got any hints for me(I've only used a VR once B4 & for only a one set gig- & thus NO time to 'play' with settings. It DID still sound great with everything at 12 o'clock)

Was thinking re patching Ch.1 & Ch.2 together for a bit of grind... thoughts...??

theory028 · #6 12-29-2010, 06:56 PM

I bridge the two channels on my VR but I'm not getting much grit or grind in the tone at all. Is there some secret to it that I'm not familiar with?

The video that you mentioned is one of the things that got me to consider the VR over the CL. Even though I'm not much of a Precision guy, and I'm certainly not one to use a pick very frequently. his tone is pretty darn cool.

JimmyM · #7 12-29-2010, 07:07 PM

i can't remember which one gets what, but you're supposed to crank the volume of one channel and use the other to control the volume.

Tim1 · #8 12-29-2010, 07:51 PM

I have recently taken to bridging the two channels on my VR recently and while I am not sure that it adds "grit or grind" it does seem to thicken the tone somewhat, so I will continue with it. Having owned an SVT2nonpro for a few years previously, it is the ability to break up earlier that I miss from the 2nonpro. On the 2nonpro IIRC it would start breaking up a bit and give what I always think of as tube compression at around ten o'clock, I don't think I have managed to get my VR near that stage as it is clean almost all the way round. The speakers fart before it gets anywhere close.
I may try using my VT pedal as an experiment, although it seems rather redundant to use a VT pedal to emulate an SVT into an SVT, but it may give me that early breakup. Don't get me wrong, I love my VR but still like to experiment.
Jimmy, I am not sure what you mean by cranking the volume of one channel and using the other to control volume - I think the second input on each channel is in parallel with its twin but padded down, so changing the volume on one will not affect the other. I would love to be wrong here, maybe there is a trick I have not tried yet....

BillyB_from_LZ · #9 12-29-2010, 09:50 PM

Linking the channels like that with a short instrument cables only connects the inputs in parallel... It doesn't allow you to run the output of one channel into the input of the other. You'd need a preamp like an Alembic F2B (or whatever it's called) to do that.

Linking them simply gives you two sets of differently voiced EQ sections to play with... With a more simple amp (like a Marshall plexi style amp, HiWatt, Bugera 1960, etc.) with a Bright and a Normal channel, you can have the normal channel do most of the work and add a bit of sizzle with the bright channel.

JimmyM · #10 12-30-2010, 06:59 PM

apologies...just had a little time to check it out in my svt, and you guys are right...i couldn't get any pre distortion for love or money. so what am i missing here? i totally thought the reason people jumped channels was to get pre tube distortion. was it just a hallucination of my yet-to-be-clouded 15 year old mind?

rodl2005 · #11 01-02-2011, 11:10 PM

After reading this thread & chatting to a couple of VR owners, I decided NOT to bridge the SVT-VR I used at the Festival we played at on NYE.
My thoughts just quickly:- was a MIV SVT-VR > SLM SVT810E AV (to match the VR I s'pose). I used my Fender PJ with flats & Alleva-Copollo EUT5 with rounds.
The SVT-VR- GREAT!!! The SLM 8x10" - not so great.
Perhaps I've been spoiled with the Bergantino's NV610 & NV215 (as far as sealed 'big' -ish cabs go) because I ended up using the 'ultra-high' switch on the amp. The cab seemed to have a big thick blanket over it blocking out it's 'clarity' !! & I am not a fan of tweeters in bass cabs.
I mean, it sounded good, big, & chunky, but compared to the NV610(Which is a 6x10"s, tweeter-less, sealed cab) it lacked a lot of clarity- to my ol' ears anyway.
I am definately not complaining, it sounded good, we had a great gig etc etc... but-for ME - gimme a Berg NV610/215/412 ANY day.
Amp was great tho. IMO - very similar to my '92 SVTII. Maybe- like Tim1 says- it stays cleaner, but I had a ball with it, & definately wouldn't mind lugging one about. BUT- my non-pro II will do me nicely!

JimmyM · #12 01-02-2011, 11:25 PM

rod, sounds like you got stuck with one of those slm osb mudbombs i complain about all the time. definitely not the era of ampeg to speak for ampeg cabs. great heads back then, but the cabs...pfft. loud cabs are much better. still have not played the berg cabs to compare, but i'm a lot happier with the way the newer cabs sound.

rodl2005 · #13 01-02-2011, 11:51 PM

Quote:

Originally Posted by JimmyM

rod, sounds like you got stuck with one of those slm osb mudbombs i complain about all the time. definitely not the era of ampeg to speak for ampeg cabs. great heads back then, but the cabs...pfft. loud cabs are much better. still have not played the berg cabs to compare, but i'm a lot happier with the way the newer cabs sound.

Thats exactly what I was thinking during the 1st set

. I was remembering you're descriptions of the late SLM 8x10's.

Then in the break I had a look see, & it WAS a SLM SVT810AV so I s'pose about an '06 model. Glad to hear the newer one's have the 'blanket' removed

Have a great '11 Jimmy

MAMMOTHvolume · #14 01-03-2011, 04:13 AM

Quote:

Originally Posted by JimmyM

apologies...just had a little time to check it out in my svt, and you guys are right...i couldn't get any pre distortion for love or money. so what am i missing here? i totally thought the reason people jumped channels was to get pre tube distortion. was it just a hallucination of my yet-to-be-clouded 15 year old mind?

more gain / lower noise are the gains of paralleling channels

blastjv · #15 01-03-2011, 11:50 AM

I jumper the channels on my VR. I play loud and get plenty of OD out of it. I'd break it down like this:

- Jumpering might let you stay a little cleaner since you are sharing duties with the two channels. For example - when you play only channel one at a certain volume you get a certain amount of overdrive because the preamp and poweramp volume are increased simultaneously as the volume knob is turned up. If you are jumpering the two channels, when you are at the same volume level (actual sound) each volume knob will be in a lower position than the one channel was to acheive the same level of volume. The Power amp will presumably be working at about the same amount of effort, but the preamps will each be working at a little lower gain.

Does that make sense?

That part of it is theoretical for me, because I didn't use jumpering to acheive any particular overdrive goals, just to give me more tonal options, and also to make sure that every tube available in that amp was in my signal path (why have tubes just sitting in there on channel 2 that never provide any benefit?). That might be silly reasoning, but it seemed to make sense at the time... I can't say if the amp sounds 'tubier' jumpered than single, but it does seem a bit bigger sounding, and like I said, it gives you more knobs and switches to mess with.

My typical way of setting this up is to get the 'best' sound I can out of each channel, and then jumper them and experiment with how much of each channel provides the best bland of the two. I have read of people using one channel to control the high end and the other to control the low end/mids, etc, but that didn't work as well for me.

Just some thoughts..... Do any of them make sense?

-JV

Tim1 · #16 01-03-2011, 11:58 AM

My experience exactly, Blast. Combining the two channels gives a thicker/fatter/tubier sound. If you've got 'em use them, the more tubes the better

blastjv · #17 01-03-2011, 12:04 PM

Great, so I'm not crazy...or maybe we're both crazy...

Oh, I should have mentioned - I go Bass input to Normal Ch 1 and then jumper between Bright 1 and Normal 2 (input lower left, jumper upper left and lower right). It does make a difference which you use as an input and which you jumper. This is the way that sounded best (fullest) to me. Other configurations sounded thin. I think the 'Bright' channel filters out lows more than it enhances highs, so that might be why...

-JV

blastjv · #18 01-03-2011, 12:26 PM

I tried diming both volumes with them jumpered, once...Scared the HELL out of me!!!!! It was LOUD!!!!! Only played about 2 notes, very lightly before I got scared of destroying something and turned way down.

FWIW, I play in a LOUD band and have the volumes on about 12:00 for Channel 1 and about 10:00 for channel 2. I do have pedals in front, but they are set to approximate unity gain, and don't boost anything.

-JV

-JV

blastjv · #19 01-03-2011, 12:32 PM

Oh, and what I've been experimenting with lately is using the 2 channels to 'create' different EQ points. By that I mean, for example, hitting the ultra high switch on one channel and then cutting treble, rather than leaving the ultra high off and boosting treble. It just allows you to come at the EQ from different angles and find new tones.

-JV

brothernewt · #20 01-03-2011, 12:51 PM

I did the jumper thing for fun... never got a chance to use it in real life gigging situation though. Bass into ch1 normal, out from ch1 bright to VT pedal, back into ch2 normal... lot's of fun ways to eq a bright OD tone and not lose lows or a good midrangey OD sound blended with a cleaner full sound.