HELP ME CHOOSE BEST SOURCE (SIGNAL TAP) FOR WET/DRY/WET RIG

[Wingnut]

Greetings All,

My question here is aimed primarily at those who use (or have used) stereo effects in a so-called "wet/dry/wet" configuration, but I'll be more than grateful for comments by any and all others too!

I'm strongly considering the development of a wet/dry/wet setup and I could sure use some suggestions or guidance from the experts in choosing the best overall way to tap the signal source used for the wet side of the rig. The tone (or dry) amp that I'll be using already has a Line-Out jack suitable for running the signal over to my stereo FX units (wet side). However, as I understand it, the signal output at that Line-Out jack may not contain or reflect any tonal influence from the power stage of the amp (i.e., its likely to be pre-amp signal only).

Sooooo, given some of the other alternative signal-tapping sources and devices out there, this raises a key question . . . which of the following three possible signal taps is likely to give me the best overall signal quality for the wet side of things:

A. LINE-OUT JACK ON TONE (DRY) AMP: Signal from pre-amp only
B. LINE-OUT JACK ON ATTENUATOR: Signal from both pre-amp and power stages
C. SUHR ISO BOX: Signal from both pre-amp and power stages (like the attenuator), but with added advantage of ground reference and phase switches

Any thoughts on this?

And frankly, another concern that I have relates to the safety of the Suhr ISO Box where the tone amp is concerned. I'm not a trained electrical or sound engineer, but if the Suhr ISO Box connects directly to an output jack on the tone amp per product instructions, then the ISO Box is essentially providing a direct load on the amp's transformer just like an attenuator would, right? Yet it doesn't appear to have any impedance selector or controls on it, which I can't seem to reconcile. Is the ISO Box simply designed with a fixed impedance deemed safe (i.e., at 8- or 16-ohms)? Or what am I missing on this?

 

[paulyc]

No, the Suhr iso box is the best method, short of having a tech install something like it into your amp so you don't have to carry it around and use another speaker cord. It is NOT a dummy load, the cab MUST be connected, all it does is steal some signal...a tech could convert your preamp only line out to power amp line out with the phase switch, volume control and an isolation transformer. I have a box made by a local tech for this purpose to use with my amps that don't have a line out already, and it has 2 paralleled output jacks for feeding stereo effects units. Bray sells one also.

 

[Wingnut]

Paul,

Thanks for your input on the ISO box and thanks also for the clarification on its use (re: speaker loading, etc.).

To my surprise, I've since learned from its builder that the Line-Out jack on the 50w amp that I'll be using is actually wired "post PI" (or after the phase inverter), which as I understand it, will give me the full or complete flavor of the amps tonal capabilities (both pre-amp and power stage), and if so, this effectively negates my need for either an attenuator or an ISO box with that particular head.

However, what you've shared with me here remains very helpful, because I have several other (lesser-powered) heads that I would one day like to explore for wet/dry/wet usage (all without FX loops or Line-Out), so it sounds like an ISO box will definitely be required for those. And as I see it, I'm far better off spending the money for a single ISO box, rather than modifying each and every one of those smaller amps that I potentially might want to use in stereo one day.

Anyway, thanks again.

 

[paulyc]

After the phase inverter is before the poweramp, it's the last 12AX7 before the power stage, so you won't have any power tube crunch (but unless you're cranking the head you wouldn't have any anyway), so unless you buy a Hot Plate or similar to attenuate the volume down to a manageable level AND steal some signal, the power tube crunch ain't happening.

 

[Little B]

As pauly said, a tap after your pi tube is only gonna get the last preamp stage of your signal.Youll miss your power section, in which is where a good bit of the magic comes from.Thats how the whole bradshaw thing in the 80s started..And he was definitely onto something with his rigs he built.Ive had great success with palmer,bradshaw, and hot plates in the past,all with their strengths and weaknesses.But there are so many choices you have nowadays to acomplish what you need- vrs just a few years ago.

 

[Wingnut]

Guys,

Thanks for the added input and I apologize for any confusion or misinformation on my part. Your comments here regarding "post-PI" vs. "post-power" made me look into the amp's documentation a bit closer, and it looks like I might have misunderstood or misquoted the amp builder regarding the Line-Out. It was a bit hard to find, but the official Owners Manual actually states the following regarding the Line Out feature on the amp in question . . .

"LINE OUT: A line level signal jack derived from the speaker output which contains the whole tone of the amplifier".

And so, of the three or more possibilities when it comes to the signal source for these Line-Out jacks (i.e., pre-amp only, post-PI or directly from the speaker output), it looks as though I've inadvertently (or luckily) stumbled into the better of the bunch on this particular amp.

 

[paulyc]

That's what you want, but I'll add a new wrinkle...most times these are not transformer isolated and can under certain circumstances introduce noise or ground loops into your system. Try it and see, but a transformer isolated line out box is the best approach most of the time.

 

[Wingnut]

Yup, I've read a significant number of posts on various forums about such anomalies (phase issues, ground loops and other noise), and I guess you'r right, I'll never really know until I actually have the setup completed and plugged in. I'll be getting to that point soon - I'm just trying to do my homework beforehand to see what additional equipment or devices I'm potentially going to need, and to be frank, I'm trying to avoid the purchase of an ISO box at this early juncture. If I HAVE to do so, then so be it, because as I said earlier, it'll be useful on other lower-powered amps for me anyway, but I'd prefer to postpone for a couple of weeks if possible.

But just to make sure that I'm perfectly clear on the specifications here . . . by definition, is the Suhr ISO box a true and fully "transformer isolated line out box" of the type you've described?

 

[moltenmetalburn]

Post power amp signal is best.

 

[Little B]

Pauly is correct again.All kinds of outerspace ground loop issues and things can occur..I also bet while youre using that line out, youll have to make sure the head is still plugged into a cab..I think thats how it usually works...I havent ran a whole head on a load out device for some time now, but I just aquired a dead mint jcm 800 and I may pull out the ol palmer on it..The pic isnt a "head loaded" line out rig, but ive had awesome success w/ all my preamps into the switchblade(in which you can assign as many dry or wet outs as you want), and then I run a dry into a vht 2150,classic, or mesa 500...sounds fantabulous!!!!!

 

[paulyc]

Jesus I want a Nightswan ! The idea of the shorter scale length really appeals to me, but I'm not a fan of the humbucker in the middle position.

Little B is correct about the Suhr Isobox in that it still has to have a speaker (load) attached.

I'd really like to make a "real" reactive load from a high wattage speaker (like a 300 watt EV) and an L pad volume control with an iso transformer by cutting the paper cone out of the speaker and leaving the voice coil intact, set the amp for whatever the ohm rating of the speaker is, and control the volume from the L pad sending it out to a power amp, those Rockman poweramps and cabs in Little B's avatar would be perfect.

 

[paulyc]

David Bray makes an iso box...I think it's 45 bucks.

 

[Little B]

Hey Pauly! Ive since this pic,got an early first version nightswan(knapp lightning paint)..its out for a complete stock overhaul...as far as the op,isnt there a badcat leash/unleash and torpedo line outs/load box- now too?

 

[Wingnut]

Wow! I just prepared and posted a lengthy reply to Little-B's earlier comment, and it completely vanished into the cosmos - what a drag! I guess I'll have to consider sitting down after dinner and starting over.

However, for now (just to be clear), I never planned on using the tone amp without speakers connected. I'll be connecting a Celestion Gold and Scumback H55-65 to its two 8-ohm (dry) speaker outputs (loaded and wired in stereo in a 2x12 cab), and probably a matched pair of 1x12 EVM-12Ls with a Carvin DCM-150 solid state power amp for the wet side. The 'Line-Out' source for the wet signal however, remains the pressing issue.

This business of phase conflicts, ground loops and other potential noise, as well as the post-power stage source for the signal made available by the ISO box is kinda why I was exploring the potential use of my attenuator. It too has a Line-Out jack with the added advantage of impedance selection for its inputs and outputs, and of course, its being fed directly by the amp's speaker outputs, so I'm assuming its "transformer isolated". But the attenuator (Aracom PRX-150) has the added advantage of offering attenuation of the relatively hefty 50w output of the dry amp for after-hour use, which the ISO box cannot.

Line-Out Amp: Apparently not so good
Line-Out ISO Box: Gravy, apparently the ideal
Line-Out Attenuator: Mmmm, not so sure ? ? ? ?

I guess I'm back to square one again (the always trusty "empirical" approach) which is to stop jawing and speculating and start pluggin' and unpluggin' until I find out the hard way. Doh! Wait a minute, I can't do that - I don't have an ISO box to test. Silly rabbit.

 

[Little B]

I mightve missed it if youve said you tried it, but did you try the line out on your amp to see what its like?...any good?..sometimes they are, more often though therye not... cant remember which mesa amp it was, but i ran its line out straight into my vht 2150 and it sounded like God!..and i recall tryin that with my other mesa's and the tone was funky and not right..So try out some things and see..Just watch that everything has a load on it and nothing's overheating or blowing up..lol...I do like your speaker choice..A bunch of my buddies are tryin to get me to try the new 2 notes torpedo load box/line outs..one is rack,the other in pedal form.. Some other good reads for this kinda stuff is anything from Bob bradshaw, Rjm,Switchblade,and Dave Friedman..all these companies are on the top of thier game w/ the wet/dry/wet stuff..

 

[Wingnut]

Nope, I haven't actually tried it out as yet. The amp itself is relatively new to me, and I've been adjusting to its various nuances, settings and controls in recent weeks, but not yet in stereo or wet/dry/wet. I'm just one of those kind of guys that likes to know ahead-of-time whether I've got things plumbed correctly or not, regardless of how it might sound. That probably sounds rather 'manic', but there's always a right and wrong way to do something, even if it seems (or sounds) right, and I think this is particularly true with electronics and signal chains, so whenever I have the opportunity, I try to inquire of other experts who actually have the experience, before I get started. Call it a 'comfort zone'.

Anyway, thanks for the added references (i.e., Bradshaw, Friedman, etc.). Also, I should probably note that I've looked into the Switchblade (maybe a year or more ago), but it was outta my reach at the time, financially speaking, and frankly, it still is. I dunno, I may just have to break down and buy this silly ISO box. Its certainly sounding that way, but I'll definitely take the time to explore the Line-Out's on both my amp and my attenuator before I go pulling any triggers. Ten years ago, a hundred and eighty bucks was nothin' - but not so today, at least not for me.

By the way, I couldn't help but notice from your earlier photo, but I've got two of the very same sorta (16- and 24-space) Mesa road-ready rack units sitting right here in my own home studio that that you've pictured there - bought 'em both new back in '91 along with my EVM-12Ls. They contain some of what appears to be the very same gear too (e.g., Furman line conditioner, TC-2290 delay, etc.). Too funny! I must be doing 'something' right, eh? Anyway, thanks again for your contributions here.

Cheers.

 

[Little B]

I have a 12 and 20 spc in that pic.. .I will be looking for a 16 and 8 spc mesa in the future..I posted that pic so you could see the switchblade in there, but i see you already have heard of it..Im trying to finish that rig but still need to pickup a cae3+,jmp1, and the new diezel preamp,plus an eventide 7600 or axe fx(for fx) and a marshall 100/100 el34 poweramp..Its turning a session/studio rig but I have gigged with it exstensively before- in a wet/dry/wet 3- 4x12 cab layout..Got lots of tone compliments on it..I may take it out on the road again if I get called back out for another east coast side Highschool assembly band tour.All depends on SAAD/MADD funding...and I realize my rig doesnt depend on any amp heads,but I have done the whole "load box/line outs" in the past..Yes, research first-always a good thing.

 

[Wingnut]

Yeah, the Switchblade looks to be 'killer' (extremely versatile), but after strongly considering it a year or more ago, I decided it was just more power or authority than I really needed (i.e., overkill for a small, home studio, amateur application). I'd love to own one, so please don't get me wrong on that score, but its just too much bang for too much buck).

I'm hoping to get the time to evaluate the Line-Out on my amp this weekend (I'd hoped to do so last weekend, but I completely forgot that it was Superbowl Sunday), and if there are issues with that Line Out, I'll try the Line-Out on my attenuator. And if neither seems to do the job, I'll pop for an ISO box. One or the other is going to provide the best solution, so I think my central question has been answered and I've reached the proverbial end of the road.

Thanks again to you and the others for your assistance.

 

[paulyc]

I don't see Nightswans come up for sale very often...where are you finding them ? Ebay ?

 

[Little B]

Pauly,ya, the usual,evilbay,GC used, CL, etc..ive gone thru 4 of em.Im on the hunt now for the rare nightswan II...theyres a few floatin around out there.I bought a regular nightswan when they first came out and i shoulda kept it..I sold it to the other guitar player in the band I was in at the time ( a christian heavy metal band), and he gave it away to a kid at a show believe it or not!..We were trying to be the christian version of racer x at the time...ill say tryin..it was fun and a blast for sure though.the kids back then just ate that stuff up..I'll post my knapp lightning when i get it back from restoration.I think it'll be a keeper..the paint on those knapps were real deep purples,more realistic lightning,etc.And I swear the necks on those are a bit chunkier than late model swans...more of a realistic les paul feel.. my luthier told me about one month till hes done with it...and I agree w/ you- the middle pickup isnt that real world useful..I do have a push/push pot that splits both pickups and the middle sounds a lot cooler that way.