FX loops coming to Metro.

[Faquinay]

Thank you very much, that answered all my questions. I'll probably knock the voltage down a bit more, next time I'm in there.

The Loop was installed in a JTM50 home build and it wasn't difficult to adapt the instructions to my needs. I will say, however, that a layout or abstract diagram would have been a welcome addition. Just an overview to say that the circuit connects here, here and here, kinda thing. The highly detailed instructions, while luxurious, were a bit like following a trail with a magnifying glass - till I'd read them through to the end. : ) Forget the quibbling, of course I'm very pleased and hope many more customers will be too.

[SDM]

I will say, however, that a layout or abstract diagram would have been a welcome addition. Just an overview to say that the circuit connects here, here and here, kinda thing.

I did do a full layout, specific to just adding the loop, that can be found in the new 100 watt MV kit instructions. Would be a good idea to also do that for the 45 and 50 watt kit layouts in the meantime, or maybe even that just instead of separate instructions as most of the install is exactly the same. Need to draw up a new 45 layout, better matched to the kit, but think I will do that to assist those installing the loops in those amps.

So a very good suggestion there. I didn't draw the kit instruction layouts for the 45, 50 watt, or '69 100 watt kits, just the MV 100 watter, so never crossed my mind to do the same type of full loop specific layout for those amps before.

[xlb3x]

Just put mine in a 12000 series build. The instructions are idiot proof. I did it in about an hour and a half after a thorough setup(tools and stuff). The thing works great and adds no coloration. Thanks guys.

[Faquinay]

I just picked up a Lexicon MPX G2 which, as you may know, connects to both the pre and the FX Loop. Trouble is I'm getting quite a bit of noise floor (hiss) I guess this is the problem discussed above re: the impedance needs of the FX Loop. Is there any way I can reduce or eliminate the noise?

[chameleon]

I have noticed the same "hiss" problem on my kit. Is it any way to convert this loop to +4dBu?

[SDM]

First off , to Faquinay , I had downloaded the manual of your unit to see what settings could possibly help or fix the issue, but manual is not so clear on what you can actually set send and returns to (not so clear a copy to read either lol). Did seem overall meant for line level signals concerning the loop though, but would really need to have a unit in hand to even try to help there. So, it may well just be meant for line level (guitar input aside), not an impedance thing, just a signal level thing, and unfortunately not much you can do about it with the unit's settings. Hopefully someone familiar with your unit will chime in and there actually is an easy solution within its settings.

To both Faquinay and Chameleon, there is no official support for converting the loop to +dBu as we decided to keep them strictly pedal level. Future versions may well have a +4dBu option -IF enough guys really need/want that option. If that happens, people could simply specify line or pedal level when ordering the loop kit.

I know that doesn't help you two right now, so please feel free to send me a PM. Will see what I can figure out, can be done to get your setups working best with your particular equipment.

[erigm]

Future versions may well have a +4dBu option -IF enough guys really need/want that option. If that happens, people could simply specify line or pedal level when ordering the loop kit.

I need/want this option in future fx loop kits!!! How about making the option switchable?

[novosibir]

How about making the option switchable?

I've been expecting this question from anyone

I'm not Steve, but I think, that this requires another, bigger PCB for some more components.
This and the additional switch makes it more expensive and more difficult for unexperienced people, to put it in an amp by themselves - and therefore presumably this wasn't Steve's intention.

Larry

[SDM]

Larry is spot on with above. Really just want to keep the whole thing as simple to install and to use as possible. Minimal amount of work needed for installing it circuit wise, in drilling the chassis for holes, and in final setup/testing. Keeping board size small is indeed another key aspect here too. Even seemingly simple provisions for another switch mean more PCB real estate. A larger board may not be an issue in a large 100 watt chassis, but in a small 50 watt chassis with say a LarMar PPIMV added on the back, every bit of space is precious.

So possible idea, for now at least, is just simply your choice of one level or the other. Not talked to George about this in a while, but will discuss it soon as a decision on this would/will effect the next run of boards that are soon going to be needed.

Any way I know George is extremely busy right now, myself as well. Everyone is welcome to add their two cents on a possible line level option of course, but would much appreciate people doing so here in the thread rather than emailing George or myself on this particular matter. Thanks.

[erigm]

Thanks Larry and Steve for the explanations. Is it a problem of swapping resistor values, or do other components need to change as well? If it was just different resistors I'd be happy with just having instructions on which resistors to switch to what value, and include those values in the kit as well (or not), and then let the end user swap them to change it to line level. Just having the instructions is most important to me. I would guess that a lot of people like to build, but don't have the knowledge/will to design and engineer. I think most modders/hobbiests would have no problem just swapping a few resistors on the board. Just a thought.

[SDM]

I think most modders/hobbiests would have no problem just swapping a few resistors on the board.

Yeah should be easy, but if it anything has even the slightest, most remote, practically inconceivable probability of something being done incorrectly, pretty much guaranteed someone will figure out a way to do it . Seriously though, you guys have really done great with the loops so far. Way less tech support needed than I thought would be (practically none, you guys are smart ). So your suggestion erigm will be taken under consideration.

Main problem there though is that the loops are pretested and adjusted. Boards still missing a few bits or have bits that will be changed, that won't be easily done.

[erigm]

I think most modders/hobbiests would have no problem just swapping a few resistors on the board.

Yeah should be easy, but if it anything has even the slightest, most remote, practically inconceivable probability of something being done incorrectly, pretty much guaranteed someone will figure out a way to do it . Seriously though, you guys have really done great with the loops so far. Way less tech support needed than I thought would be (practically none, you guys are smart ). So your suggestion erigm will be taken under consideration.

Main problem there though is that the loops are pretested and adjusted. Boards still missing a few bits or have bits that will be changed, that won't be easily done.

Totally understand. Maybe just have to send out the boards tested and approved as instrument level, and then provide instructions on how to change to line level, with a disclaimer that you assume no responsibility, and then the warranty is null and void.

Or log in a some kind of "guest" and give the line level mod instructions, then you can assume no responsibility. That may cut down on your tech support.

[vh junkie]

One more vote here for a line level loop! Be it dedicated or switchable...

[chameleon]

Hi SDM, I've sent you a PM. Let me know if I can help you anyway, I have long experience in circuit simulation and electronics design. Don't know if there's a public SCH of this loop (haven't really looked for it as I would understand if you want to keep it secret so I'm not asking for it), but I think it won't be too much difficult to mod it to work on higher signal levels if the circuit/components have enough headroom.

[erigm]

Hi SDM, I've sent you a PM. Let me know if I can help you anyway, I have long experience in circuit simulation and electronics design. Don't know if there's a public SCH of this loop (haven't really looked for it as I would understand if you want to keep it secret so I'm not asking for it), but I think it won't be too much difficult to mod it to work on higher signal levels if the circuit/components have enough headroom.

I think headroom was the name of the game with this loop. Most loop only allowing about a 30v swing, where this one can handle more than 100v. Correct me if I'm wrong Steve.