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Gear / Technical Help => Battery Boxes, Preamps, Mixers, ADCs, and Processors => Topic started by: drewski1986 on November 24, 2009, 04:36:02 PM
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I've always run this box as an all in one and now I am going to add the V2. Any idea as to what gain to set the V2 on to start as well as the FR-2LE? I'll be running this for Phish in C'ville for the first time. I also asked this question in the Furtooli team thread but thought maybe some V2 people would have some insight here as well. Thanks for any advice.
Drew
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Ahhhhhh.......he broke down and got a pre, and a V2 no less.
I read somewhere that the FR2LE has active electronics between the RCA line input and the gain control, so I would suggest running low gain on the V2 to start with, and trim up with the Fostex.
Otherwise, you could be seeing good levels on the recorder, and actually be getting analog clipping on the recorder at the input. I would try going with 20 or 25 db gain on the V2 and see how you like it.
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Test test test!
Take a really bassy source and send it into the v2 > fr2le.... Listen for distortion at various levels as indicated by the fr2le's meters.
Also do this using sine waves at various frequencies.. Look at the waveforms you record and visually inspect for distortion.
Etc.
I think it is critical to determine how hot you can safely run your recorder.
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TRS jacks or XLRs on the fostex? from what I remember, they have different specs for what they can handle. If you need some adaptors, I've got some XLR>1/4" you can use to test.
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Thanks for the replies. I have to use 1/4" with the pre from what I remember from the Fostex Manual. This will also disable the trim controls on the recorder, so it seems I will have the gain/trim on the V2 and the gain on the recorder to play with. I'm thinking of starting out at 25 on the V2 with the recorder all the way down and see what I get. Just don't have any experience yet with a pre.
edit: from the fostex manual
Analog In
Line In (TS phone jack Unbalanced)
Input impedance more than 10k ohms
Nominal Input Level -10dbV
Maximum Input Level +2dbV
Mic In (XLR)
Input Impedance More than 6k ohms
Nominal input level -50 dBu to -10 dBu
Maximum input level +2 dBu
I'll be using the Line in. I still don't have a clue what these numbers mean.
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From the FR2LE specs, the max line in is +2dbV (not +2dbv as you state -- careful, a dbV isn't the same as a dbv, but a dbv = a dbu).
Anyway, that is really pretty low. +2dbV = +4.2 dbu
The V2 puts out a max of 27dbu (23dbu louder than the FR2LE can take), so you'll need to run it really low.
The V2 has a minimum gain of 10db (less the -10db from the trim). I'd set the V2 at the 10db gain level, maybe the 15db gain level max.
Your km184's have a sensitivity of 15mv/Pascal (Pa = 94db SPL), so with that sensitivity and with 10db of gain from your V2, you'll clip if the sound in the room gets to 122db (perhaps less since the km184 sensitivity is measured at 1k Hz, so with a lot of low end energy you could be clipping the FR2LE at something less than 122db SPL). 122db is loud, but not out of the realm of possible for a loud band a small club really close to the stacks.
Anyway, I haven't run this rig, but from the specifications, I'd run the V2 at the minimum 10db gain, and maybe even dial that back an additional 5db using the trim knobs, and from there set your levels using the FR2LE dial.
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Thanks Todd. I have made the corrections to the specs I posted. As I said, I really don't know much about the specs, but it is sounding to me that this may not be an ideal situation. The V2 may put out too hot a signal for this box. I guess I will give it a try and see what happens. I may be in the market for another recorder if it doesn't work out.
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Best to try it for awhile and see what you think, my rec's should be on the conservative side so you won't run into problems on your initial runs. The RCA outs on the V2 are something like 4db or 6db lower, so if you're using those, it should help. It'll probably be fine to use the V2 with the FR2LE, though you probably won't be needing much gain out of the V2.
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I'm sure it will work fine, but isn't the whole idea to get the gain from the V2? Also my FR-2LE was modded by Busman. Not sure if this will make a difference or not.
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The busman mod may well have changed the gain structure and have raised the max input level, I know that is something Doug Oade often does. You should contact busman to see how the changes affect your input level.
Also, if he says they haven't changed, you might talk to him about another mod. Assuming the FR2le has a minimum amount of gain to the analog input signal before it hits the internal A/D converter chip, busman might be able to change the gain structure so the FR2le applies a much smaller amount of minimum gain which would allow you to use more gain from the V2. It is very likely that the gain is set on the internal op amps by a resistor(s), so simply by changing some resistors, he might be able to change the gain structure.
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Thanks Todd. I have made the corrections to the specs I posted. As I said, I really don't know much about the specs, but it is sounding to me that this may not be an ideal situation. The V2 may put out too hot a signal for this box. I guess I will give it a try and see what happens. I may be in the market for another recorder if it doesn't work out.
The PMD661 has a pro line level XLR line in that can take a very hot input. I run my preamps at the 36db setting, and have the gain knob on the recorder turned all the way up at 6 to 7 to get good levels.
I think you might have to go to something like that unit, or even a 7xx, to be able to really drive a V2 the way it was intended.
Jeff told me he likes to run both his V2 and his V3 at at least 35db with his KM84i pair into his 744T, and I know Mark also likes to run his V2 hard with his 4011s, so I think you are about to experience a case of the upgade infection.
Upgrade infection is where you add a piece of gear to your chain thinking it will be a solution, only to find that it that forces you to upgrade other components. Soon you will be switching to AKGs. ;)
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Soon you will be switching to AKGs.
AKG's? I thought we were talking upgrade?
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Soon you will be switching to AKGs. ;)
AKG's???? I thought we were talking upgrade.
So, which one of Chris King's sources of Phish Cinci did you tell him sounded best? I must have misunderstood him. ;D
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If we're talking about different recorders, I'll put in my 2c for the Sony D50.
It can take a +24dbu line input, which I think is awesome. The line input is unbalanced, so that input level is high enough to take the max (unbalanced) line output of the Lunatec V2/V3 without clipping. It really sounds nice on the line inputs too. I've been using it as my main 2ch recorder, fed by the EAA PSP2.
DATBRAD is right about the upgrade infection, but if you like the sound of the FR2le on the line inputs and want to run the V2 hotter, you might want to check with busman about lowering the minimum gain. That might be your cheapest option if you want to run the V2 hotter.
I still daydream about the 661 since it seems like a great 2ch recorder option, but I can't justify anymore gear at this point.
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The V2 puts out a max of 27dbu (23dbu louder than the FR2LE can take), so you'll need to run it really low.
The V2 has a minimum gain of 10db (less the -10db from the trim). I'd set the V2 at the 10db gain level, maybe the 15db gain level max.
Your km184's have a sensitivity of 15mv/Pascal (Pa = 94db SPL), so with that sensitivity and with 10db of gain from your V2, you'll clip if the sound in the room gets to 122db (perhaps less since the km184 sensitivity is measured at 1k Hz, so with a lot of low end energy you could be clipping the FR2LE at something less than 122db SPL). 122db is loud, but not out of the realm of possible for a loud band a small club really close to the stacks.
You could add an in-line 10 dB pad at the output of the V2 so you can run the V2 more in the middle of its gain range and avoid overloading the FR2LE's inputs. It's kinda sad to burn up 10 dB of clean gain, but if it avoids clipping the inputs it would be worth it.
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When I first got my V2 (and I was using KM184's) I was running it into an unmodded SBM-1. I went RCA > RCA and set the V2 to about 20dB gain and around 7-8 on the SBM-1. Got great results.
Since the line inputs on the Fostex appear to be 1/4" TS, they are unbalanced. Have a nice set of RCA > 1/4" cables made. There is no point in using an balanced to unbalanced cable (maybe with a 10dB in-line attenuator). The attenuator could potentially reduce signal quality and if you have to unbalance the signal anyway, just go unbalanced all the way. Get a 1ft long unbalanced cable (keep it short) and you will be set. This is IMO of course, the best way to run this rig. You will be able to get a bit more gain from the V2 and not have to worry about overloading the line inputs on the Fostex.
Good luck!
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When I first got my V2 (and I was using KM184's) I was running it into an unmodded SBM-1. I went RCA > RCA and set the V2 to about 20dB gain and around 7-8 on the SBM-1. Got great results.
Since the line inputs on the Fostex appear to be 1/4" TS, they are unbalanced. Have a nice set of RCA > 1/4" cables made. There is no point in using an balanced to unbalanced cable (maybe with a 10dB in-line attenuator). The attenuator could potentially reduce signal quality and if you have to unbalance the signal anyway, just go unbalanced all the way. Get a 1ft long unbalanced cable (keep it short) and you will be set. This is IMO of course, the best way to run this rig. You will be able to get a bit more gain from the V2 and not have to worry about overloading the line inputs on the Fostex.
Good luck!
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