Author Topic: question about SoundPro Preamp (now with brickwallingC) (Read 5521 times)

Chad817 · « **on:** June 23, 2005, 06:15:09 PM »

I just picked up this model:

http://www.soundprofessionals.com/cgi-bin/gold/item/SP-PREAMP

now, soundpro's site states that this box will eliminate the need for a battery box (I run the soundpro 853's), and the pre will power the mics. What I'm wondering..is that since both the batt box and the preamp run on 9v...am I hurting myself by just running the preamp and letting that power the mics? I guess what I'm worried about is underpowering the mics, since it's using the 9v to both power the mics and preamp. Am I off base thinking that? I suppose I could run mics>batt box>preamp>jb3..would I be degrading the signal by running the batt box into the preamp?

Any help would be appreciated..and also any feedback on the sp preamp from those that run it. I really didn't find too much about it via the search. Thanks.

jeromejello · « **Reply #1 on:** June 24, 2005, 04:47:08 AM »

i way i understand it, the sp-pre is a combo of bias voltage (9v) for the mics (which the battery box usually does) AND provides adjustable gain for the mics (which most battery boxes do not provide)

you shouldn't be 'under powering' your mics... the only disadvantage is the decreased time in which you will have power since you are powering the mics and providing gain.

the usual battery box claims some outragous battery life (at least a couple of months of taping) say 500 hours (just a guess) and the sp-pre is only like 75 hours.

i know nothing

edit for clarity

Chad817 · « **Reply #2 on:** June 25, 2005, 01:56:34 AM »

well, made the first run with it tonight and had some severe brickwalling. For those that run the sp-pre into a jb3, where do you generally set the levels on the jb3? Tonight I had the jb3 at 0, ran the preamp at +29 with the knob about halfway..and had brickwalling on the levels about half way. When I had the jb3 and the preamp at 0....my levels were very low..even with the knob on the pre all the way up. I'm not sure what to do here...either deal with really low levels in post, or brickwall. Would I have had better results with the jb3 at +12 and the pre at 0, and just inching up the knob a bit? That probably would have helped the brickwalling...but I guess I'd wonder why I'm even running the pre then, as I'm applying minimal if any gain from it in that situation and relying on the jb3 for amplification.

Would running the batt box before the pre given more power to the mics and prevented the brickwalling?

I wouldn't call the show quiet..but it certainly wasn't overpowering either.

using sp 853's

Ray76 · « **Reply #3 on:** June 25, 2005, 08:48:18 AM »

Quote from: Chad817 on June 25, 2005, 01:56:34 AM

well, made the first run with it tonight and had some severe brickwalling. For those that run the sp-pre into a jb3, where do you generally set the levels on the jb3? Tonight I had the jb3 at 0, ran the preamp at +29 with the knob about halfway..and had brickwalling on the levels about half way. When I had the jb3 and the preamp at 0....my levels were very low..even with the knob on the pre all the way up. I'm not sure what to do here...either deal with really low levels in post, or brickwall. Would I have had better results with the jb3 at +12 and the pre at 0, and just inching up the knob a bit? That probably would have helped the brickwalling...but I guess I'd wonder why I'm even running the pre then, as I'm applying minimal if any gain from it in that situation and relying on the jb3 for amplification.

Would running the batt box before the pre given more power to the mics and prevented the brickwalling?

I wouldn't call the show quiet..but it certainly wasn't overpowering either.

using sp 853's

I never add any gain to the jb3 on the jb3 side. all the gain is added with the pre.
Ray

jeromejello · « **Reply #4 on:** June 25, 2005, 12:00:22 PM »

Quote from: Chad817 on June 25, 2005, 01:56:34 AM

well, made the first run with it tonight and had some severe brickwalling. For those that run the sp-pre into a jb3, where do you generally set the levels on the jb3? Tonight I had the jb3 at 0, ran the preamp at +29 with the knob about halfway..and had brickwalling on the levels about half way. When I had the jb3 and the preamp at 0....my levels were very low..even with the knob on the pre all the way up. I'm not sure what to do here...either deal with really low levels in post, or brickwall. Would I have had better results with the jb3 at +12 and the pre at 0, and just inching up the knob a bit? That probably would have helped the brickwalling...but I guess I'd wonder why I'm even running the pre then, as I'm applying minimal if any gain from it in that situation and relying on the jb3 for amplification.

Would running the batt box before the pre given more power to the mics and prevented the brickwalling?

I wouldn't call the show quiet..but it certainly wasn't overpowering either.

using sp 853's

fwiw, one of the reasons i didnt want a sp-pre was the 3 fixed settings 0, 29, 50... too drastic.

but ray is right, since you have the pre, you would want gain to be provided by that. be careful of negative gain on the jb3... i had it introduce artifacts... ymmv.

i dont think running the battery box before the preamp is the solution.

Chad817 · « **Reply #5 on:** June 25, 2005, 04:14:55 PM »

am I getting any benefit by running the sp pre then? Like I said this wasn't a loud show...so If I had run the jb3 at 0 and the pre at 0...my levels would have been pretty low...and sure I could have boosted them in post..but then I'd just be doing the same thing I was doing before having the pre. The noise floor should be a bit lower with the pre though, so maybe the recordings would sound a bit better after boosting in post?

Perhaps I should look into modding the mics to accept higher spl's

Ray76 · « **Reply #6 on:** June 25, 2005, 04:47:57 PM »

Quote from: Chad817 on June 25, 2005, 04:14:55 PM

am I getting any benefit by running the sp pre then? Like I said this wasn't a loud show...so If I had run the jb3 at 0 and the pre at 0...my levels would have been pretty low...and sure I could have boosted them in post..but then I'd just be doing the same thing I was doing before having the pre. The noise floor should be a bit lower with the pre though, so maybe the recordings would sound a bit better after boosting in post?

Perhaps I should look into modding the mics to accept higher spl's

exactly. modding them for phantom power greatly improves them.

Chad817 · « **Reply #7 on:** June 25, 2005, 06:31:51 PM »

looks like that is the direction I'm going to have to take. Thanks for the advice +T

final question: If I get the phantom mod..then I'm going to need an mp-2 or something (like this: http://www.soundprofessionals.com/cgi-bin/gold/item/DEN-PS2-MINI) to provide 48v...at that point would it be a good idea to still run into the sp-preamp? I'd imagine I'd have to have a xlr>mini adapter before the preamp...how would that effect things? (and if I went the route of the denecke ps-2 that I linked, I could just run the mini out from that into the sp-preamp. I'm not nullifying the benefits of the mod and phantom power by having them terminate in a 1/8 into the preamp am I? (I would hope not, since that's exactly what the denecke ps-2 would do) Sorry if this is a stupid question, I'm just trying to clarify. I've always gone the simple mics>batt box>recorder method before, so I'm not too up on phantom power.

as far as the 0,29, and 50 settings on the sp-preamp..I was under the impression those would be the max amplification with the knob all the way up. For instance, if I had it set at 29, then adjusting the knob would take it from 0 to +29.

Evil Taper · « **Reply #8 on:** June 26, 2005, 04:25:22 AM »

I sent my SP-PREAMP back for a full refund. The thing doesn't do what WE want it to do. That +29 setting is providing a 29db boost to the sound no matter where the knob is set at, that's just to adjust the volume of it. The +29 seemed to be way too much for my DPA 4061s and those are far less sensitive than the AT853s are, I own both and use them with the JB3. The +0 flat setting at full gain on the sp-preamp is identical to using a sound pros standard batt box. Send it back and get the ps-2/ad-20 combo like all the other 853 jockies use.

Ray76 · « **Reply #9 on:** June 26, 2005, 05:52:14 AM »

Quote from: Evil Taper on June 26, 2005, 04:25:22 AM

I sent my SP-PREAMP back for a full refund. The thing doesn't do what WE want it to do. That +29 setting is providing a 29db boost to the sound no matter where the knob is set at, that's just to adjust the volume of it. The +29 seemed to be way too much for my DPA 4061s and those are far less sensitive than the AT853s are, I own both and use them with the JB3. The +0 flat setting at full gain on the sp-preamp is identical to using a sound pros standard batt box. Send it back and get the ps-2/ad-20 combo like all the other 853 jockies use.

Thats not necessarily true hoss. It varies with different enviroments. You record a lot of metal shows, but I have heard good tapes coming from someone using the preamp. blanket statements are dangerous, mr evil. Experiences vary.

Evil Taper · « **Reply #10 on:** June 26, 2005, 06:26:06 AM »

just speakin from my personal experience....and i'm a fucking extremist and like to make my points clear, non of this flip flop bullshit....so enough with the blanket statement slander there bubba...you know how i am (and those that don't, my bad)

Ray76 · « **Reply #11 on:** June 26, 2005, 07:26:44 AM »

Quote from: Evil Taper on June 26, 2005, 06:26:06 AM

just speakin from my personal experience....and i'm a fucking extremist and like to make my points clear, non of this flip flop bullshit....so enough with the blanket statement slander there bubba...you know how i am (and those that don't, my bad)

youse a bitch. fick dich du schlampe. the taliban are extremists too. also dubya and the guy that pickets GI funerals. ALl extremists.

ray

Chad817 · « **Reply #12 on:** June 27, 2005, 12:45:45 AM »

would it be worth my while to look at 20db attenuators to go between the mics and the sp pre? Effectively getting +9 from the pre then, on the +29 setting. Or variable attenuators...bringing the mic signal down enough so that the +29 added by the pre brings it up to a good, no distorted level.

leegeddy · « **Reply #13 on:** June 27, 2005, 01:16:56 AM »

Quote from: Chad817 on June 27, 2005, 12:45:45 AM

would it be worth my while to look at 20db attenuators to go between the mics and the sp pre? Effectively getting +9 from the pre then, on the +29 setting.

first of all, what type of music do you record? loud concert level, unamplified acoustic, nature recording, etc.?

the best method of powering the AT853 mics is phantom power. someone suggested the deneke ps-2/ad20 combo already.

if you're a stealth taper, you could go with this setup:

AT853 > AT8533x (phantom power modules) > deneke ps-2 > pair of hosa mit-176 (line transformer) > jb3 (via 1/8" mini)

the above is a very compact rig and will produce solid recordings without ever brickwalling.

you can substitute the hosa mit-176 xformers with the deneke ad20 to utilize the toslink output to feed the jb3 a digital signal.

you also mentioned a small preamp/p48 supply like the SD mp-2. several folks here run that exact same gear combo with great results.

many choices here.... and it's really dependant on what your budget is. my advise is to go with phantom powering solution and move away from the battery power. there's a huge difference in the quality between the 2 powering methods.

marc

Chad817 · « **Reply #14 on:** June 27, 2005, 01:23:19 AM »

mainly acoustic or rock. I don't do much stealthing so size isn't a huge issue. Ideally I'd love to go the ps-2>ad-20 route, but I am also working within a budget here, at least for the time being. I think what I may look into is phantom modding the 853s and picking up a digi mod ua-5. In the meantime, I'm wondering if I could get away with running the sp preamp with attenuators in front of it.

how much do the hosa mit-176 line transformers go for?

leegeddy · « **Reply #15 on:** June 27, 2005, 01:36:24 AM »

Quote from: Chad817 on June 27, 2005, 01:23:19 AM

mainly acoustic or rock. I don't do much stealthing so size isn't a huge issue. Ideally I'd love to go the ps-2>ad-20 route, but I am also working within a budget here, at least for the time being. I think what I may look into is phantom modding the 853s and picking up a digi mod ua-5. In the meantime, I'm wondering if I could get away with running the sp preamp with attenuators in front of it.

how much do the hosa mit-176 line transformers go for?

for acoustic shows, you may not need the attenuators. for normal rock shows, you could probably get away with using -10dB attenuation.

hosa mit-176 are around $20/ea. from various online shops.

marc

Chad817 · « **Reply #16 on:** June 27, 2005, 01:45:48 AM »

thanks for the advice.

I'm guessing at this show on Friday if I had -10 attenuation things would have been fine. I guess I'll think it over awhile. I definitely think I will go the phantom mod route..but then it's going to be a matter of deciding on a ua-5, ps2 and ad20 combo, or just running the ps2 and relying on the jb3 pre

Chad817 · « **Reply #17 on:** June 28, 2005, 05:17:31 PM »

after reading up on the ad-20 and the fixed gain on that as well, I think the easiest and best route for me to go is a digi-mod ua-5 and the phantom mod to the soundpro 853's. The all in one of the ua-5 just seems to good to pass up. Now I just need to find one in the yard sale

divamum · « **Reply #18 on:** July 04, 2005, 05:57:20 PM »

Late in on this, but just my experience:

running at 831>sppre>jb3 and also CMC8>sppre>jb3 was NOT a success - if it was set at 29, it brickwalled (badly) and at 0, I couldn't get the gain up enough to get a decent signal even if I boosted it on the JB3 itself. I was disappointed, since the budget wouldn't stretch to an AD20 with the mod for 1/8 and plug in power. (I'm recording classical singing - all acoustic)

The budget-friendly solution for me was a Reactive preamp (available at www.reactivesounds.com or www.minidisco.com); similar in spec to the SP version, but for whatever reason I can easily get the right levels w/both sets of mics - it's a simple knob affair and you just turn it till you see the clipping light thhen knock it back a degree or two. No, it's not in the league of the Denecke and its friends, but it does the job, w/the JB3 internal AD taking care of that side of things. I can get good levels, it was w/in my budget and it's doing adequately until I can afford something significantly better.

FWIW.

Chad817 · « **Reply #19 on:** July 04, 2005, 10:25:30 PM »

ah, that's what I was hoping to get from the sp preamp. Regardless, I ended up going with a ua-5 from someone on the boards, hopefully finalizing the sale this week. Then, phantom modding my 853s and I should be good to go.

+T to ya

Author Topic: question about SoundPro Preamp (now with brickwallingC) (Read 5521 times)

Ray76

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Ray76