Very low line/phono volume

wat?

to rephrase, i advised against using a phono preamp. trivially, the way to use a phono preamp along with an NI audio interface is as follows: we go from the phono level output of a turntable (say, a 1210; NOT the line-level output of an ST-150 or such) into the preamp. the preamp's output is connected to an input of the NI audio interface. that input now needs to be switched to LINE. (we don't want to pre-amplify and RIAA twice.)

the problem now is as follows. your typical stand-alone phono preamp provides between 35-45dB amplification, assuming it is fed an MM signal. it turns out the amplified output of such a preamp is too hot for NI interfaces to handle. (exceptions: (i) you're using a cartridge with very low output but that would be uncommon. DJ carts usually are high output; (ii) you're playing a vinyl record with very low volume.)

i've attempted this with several preamps, several MM carts, and two NI audio interfaces (S4 and TA6). in each case, the input of the NI interface clips. there's nothing you can do about it, either, because the NI interfaces have no analog gain on their inputs. sure, you can turn down the volume via software/driver. however, that doesn't help. reducing the volume at that point is too late, the damage has already been done. then, you're merely attenuating a clipped signal.

 

I just find it hard to believe that a preamp would put out such a hot signal through RCAs that it would cause the line input of a decent sound card to clip.

The Audio 6 has a gain of -2.6dB on its line inputs so it can't be causing the problem itself. If you get a clipped signal it must have been clipped before the A6. And what kind of levels do the preamps you've tested produce? dB amplification is just a ratio so it doesn't mean anything.

My CDJs put out quite a hot signal too but I can easily record through my Audio 4 without getting anywhere near clipping.
Are DJ carts really that much louder than a typical Hifi one?

 

They do make phono preamps with level control

Here is an intire page full http://www.phonopreamps.com/index.html

That should solve your clipping issue

 

looks like this is going to work fine

 

Here is a good article ( from amazon )

http://www.amazon.com/gp/richpub/syltguides/fullview/21PCGJR9SBLQP

Explains why this works quite well. Much better then I can.

 

well, i reported my practical experiences. you, on the other hand, just seem to speculate. or have you run any tests?

i don't think you understand what the number of -2.6dB in the specs means. the number just means that a line level signal connected to an A6 input that goes through the AD-DA chain and to an A6 output will be attenuated by 2.6dB. your logic is flawed. from this number, it doesn't follow that the A6 won't clip when given an extreme voltage on one of its inputs.

i agree it's not ideal. however, it's not meaningless. gain, measured as the ratio between the magnitude of output and input signals (unit: dB), is an important characteristic of an amp.

it's the best i could do. obviously, the power of the signal prior to pre-amplification varies due to various factors (the record, the cartridge, etc.) so you'd really have to do some measuring.

you gotta be careful there. the signal from your CDJs may sound "louder" due to the fact that more DRC is possible in digital. however, peak amplitude may not be higher than a signal output by an external phono preamp.

i think so. although nowadays, there is a tendency to make Hi-Fi carts output higher and higher voltages. (but the same design goal appears to exist for DJ carts as well.)

 

You're missing the context.

OP says that when he plays real vinyl, it's not loud enough. Someone suggested getting a phono preamp. I note that I get clipping with a preamp providing 37dB amplification (not on a Z2, though).

Looking at the specs of the Z2:
maximum input level on the phono inputs: -22dBu / 62mVrms
maximum input level on the line and aux inputs: 13dBu

I don't know how much amplification the built-in phono preamps in the Z2 provide. But if it's close to the 32dB gain of other NI interfaces, it doesn't look as if an external phono preamp is the way to go. Yes, an external phono preamp with an analog gain adjustment is a sure-fire way to avoid clipping. But if I have to keep that analog gain down, I might not make the signal significantly louder as compared to the Z2's internal preamps.

Instead, the solution which I recommend is the one given by makar in his earlier post #10. Turn down the master in the Traktor software.

 

I've just tested running my Audio2DJ at FULL volume into the Line inputs of my Audio4DJ and there is still no visible clipping in Audacity.

The LEDs do go red on the A4 but there is no visible clipping of the waveform recorded.

You must have some insane preamps if they can put out a higher output level than an Audio2 at max (9.6dBu/3.3V Peak).

Nominal output for a Cambridge Audio Azur 551P is 0.3V...

 

So I went home and disconnected my phono preamp on my main amp (the same one i used to digitize my vinyl collection) and hooked up one of my tables to the line input, boosted it to match the digital output volume of the internal mixing mode. ( I was doing this years ago to match phono to cdj's and other digital outputs tho not on NI gear ). Why? I'm an audio engineer by trade and it seemed like a good option rather than turning down the digital outputs ( which is def. the easier option)

It worked fine. No clipping, timecode vinyl worked as normal. Still have to recalibrate it everytime you switch from regular vinyl to time code ( there is another thread on that already )

Of course this is just my experience with the gear i use, but as with all audio sources there is always a way to get the signal from point a to point b the way you want it. Just have to dig till you find it.

Malzfreund you def. have a better grasp on the technical aspects of NI gear, so I would not disregard your experience with this situation. I could just have lucked out. Gear can be picky lol.

If you don't want to spend the cash and risk not fixing your issue turn down the digital. Easy, or just jack your gains when switching. Or any of the other fixes mentioned.

 

i haven't tested with the A4DJ, I have tested extensively with the S4. (I've had the opportunity to test once or twice with a TA6. but since i don't own a TA6 myself, this is mostly about the S4.) Preamps used were a CA 640p and a Rolls preamp (don't know which model). I tested with various carts (Ortofon Concorde DJ E, Shure M 97 E, Ortofon 510 mkii) and various modern house and techno music records that have gone through a record cleaner and are in near-mint condition.

turntable is a 1210 m3d which has recently been serviced. cart and tonearm are properly aligned. i recorded both with ASIO (in Wavelab, Audacity doesn't support ASIO) and with MME (I recorded in audacity). With every cart but the 510mkii (which has lower-power output), the level meter frequently indicates clipping. it doesn't happen with every record (records obviously do differ in volume), but it happens often enough. when looking at the waveforms in detail, i can spot typical digital clipping (peaks and troughs of the waveform have been "clipped off").

clipping also occurs when i lower the volume of the recording device (on the S4, this is not possible when using ASIO). i still get clipping. the amplitude is reduced, yes. but you can still spot that the signal clipped.

i did various other sanity checks: i recorded at different sampling rates and bit depths and i tested both LINE inputs. lastly, i also get clipping when recording the signal from a sony mini-disc player set to maximum volume. to me, my finding looks pretty robust.

EDIT: btw, i previously owned an A4DJ and didn't see it clipping. but that was ages ago, using a much older NI driver, a different windows box, etc. (especially the A4DJ driver was very different, providing much less gain. instead, it had a setting where you could boost the volume of the inputs when they were set to phono.)

 

There must be something wrong with either your S4 or S4s in general if a preamp putting out consumer-level outputs (0.3V) will cause the line-ins to clip no matter what settings you use.

It seems Nomac had no problems using a preamp through the Z2, and I would expect my A4DJ to handle it fine also.

 

Im a s4 owner and there is a long thread on this issue: phono input that cannot get to 0db not even with the gain, bass, mid, high eq at max when playing older, softly recorded records.

NI knows about the issue and ignored it for the s4. And it did not use the feedback for the Z2 it seems :S

 

hey guys same problem here i think.. to rephrase:
phono and line in are about 50% of the volume that comes from my computer (media player, system sounds & traktor)
wondering if there is any way to force it to lower that USB input volume since OSX dosen't let you do it in any way?

it makes it sketchy switching to other inputs: cell phone, vinyl. whatever requires me to double the gain on my master out. never a fun time to switch back if you forget.. any tips at all? software or hardware