Tascam 48 +4/+8dbm switch - where is it?

[Morbach]

Hi y'all, I've worked with Tascam since my very first recording more than 20 years ago (Tascam 244, when I was aged 14..), owned a Tascam my whole life.

Ok now to business, I recently bought a 48, mint condition, came with RCA cables, I tested recording with the RCA (while I had the XLR multi cables sent my way) and sounded amazing.

XLR arrived, I got rid of the RCA, real happy now my set up is fully balanced. Then did first recordings with it, at low level (way below VU's 0), and the output, to either my mixing board or digital interface, audio comes clipping.

Found manual, started reading it, so apparently there is a +4 +8 switch inside (on the REC/REPRO amplifier circuit board says there), +8 would explain next gear in signal chain clipping even at low level.

So I open the machine, the back and the rear panels, see a lotta stuff but nowhere clearly stating either "Rec/Repro board" or anything similar, or even "on/off" switch kinda thing.

Why would they expose all calibration, very well mapped on the bottom panel, and hide something as simple and important as this??!

Please someone help me find it, without having to tear my machine apart, and/or risking ruining calibration.

Pictures attached of the only thing I found that look like could possibly be it, at the bottom, next to the channel boards. If that's it, is that a on/off switch? or something I have to calibrate?

Thanks! Best JM

 

[SkywaveTDR]

There is a small while colored push button switch on each card that defines the output level. Look at the owners/service manual. The marking for it's purpose is silkscreened onto the card.
Yes, you have to take the cards out to change this so usually +4dBu is good enough. Why do you want a +8 setting?
The balanced and unbalanced output are often with no output due to bad muting relays. I change 16 of them on some machines. I put them into IC sockets to make changing easy. People that put phantom power into their machines are asking for trouble and they usually get it.
If the +4 output does not give a acceptable level then I have to think there is more to the story that just the output level.
The XLR connection go through more circuits so the cleaner signal comes from RCA connections that are before the high level amplifiers. Are you running 100 foot lines? You don't need XLR unless long lengths are involved. XLR cables and use usually just increases the cost of doing business.

 

[Morbach]

Thanks a lot for the information, I at first understood it'd be one main switch, not individual switches on each channel's boards. I don't have the service manual.

Unfortunately that didn't solve my problem, as taking out the boards the switches were on 4 not 8. Pardon me if I expressed myself poorly, but I did not want to turn the switches to 8, it's the other way round, the outputs of the machine clip the inputs of my next gear on signal chain (either a soundcraft 16 channel sound board or RME fireface 800 interface), and I don't have a pad on either to compensate.

The reason I went for balanced without thinking twice when I got the 48, is because I had a 38 before, that I would do sessions with my small setup, but also take to high end studios on request by clients, to track drums or guitars etc, and many a times I had trouble connection the 38 to lunchbox preamps, ssl soundboards etc as levels would not really "speak to each other", so I upgraded my whole system, and thought having everything balanced would be the end of my trouble.

Why else would a recording recorded at low level, clip at the inputs of the next gear in signal chain?

Thank you so much for your assistance.

 

[SkywaveTDR]

On mixing boards that use XLR connections the standard level for that connection is +4dBu.
If there is clipping then there is a knob called trim on the channel that should be able to reduce the gain to the first stage. On interfaces the interface has mixer setting that tell it how to respond to signals such as settings of -10, 0dB or +4 or even +8dBu. You can not just hook up and hope for the best but you need to set the equipment up right to use the equipment. Most manufactures do not know what you will be hooking to their equipment so all they can do is provide trim pots or sensitivity setting in the software. I have seen people get in trouble all the time when I was Chief Engineer for stations in that they would fool with a settings not knowing what it was and upset the setup that a technical person set it to. Hooking a Tascam 48 to a microphone input will of course overload it. First make sure the phantom power is off before hookup and then look for a button that says line rather than Mic input. The Tascam mixers had these buttons and I can not see why even more expensive mixers would leave it out.

 

[Morbach]

The issue is exactly that, the Soundcraft trimmed all the way is still clipping, there's no -10 or -20 pad button, and no mic/line selector.

Of course a system must be set up properly and not just connected "hoping" it'll work. And I wouldn't ever think of sending 48v to the tape machine. In my book though, a balanced +4 output of a tape machine still should talk with a +4 mic/line input of a mixer without any problem.

And true my RME interface have 3 input levels but for some reason it's doesn't change anything (the output selector right next to it jump the levels instantly, the inputs no difference. I bought it second hand maybe there's some issue there?)

If the two pieces of gear just work with different levels really and there's nothing that can be done about it, I'll just buy a RCA-1/4" multi cable, although I'm so not so happy with that, I tested the RCA to 1/4 and the opposite happens the sounds comes good and clear but kind of low, so I'll have to compensate with the Soundcraft pre amps, and my intention after using $1000 dollar preamps direct to tape was to work with a "clear" signal right out of the machine, without having to use mixer preamps...

 

[SkywaveTDR]

Well it all depends on the Soundcraft board input if they say they are Mic or Line level devices. What does the specs sheet say the input range is suppose to be? I have always worked with Tascam mixers, or PR&E at radio stations but some Wheatstone and I never had a problem. I think the one Church I was at had a Crest mixer. It had 56 inputs. It took two to run it.
What RME device do you have? Which Soundcraft mixer? I could look up the specs that way.

The 48 puts out -10dBV out of the RCA connectors at 0 Vu.

 

[Morbach]

The Soundcraft is a GB2R 12.2, the RME is a fireface 800, the RME as I stated before have three levels of input, but for some reason doesn't alter anything (unlike the three levels of output, that jump the sound to three very noticeable levels, I bought it second hand so maybe something is just wrong with it?). Wouldn't be a problem with the RME though if I could trim the levels lowering the faders before the direct outs on the Souncraft, as I sometimes do coming from the preamps to record digital. Lowering the faders is just trimming the sound, doesn't alter it, not the same as amplifying with the gain trim pots right? I bought a RCA to 1/4 multicable for upcoming projects because I need to have the machine running, but would love to at some point have it all set to proper +4 levels to avoid using the Soundcraft preamps.

 

[SkywaveTDR]

A RCA to 1/4" is not going to be balanced and the level will still be -10dBV.
I downloaded the 12/2 manual and it is clear that the XLR inputs are only designed to work with Mic inputs so you can not put line level ins there. The 1/4" TRS are balanced and are designed for the XLR outputs and have a +30 dBu max signal. The TRS in case you are not on top of that means that the T is the tip which is the hot Plus signal same as XLR pin 2, the R is the ring which is the minus signal same as XLR 3. The the Shield is the same as ground on XLR pin 1. You would be better off just getting some connectors and wiring your own cables like this although you could buy them I suppose. When figuring out why something does not work you need to go to Technical manuals that of the unit you are having trouble with and look into them to see what the device is designed to operate with. This could explain a lot. I am used to Tascam mixers or even those mixers in AM and FM studios in stations I built or Engineered at and they all get along well with either -10 dBu or +4 dBu signals- they have program pins or dip switches to set these gains.

 

[SkywaveTDR]

The RME 800 has Analog input gain setting in section 7.2 of the manual. If these do not alter the level for the +4 input then there may be defects to the interface or at least a call to their support people to discuss why they do not change. These setting are by software not switches or buttons. I hope this adds some help to the situation. Either item should work with the 48.