TASCAM 388 with (OLD) LEXICON 200 (transformer balanced XLR) ???

[Tronic Blanc]

Hello. I could really use some help connecting the TASCAM 388 EFFECT BUS to a recently purchased old school LEXICON 200 REVERB unit. This is the one with the transformer-balanced XLR ins/outs. I can't even figure out of the EFF send on the 388 is balanced or not...let alone what cables to use to patch in the old LEXICON via XLR ins/outs...

The Tascam 388 manual and Lexicon 200 manual detail the dBu and impedances of each connection, but honestly, I'm still baffled about the very practical "choice of exact cable to buy"....so maybe you can set me straight on what to pick up to cable this unit into my 388's EFF SEND/RETURN? Many thanks...


--->
1/4" EFFECT OUT of TASCAM 388:

SINGLE 1/4"
OUTPUT IMPEDANCE: 100 ohms
NOMINAL LOAD IMPEDANCE: 10 kohms
MINIMUM LOAD IMPEDANCE: 2 kohms
NOMINAL OUTPUT LEVEL: 0 dBu​

--->
L(mono) XLR INPUT OF LEXICON 200:

2 X BALANCED 3 pin XLR (USING ONLY LEFT CHANNEL - I ASSUME)
INPUT IMPEDANCE > 50 kilohms
There is a REAR PANEL GAIN SWITCH that toggles between 0 dB and + 20dB.
"rear panel GAIN SWITCH allows the unit to accommodate input levels from -18 to +24 dBm" - from manual​

So far, I'm thinking a 1/4" TRS to XLR cable from EFFECT OUT of TASCAM 388 into left channel of LEXICON 200

--->
2 X XLR OUTPUTS of LEXICON 200:

LEFT and RIGHT outputs are balanced and transformer-coupled, accepting 3-pin female XLR connectors. Output impedance is < 150 ohms, and maximum output level is +24 dBm.
(there's also an output level adjustment screw, with maximum of + 24dBu...so I assume I could technically lower it also if need be...)​

--->
2 X 1/4" EFFECT RETURN of TASCAM 388:

2 X 1/4" Phono
INPUT IMPEDANCE: 22 kohms
NOMINAL INPUT: 0 dBu
MAXIMUM INPUT LEVEL: + 16 dBu​

For this, I'm wondering if I should use 2 separate XLR to TRS cables coming from the LEXICON XLR OUTS to the dual 1/4" EFFECT RTN inputs of the TASCAM 388....or is it 2 separate XLR to TS cable? Or even weirder....maybe a single LEFT OUT XLR into Y-split cable of dual TS???? I'm thrown by this dual 1/4" EFF RETURN port on the 388. I really am hoping these specs above allow for a simple set of 2 x XLR to TRS and keep it balanced...

 

[witzendoz]

If you connect the 388 to the Lexicon using a TRS to XLR cable it will work fine. The 388 is more than likely not balanced, but plugging an TRS plug into an unbalanced TS socket shorts pins 1 & 3 of the XLR which is what you do when you make an unbalanced to balanced adaptor cable.

Use the Lexicon duel outs to the duel effects returns as by panning then effect returns you get a stereo reverb effect (wider image). Again use XLR to TRS cables as it will allow a balanced out to plug into an unbalanced input. You may have to fiddle with the level to match them but you have plenty of options by the look of it.

Alan.

 

[Tronic Blanc]

If you connect the 388 to the Lexicon using a TRS to XLR cable it will work fine. The 388 is more than likely not balanced, but plugging an TRS plug into an unbalanced TS socket shorts pins 1 & 3 of the XLR which is what you do when you make an unbalanced to balanced adaptor cable.

Use the Lexicon duel outs to the duel effects returns as by panning then effect returns you get a stereo reverb effect (wider image). Again use XLR to TRS cables as it will allow a balanced out to plug into an unbalanced input. You may have to fiddle with the level to match them but you have plenty of options by the look of it.

Alan.

I picked up 2 XLR to 1/4" TRS cables on your advice, and hooked up the back of the reverb into the EFF Returns of the 388....problem is, the signal is SOOOOOOOOO weak. It sounds amazing, but the output of the unit is barely audible.

What's weird to me, and a bit confusing is, I have the little blue TASCAM 388 EFF knobs for each channel totally dimed, and the top EFF section (with the dual EFF GAIN and EFF PAN knobs) also dimed. The unit is putting out fully wet signal. Sounds incredible when it returns to the board, but I can only hear it at all if I listen to ONLY the EFF bus, because the minute I hit the red REMIX button on a channel, that channel volume is so loud that even with the faders very very low, it still totally drowns out the entire EFF bus signal. I'm listening through powered monitors through the XLR stereo outs (with the "BALANCED" switch on).

Is this something that has to do with the XLR - 1/4" TRS cables I'm using? Like a balancing issue where it really needs a "TS" on the returns? Or is it something I need a preamp for?!! Before it returns to the EFF bus?!!!? That would be weird. Or maybe I can just turn up the little "output screws" a TON on the face of the Lexicon 200. The weird thing is, I hooked up a Holy Grail reverb pedal to this same bus not long ago, and I could hear it loud n clear. It has me curious if the Lexicon outputs are actually shot....or like if the transformers are shot or something...

 

[j.harv]

Do you have the eff/ aux master knobs that are under the row of red record butttons turned up?

 

[witzendoz]

I picked up 2 XLR to 1/4" TRS cables on your advice, and hooked up the back of the reverb into the EFF Returns of the 388....problem is, the signal is SOOOOOOOOO weak. It sounds amazing, but the output of the unit is barely audible.

In your 1st post you said that there are many options on the lexicon for adjusting the input and output volume Input: There is a REAR PANEL GAIN SWITCH that toggles between 0 dB and + 20dB. "rear panel GAIN SWITCH allows the unit to accommodate input levels from -18 to +24 dBm" And the output of the lexicon: maximum output level is +24 dBm. (there's also an output level adjustment screw, with maximum of + 24dBu.

So you can turn up the input and output of the lexican to suit? there must be somthing wrong with the way you have the gain structure setup?

What's weird to me, and a bit confusing is, I have the little blue TASCAM 388 EFF knobs for each channel totally dimed, and the top EFF section (with the dual EFF GAIN and EFF PAN knobs) also dimed. The unit is putting out fully wet signal. Sounds incredible when it returns to the board, but I can only hear it at all if I listen to ONLY the EFF bus, because the minute I hit the red REMIX button on a channel, that channel volume is so loud that even with the faders very very low, it still totally drowns out the entire EFF bus signal. I'm listening through powered monitors through the XLR stereo outs (with the "BALANCED" switch on).

Is this something that has to do with the XLR - 1/4" TRS cables I'm using? Like a balancing issue where it really needs a "TS" on the returns? Or is it something I need a preamp for?!! Before it returns to the EFF bus?!!!? That would be weird. Or maybe I can just turn up the little "output screws" a TON on the face of the Lexicon 200. The weird thing is, I hooked up a Holy Grail reverb pedal to this same bus not long ago, and I could hear it loud n clear. It has me curious if the Lexicon outputs are actually shot....or like if the transformers are shot or something...

You must have this connected wrong, I can't see this having anything to do with the cables themselves.

Alan.

 

[Tronic Blanc]

Hi Alan. Yeah I just picked up a couple of XLR to TS (unbalanced) cables and sure enough, they work excellently! There's tons of signal now. The TRS balanced 1/4" actually hurt the signal. I read somewhere in the manual that weird phasing issues can happen that negate most of the signal if you don't do the right balanced/unbalanced cables. Maybe that was it.

 

[witzendoz]

Hi Alan. Yeah I just picked up a couple of XLR to TS (unbalanced) cables and sure enough, they work excellently! There's tons of signal now. The TRS balanced 1/4" actually hurt the signal. I read somewhere in the manual that weird phasing issues can happen that negate most of the signal if you don't do the right balanced/unbalanced cables. Maybe that was it.

The only thing I can think of is that the contacts inside the TS sockets in the Tascam are not making a clean contact to the Sleeve and ring of the TRS plugs, could be the design of the Tascam sockets, sorry to give you a bum steer in that direction, glad it's all sorted now.

Alan.

 

[lo.fi.love]

Hi,

I use a Tascam 208 mixer and I've had similar issues plugging TRS plugs into the 1/4" jacks on the mixer's Line Ins. I found the same thing, that when I switched to 1/4" TS plugs, everything worked correctly.

I think it's nothing to do with the connector or cable, it's all to do with the jack on your 388.

 

[Studio388]

Hi Alan. Yeah I just picked up a couple of XLR to TS (unbalanced) cables and sure enough, they work excellently! There's tons of signal now. The TRS balanced 1/4" actually hurt the signal. I read somewhere in the manual that weird phasing issues can happen that negate most of the signal if you don't do the right balanced/unbalanced cables. Maybe that was it.

Hi Tronic did you find anything further? So the Send and Rcv 1/4 inserts on the back of 388 need to be unbalanced TS?

 

[drtechno]

Hi Tronic did you find anything further? So the Send and Rcv 1/4 inserts on the back of 388 need to be unbalanced TS?

yes, because the gear convention for effects were 1/4 inch or rca unbalanced when the 388 was made.
The question becomes if the OP can use pin 2&3 of the lexi by itself or has to convert the xlr input to be unbalanced with a 2K resistor in series on pin2.

 

[sweetbeats]

yes, because the gear convention for effects were 1/4 inch or rca unbalanced when the 388 was made.
The question becomes if the OP can use pin 2&3 of the lexi by itself or has to convert the xlr input to be unbalanced with a 2K resistor in series on pin2.

?

Audio interconnects were, and continue to be, both balanced and unbalanced for effects and otherwise. There wasn’t a standard then or now. It depends on the device. And there was and remains special consideration to be made as to how to interface balanced and unbalanced equipment, and one should *always* consult the manual first to see what it says about this. And if it says nothing, usually you short pin 2 or pin 3 to pin 1. If one doesn’t work you try the other. I’ve never heard of converting balanced to unbalanced by adding a resistor if any value to the low or high side of the balanced signal path. All that would do is make the balanced signal imbalanced, not unbalanced. And you can’t just ignore pin 1. It either connects to the shield at the unbalanced and of the interconnect, or it floats at one end or the other depending on the gear and the setup. Does the Lexicon manual say something about adding a 2K resistor in series with pin 2 or pin 3 of the input? And, assuming the Lexicon box is internally unbalanced, how would doing anything to the input have any impact on unbalancing the output?

 

[drtechno]

?

Audio interconnects were, and continue to be, both balanced and unbalanced for effects and otherwise. There wasn’t a standard then or now. It depends on the device. And there was and remains special consideration to be made as to how to interface balanced and unbalanced equipment, and one should *always* consult the manual first to see what it says about this. And if it says nothing, usually you short pin 2 or pin 3 to pin 1. If one doesn’t work you try the other. I’ve never heard of converting balanced to unbalanced by adding a resistor if any value to the low or high side of the balanced signal path. All that would do is make the balanced signal imbalanced, not unbalanced. And you can’t just ignore pin 1. It either connects to the shield at the unbalanced and of the interconnect, or it floats at one end or the other depending on the gear and the setup. Does the Lexicon manual say something about adding a 2K resistor in series with pin 2 or pin 3 of the input? And, assuming the Lexicon box is internally unbalanced, how would doing anything to the input have any impact on unbalancing the output?

actually there are several interconnect standards.
The question on if it would need a 2K would be if it was needed for the correct gain structure.
Putting a resistor on the + input to a transformer converts the input to be that impedance unbalanced. This is normal signal transformer theory. The lexicon wouldn't need anything adapted from its output going into an unbalanced in unless its too hot even with the gain setting in low. Then it would need an attenuator.

since the tape machine is -10 ; select the low gain structure on the lexicon.