TRS, TS and RCA jack crisis


Bronze Member
Username: Garo


Post Number: 13
Registered: Aug-05
Can anyone offer any help / advice.

I've just bought a new mixer and i've got some severe humming issues and i can't find the problem.

The mixer (vestax PMC 37 pro) has 3 differant outputs;

Master out - Balanced 1/4" output
Submaster out - Unbalanced 1/4" output
Rec out - RCA output.

My Amp, which the mixer is plugged into only has RCA inputs (Camridge Audio Azur 640A)

What i've done is bought a 1/4" unbalanced to RCA cable (3m long)and connected the two units. There's a loud humming when the amp is switched to the mixer. I've also grounded the mixer to the amp and played about with various main plug combinations but to no avail.

Can anyone suggest what the problem may be and if converting 1/4" jacks to RCA might be the cause of all this.

Would appreciate anyones help as i've spent alot of money on this mixer to get a great sound and it sounds awful!


Hello, i have same mixer and i think you are wrong. Both outs (master and submaster) are balanced. This outputs require a balanced TRS to unbalanced RCA cable that isn't common. See the 1/4 jack of your cable, they must have two rings (stereo) instead of one (mono).

vestax PMC 37 pro Specifications:
INPUTS: Phono inputs: stereo (RIAA 42dBv; RCA) x 4; Line inputs: stereo (-10dBv; RCA;) x 4; Mic. Inputs: (-54dBv; Jack ¼ inch) x 2; Effect return: stereo (-10dBv; Jack ¼ inch) x2

OUTPUTS: Master out: stereo ( -4 dB; Jack ¼ inch bal.); SUB Master out: stereo (-4 dB Jack ¼ inch bal.); Cue out: stereo (-10dB RCA) Monitor headphone out: stereo (150 mW; Jack ¼ inch); Aux. send: Stereo(-10dB; Jack¼ inch) x2.

CHANNELS: 3/ 5 Channels; (3 stereo, 2mono); Channel 1 + 2 + 3: Input selector: PHONO-LINE x4; Input assign switch:4 position switch (input1-4); Input gain control ; Bal. L-R; Equaliser and Filter bypass switch; Isolator type 3-band equaliser: low -infinite/+ 6dB; mid infinite/+ 6dB; high -infinite/+ 6dB. Sweep filter fader : FILTER-DRY; Sweep control: MAX-MIN; Aux. 1 selector: pre-off-post; Aux. 2 selector: pre-off-post; Cue selector: off-on; Special cue LED bar display; Crossfader assign switch: A-master-B; Input PCV-fader (User replaceable). Channel 4+ 5 (Mic): Volume control ( each); Equali ser hig h+/-16dB at 8 kHz, l ow+/ -16dB at 80 Hz Aux. send control: AUX 1-OFF-AUX 2;

MASTERS: Master: Master balance: L-R; Master volume control, Stereo output level LED bar display; SUB Master: Volume control;
AUX/ Effect: Aux. 1 send control; Effects 1 return control; Aux. 2 send control; Aux. 2 return control. Monitor: Monitor select switch: CUE-MASTER-AUX1-AUX2; Split cue switch: SPLIT-STEREO; Phones level control; Crossfader: Channel A-B; Crossfader curve control;

FREQUENCY RESPONSE: 20-20000 Hz+ 0 / -3dB

S/ N RATIO: 85dB

DIMENSIONS: (WxHxD) 262 x 105 x 390 mm;


Bronze Member
Username: Garo


Post Number: 14
Registered: Aug-05
OK, so Vestax got it wrong and they're selling a mixer with two balanced outputs and only claiming it has one!?!?. Regardless of that, have you got one of these balanced 1/4inch to RCA interconnects? if so, where can you find them!!

Gold Member
Username: Project6

Post Number: 6760
Registered: Dec-03
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