[Janner]

Hi there,

I just finished my MP573 together with the EQ573II.
Super nice Kit’s and a lot of fun to build. I just have a
little problem linking both units. I turn on the rack (I run them
in a Fredenstein Bento 2) and send a signal to the MP and the EQ
is in Pre Mode. Then I have audio dropouts and a little background noise.
I switch the XLR/OFF/PRE switch on the EQ several times and then it
works. If the signal from the Interface goes direct to the EQ I never experienced
this problem. The link cable seems also ok. Is it the toggle switch on the eq? Or
a defective Relais or IC?


if the noise is cycling, the eq functions all work
funny is the low cut. if I turn it up to 360 the interval of the noise becomes faster
and again, if i do some moves with the toggle switch (xlr/off/pre) the problem goes away.
If I turn down the Rack and power it up again the problem is there again

here is a link to a soundfile of the noise
https://soundcloud.com/socek/eq573ii-noise-only/s-n2IJkJVGkxH?si=c94e1fa2ed2c43cb94f5c787eb7c26c5&utm_source=clipboard&utm_medium=text&utm_campaign=social_sharing


can somebody help me out with this?

greetz,

jan

[JPK]

It is a problem of 0V reference between the MP and the EQ during the power up.
One solution, if your lunchbox has enough juice is to remove the slow start on the MP573 by shorting the 2 side pins of U1 (LM317T). You can leave U1 in place.

[Janner]

Thank you for your answer and the clarification.

The Bento 2 overall got 900mA, that means 450mA per slot right?

But is it an issue caused by the Rack or is it "just there" because of the slow start of the MP?

Shortening the legs at L1 without a linked EQ Module would be also no prob?

Greetz,

Jan

[JPK]

The Bento 2 overall got 900mA, that means 450mA per slot right?
It should be OK.

But is it an issue caused by the Rack or is it "just there" because of the slow start of the MP?
Some rack PSU's can't stand the high inrush current of the MP573 this is why we had to add a slow start.

Shortening the legs at L1 without a linked EQ Module would be also no prob?
It is not shortening but shorting and it is not L1 but U1. If it works it will work in any configuration.

[Janner]

Got it! Works like a charm now.

Thanks a lot for the quick help

[ddld]

Hi,

(I'm posting this here because I think my issue is related. I'll repost as a new topic if it doesn't get a response)

I have the EQ-573II linked to an MP573, both housed in a Wes Audio Supercarrier II rack, linked with the link cable. When I power up the rack with the switch on the EQ set to 'PRE', I hear a repeating pulse at approx. 120 BPM. If I switch the input selector from PRE to anything else, it disappears. When I switch back it appears again. This will go on for about half a minute, until the clicking stops. Usually, it is fine after that.

I'm using these units as part of my main vocal chain during in-studio rehearsals. A few days ago the clicking took a bit longer to stop than normal, and it returned midway through a session. I power cycled the rack, and it was back to normal after that. Normal being: a few clicks on startup, then fine.

I have some questions about this:

• From JPK's comments above it appears that the MP has a slow startup mechanism to prevent some less powerful lunchboxes from overloading, and that this process leads to a temporary grounding issue between the linked EQ and the MP, is that a correct summary?
• JPK suggests to remove the slow startup behavior if the rack has enough power. I would prefer not to modify the unit. Is it harmful in the long run to just keep it in?
• How long does the startup process usually take?
• Do you expect that the clicking doesn't occur if I start up the MP with the EQ in bypass mode, wait for the warmup process to finish, and  then put the EQ in the signal path? If so, it might be a good idea to add this to the (still missing?) manual for the EQ.

Regards,

ddld


(edit: answered part of my own questions by reading better)

[JPK]

JPK suggests to remove the slow startup behavior if the rack has enough power. I would prefer not to modify the unit. Is it harmful in the long run to just keep it in?
This is a very simple mod and I recommende doing it if your lunchbox has enough power (this slow startup circuit doesn't exixt in the original Neve).

How long does the startup process usually take?
1 second?

Do you expect that the clicking doesn't occur if I start up the MP with the EQ in bypass mode, wait for the warmup process to finish, and  then put the EQ in the signal path?
Absolutely.

If so, it might be a good idea to add this to the (still missing?) manual for the EQ.
Agreed!