Whoops

Re: Spectra Sonics 110 pre with Opamp Labs 109 EQ
« Reply #40 on: January 09, 2021, 07:26:57 PM »
Whoops, Have you read the document by Richard Guy?  He covers all aspects of wiring SS cards as preamps.  The one I have is for the 101, but should be nearly identical.

Hi,
I was the one that published the Richard Guy doc in the past around here, it's a great doc and probably it's what I will follow in my rack up.
But has I still haven't done it I was interested to know how craigmorris74 did it because it could bring some other ideas on how to perform the rack up.


Whoops

Re: Spectra Sonics 110 pre with Opamp Labs 109 EQ
« Reply #41 on: January 09, 2021, 07:39:35 PM »
Here's a wiring diagram I whipped up.  If anyone spots any mistakes, I'll fix it.  I wired this according to what JLM and Matta posted on the "Racking Spectra Sonics 101"  thread.

Hi mate,
I would definitely not doing it that way.
I keep the 0v reference and Chassis connections separate.
To chassis I only connect Pin1, all the shields and the IEC Earth Pin.

Really good reference article on the subject:
https://www.ranecommercial.com/legacy/note151.html

Although 0V is referenced to Earth, they're not the same thing, and you should only connect 0V to Chassis at one point only, and doing that connection through a 10r restistor and 0.1uf cap is better.

PCB connects directly to 0v but at one point only. You have 2 connections from the PCB to 0v.


« Last Edit: January 09, 2021, 08:14:48 PM by Whoops »

Whoops

Re: Spectra Sonics 110 pre with Opamp Labs 109 EQ
« Reply #42 on: January 09, 2021, 08:04:07 PM »
you have multiple connections from the circuit to the case and then to 0V, that can potentially create ground loops.

I would definitely do it this way (all cable shields not drawn on the schematic connect to case also, only on one side of the shield) :


craigmorris74

Re: Spectra Sonics 110 pre with Opamp Labs 109 EQ
« Reply #43 on: January 09, 2021, 09:49:22 PM »
I've already booked it up that way (two channels, in fact), and they're see quiet.  Used them today and they were great.

rackmonkey

Re: Spectra Sonics 110 pre with Opamp Labs 109 EQ
« Reply #44 on: January 09, 2021, 11:45:51 PM »
Craig, have you had a chance to try out the EQ?
Whether you think you can or you think you can't, you're probably right.

craigmorris74

Re: Spectra Sonics 110 pre with Opamp Labs 109 EQ
« Reply #45 on: January 10, 2021, 06:04:29 PM »
Craig, have you had a chance to try out the EQ?

Not yet, hope to get to it soon, though.


 

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