Hayes Middlesex Pre/Channel

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Just google Hayes Middlesex console and the sequence of numbers on the first post. I'm guessing leadbreath is keeping it on the DL for a reason but it's not hard to figure out.
 
I pm'd you just in case. A channel of this would be amazing! I couldn't tell by the downloads but what kind of in and out iron for this beast?
 
leadbreath said:
Awesome Ian, thanks that makes more sense now.

I've also  realised that we are missing another important piece - The drawing for the Band pass filter?
I've heard that this is an important part of the sound of this desk, not sure what frequencies we're talking of here but I can try and find out. Would be good to try and replicate it as accurately as possible.

It probably uses the same topology as the other two. The treble circuit is already a peaking boost but shelving cut. It would be trivial to alter it so it was peaking for both boost and cut. I would not be surprised if the set of frequencies used followed those of the well known brilliance control.

Cheers

Ian
 
  I pm'd you just in case. A channel of this would be amazing! I couldn't tell by the downloads but what kind of in and out iron for this beast?
 

Input and Output iron can be sourced from Mr Brian Sowter:

http://www.sowter.co.uk/vintage-audio-transformers.php
 
leadbreath said:
  I pm'd you just in case. A channel of this would be amazing! I couldn't tell by the downloads but what kind of in and out iron for this beast?
 

Input and Output iron can be sourced from Mr Brian Sowter:

http://www.sowter.co.uk/vintage-audio-transformers.php

I guess I meant what ratios for the in/out. Sowter is a little too pricy for me in the us but I can talk to David at cinemag and he can probably wind me up something.
 
Sowter page states,

input-  Ratio 1:3.16 with -5 dB, -10 dB and -15 dB secondary taps. Very large 100% Mumetal core and thick Mumetal can. Colour coded leads. Primary inductance 15H approx -0.5 dB at 8 Hz with 200 ohm microphone.

output- 100% Mumetal output transformer ratio 1:1.77. Total DCR referred to secondary 160 Ohms aprox. Max level +18dBu at 20 Hz
 
Handy manual that, makes so much more sense once you have some schematics to refer to when reading.

I see they mention the Band Pass has a Cut at 25Hz and 25kHz can someone smarter than me implement this circuit using the topology of the Bass/ Treble circuit?

I was also wondering if it could be possible to implement a switch with the frequencies mentioned in the manual within the Treble circuit so it can be used in the Presence mode too??

 
Allright looks like I'm on my own on this one

Ive got a rough idea at implementing the circuits as per previous posts problem is my simulation software is not working  as PC is knackered.
I'm busy rebuilding the PC and will update if the mods mentioned are feasible.
 
leadbreath said:
Allright looks like I'm on my own on this one

Apologies, I would have responded but I was rather ill yesterday. Really bad stomach ache. Doctor thinks I may have gall stones. Got to go back today and have blood tests and possibly an ultrasound.

Cheers

Ian
 
Hey Ian

No need to apologize ,  you've already been a great help on this project and countless others.

Hope you get better soon, I have also had some issues with gall bladder and its not nice.
Strangely my guts were fine but I had a really bad pain above my right shoulder blade?!!
What worked for me was artichoke extract capsules, never had any more issues since(touch wood)

Mick
 
Hey Guys!

What are these resistors labelled "AOTI" in the input and output amplifiers? Also does the part labelled "Gain Control" just supposed to connect to a potentiometer or is it suggesting that it leads to a different circuit? Sorry if these questions are elementary, still learning a lot of this stuff!
 
leadbreath said:
Right here we go:

Input Amp

Is this supposed to be the mic preamp section? If so, I wonder how the nesessary gain is achieved. As far as I can tell this circuit will provide a gain of around 20dB + whatever extra gain the input Tx can achieve. Am I missing something?
 
ding said:
I imagine with the output amp.

Well, the output amp  (and an output Tx) will definitely add more gain but I can't see the reason of having such a small gain in the input amp. Unless it's not a mic preamp, I'm definitely missing something :)
 
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