ding

Re: Hayes Middlesex Pre/Channel
« Reply #20 on: February 12, 2016, 10:06:51 PM »
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.


hitchhiker

Re: Hayes Middlesex Pre/Channel
« Reply #21 on: February 12, 2016, 10:17:27 PM »
Not getting anything?  Can you post a link to what you find?

Dylan W

Re: Hayes Middlesex Pre/Channel
« Reply #22 on: February 12, 2016, 10:27:38 PM »
Not getting anything?  Can you post a link to what you find?

Try downloading the posted files and see if that helps.  ;)

ding

Re: Hayes Middlesex Pre/Channel
« Reply #23 on: February 12, 2016, 10:30:35 PM »
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?

ruffrecords

Re: Hayes Middlesex Pre/Channel
« Reply #24 on: February 13, 2016, 03:19:25 AM »
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
www.customtubeconsoles.com
https://mark3vtm.blogspot.co.uk/
www.eztubemixer.blogspot.co.uk


'The only people not making mistakes are the people doing nothing'

hitchhiker

Re: Hayes Middlesex Pre/Channel
« Reply #25 on: February 13, 2016, 11:50:21 AM »
Thanks Ding!  I don't know much about the that console, Hayes Middlesex was news to me!
« Last Edit: February 13, 2016, 12:00:54 PM by hitchhiker »

leadbreath

Re: Hayes Middlesex Pre/Channel
« Reply #26 on: February 13, 2016, 04:29:55 PM »
Quote
  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
f**k marlbro's and weed ill stick to smoking germanium and silicon

hitchhiker

Re: Hayes Middlesex Pre/Channel
« Reply #27 on: February 13, 2016, 05:35:58 PM »
Were the line inputs unbalanced?

ding

Re: Hayes Middlesex Pre/Channel
« Reply #28 on: February 13, 2016, 07:49:49 PM »
Quote
  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.

hitchhiker

Re: Hayes Middlesex Pre/Channel
« Reply #29 on: February 14, 2016, 11:04:34 AM »
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


pucho812

Re: Hayes Middlesex Pre/Channel
« Reply #30 on: February 14, 2016, 07:23:28 PM »
not sure  if anyone has seen this yet?
You tell me whar a man gits his corn pone, en I'll tell you what his 'pinions is.

leadbreath

Re: Hayes Middlesex Pre/Channel
« Reply #31 on: February 15, 2016, 09:58:30 AM »
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??

« Last Edit: February 17, 2016, 05:13:01 AM by leadbreath »
f**k marlbro's and weed ill stick to smoking germanium and silicon

leadbreath

Re: Hayes Middlesex Pre/Channel
« Reply #32 on: February 17, 2016, 05:12:06 AM »
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.
f**k marlbro's and weed ill stick to smoking germanium and silicon

ruffrecords

Re: Hayes Middlesex Pre/Channel
« Reply #33 on: February 17, 2016, 05:45:29 AM »
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
www.customtubeconsoles.com
https://mark3vtm.blogspot.co.uk/
www.eztubemixer.blogspot.co.uk


'The only people not making mistakes are the people doing nothing'

leadbreath

Re: Hayes Middlesex Pre/Channel
« Reply #34 on: February 17, 2016, 08:22:43 AM »
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
f**k marlbro's and weed ill stick to smoking germanium and silicon

skeeler87

Re: Hayes Middlesex Pre/Channel
« Reply #35 on: February 20, 2016, 11:30:58 AM »
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!

hitchhiker

Re: Hayes Middlesex Pre/Channel
« Reply #36 on: February 20, 2016, 03:52:18 PM »
My guess is AOT1 says  Adjust On  Test One

Re: Hayes Middlesex Pre/Channel
« Reply #37 on: April 26, 2016, 02:36:41 PM »
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

Re: Hayes Middlesex Pre/Channel
« Reply #38 on: April 26, 2016, 05:16:52 PM »
I imagine with the output amp.

Re: Hayes Middlesex Pre/Channel
« Reply #39 on: April 26, 2016, 07:03:58 PM »
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 :)