YannLu

Re: 500 Series YannLu Audio EQ-500 (Harrison MR replica)
« Reply #20 on: January 23, 2018, 02:12:46 AM »
Correct Carl !
This is a bi-color LED with common anode in the middle (A).
Then short (for green colour) and long (for orange colour) legs are mentioned on the J1 connector.


Re: 500 Series YannLu Audio EQ-500 (Harrison MR replica)
« Reply #21 on: January 28, 2018, 10:15:55 AM »
Ok I'm starting the calibration. When connecting the oscilloscope the balanced outputs (+ and-) are what pins on the connector? I think I have it as pin 2 for + and pin 4 for -. Is this correct? Each probe has a clip and a hook so Ch1 and Ch2 clips to pin 5 which is audio ground and Ch1 probe to pin 2 and Ch2 probe to pin 4. I'm getting what looks like noise I'm I doing this correctly?

Re: 500 Series YannLu Audio EQ-500 (Harrison MR replica)
« Reply #22 on: January 28, 2018, 11:07:14 AM »
Hi Yann, I figured it out. I have an extension jig for calibrating 500 series outside of the chassis and this pinout configuration I was using was incorrect. All things are good an moving on to the next steps.

Re: 500 Series YannLu Audio EQ-500 (Harrison MR replica)
« Reply #23 on: January 28, 2018, 12:04:58 PM »
Everything is calibrated and I'm experiencing distortion when engaging the high filter with out without other filters engaged. It distorts everything across the frequency range like a distortion pedal or a smashed 1176. All other filters are acting fine and doing there job well when the high filter is disengaged. Your thoughts?

Re: 500 Series YannLu Audio EQ-500 (Harrison MR replica)
« Reply #24 on: January 28, 2018, 01:39:49 PM »
Well I solved my own problem following prudent steps such as floating solder joints in the high filter section starting with switches and pots. I found a solder bridge on the gain pot for the high filter and removed it. All others were re-floated on frequency and switches just to make sure. Retested and distortion is gone but the filter is acting strange so back to the
"0db gain pot calibration" and after rechecking all frequencies the high was out so I tweaked it back in to spec and re-installed it into the 500 chassis. I ran tests on kick, snare, acoustic guitar and some vocal tracks. I'm really liking the sound of the eq on all sources particularly the acoustic guitar and vocals. All adjustments were rather broad and small but added a nice pleasing shape and sound without adding unwanted character that some of my other EQs would add. All around I'm pretty darn happy with the results. Great work Yann!

YannLu

Re: 500 Series YannLu Audio EQ-500 (Harrison MR replica)
« Reply #25 on: January 28, 2018, 03:25:52 PM »
Hi Carl,

Thank you for sharing your experience in the building and I am very happy that its sounds nice to you !

You pointed several things I could upgrade in the Build Guide :

1. I will specify each connector pin of my modules:

PIN          FUNCTION
1               CHASSIS GROUND
2              OUTPUT+
3               /
4               OUTPUT-
5               AUDIO GROUND
6               /
7              INPUT-
8              INPUT-
9              INPUT+
10           INPUT+
11           /
12           +16VDC
13           POWER SUPPLY GROUND
14          -16VDC
15           /
BTW I am looking for a solution to balance the outputs without double trace scope...

2. I totally agree with the utility of an extension board to have access to the calibration trimmers without removing some panels of the lunchboxes or PSU 500 racks...
3. It still very important to make a visual check overview of all the solder joints.
4. Always re-calibrate the 0dB pots after perfect debugging.

Re: 500 Series YannLu Audio EQ-500 (Harrison MR replica)
« Reply #26 on: January 28, 2018, 03:59:12 PM »
I think that getting away from the scope would open this up to more people as admittedly I was a bit hesitant. I knew that one day I would have to get a scope anyway so it pushed me a bit and I'm glad i did.

It sounds great and I have used it on several prerecorded sources already. Nicely transparent and I like it for some subtle broad strokes. Not a big thing but it would be nice if the mids went down to 200 hz, although I understand it would not follow the original but it would make this a well rounded eq with great coverage. With that said it seems to be fairly transparent and I like that.
« Last Edit: January 28, 2018, 04:03:32 PM by Carl Cress »

YannLu

Re: 500 Series YannLu Audio EQ-500 (Harrison MR replica)
« Reply #27 on: January 29, 2018, 07:47:29 AM »
Yes the target was to redesign as close as possible to the original MR serie
But now I am thinking to upgrade with some improvement and you are right, in the frequencies ranges.
Actually it is possible to modify the mid range by replacing the 2 film caps (C32-33).
For example : 15nF theorically gives a range from 200 Hz to 4400 Hz after calculation.

« Last Edit: January 31, 2018, 08:33:59 AM by YannLu »

Re: 500 Series YannLu Audio EQ-500 (Harrison MR replica)
« Reply #28 on: January 29, 2018, 03:02:31 PM »
Thanks for the info on the Mid frequency mod. This will make it so much more usable for bass, kick and snare for the lo-mid muddy area. If you make this change and print the faceplate to match I'll take a extra  faceplate when I order the next one :) 

By the way the highs are sublime. And now that I can massage my low mid-bass relationship this EQ it will be used quite frequently. You got a winner here Yann.

YannLu

Re: 500 Series YannLu Audio EQ-500 (Harrison MR replica)
« Reply #29 on: January 30, 2018, 02:26:36 PM »
Yes Carl, First I have to validate the mid range with the new caps then I re-design the plate and I order the upgraded batch.
Other suggestions regarding the other ranges ? They actually overlap a lot !

I got many good feedbacks about the hi-mid and high range quality and soft transparency. Thank you !



Re: 500 Series YannLu Audio EQ-500 (Harrison MR replica)
« Reply #30 on: January 30, 2018, 04:46:09 PM »
Thanks Yann, no I think with that extension in to the 200hz area it will be a pretty versatile eq. And yes there is a lot of overlap on the others. I’m going ahead with the 15nf caps to see if it does what I expect. I’m thinking I should recheck the calibration on the mids afterwards. And I’ll let you know my thoughts.

YannLu

Re: 500 Series YannLu Audio EQ-500 (Harrison MR replica)
« Reply #31 on: January 31, 2018, 08:39:16 AM »
I just tested with 15nF film caps 5% it gives midrange between 200 and 4300 Hz.

I also think it is perfect to cut unwanted muddy and boxy freq or boost the slap of a snare or the bite of a guitar.

I am ordering the new front plates in a couple of days.

Re: 500 Series YannLu Audio EQ-500 (Harrison MR replica)
« Reply #32 on: January 31, 2018, 08:45:23 AM »
Great news Yann! I'll be ordering another soon.

Re: 500 Series YannLu Audio EQ-500 (Harrison MR replica)
« Reply #33 on: January 31, 2018, 10:11:57 AM »
Great news Yann! I'll be ordering another soon.

+1

Will be doing the same!

YannLu

Re: 500 Series YannLu Audio EQ-500 (Harrison MR replica)
« Reply #34 on: February 02, 2018, 09:18:20 AM »
Here is the new version with the upgraded midrange marking.

Contact me for purchasing : [email protected]
« Last Edit: February 02, 2018, 09:33:00 AM by YannLu »

Winetree

Re: 500 Series YannLu Audio EQ-500 (Harrison MR replica)
« Reply #35 on: February 02, 2018, 07:45:00 PM »
How much for 2 of the 200HZ faceplates shipped to 91730 U.S.A.

YannLu

Re: 500 Series YannLu Audio EQ-500 (Harrison MR replica)
« Reply #36 on: February 03, 2018, 07:31:05 AM »
Price for upgraded faceplate : 50 euros per piece.
Shipping cost is free.

Re: 500 Series YannLu Audio EQ-500 (Harrison MR replica)
« Reply #37 on: February 07, 2018, 07:57:47 AM »
Did the switch on the mid caps and that made a fantastic difference. I'll order the extra faceplate when I order my second eq.

YannLu

Re: 500 Series YannLu Audio EQ-500 (Harrison MR replica)
« Reply #38 on: February 16, 2018, 03:06:16 PM »
FYI I just received upgraded front plates.

Re: 500 Series YannLu Audio EQ-500 (Harrison MR replica)
« Reply #39 on: February 21, 2018, 10:51:01 AM »
I received the partial kit the other day and am looking forward to building and using the EQ.

Yann is a great chap and his support has been top notch so far!   :)