bruno2000

Re: EQN build thread
« Reply #320 on: November 22, 2010, 06:22:25 PM »
I've had really good luck unsoldering Grayhills with soldering "tweezers" with large (30mm) blades. I paid about $30 US for a pair, and they worked great, since you heat up all of the pins at once.
I have also had (now, the reason for the tweezers) a couple of defective Grayhill switches.  Seems that when they assembled them, they left out one of the wiper assemblies.  After that, I ALWAYS check the switches BEFORE soldering them in,
Just my $0.02 (US)
Best,
Bruno2000


canidoit

Re: EQN build thread
« Reply #321 on: December 07, 2010, 12:01:20 PM »
Is this right, that ALL Cog caps do not require polarity positioning?
iva dunit formerly known as canidoit

Re: EQN build thread
« Reply #322 on: December 07, 2010, 12:03:31 PM »
Is this right, that ALL Cog caps do not require polarity positioning?

yes
http://www.lazpro.com
I reserve the right to not sell to idiots

canidoit

Re: EQN build thread
« Reply #323 on: December 07, 2010, 12:48:40 PM »
Thanks Pete.

Is there any special requirements regarding the BC184C transistors for the Opamps. Like do they have to be matched or a certain HFE?

To minimize my chances of a noisy transistor like Mako, should I install a certain HFE transistor?
iva dunit formerly known as canidoit

Re: EQN build thread
« Reply #324 on: December 07, 2010, 12:52:11 PM »
I grab the first one out of the bag. There was talk of hfe above 600, but I don't know how true.
http://www.lazpro.com
I reserve the right to not sell to idiots

canidoit

Re: EQN build thread
« Reply #325 on: December 07, 2010, 07:09:28 PM »
I can't remember ever being so excited to build something as this project. Thanks to Peter and all who contributed to the thread.

Mine worked perfectly from the get-go using a 51X jig, but I'm still waiting for the DC/DC converter to put it into my 500 rack. I've posted some notes on a page here:

http://mnats.net/pp-eqn_notes.html

Careless me - I lost one of the 1mm sockets for the DC converter...if anyone is building a 51X version you should have two to spare. I've got some extra bits and bobs I can trade for another socket if anyone is willing. *edit* - Sorted. Thanks to 12Volts.
Mako, in your weblink you spoke of how you discovered your opamp was the cause of a noise issue. How did you know that?
Was that
- by simple de-solder and replace and see if that was the issue
- is it a common problem solving method of noisy opamps by replacing transistor BC184C
- or you increased HFE on your transistors when you replaced them to increase your chances of solving the issue
- or something else?

Thanks
iva dunit formerly known as canidoit

briomusic

Re: EQN build thread
« Reply #326 on: December 08, 2010, 04:27:24 AM »
I don't think Mako's noise problem was related to the hfe value of the transistor, but rather due to an actually faulty component. The chance of this happening is rather low. I have built 6 EQNs (including 12 opamps) and didn't have any problems with noise. what I have heard about the BA283 stage in general (this is the output stage used in the EQN - NOT the opamp) is to use high-hfe transistors for the first BC184 in the darlington configuration, this would be TR2 on the mainboard. I usually try and find one with over 600 hfe, but I haven't actually ever made a test to see how much difference it makes. I wouldnt worry about this too much, if a transistor turns out to be faulty, just swap it out, they are not exactly expensive.

canidoit

Re: EQN build thread
« Reply #327 on: December 08, 2010, 05:49:21 AM »
Anyone experience with this build notice anything wrong with my opAmps, like do the transistors face correctly?


My pin configuration for the BC184C looks like this.

Flat top
L-C-R
Curved bottom

The center leg bends backwards to fit in the PCB middle hole for that transistor?
iva dunit formerly known as canidoit

canidoit

Re: EQN build thread
« Reply #328 on: December 08, 2010, 10:22:21 AM »
Pete on your BOM it sais R19 is 7.5K. I have read people using 4.53K for R19 to get the unit working like a 1073, 1084 EQ.

Why have you set R19 at 7.5K instead. Is this a sharper or wider Q and does it sound better?
iva dunit formerly known as canidoit

dmp

Re: EQN build thread
« Reply #329 on: December 08, 2010, 10:37:57 AM »
Quote
Pete on your BOM it sais R19 is 7.5K. I have read people using 4.53K for R19 to get the unit working like a 1073, 1084 EQ.
Why have you set R19 at 7.5K instead. Is this a sharper or wider Q and does it sound better?
This is discussed on Page 10 and then again on page 15.


JBVries

Re: EQN build thread
« Reply #330 on: December 08, 2010, 11:09:43 AM »
Anyone experience with this build notice anything wrong with my opAmps, like do the transistors face correctly?
My pin configuration for the BC184C looks like this.

Flat top
L-C-R
Curved bottom

The center leg bends backwards to fit in the PCB middle hole for that transistor?

Yes you will have to bend the emitter back a little bit but that's no big deal. I just compared your pic to my op-amps that just happen to be sitting here as I finished them last night and they look fine to me.  Maybe Peter can confirm though  ;D
« Last Edit: December 08, 2010, 06:01:22 PM by JBVries »
A little bit of the sonic mayhem I bring to the table.....

http://www.soundcloud.com/jbvries

canidoit

Re: EQN build thread
« Reply #331 on: December 08, 2010, 05:12:11 PM »
Yes you will have to bend the emitter back a little bit but that's no big deal. I just compared your pic to my op-amps that just happen to be sitting here as I finished them last night and they look fine to me.  Maybe Peter can confirm though  ;D
I think it's important for eagle eye overview of correct completed boards for newbies who like visual confirmation of their build. Thanks JB  :)

This is discussed on Page 10 and then again on page 15.
Thanks dmp, yeah I have read those posts, about the sharper and wider Q but I am very curious as to why Pete would do the 7.5K if it's not similar to a 1073/1084 setup when using the 4.53K. So I am thinking maybe its a magic EQ settings that sounds better maybe? Just want to know my options before making the solder of the part.
iva dunit formerly known as canidoit

dmp

Re: EQN build thread
« Reply #332 on: December 08, 2010, 05:21:04 PM »
Quote
magic EQ
I think what is most important is to use a resistor made of fairy dust... haha, just kidding.

Re: EQN build thread
« Reply #333 on: December 09, 2010, 07:09:22 AM »
Best to use the extremely rare Com-Mon-sen5e components.
Leave them near the pcb overnight and they'll find their own way.

« Last Edit: December 09, 2010, 07:25:54 AM by peter purpose »
http://www.lazpro.com
I reserve the right to not sell to idiots

Marcocet

Re: EQN build thread
« Reply #334 on: December 09, 2010, 02:03:15 PM »
Hey, how'd you get that picture of my feet?


JBVries

Re: EQN build thread
« Reply #335 on: December 14, 2010, 06:18:06 PM »
Just to make things a little easier on future builders. Make sure you have the flat part of the shaft opposite position 2 and drop pins in these locations....

12 and 6
12 and 8
12 and 5
12 and 5

Left to right...



If this is incorrect please give a shout so I can take this down but I'm pretty sure it's right.
A little bit of the sonic mayhem I bring to the table.....

http://www.soundcloud.com/jbvries

canidoit

Re: EQN build thread
« Reply #336 on: December 17, 2010, 03:26:22 AM »
JBVries, thanks, that has come in handy!

Can someone please tell me what goes to these following holes circled in green and what is the purpose of them? There are 7 of them that I have circled.
eg. 2- you put the header pins there so that you can jumper them for calibration?



Also the HS1 heatsink's legs, are you soldering those to the PCB board? I tried soldering them but I can't get the solder to stick on the legs??


Thanks
« Last Edit: December 17, 2010, 03:31:11 AM by canidoit »
iva dunit formerly known as canidoit

JBVries

Re: EQN build thread
« Reply #337 on: December 17, 2010, 03:34:02 AM »
Are you asking as a hypothetical question or a literal question? I think some of the holes you outlined are just left empty as they were likely part Peter's prototyping/final troubleshooting process that became superfluous to the build.

With HS1 you just gotta turn up the heat on your soldering iron. They should solder in just fine although I just did one for stability, and that way less heat is dissipated directly to the PCB.
« Last Edit: December 17, 2010, 04:04:55 AM by JBVries »
A little bit of the sonic mayhem I bring to the table.....

http://www.soundcloud.com/jbvries

12volts

Re: EQN build thread
« Reply #338 on: December 17, 2010, 04:21:37 AM »
JBVries, thanks, that has come in handy!

Can someone please tell me what goes to these following holes circled in green and what is the purpose of them? There are 7 of them that I have circled.
eg. 2- you put the header pins there so that you can jumper them for calibration?



Also the HS1 heatsink's legs, are you soldering those to the PCB board? I tried soldering them but I can't get the solder to stick on the legs??


Thanks


They are known as vias. They are used to transfer signal or power tracks to the opposite side or layer of a board
to make routing easier. Sometimes things are more simple than you think. :O)


Frank

canidoit

Re: EQN build thread
« Reply #339 on: December 17, 2010, 06:04:33 AM »
Thanks guys!

I just don't want to miss a step.

As you know, I am not that electronically inclined as some of you folks.  ;)

Did any of you guys get nuts and bolts with your Mini 1066 transformer or EQN kit or do you have to source them yourself?
« Last Edit: December 17, 2010, 06:27:05 AM by canidoit »
iva dunit formerly known as canidoit


 

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