gar381

gar918BC build thread
« on: January 25, 2016, 06:56:57 PM »
The Build PDF manual is good but here a few notes that might make the kit
A little less confusing.....

1) The little bag with the Millmax pins also contains Q1 and Q2 which are BC560C Matched Pair.
NOTE:  This matched pair of transistors are different transistors than my other gar kits (2520, 1731)
and are not interchangeable.

2) The  small bag of 3 transistors labeled Q5,Q6,Q7 are BC550C
3) The tape strip with 2 transistors are Q3,Q4 BC560C
      See Page 6 of the manual for location
4) The little bag of caps..
      The tan ones are CD1, CD2.
      The blue ones.. see page 4 of the assembly manual
      for value and location.
5) Please meter the resistors to determine value.  See page 7 of the
      manual for value and location.
6) There are 12 diodes in this build.  Make sure the band on the diodes(cathode)
      goes in the circles on the silkscreen.  Note.. All diode pads on the PCB are
      square.  No other pads on the pcb are square.  See page 5 of the manual.
7) After assembly PLEASE double check for unwanted solder bridges
      on the Bottom of the PCB. See page 9 of the manual and make
      SHURE THAT on the top of the PCB that no component lead wires
      are touching each other.   
8) When inserting your new DOA into the millmax sockets of
      a module, Please insert straight down and not at an angle.
      DO NOT push down on the component parts but use the edges
      of the DOAs PCB.  Remove DOAs the same way.  Pull straight up
      from the edges of the PCB and not at an angle.
9) Never insert a DOA or a module with the power on.

10) HAVE FUN !!       :) :) :)

A pdf download of the manual can be found here:

http://capi-gear.com/catalog/support_docs.php#opamps   


GARY

 
« Last Edit: January 26, 2016, 02:14:04 PM by gar381 »
RETIRED.....  from 51yrs in Show Biz

gar2520, gar1731 and gar918 DOAs at  http://capi-gear.com/catalog/index.php?cPath=71_72
NEW Sphere section added http://gar381interests.com/gar381interests.html


gar381

Re: gar918BC build thread
« Reply #1 on: January 25, 2016, 06:58:19 PM »
Reserve  :)
RETIRED.....  from 51yrs in Show Biz

gar2520, gar1731 and gar918 DOAs at  http://capi-gear.com/catalog/index.php?cPath=71_72
NEW Sphere section added http://gar381interests.com/gar381interests.html

3nity

Re: gar918BC build thread
« Reply #2 on: December 09, 2016, 07:31:18 PM »
Looks like Im the only one building this...
Anyways...i was finishing the first one when solderings the mill max pins i heard some craking noises ...not sure if it was some components burning...i did follow the build guide and last step is to solder those mill max pins..🤔 anyone?

Havent tested yet though.
Life is a path, death the destination.

gar381

Re: gar918BC build thread
« Reply #3 on: December 12, 2016, 12:01:12 AM »
Yes... Last

I have built lots of these guys.  Love them for Balanced receivers and summing.

GARY
RETIRED.....  from 51yrs in Show Biz

gar2520, gar1731 and gar918 DOAs at  http://capi-gear.com/catalog/index.php?cPath=71_72
NEW Sphere section added http://gar381interests.com/gar381interests.html

3nity

Re: gar918BC build thread
« Reply #4 on: December 12, 2016, 09:49:32 AM »
Thanks Gary.
Yes i know pins are last.
But when i was solderings i heard some craking noises..is that normal.
Life is a path, death the destination.

living sounds

Re: gar918BC build thread
« Reply #5 on: December 27, 2016, 04:02:10 AM »
Hi Gary,

would it be detrimental to build the op amp with BD139-16 / BD 140-16 instead of MJE172 / MJE182? I've still got lot's of the former and sourcing the latter would be a little difficult.

Thanks!

3nity

Re: gar918BC build thread
« Reply #6 on: December 27, 2016, 10:56:16 AM »
they dont seem to be compatibles!
Life is a path, death the destination.

living sounds

Re: gar918BC build thread
« Reply #7 on: December 27, 2016, 01:59:11 PM »
they dont seem to be compatibles!

Well, they're pin compatible, there's a  918 schematic that uses those (and otherwise exactly the same components in the relevant part of the circuit ) and these are very common in 2520 pinout based op amp output stages.  I've read people have switched out BDs for MJEs in 2520 op amps, too.

http://www.pcb-audio.com/pcb-audio_com/schema-j918.png

Am I missing something?

gar381

Re: gar918BC build thread
« Reply #8 on: December 28, 2016, 04:31:18 PM »
I never tried them but they should work. 
They may sound slightly different but give them a try.
There is always the good old Hakko 808 if you don't
like them.

GARY
RETIRED.....  from 51yrs in Show Biz

gar2520, gar1731 and gar918 DOAs at  http://capi-gear.com/catalog/index.php?cPath=71_72
NEW Sphere section added http://gar381interests.com/gar381interests.html

living sounds

Re: gar918BC build thread
« Reply #9 on: December 29, 2016, 05:33:23 AM »
Thanks Gary, I'll try it. Will do a comparison as well, maybe the MJE transistors are part of the special sauce of superior sounding op amps.  8) I'll report back.